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SC5304A Operating & Programming Manual

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1. OV Attenuation range ie 0 to 30 in 1 dB steps o 0 to 90 in 1 dB steps Input voltage standing wave ratio VSWR Preamp Off 0 dB input attenuation aq ONG DN RD D UE EN ETE 1 5 2 Cla AC lt 1 75 Preamp On 0 dB input attenuation COUR CI HOO un URL 1 5 PASEOS t0 3 6 GHZ AND 1 9 Gain range 1GHz 09 Minimumi 9 Pe PN 60 dB typical Maximum Preamplifier disabled 9 esee 30 dB typical Maximum Preamplifier enabled 09 essent 50 dB typical Preamplifier gain oii 20 dB typical 12 Large and fast DC transients could damage the input solid state devices Slow ramp up of DC to 10 V is sustainable RF Amplitude accuracy 15 C to 35 C ambient RF gain response flatness uncorrected essere tentent tents 8 dB typ RF gain flatness response corrected OP sees ttnntnnns 0 75 dB Absolute gain accuracy corrected 7 0 9 dB 0 5 dB typ IF Amplitude accuracy 15 C to 35 C ambient IF in band response flatness uncorrected typ IF in band response corrected 9 0 5 dB SC5304A Operating amp Programmi
2. Designed to meet the requirements of EN 61326 1 IEC 61326 1 Class A emissions Basic immunity 1 EN 55011 CISPR 11 Group 1 Class A emissions AS NZS CISPR 11 Group 1 Class A emissions FCC 47 CFR Part 15B Class A emissions ICES 001 Class A emissions M Meets the requirements of 2006 95 EC Low Voltage Directive safety 2004 108 EC Electromagnetic Compatibility Directive EMC Directive Warranty 22 22221 1 year parts and labor on defects in materials or workmanship 1 Meets requirements of IEC 60068 2 1 and IEC 60068 2 2 Operating temperature may be extended to 55 C with appropriate user provided cooling solution Contact SignalCore for recommended minimum airflow rates 2 Meets requirements of IEC 60068 2 1 and IEC 60068 2 2 3 Meets requirements of IEC 60068 2 56 and MIL PRF 28800F Class 3 4 Meets requirements of IEC 60068 2 56 and MIL PRF 28800F Class 3 5 Meets requirements of IEC 60068 2 27 and MIL PRF 28800F Class 3 6 Meets requirements of IEC 60068 2 27 and MIL PRF 28800F Class 3 7 Meets requirements of IEC 60068 2 64 and MIL PRF 28800F Class 3 8 Meets requirements of IEC 60068 2 64 and MIL PRF 28800F Class 3 5 5302 Operating amp Programming Manual 66 SignalCore Inc 13401 Pond Springs Rd Suite 100 g n a 1 Austin TX 78729 USA
3. SMA female Qutput amplitud 20 dBm max SC5304A Operating amp Programming Manual 65 General Specifications Environmental Operating temperature uiaiia En eal aua 0 C to 40 C Storage temperature 2 40 C to 70 C Operating relative humidity s 1096 to 9096 non condensing Storage relative humidity 6 sese 596 to 9096 non condensing Operating shock 5 sesenta 30 g half sine pulse 11 ms duration Storage shock 9 2 itn 50 g half sine pulse 11 ms duration Operating vibration 7 44404040 sees trennt tenta tnnt tnnt 5 Hz to 500 Hz 0 31 grms Storage vibration 8 AD laii eiie 5 Hz to 500 Hz 2 46 grms Altitude 2 000 m maximum maintaining 25 C maximum ambient temperature Physical Dimensions W x H x D max envelope eese 8 5 x 1 75 x 12 5 6 1 165 Power consumption tentant eh HE n dx 34 W typical libuit 90 264 VAC Communication Interface 5 2 nce e ederet seb Qaod ED needa au VETE ana USB Designed to meet the requirements of IEC 61010 1 EN 61010 1 UL 61010 1 CSA 61010 1 Electromagnetic Compatibility EMC
4. 19 E 19 Enabling and Disabling the RF 11 eene enne 19 Changing the RF Synthesizer 2 19 Selecting the IF Filter Path petere eter onec US 19 Setting the Reference Clock 20 Adjusting the Reference Clock ACCULAaCy ccssccccsssssceceessscecseaececeesaeeeceeaaeeeceeaaeseseesaeeeceesaeeeseesueeeceesaeseeeees 20 Setting Spectral Inversion in the IF 20 Storing Data into the User EEPROM 5 20 Setting the Phase of the IF Signal erret eoe e eve OE Ve YU ree Euer nva se 20 Querying the SC5304A Writing Request Registers Directly Reading Device Status Data ustedes 21 Reading Temperature Data cccssscccccccsssessnsscecececsssesesaeseeececessesaaaeeeeeessessesaeaeseeecessesesaeaeeeeseesseseaeaneeeeens 22 Reading Calibration EEPROM Data cccsssscccccecessesssaecesecscessesaaaeceeeescessesaeaesececseseesaeaeeeeesesseseaeaeeeenens 23 Reading User EEPROM eerte ENEE 24 Working With Calibration Data EEPROM Data CONTENE sarii URS 26 28 Gain COPECTION e 28
5. H MPR 7 SC5304A Theory of Operation aa 8 Signal Path Descriptio 2 RR 9 Local Oscillator 12 Frequency Tuning Mode Ssss a 13 Setting the SC5304A to Achieve Best Dynamic 14 Operating the SC5304A Outside Normal 2 15 SC5304A Programming Interface Device 16 ThE SC5304A 05 nhe Eg eae ee ten dena gH EAE RES de RR 16 Writing the Device Registers a 17 Reading the Device 04401 1000 nnne nennen nnns seen ne sias esent 17 SC5304A Operating amp Programming Manual i Using the Application Programming Interface API 17 Setting the SC5304A Writing Configuration Registers Directly Configuration 18 Tuning the RF 18 Changing the Attenuator 19
6. Do something with the device Close the device int status sc5304a_CloseDevice devHandle SC5304A Operating amp Programming Manual 36 Function Definition Return Input Description Example Function Definition Return Input Description Example Function Definition Return Input sc5304a_RegWrite int sc5304a_RegWrite deviceHandle devHandle unsigned char commandByte unsigned int instructWord The status of the function deviceHandle devHandle handle to the opened device unsigned char commandByte the address byte of the register to write to unsigned int instructWord the data for the register sc5304a_RegWrite writes the instructWord data to the register specified by the commandByte See the register map in Table 2 for more information This function should rarely be used To set the RF attenuator value to 10 cB int status scb304a RegWrite devHandle 0x11 0x020A sc5304a_RegRead int sc5304a_RegRead deviceHandle devHandle unsigned char commandByte unsigned int instructWord unsigned int receivedWord The status of the function deviceHandle devhandle handle to the opened device unsigned char commandByte the address byte of the register to write to Unsigned int instructWord the data for the register Unsigned int receivedWord data to be received sc5304a_RegRead reads the data requested by the instructWord data to the register specified
7. EEPROM Data Content The following list describes the data contents of the EEPROM in detail All addresses shown are the starting offset positions in the EEPROM and are the starting address for block of data Manufacturing Information 0x00 This is an unsigned integer value that contains information used by the factory for production purposes Product Serial Number 0x04 This is an unsigned integer value that contains the SC5304A serial number It is unique for every product produced It is used for the purpose of tracking the history of the product RF Module Serial Number 0x08 This is the serial number of the shielded RF metal enclosure containing the analog and RF circuitry All calibration data are stored on the EEPROM within the enclosure Calibration data are written to this EEPROM at the factory are tracked using the RF module serial number for the SC5304A Product Manufacture Date OxOC This is an unsigned integer byte 3 is the Year byte 2 is the Month byte 1 is the day of the month and byte O is the hour of the day Last Calibration Date 0x10 This is an unsigned integer byte 3 is the Year byte 2 is the Month byte 1 is the day of the month and byte is the hour of the day Firmware Revision 0 2 This is a float 32 value containing the firmware revision LO Hardware Revision 0x30 This is a float 32 value containing the local oscillator hardware revision SC Hardware Revision 0x34 This is a float 32 v
8. asie09 1eeur CU einpoiy UE 69 saa Tid 2 118 ZHWSZS8 eun ZHIN 972 909 2 0007 01 2 15 97 7 C H MU H 00 aq J 4 5 9 zs V lt OIA f Vf U SOYOUMS sJojenuenv 02 1948 ino 4l 22 janaj Indu Xew 0 ap 06 0 OZ 3nduj aR uenv 141 3 2 7HIN 006 ZHN OL 1 di A 1 aR 1 i 1 gt gt qu i L j 4 Mp 4 lt p Ur F3 99 pH 0 0 0 0 nm 9 06 0 gg zuenv 41 24 ZHIN 5 9 ZHN 549 ueny 4H dH 07323 einpolwy 87 Figure 4 Block diagram of SignalCore 3 9 GHz downconverters 10 SC5304A Operating amp Programming Manual The RF attenuator with a O to 30 dB attenuation range and attenuation steps of 1 dB is located between the preamplifier and the first mixer The RF attenuator is used to set the signal amplitude to a user defined level at the mixer when the RF input level is higher than that level This attenuator is adjusted to obtain the required distortion levels Lowering the RF level with the attenuator at the mixer operates the device in a more linear region However suppressing the RF level too low before the mixer reduces the signal to noise ratio so the user must set this level
9. bool lo1PII3Lock bool lo2PIILock bool lo3PlILock bool lo1PII1Lock bool lo1PII2Lock bool extRefDetected bool refClkOutEnable bool extRefLockEnable bool ifBandSelect bool preampEnable bool standbyEnable deviceStatus t typedef struct ifResponseCorrect t float ampCorrect float phaseCorrect ifResponseCorrect_t Function Definitions and Usage The functions listed below are found in the sc5304a dll dynamic linked library for Windows operating systems or in the libsc5304a so shared library for the Linux operating system These functions are also provided the LabVIEW library scb304a llb The LabVIEW functions contain context help Ctrl H to provide further clarification of each function Function Definition Return Output Description Function Definition Return Output sc5304a_SearchDevices int sc5304a_SearchDevices char serialNumberList The number of devices found char serialNumberList pointer list to serial numbers sc5304a_SearchDevices searches for SignalCore SC5304A devices connected to the host computer and returns an array containing their serial numbers The user can use this information to open the device s with their serial numbers See sc5304a_OpenDevice function for information on how to open a device sc5304a_OpenDevice deviceHande sc5304a_OpenDevice char devSerialNum device handle to the opened device char devSerialNum char pointer to a serial num
10. The use of a hybrid tuning architecture is important for improved phase noise and improved close in phase spurious responses Operating LO1 at such high frequencies internally to obtain a 1 MHz to 3 9 GHz RF range requires that the phase noise at these frequencies is sufficiently low so that the converted RF signal phase noise is not degraded significantly For example to downconvert a 100 MHz RF signal 101 is tuned to 4775 MHz which is about 48 times higher in frequency than the input frequency To further ensure phase noise remains low farther away from the carrier especially at 100 kHz and 1 MHz offsets a YIG oscillator is used It important to realize that having a phase noise plateau out to several tens of MHz which is a very common phenomenon with VCO based synthesizers is not acceptable for many applications Another reason for a hybrid tuning architecture is to reduce the phase spurs associated with phase locked loops A simple fractional PLL may provide resolution to 1 Hz but it cannot provide 1 Hz frequency tuning steps with low fractional phase spurs By using two DDS circuits to provide the 1 Hz tuning steps and mathematically ensuring that DDS generated spurs are suppressed within the architecture LO1 is made to fine tune to exact frequencies that is the frequency synthesized is an exact integer multiple or division of the reference signal The second local oscillator LO2 is fixed at 4 0 GHz synthesized using an integer PLL
11. EEPROM Address 15 8 0x00 Read Byte 1 Cal EEPROM byte data Read Byte O Open Open Open Open Open Open Open Open FETCH USER EEPROM 0722 7 0 EEPROM Address 7 0 0x00 15 8 EEPROM Address 15 8 0x00 Read Byte 1 User EEPROM byte data Read Byte O Open Open Open Open Open Open Open Open CAL EEPROM BULK 7 0 EEPROM Start Address 7 0 0x24 15 8 EEPROM Start Address 15 8 Read Byte 63 Cal EEPROM data Start Address 63 Read Byte O Cal EEPROM data Start Address USER EEPROM BULK 7 0 EEPROM Start Address 7 0 0x25 15 8 EEPROM Start Address 15 8 Read Byte 63 User EEPROM data 9 Start Address 63 Read Byte O User EEPROM data Start Address Reading Device Status Data To obtain the device status write request register DEVICE STATUS 0x18 with 0 00 in the data byte followed by querying the two bytes of data at the corresponding USB endpoint The returned data are summarized in Table 4 It is important to note that the first local oscillator has three phase detectors in the synthesizer so all three phase detectors must be ANDed to indicate the proper phase locked status The three bits that indicate the status of the three phase detectors are 13 10 and 9 SC5304A Operating amp Programming Manual 21 Table 4 Description of the status data bits Bit 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 Description 10 MHz TCXO PLL lock status 100 M
12. MHz After performing digital spectral inversion and performing an FFT take the subset of frequency components from 28 5MHz to 31 5 MHz and subtract 30 MHz to obtain the offset frequencies of 1 5 MHz to 1 5 MHz Use this set of offset frequencies to compute the gain and phase corrections to be applied to the original signal spectrum at 28 5 MHz to 31 5 MHz This algorithm may not be sufficient for computation of broadband signals due to the lack of computation speed and correction accuracy The calibration stored does not account for in band phase and amplitude variations due to temperature and these variations may cause sufficient errors especially in broadband digital signals The user should apply in situ equalization to correct for the in band amplitude and phase errors Function SC5304A ConvertRawTempData Definition int sc5304a_ConvertRawTempData unsigned int rawTempData float temperature Input unsigned int rawTempData 16 bit rawTempData stored in a 32 bit unsigned int Output float temperature temperature value of the device in degrees Celsius Description SC5304A_ConvertRawTempData converts the rawTempbData into a floating point number SC5304A Operating amp Programming Manual 48 Function Definition Input Output Description Function Definition Input Output Description sc5304a spline int sc5304a spline double xArray double yArray int nPoints double firstBoundary double
13. Settings The ATTENUATOR SETTING 0x11 register has two data bytes needed to set the value of a specific attenuator The MSB sets the target attenuator and the least significant byte LSB contains the attenuation value The MSB values and corresponding attenuator locations are as follows MSB value Attenuator 0 00 ATTEN2 0 01 IF3_ATTEN1 0x02 RF ATTEN 0x03 ATTEN The LSB contains the attenuation value in 1 dB steps for the attenuator specified in the MSB For example to set the RF attenuator to 15 dB the command bytes would be 0x11 0x02 OxOF Enabling and Disabling the RF Preamplifier The RF PREAMPLIFIER SETTING 0x12 register has one data byte that enables or disables the RF preamplifier It is recommended that the preamplifier only be enabled when the RF input signal is less than or equal to 30 dBm Enabling the preamplifier increases the receiver sensitivity for low level signals Setting the LSB of the data byte high or low will enable or disable the RF preamplifier respectively For example to turn on the preamplifier the command bytes would be 0x12 0x01 Changing the RF Synthesizer Mode The RF MODE SETTING 0x13 register has one data byte that provides two tuning modes for the device Fast Tune and Fine Tune By default the Fast Tune mode is disabled Normal mode Asserting high bit 3 of the data byte will enable Fast Tune mode Fast Tune enables the device to achieve faste
14. THE ABOVE RELIABILITY OF OPERATION OF THE SOFTWARE PRODUCTS CAN BE IMPAIRED BY ADVERSE FACTORS INCLUDING BUT NOT LIMITED TO FLUCTUATIONS IN ELECTRICAL POWER SUPPLY COMPUTER HARDWARE MALFUNCTIONS COMPUTER OPERATING SYSTEM SOFTWARE FITNESS FITNESS OF COMPILERS AND DEVELOPMENT SOFTWARE USED TO DEVELOP AN APPLICATION INSTALLATION ERRORS SOFTWARE AND HARDWARE COMPATIBILITY PROBLEMS MALFUNCTIONS OR FAILURES OF ELECTRONIC MONITORING OR CONTROL DEVICES TRANSIENT FAILURES OF ELECTRONIC SYSTEMS HARDWARE AND OR SOFTWARE UNANTICIPATED USES OR MISUSES OR ERRORS ON THE PART OF THE USER OR APPLICATIONS DESIGNER ADVERSE FACTORS SUCH AS THESE ARE HEREAFTER COLLECTIVELY TERMED SYSTEM FAILURES ANY APPLICATION WHERE A SYSTEM FAILURE WOULD CREATE A RISK OF HARM TO PROPERTY OR PERSONS INCLUDING THE RISK OF BODILY INJURY AND DEATH SHOULD NOT BE SOLELY RELIANT UPON ANY ONE COMPONENT DUE TO THE RISK OF SYSTEM FAILURE TO AVOID DAMAGE INJURY OR DEATH THE USER OR APPLICATION DESIGNER MUST TAKE REASONABLY PRUDENT STEPS TO PROTECT AGAINST SYSTEM FAILURES INCLUDING BUT NOT LIMITED TO BACK UP OR SHUT DOWN MECHANISMS BECAUSE EACH END USER SYSTEM IS CUSTOMIZED AND DIFFERS FROM SIGNALCORE TESTING PLATFORMS AND BECAUSE A USER OR APPLICATION DESIGNER MAY USE SIGNALCORE PRODUCTS IN COMBINATION WITH OTHER PRODUCTS IN A MANNER NOT EVALUATED OR CONTEMPLATED BY SIGNALCORE THE USER OR APPLICATION DESIGNER IS ULTIMATELY RESPONSIBLE FOR VERIFYING AND VALIDATING THE SUITABILITY
15. affect spectral regions out to a couple of MHz SignalCore uses mathematical algorithms to properly select the synthesizer parameters used in the multiple loop fractional N PLL to ensure that typical sideband spurious products are better than the specifications 11 Specifications are valid for all modes of frequency tuning whether is it PLL only mode or DDS driven mode As the YIG oscillator is sensitive to magnetic fields magnetic noise due to electrical fans supply transformers and other magnetic producing devices may induce sideband noise on the signals when they are place in close proximity It is recommended that users should exercise good technical judgment when such devices needed an example is mounting a cooling fan on the downconverter SC5304A Operating amp Programming Manual 100 MHz carrier 100 MHz carrier 10 MHz span 200 kHz span 50 0 50 3 1 Frequency offset MHz Offset Frequency kHz 100 MHz Carrier 1 kHz span 0 1 0 0 0 1 0 2 0 3 0 4 Offset Frequency kHz Figure 9 Plots show the raw spectral purity for a 100 MHz input RF signal LO 4 775 GHz Note that the power supply noise of 60 Hz and its harmonics are in the noise SC5304A Operating amp Programming Manual 57 Amplitude Specifications Input Range AC preamp disabled tenes eiit ic teet ect dace tra tereti neca cde 27 dBm max AC preamp enabled iani udo Regen nde t din dt REL eh cae 23 dBm max
16. by the commandByte See the register map in Table 3 for more information To read the status of the device unsigned int deviceStatus int status scb304a RegRead devHandle 0x18 0x00 amp deviceStatus sc5304a_SetStandby int sc5304a_SetStandby deviceHandle devHandle bool standbyStatus The status of the function deviceHandle devhandle handle to the opened device SC5304A Operating amp Programming Manual 37 Description Function Definition Return Input Description Function Definition Return Input Description Function Definition Return Input Description Function Definition Return Input Bool standbyStatus set to true 1 to set device in standby mode sc5304a SetStandby puts the device in standby mode where the power to the analog circuits is disabled conserving power sc5304a_SetFrequency int sc5304a_ SetFrequency deviceHandle devHandle unsigned int frequency The status of the function deviceHandle devhandle handle to the opened device unsigned int frequency frequency in Hz sc5304a_SetFrequency sets the RF frequency sc5304a_SetAttenuator int sc5304a_SetAttenuator deviceHandle devHandle unsigned int attenValue unsigned int attenuator The status of the function deviceHandle devhandle handle to the opened device unsigned int attenValue the value assigned to the attenuator unsigned int attenuator the designated attenuator s
17. device attributes and raw calibration data EEPROM DATA ADD HEX POINTS BYTES Array matrix DESCRIPTION Manufacturing Information Product Serial Number RF Module Number Product Manufacture Date Last Calibration Date Firmware Revision LO Hardware Revision SC Hardware Revision Calibration Temperature TCXO DAC Value Reserved YIG Calibration Reserved IF Filter O Bandwidth IF Filter 1 Bandwidth Temperature Coefficients IF3 FILTERO Response Calibration IF3 FILTER1 Response Calibration Reserved IF Invert Gain IF3 FILTER1 Gain IF Attenuator Calibration RF calibration Aa 555555 1 1 1 1 1 1 1 1 1 2 Table 5 lists the calibration EEPROM map of the SC5304A indicating how and where board information and calibration data are stored Since there are only 16k bytes on the EEPROM SignalCore recommends that all data be read into host memory on initialization of the device and parsed for further mathematical manipulation Having it available on host memory at all times during an application will greatly increase the speed of data manipulation Another recommendation is to store the data to a file and have the application read the file rather than the EEPROM to retrieve data on each execution SC5304A Operating amp Programming Manual 25 because of the relative slow EEPROM read rate The scb304a ConvertRawCalData function is helpful to convert EEPROM data to their original format and types
18. ires teste Temperature compensated crystal oscillator aging x last adjustment time lapse temp stability cal accuracy Initial calibration accuracy 0 05 ppm Temperature stability 9 20 C 0 30 0 25 ppm 1 0 ppm 1 ppm First year 25 C 5 5304 Operating amp Programming Manual 54 Frequency accuracy 7 frequency reference accuracy RF input frequency Hz 5 The frequency reference refers to the DEVICE internal 10 MHz TCXO time base Accuracy is in parts per million or ppm 1x10 5 6 The customer must apply sufficient cooling to the device to keep the unit temperature as read from its internal temperature sensor within the range of 40 C to 45 C at an ambient temperature of 25 C 7 This is the accuracy of the device for any given input RF signal Sideband phase noise dBc Hz 80902 RF Frequency Offset 100 MHz 1000 MHz 2000 MHz 3500 MHz 100 Hz 88 87 85 83 1 kHz 100 99 98 97 10 kHz 108 107 106 105 100 kHz 120 119 118 117 1 MHz 143 142 142 141 10 152 152 150 148 Phase Noise dBc Hz 100 MHz 1000MHz 3500 MHz 100 MHz Offset Frequency kHz 9 Figure 8 Typical measured sideband noise SC5304A Operating amp Programmin
19. secondBoundary double yInterpolant double xArray the set of independent values double yArray the set of x dependent function values size is the same as xArray int nPoints the number of points in xArray double firstBoundary the second derivative of the first point in the set double secondBoundary the second derivative of the last point in the set double yInterpolant the return set of interpolants Returns the Spline interpolants of the input parameters sc5304a splinelnterp int sc5304a splinelnterp double xArray double yArray double yInterpolant double nPoints double x double interpolatedYValue double xArray the set of independent values double yArray the set of x dependent function values size is the same as xArray double yInterpolant the returned interpolant from spline int nPoints the numbers of points in xArray double x the value at which interpolation is performed double interpolatedYValue the corresponding interpolated value at x Returns the Spline interpolated value SC5304A Operating amp Programming Manual 49 CALIBRATION amp MAINTENANCE The SC5304A is factory calibrated and ships with a certificate of calibration SignalCore strongly recommends that the SC5304A be returned for factory calibration every 12 months or whenever a problem is suspected The specific calibration interval is left to the end user and is dependent upon the accuracy required for a particular appl
20. surface acoustic wave SAW filter The final IF filter has two programmatically selectable paths switching either between two filter paths with different bandwidths or between one filter and one bypass no filter path Filters in the first and second IF stages are not as selective as the final IF filter but they ensure good isolation between local oscillators LO Keeping each LO isolated helps to suppress unwanted spurious signals Frequency accuracy is provided by an onboard 10 MHz temperature compensated crystal oscillator TCXO which can be phase locked to an external reference source if required and it is recommended to do so in applications that may require a more stable and accurate base reference Signal Path Description Figure 4 depicts an overall block diagram of the SC5304A Starting from the upper left the RF input of the SC5304A is AC coupled followed by an elliptic low pass filter which has a sharp cut off frequency slope to ensure the images and unwanted frequencies are well suppressed Next a bypass switch enables or disables the internal preamplifier in the path of the RF signal directly after the input filter The advantage of placing the amplifier before the attenuators is to increase the downconverter sensitivity when the preamplifier is selected This switch is programmatically controlled and can be toggled as required enabling the preamplifier to boost input signals of very small amplitude Due to losses in the attenuato
21. to compromise between noise and linearity The RF signal is mixed with the first local oscillator LO1 and the difference component is selected as the wanted intermediate frequency IF The first IF stage after the RF mixer referred to as IF1 in the programming section is heavily filtered and carefully amplified to maintain the best compromise between signal dynamic range and linearity The filters provide isolation between the first and second stage mixers to reduce in band inter modulation spurious signals from the mixing of high order harmonics of the IF and LO frequencies The filters in this stage also suppress the mixer LO leakage If not filtered LO leakages can potentially cause saturation in the preceding stages of the signal path and degrade the linearity performance of the device There is an adjustable attenuator following the output of the first mixer which is used to suppress leakages from LO1 that appear in band when the downconverter is tuned to frequencies less than the bandwidth of the device For example if the bandwidth of the system is 20 MHz 101 leakage will appear in band if the frequency is tuned below 20 MHz Technically LO leakages should not appear in band until the device is tuned below 10 MHz but the non ideality of the filter allows sufficient leakage at higher frequencies Setting this attenuator will attenuate both the IF1 signal and the LO1 leakage making the device respond more linearly As always the compromise
22. 00Enable changes REF OUT between 10MHz to 100 MHz sc5304a_SetReferenceClock configures the reference clock behavior of the device sc5304a_SetReferenceDac int sc5304a_SetReferenceDac deviceHandle devHandle unsigned int dacValue The status of the function deviceHandle devhandle handle to the opened device 16 bit value for the reference DAC sc5304a_SetReferenceDac set the value of the DAC that tunes the internal reference TXCO The user may choose to override the value stored in memory to improve frequency accuracy Unsigned int dacValue sc5304a Setlflnversion int sc5304a Setlflnversion deviceHandle devHandle bool iflnvertEnable The status of the function deviceHandle devhandle handle to the opened device Bool iflnvertEnable enable spectral inversion sc5304a Setlflnversion enables the down converted signal to be spectrally inverted with respect the RF input This may be beneficial for some applications sc5304a_SetSignalPhase int sc5304a_SetSignalPhase deviceHandle devHandle float phase The status of the function deviceHandle devhandle handle to the opened device float phase phase in degrees 0 360 deg 0 1 resolution SC5304A Operating amp Programming Manual 40 Description Function Definition Return Input Description Function Definition Return Input Output Description Example sc5304a SetSignalPhase increases the phase of the signal by the amount spe
23. 04A USB RF Downconverter 1 IEC Power Cord 1 USB cable 1 Software Installation CD Setting Up and Configuring the SC5304A The SC5304A is a rugged actively cooled device for either benchtop or rack mounted use However even an actively cooled device still requires attention to ensure the device can properly shed the heat it generates Inadequate airflow can cause the temperature inside the RF housing to rise above the maximum for this product leading to improper performance and potentially reducing product lifespan or causing complete product failure Maintain adequate air space around the unit at all times Cooling for this device is sufficient when the on board temperature sensor indicates a rise of no more than 20 C above ambient temperature under normal operating conditions SC5304A Operating amp Programming Manual 4 The SC5304A is a benchtop subsystem downconverter with user I O located on both the front and rear faces of the unit as shown in Figure 1 and Figure 2 Each location is discussed in further detail below Figure 1 Front view of the SC5304A Figure 2 Rear view of the SC5304A Signal connections ports to the SC5304A are of three types N SMA and BNC Exercise caution when fastening cables to the signal connections Over tightening any connection can cause permanent damage to the device The condition of your system s signal connections can significantly affect measurement accuracy and repeatabilit
24. 05000 0 04500 0 04800 0 05600 0 05000 0 00038 0 00035 0 00029 0 00038 0 00038 0 00035 0 00029 0 00038 IF3_FILTERO Response Calibration 0x204 This is a 3x51 float matrix and data is read back row by row This set of data measures pass band amplitude variation with respect to the center IF and phase deviation from linear phase of filter IF3 FILTERO There are a total of 51 offset frequency points from the center IF frequency measured inside the bandwidth of the filter Table 7 is an example of the data and format IF3 FILTER1 Response Calibration 0x46C This is a 3x51 float matrix and data is read back row by row This set of data measures pass band amplitude variation with respect to the center IF and phase deviation from linear phase of filter IF3 FILTER There are a total of 51 offset frequency points from the center IF frequency measured inside the bandwidth of the filter Table 7 is an example of the data and format Table 7 Relative IF gain and phase response calibration and format Frequency Offset MHz 12 115 5 5 0 5 115 12 Gain Error 58 2 20 6 0 9 ns 0 2 0 0 03 0 2 12 8 304 Phase Error radians 286 138 053 012 0 011 129 134 IF Invert Gain Correction 0x788 This is a float that contains the change in IF gain when the device is switched to invert the IF spectrum The default gain in the IF is the non i
25. 1 2 0 0 E ea o a 998 999 1000 Frequency MHz 1001 Power dBm 1002 100 110 1998 1999 2000 Frequency 2001 MHz 2002 Figure 15 Plots show the typical IMD performance with two 20 dBm signals at the input 0 dB RF attenuation preamp disabled and conversion gain of 20 dB 27 Specifications are based on 0 dB RF attenuation 0 dB IF1 attenuation two 20 dBm tones with 1 MHz separation at the mixer final IF attenuators set to maintain 0 dBm at the IF output 28 Specifications are based on 0 dB RF attenuation 0 dB IF1 attenuation two 30 dBm tones with 1 MHz separation at the mixer final IF attenuators set to maintain 0 dBm at the IF output 29 These are in band measurements and not out of band measurements Out of band signal tones exist outside the IF filter bandwidth of the device and thus may provide better IP3 measurements However using in band signal tones provide better estimation of the device non linear effects on broadband signals Input second harmonic distortion SHI dBm Input second harmonic intercept 400 MHz 1000 MHz 1 8 GHz point dBm Preamplifier disabled 62 62 58 Preamplifier enabled 32 33 30 SC5304A Operating amp Programming Manual 63 Input compression point dBm 100 MHz 1 GHz 1 GHz 2 5 GHz 2 5 GHz 3 9 GHz Preamplifier disabled 1 1 5 2 Preamplifier enabled
26. 23 20 19 Dynamic range Measurement dynamic range G9 esses 185 dB Instantaneous dynamic range GJ esent tentent ttn ttn gt 150 dB ov gt 2 2 5 2 E 75 75 2 o Power level input mixer dBm 2nd Harmonic Distortion Noise Figure 16 Instantaneous dynamic ranges plotted with preamplifier disabled for 1000 MHz measured data Mixer level is at input level 30 Measurement dynamic range refers to the device SNR measurement capability using 2 or more configurations settings For example the user could set in sufficient RF attenuation to capture the high level signals and then turn on the preamplifier to measure low level noise 31 Instantaneous dynamic range refers to the instantaneous device SNR measurement using a single configuration setting For example the user could set the downconverter to receive a 0 dBm signal at the mixer while at the same setting be able to measure the signal noise floor to 150 dB below its peak SC5304A Operating amp Programming Manual 64 Reference Inputs and Outputs Reference output specifications Center frequency 92 ticae dee rebate stia dat ERE des votado 10 MHz 100 MHz Am plitude 3 dBm typ Wave lorD MES Sine cte a it
27. 9001 01 Adapter Type N Male to SMA Female to 18 GHz VSWR 1 15 9 18 GHz Stainless Steel Body RoHS Compliant 7109002 01 Adapter BNC Male to SMA Female to 4 GHz VSWR 1 2 9 4 GHz Nickel plated Brass Body RoHS Compliant 7109003 01 Adapter SMA Male to BNC Female to 4 GHz VSWR 1 2 4 GHz Nickel plated Brass Body RoHS Compliant 7109004 01 Termination Type N Male to 18 GHz VSWR 1 25 18 GHz 2 Watts Dissipating 50 Nickel plated Brass Body RoHS Compliant 7109005 01 Termination SMA Male 50 1 Watt VSWR 1 2 9 18 GHz 1 Watt Dissipating 50 Stainless Steel Body RoHS Compliant 7109006 01 Termination BNC Male 50 O 2 Watt VSWR 1 15 9 3 GHz 2 Watts Dissipating 50 O Nickel plated Brass Body RoHS Compliant 7109012 01 Cable Assy USB Type A to Type B 2 m Black SC5304A Operating amp Programming Manual 51 APPENDIX SPECIFICATIONS Definition of Terms The following terms are used throughout this datasheet to define specific conditions Specification spec Typical data typ Nominal values nom Measured values meas Defines guaranteed performance of a calibrated instrument under the following conditions e 3 hours storage at room temperature standardized to 25 C followed by 30 minutes minimum warm up operation e Specified environmental conditions are met within the specified operating temperature range of 0 C to 40 C unless otherwise noted e Recommended cal
28. ETTING 0x12 7 0 Open Open Open Open Open Open Open Enable 0x00 Fast RF MODE SETTING 0x13 Tune 7 0 Open Open Open Open Open Enable Fine Tune 0x00 IF BAND SELECT 0x15 7 0 Open Open Open Open Open Open Open Band 0x00 100 MHz RefOut Lock REFERENCE SETTING 0x16 7 0 Reserv OutSel Enable Enable 0x00 7 0 DAC d 7 0 0x00 REFERENCE DAC 0x17 7 0 7 01 15 8 DAC word 15 8 0x00 IF INVERT SETTING Ox1D 7 0 Open Open Open Open Open Open Open Enable 7 0 EEPROM DATA 7 0 WRITE USER EEPROM 0x23 15 8 EEPROM Address 7 0 23 16 EEPROM Address 15 8 7 0 Units Val 7 4 Tenths Val 0x00 PHASE SETTING 0x32 nis valge DR 15 8 Units Value 13 8 0x00 Tuning the RF Frequency The frequency of the first local oscillator LO1 is set by writing the RF_FREQUENCY register 0x10 This register requires the address byte plus four data bytes these data bytes being the bytes comprising an unsigned 32 bit integer The data bytes contain the frequency tuning word in Hertz For example to tune to a frequency of 2 4 GHz the data word would be d2400000000 in decimal or Ox8FOD1800 hexadecimal Breaking this command down to the five bytes sent via the USB interface the command bytes would be 0x10 Ox8F OxOD 0x18 and 0x00 with 0x10 being the first byte sent SC5304A Operating amp Programming Manual 18 Changing the Attenuator
29. Hz VCXO PLL lock status LO1 PLL Main lock status LO2 PLL lock status LO3 PLL lock status LO1 PLL1 lock status LO1 PLL2 lock status Reserved External reference detected Reference output enabled Reference lock enabled IF3 FILTER1 selected RF preamplifier enabled Device standby enabled Reserved Reserved Reading Temperature Data To obtain temperature data write request register FETCH TEMPERATURE 0x19 with 0x00 in the data bytes followed by reading two bytes Once data is received the two bytes of data need to be processed to correctly represent the data in temperature units of degrees Celsius Data is returned in the first 14 bits 13 0 Bit 13 is the polarity bit indicating whether it is a positive 0x0 or negative 0x1 value The temperature value represented in the raw data is contained in the next 13 bits 12 0 To obtain the temperature ADC code the raw data should be masked logically AND ed with Ox1FFF and the polarity should be masked with 0x2000 The conversion from 12 bit ADC code to an actual temperature reading in degrees Celsius is shown below It is not recommended to read the temperature too frequently especially once the SC5304A has stabilized in temperature The temperature sensor is a serial device located inside the RF module Positive Temperature ADC code 32 Negative Temperature ADC code 8192 32 SC5304A Operating amp Programming Manual Therefore like any other serial device
30. IF RESPONSE eu er Pong ree e VR 30 Software Library Functions lt EISES 33 Definitions a EE 34 Function Definitions and USage erento rein eene eet ee Pea eee qoe a ee ae ER Ee ae 35 Calibration amp Maintenance 50 SC5304A Operating amp Programming Manual ii SC5304A Accessories Port cetero E AAEE ee esee vae eue tua Pe eva epe EVE eae FANS 51 Ordering Information ierit C ead eae 51 Appendix A Specifications 52 iii SC5304A Operating amp Programming Manual IMPORTANT INFORMATION Warranty The warranty terms and conditions for all SignalCore products are also provided on our corporate website Please visit http www signalcore com for more information This product is warranted against defects in materials and workmanship for a period of one year from the date of shipment SignalCore will at its option repair or replace equipment that proves to be defective during the warranty period This warranty includes parts and labor Before any equipment will be accepted for warranty repair or replacement a Return Material Authorization RMA number must be obtained from a SignalCore customer service representative
31. MHz to 3 9 GHz and the IF output is fixed at 70 MHz When the input frequency is lower than the intermediate frequency the device technically behaves as an upconverter The SC5304A up converts when the input frequency ranges from 1 MHz to 70 MHz converted spectrum polarity may be inverted or non inverted by programming the device accordingly Fundamentally each conversion stage consists of a frequency mixer that mixes two input signals and producing a wanted third The wanted third component is selected via a frequency filter among other signals generated in the mixing process The three primary components of the signals in each conversion mixer are commonly known as the local oscillator LO radio frequency RF and the intermediate frequency IF as shown in Figure 3 RF RX IF LO Figure 3 Frequency conversion stage using a mixer Where R represents the RF component L represents the LO component and represents the IF component The LO is resident in the downconverter and is either frequency tunable or fixed in frequency depending on the stage The first IF stage is an up conversion stage all input signals are converted to an IF higher than the highest input frequency specified The second and third stages successively convert this high first IF down to the final IF of 70 MHz Having a high first IF allows the downconverter to achieve very high image rejection ability This image free architecture achieves high image rejecti
32. OF SIGNALCORE PRODUCTS WHENEVER SIGNALCORE PRODUCTS ARE INCORPORATED IN A SYSTEM OR APPLICATION INCLUDING WITHOUT LIMITATION THE APPROPRIATE DESIGN PROCESS AND SAFETY LEVEL OF SUCH SYSTEM OR APPLICATION SC5304A Operating amp Programming Manual 3 GETTING STARTED Unpacking All SignalCore products ship in antistatic packaging bags to prevent damage from electrostatic discharge ESD Under certain conditions an ESD event can instantly and permanently damage several of the components found in SignalCore products Therefore to avoid damage when handling any SignalCore hardware you must take the following precautions e Ground yourself using a grounding strap or by touching a grounded metal object e Touch the antistatic bag to a grounded metal object before removing the hardware from its packaging e Never touch exposed signal pins Due to the inherent performance degradation caused by ESD protection circuits in the RF path the device has minimal ESD protection against direct injection of ESD into the RF signal pins e When notin use store all SignalCore products in their original antistatic bags Remove the product from its packaging and inspect it for loose components or any signs of damage Notify SignalCore immediately if the product appears damaged in any way Verifying the Contents of your Shipment In addition to this User Guide verify that your SC5304A kit contains the following items Quantity Item 1 SC53
33. Phone 512 501 6000 PRESERVING SIGNAL INTEGRITY Fax 512 501 6001 oy S
34. RY FUNCTIONS SignalCore s philosophy is to provide products to our customers whose lower hardware functions are easily accessible For experienced users who wish to use direct low level control of frequency and gain settings having the ability to access the registers directly is a necessity However others may wish for simpler product integration using higher level function libraries and not having to program device registers directly The functions provided in the 5 5304 dynamic linked shared or LabVIEW libraries are sc5304a_SearchDevices sc5304a_OpenDevice e sc5304a_CloseDevice sc5304a_RegWrite sc5304a_RegRead e sc5304a_InitDevice sc5304a_SetStandby e sc5304a_SetFrequency e sc5304a_SetPreamp e 5 5304 SetSignalChain sc5304a_SetSynthesizerMode e sc5304a SetlfFilterPath e sc5304a_SetReferenceClock sc5304a_SetReferenceDac e sc5304a Setlflnversion e sc5304a_WriteUserEeprom sc5304a SetSignalPhase e sc5304a_GetDeviceStatus e 5 5304 GetTemperature e sc5304a_ReadCalEeprom e sc5304a_ReadUserEeprom sc5304a_ReadUserEepromBulk sc5304a_GetRawCalData e sc5304a_GetCalData sc5304a CalcAutoAttenuation e sc5304a_CalcGain e 5 5304 CalclfResponseCorrection sc5b304a ConvertRawCalData sc5304a_ConvertRawTempData e sc5304a spline e sc5304a splinelnterp SC5304A Operating amp Programming Manual 32 Each of these functions is described in more detail on the f
35. SN A SignalCore PRESERVING SIGNAL INTEGRITY SC5304A 1 MHz to 3 9 GHz RF Downconverter with USB Interface Operating amp Programming Manual 2012 SignalCore Inc support signalcore com CONTENTS Important Information 1 Copyright amp eite terere aree tes aree to aoo vendas 2 International Materials 2 CE European Union amp Safety Compliance 00 2 Recycling 3 Warnings Regarding Use of SignalCore Products 20 0404 0 00 0 3 Getting Started 4 Verifying the Contents of your Shipment 4 Setting Up and Configuring the SC5304A 4 0 112001 0 4 Sigla COD nectlolis II uM M 6 ife iforgilzp coc 6 USB Communication Connectlori us coeno rette npe EY Ro ane Ce Finn o amp 6 Mode LL O 7 7
36. additional assistance in writing an appropriate API other than that provided on the software installation CD please contact SignalCore The SC5304A USB Configuration The SC5304A USB interface is USB 2 0 compliant running at Full Speed capable of 12 Mbits per second It supports 3 transfer or endpoint types e Control Transfer e Interrupt Transfer e Bulk Transfer The endpoint addresses are provided in the C language header file and are listed below SC5304A Operating amp Programming Manual 16 Define SignalCore USB Endpoints define 5 ENDPOINT INT define 5 define 5 ENDPOINT BULK H define 5 ENDPOINT OUT BULK Define for Control Endpoints H define USB ENDPOINT IN 0x80 H define USB ENDPOINT OUT 0x00 define USB TYPE VENDOR 0x02 5 define USB RECIP INTERFACE 0x01 The buffer lengths are sixty four bytes for all endpoint types The user should not exceed this length or the device may not respond correctly Furthermore all registers require five bytes or less with the exception of registers Ox24 FETCH CAL EEPROM BULK and 0x25 FETCH USER EEPROM BULK These two registers return sixty four bytes of valid data upon executing a device read Writing the Device Registers Directly Device commands for the SC5304A vary between two bytes and five bytes in length The most significant byte MSB is the command register address that specifies how the dev
37. alue containing the signal chain hardware revision Calibration Temperature 0x50 This is a float 32 value containing the temperature at which the device was calibrated TCXO DAC Value 0x54 This is an unsigned integer containing the value for the reference DAC to adjust the precision of the temperature compensated crystal oscillator TCXO YIG Calibration 0x64 Data is reserved for device use IF Filter Bandwidths 0x184 0x188 These two float 32 data points contain the filter bandwidths of IF3 FILTERO and IF3_FILTER1 respectively These are only available if the product contains non standard filters different from those provided with the base product Gain temperature coefficients 0x1A0 This is a 3x8 float matrix where data is concatenated by rows that is data is read back row by row These coefficients derived during calibration are needed to compute for gain as a function of temperature They are 274 order polynomial coefficients and are measured over eight different frequencies See Gain Correction section for more information on gain SC5304A Operating amp Programming Manual 26 correction factors Table 6 is an example of the coefficient data and its format Variables a4 and a are the first and second order coefficients Table 6 An example of gain temperature coefficients data and format dde 50 0 250 500 1000 1500 2500 2800 3800 0 04500 0 04800 0 05600 0
38. ance of 50 O Maximum input power is 13 dBm Indicator LEDs The SC5304A provides visual indication of important modes There are two LED indicators on the unit Their behavior under different operating conditions is shown in Table 1 Table 1 LED indicator states LED Color Definition STATUS Green Power good and all oscillators phase locked STATUS Red One or more oscillators off lock STATUS Off Power fault Device is open green closed off this indicator is also ACTIVE Green Off user programmable see register map ACTIVE Orange User initiated standby mode 6 USB Communication Connection The SC5304A communicates with a host computer through a standard Type B USB connector located on the rear panel of the unit SignalCore provides a 79 2 meter Type A to Type B USB cable in the shipping kit Cables as long as 197 5 meter may be used in accordance with the USB 2 0 specification with a maximum round trip delay of 1 5 us including hubs between the host computer and the device Maximum per cable delay is set by the specification at 5 2 nanoseconds per meter SC5304A Operating amp Programming Manual Power Switch This switch turns the unit on and off The switch is SPDT breaking both the line and neutral legs of the circuit for added safety Protective earth grounding is provided through the center pin and is bonded to both the SC5304A enclosure the internal AC DC pow
39. and clearly marked on the outside of the return package SignalCore will pay all shipping costs relating to warranty repair or replacement SignalCore strives to make the information in this document as accurate as possible The document has been carefully reviewed for technical and typographic accuracy In the event that technical or typographical errors exist SignalCore reserves the right to make changes to subsequent editions of this document without prior notice to possessors of this edition Please contact SignalCore if errors are suspected In no event shall SignalCore be liable for any damages arising out of or related to this document or the information contained in it EXCEPT AS SPECIFIED HEREIN SIGNALCORE INCORPORATED MAKES NO WARRANTIES EXPRESS OR IMPLIED AND SPECIFICALLY DISCLAIMS ANY WARRANTY OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE CUSTOMER S RIGHT TO RECOVER DAMAGES CAUSED BY FAULT OR NEGLIGENCE ON THE PART OF SIGNALCORE INCORPORATED SHALL BE LIMITED TO THE AMOUNT THERETOFORE PAID BY THE CUSTOMER SIGNALCORE INCORPORATED WILL NOT BE LIABLE FOR DAMAGES RESULTING FROM LOSS OF DATA PROFITS USE OF PRODUCTS OR INCIDENTAL OR CONSEQUENTIAL DAMAGES EVEN IF ADVISED OF THE POSSIBILITY THEREOF This limitation of the liability of SignalCore Incorporated will apply regardless of the form of action whether in contract or tort including negligence Any action against SignalCore Incorporated must be brought within one year a
40. and a fixed narrow tune VCO with very low phase noise The typical raw phase noise of the second stage oscillator is less than 150 dBc Hz 9 1 MHz offset LO2 phase noise contribution to the overall phase noise of the device is less than 1 dB LO1 dominates the phase noise of the device The third local oscillator LO3 is synthesized using a fractional PLL and has phase noise lower than both LO1 and LO2 and is switchable between two frequencies 605 MHz and 745 MHz the later frequency being the default Both of these frequencies will set the output IF center frequency at 70 MHz However at the default frequency the final 70 MHz IF output spectral polarity is the same as that of the input RF whereas the 605 MHz frequency will create an inverted IF spectrum If LO3 is set to 605 MHz by calling the sc5304a Setlflnversion function or register the IF output spectral content will be inverted with respect to the input RF spectrum See Figure 5 for a graphical representation of this process SC5304A Operating amp Programming Manual 12 Non Inverted Conversion m RF lt Inverted Conversion Ite Figure 5 Graphical representation of IF inversion Inverted spectral conversion is convenient for digitizers that sample the IF in the even Nyquist zones because it eliminates the need to perform digital inversion of the acquired spectrum All local oscillators are phase locked to an internal 100 MHz voltage controlled crystal oscill
41. and application the output IF level should be about 3 dB below full scale of the digitizer to maximize its signal to noise dynamic range SignalCore provides a simulation tool that mimics the behavior of the SC5304A The user may run the simulator to get an understanding of what the parameters need to be set on the downconverter to achieve certain performance Additionally the function scb304a CalcAutoAttenuation helps the user obtain the necessary attenuator parameters to setup the device up for best compromise of linearity and noise performance for a given set of input and output parameters There is a programmable attenuator in the first IF section Atten that can be used to improve linearity in general The primary use of this attenuator is to suppress the LO1 leakage in the IF band when the downconverter is tuned below the bandwidth frequency This in band leakage affects the linearity of the device as it may inter modulate with the IF signal to produce third order spurious products The level of the leakage is equivalent to a typical 25 dBm RF signal at the mixer The user should set 5 dB to 10 dB OF attenuation when operating at these low frequencies Operating the SC5304A Outside Normal Range The SC5304A is capable of tuning below 1 MHz and above 3 9 GHz These frequencies lie outside of the specification range and performance will be degraded if operated in these outer margins However for some applications the reduced dynamic ran
42. ata whether floats or unsigned 32 bit integers are stored as flattened unsigned 32 bit words Each data point is comprised of four unsigned bytes so data must be read back in multiples of four bytes with the least significant byte stored in the lower address After the data are read back they need to be un flattened back to their original type Since the four bytes constitutes the four bytes of an unsigned 32 bit integer converting un flattening to an unsigned value simply involves concatenation of the bytes through bit shifting To convert to floating point representation is a little more involved First convert the four bytes into an unsigned 32 bit integer value and then in C C etc type cast a float pointer to the address of the value In C C the code would be float Y float amp X where X has been converted earlier to an unsigned integer An example written in C code would look something like byte value 4 read in earlier unsigned int uint32 value float float32 value int count 0 while count 4 uint32 value unit32 value byte value count lt lt count 8 count float32_value float amp uint32_value SC5304A Operating amp Programming Manual 23 Reading User EEPROM Data Once data has been written to the User EEPROM it can be retrieved using the process outlined above for reading calibration data but calling the FETCH USER EEPROM or FETCH USER EEPROM BULK registers
43. ation 1 Determine a fitted polynomial function for the amplitude error gain and multiply this function with the uncorrected amplitude spectrum Add the two values if dealing in decibels Additionally determine a fitted polynomial function for the phase error and add values derived from this function with the uncorrected phase To derive let X e be the measured uncorrected value 9 be the fitted polynomial to the calibrated error values and be the corrected measured value Also let denote the principle value of the phase of the above terms and we can relate all the terms as Y e E e x eJ e e rgtr e g eJo Ix ei eral o eror p From the above equation we see that the magnitude terms are multiplied and the phase terms added In the discrete sense digitized for every frequency value w we apply the above equation to correct for the non ideality of the IF filter 2 The other method finds the magnitude and error points through interpolation methods such as Spline then multiplying the error magnitude with the uncorrected magnitude and adding the error and uncorrected phases This is similar to method 1 but instead of using a fitted function to obtain the error values interpolation is used Interpolation is generally a slower process This is the method implemented in the library function sc5304a CalclfResponseCorrection SC5304A Operating amp Programming Manual 31 SOFTWARE API LIBRA
44. ator VCXO which sets their close in phase noise performance The 100 MHz VCXO is in turn phase locked to the internal 10 MHz TCXO for frequency accuracy and stability For better frequency accuracy and stability than the TCXO onboard the SC5304A or for frequency synchronization the user can programmatically set the device to phase lock the TCXO to an external 10 MHz reference source by programming the REFERENCE_SETTING register It is important to note that the TCXO will only attempt to lock to an external source if one is detected A typical external reference source minimum level of 10 dBm is required for detection to be successful A reference source level of 0 dBm to 3 dBm is recommended for normal operation The reference source is fed into the device through the ref in port The device can also export a copy of its internal reference through the ref out port The output reference frequency is selectable for either 10 MHz or 100 MHz output By default routing of the reference signal to the ref out port is disabled It can be enabled by programming the REFERENCE_SETTING register This reference frequency is sourced from the internal 100 MHz OCXO and the default output selection is 10 MHz which is divided down from the 100 MHz VCXO The output reference level is typically 3 dBm Frequency Tuning Modes Tuning of SC5304A superheterodyne downconverter is accomplished through the tuning of LO1 LO1 has two sets of control parame
45. ature int sc5304a_GetTemperature deviceHandle devHandle float temperature The status of the function deviceHandle devhandle handle to the opened device float temperature temperature in degrees C sc5304a_GetTemperature retrieves the internal temperature of the device sc5304a_ReadCalEeprom int sc5304a_ReadCalEeprom deviceHandle devHandle unsigned int memAdd unsigned char byteData The status of the function deviceHandle devhandle handle to the opened device EEPROM memory address the read byte data sc5304a_ReadCalEeprom reads back a byte from the memory address of the calibration EEPROM unsigned int memAdd unsigned char byteData sc5304a_ReadUserEeprom int sc5304a_ReadUserEeprom deviceHandle devHandle unsigned int memAdd unsigned char byteData The status of the function deviceHandle devhandle handle to the opened device EEPROM memory address the read byte data sc5304a_ReadUserEeprom reads back a byte from the memory address of the user EEPROM unsigned int memAdd unsigned char byteData sc5304a_ReadUserEepromBulk int sc5304a_ReadUserEepromBulk deviceHandle devHandle unsigned int startMemAdd unsigned char byteDataArray The status of the function SC5304A Operating amp Programming Manual 42 Input Output Description Example deviceHandle devhandle handle to the opened device EEPROM start memory address the read 64 bytes of data sc5304a_Rea
46. ber serial numbers are not limited to numerical values SC5304A Operating amp Programming Manual 35 Description sc5304a_OpenDevice opens the device and turns on the front panel access LED if successful This function returns a handle of USB type to the device for other function calls Function sc5304a CloseDevice Definition int sc5304a CloseDevice deviceHandle devHandle Return The status of the function Input deviceHandle devHandle handle to the device to be closed Description sc5304a CloseDevice closes the device associated with the device handle and turns off the access LED of the front panel if it is successful Example To exercise the functions that open and and close the USB device Declaring char deviceList deviceHandle devHandle int devicesFound int i Mlocate memory deviceList char malloc sizeof char MAXDEVICES MAXDEVICES 50 serial numbers to search for i 0 i lt MAXDEVICES i deviceList i char malloc sizeof char SCI SN LENGTH SCI SN has 8 char devicesFound sc5304a_SearchDevices deviceList printf There are d SignalCore USB devices found M devicesFound 0 while lt numOfDevices printf Device d has Serial Number s Mn i 1 deviceList i i devHandle sc5304a OpenDevice deviceList 0 get a handle to the first device on the List Free memory for i 0 i lt MAXDEVICES i free deviceList i free deviceList
47. cified sc5304a_WriteUserEeprom int sc5304a_WriteUserEeprom deviceHandle devHandle unsigned int memAdd unsigned char byteData The status of the function deviceHandle devhandle handle to the opened device unsigned int memAdd memory address to write to unsigned char byteData byte to be written to the address sc5304a_WriteUserEeprom writes one byte of data to the memory address specified sc5304a_GetDeviceStatus int sc5304a_GetDeviceStatus deviceHandle devHandle deviceStatus_t deviceStatus The status of the function deviceHandle devhandle handle to the opened device deviceStatus deviceStatus outputs the status of the device such as PLL lock sc5304a_GetDeviceStatus retrieves the status of the device such as LO phase lock status and current device settings Code showing how to use this function deviceStatus_t devStatus devStatus deviceStatus_t malloc sizeof deviceStatus_t int status scb304a GetDeviceStatus devHandle devStatus if devStatus vcxoPllILock printf The 100 MHz is phase locked Mn else printf The 100 MHz is not phase locked n free deviceStatus SC5304A Operating amp Programming Manual 41 Function Definition Return Input Output Description Function Definition Return Input Output Description Function Definition Return Input Output Description Function Definition Return sc5304a_GetTemper
48. dUserEepromBulk reads back 64 bytes beginning at the start memory address of the user EEPROM Code to read back 512 bytes of data starting at address 1024 into eepromData unsigned int memAdd unsigned char byteData unsigned char eepromData unsigned char malloc 512 unsigned char bufferln unsigned char malloc 64 int i 0 int bufferCount 0 unsigned int add 1024 while bufferCount lt 8 int status scb304a ReadUserEepromBulk devHandle add bufferCount 64 bufferln for i20 i 64 i eepromData i bufferCount 64 bufferln i bufferCount free bufferln Function Definition Return Input Output Description Example Function Definition Return Input Output sc5304a_GetRawCalData int sc5304a_GetRawCalData deviceHandle devHandle unsigned char rawCalDataArray The status of the function deviceHandle devhandle handle to the opened device unsigned char rawCalDataArray the entire calibration EEPROM contents sc5304a_GetRawCalData reads the entire calibration EEPROM into the rawCalDataArry The array must be allocated for at least 15168 bytes See code block example below for using sc5304a_ConvertRawCalData sc5304a_GetCalData int sc5304a_GetCalData deviceHandle devHandle deviceAttribute_t deviceAttributes calibrationData_t calData The status of the function deviceHandle devhandle deviceAttribute_t deviceAttributes handle to the op
49. e Tene oc orem inet ae en ence ML MO tS 50 O nominal e ea a TY Pe Female SMA Frequency ACCUL ACY iussit reri iin irte Gem ek od ne n dr See Frequency reference Reference input specifications aur gdussidiwA E 10 ATA PUG 10 dBm min 13 dBm max Phase lock range 10 ppm typ IM PECANCE RR paa 50 nominal LM ULL Connector Female SMA 32 The output reference frequency may be selected programmatically for 10 MHz or 100 MHz The 100 MHz may be used to drive digitizer ADC directly Port Specifications RF input edipi Due ee ix ict eR n M es EUR Raps e 500 AC roo gag SMA female T EIER 120 dBm IF output Output impedance sees esp eye nd dixe del tice iE i Rc Ree eS 500 pile A 1 6 rli he AC
50. ead mode For example to write 123 to address 1234 of the user EEPROM the command bytes would be 0x23 0x04 OxD2 0 78 Setting the Phase of the IF Signal When the device is tuned to a fixed RF frequency some applications may need to change the phase of the down converted signal for various reasons The IF output phase can be programmatically adjusted in 0 1 degree increments from O to 360 degrees Changing the phase is accessed through the register PHASE SETTING 0x32 which has two data bytes The first 4 bits contain the tenths value while bits 13 4 hold the units value SC5304A Operating amp Programming Manual 20 QUERYING THE 5 5304 WRITING REQUEST REGISTERS DIRECTLY The request set of registers are shown below in Table 3 To obtain requested data from the device requires two steps 1 Write the request register via the OUT endpoint with the appropriate data if any required 2 Read the USB IN endpoint to obtain the data requested Table 3 Query registers Data Register Address Byte Bit 7 Bit 6 Bit5 Bit 4 Bit 3 Bit 2 Bit 1 Bit O Default FETCH DEVICE STATUS 0x18 7 0 Open Open Open Open Open Open Open Open 0x00 Read Byte 1 7 0 Device status 7 0 Read Byte O 15 8 Device status 15 8 FETCH TEMPERATURE 0x19 7 0 Open Open Open Open Open Open Open Open 0x00 Read Byte 1 Temp data 7 0 Read Byte O Open Open Sign Temp data 12 8 CAL EEPROM 0x20 7 0 EEPROM Address 7 0 0x00 15 8
51. ee header file sc5304a_SetAttenuator sets the value of the designated attenuator sc5304a_SetPreamp int sc5304a_SetPreamp deviceHandle devHandle bool preampStatus The status of the function deviceHandle devhandle handle to the opened device Bool preampStatus turn on off the preamp sc5304a_SetPreamp enables or disables the RF preamplifier sc5304a_SetSignalChain int sc5304a_SetSignalChain deviceHandle devHandle attenuator_t atten bool preampStatus The status of the function deviceHandle devhandle unsigned int atten handle to the opened device values to the attenuators SC5304A Operating amp Programming Manual 38 Description Example bool preampStatus enable disable the preamp sc5304a_SetSignalChain sets all the attenuators and the preamp state This simplifies the programming flow when used with sc_5304a_CalcAutoAttenuation which returns the attenuator_t structure Define attenuator_t atten and use it in the function attenuator_t atten bool preamp 0 atten attenuator_t malloc sizeof attenuator_t casting may not be necessary set for rfLevel 0 dBm mixerLevel 20 ifLevel 0 dBm Pream off atten gt if3Atten2Value 8 atten gt if3Atten1Value 2 atten gt rfAttenValue 20 atten gt if1AttenValue 0 int status sc5304a_SetSignalChain devHandle atten preamp free atten Function Definition Return Input Description Function D
52. efine INPUTOUTRANGE 8 define NOREFWHENLOCK 9 define NORESOURCEFOUND 10 define INVALIDCOMMAND 11 SC5304A Operating amp Programming Manual 33 Type Definitions typedef unsigned char bool typedef struct deviceAttribute t unsigned int productSerialNumber unsigned int rfModuleSerialNumber float firmwareRevision float loHardwareRevision float scHardwareRevision unsigned int calDate size of 4 year month day hour unsigned int manDate size of 4 year month day hour deviceAttribute_t typedef struct calibrationData_t float rfCal RF gain calibration float ifAttenCal IF attenuators calibration float ifFilOResponseCal IF filter O response calibration float ifFilTResponseCal IF filter 1 response calibration float tempCoeff temperature coefficients float rfCalTemp temperature TO at which calibration was done float ifFilter1GainError Gain error when switched to filter 1 path float ifFilterOBw filter O BW in MHz float ifFilter1Bw filter 1 BW in MHz float invertGainError gain error when spectral inversion enabled unsigned int tcxoDac The TCXO dac value at TO calibrationData_t typedef struct attenuator_t unsigned int if3Atten2Value unsigned int if3Atten1Value unsigned int rfAttenValue unsigned int if1AttenValue attenuator_t typedef struct deviceStatus t bool tcxoPllLock bool vcxoPllLock SC5304A Operating amp Programming Manual 34
53. efinition Return Input Description Function Definition sc5304a_SetSynthesizerMode int sc5304a_SetSynthesizerMode deviceHandle devHandle bool fastTuneEnable unsigned int fineTuneMode The status of the function deviceHandle devhandle handle to the opened device bool fastTuneEnable enable disable faster frequency stepping unsigned int fineTuneMode selection of 1 MHz 25 kHz 1 Hz step resolution sc5304a_SetSynthesizerMode enables disables fast tuning and sets the step resolution of the downconverter sc5304a_ SetlfFilterPath int sc5304a SetlfFilterPath deviceHandle devHandle bool ifFilterPath The status of the function deviceHandle devhandle Bool ifFilterPath sc5304a SetlfFilterPath selects the IF filter handle to the opened device selection of IF filter O or filter 1 sc5304a_SetReferenceClock int sc5304a_SetReferenceClock deviceHandle devHandle SC5304A Operating amp Programming Manual 39 Return Input Description Function Definition Return Input Description Function Definition Return Input Description Function Definition Return Input bool lockExtEnable bool RefOutEnable bool Clk100Enable The status of the function deviceHandle devhandle bool lockExtEnable handle to the opened device enables phase locking to an external source bool RefOutEnable enables the clock to driven out the REF OUT port bool Clk1
54. emarks or trade names of their respective companies International Materials Declarations SignalCore Incorporated uses a fully RoHS compliant manufacturing process for our products Therefore SignalCore hereby declares that its products do not contain restricted materials as defined by European Union directive 2002 95 EC EU RoHS in any amounts higher than limits stated in the directive This statement is based on the assumption of reliable information and data provided by our component suppliers and may not have been independently verified through other means For products sold into China we also comply with the Administrative Measure on the Control of Pollution Caused by Electronic Information Products China RoHS In the current stage of this legislation the content of six hazardous materials must be explicitly declared Each of those materials and the categorical amount present in our products are shown below db x a PASTE BRK 2RR Hexavalent Polybrominated Polybrominated Model Name Leag Mercury Cadmium Chromium biphenyls diphenyl ethers Pb He ca 5304 v v v v v indicates that the hazardous substance contained in all of the homogeneous materials for this product is below the limit requirement in SJ T11363 2006 An X indicates that the particular hazardous substance contained in at least one of the homogeneous materials used for this product i
55. ened device device attributes SC5304A Operating amp Programming Manual 43 Description Example Function Definition Input Output Description Example calibrationData t calData structured calibration data sc5304a GetCalData returns the device attributes such as serial number calibration date and also structured calibration data used for gain calculation and correction See code block example for scb304a ConvertRawCalData sc5304a_ConvertRawCalData int sc5304a_ConvertRawCalData unsigned char rawCalData deviceAttribute_t deviceAttributes calibrationData_t calData unsigned char rawCalData entire cal EEPROM data in raw byte format calibrationData_t calibrationData current calibration data deviceAttribute_t deviceAttributes device attributes sc5304a_ConvertRawCalData organizes decodes the entire 15168 bytes of raw calibration data read from the EEPROM and returns two data formats deviceAttribute_t and calibrationData_t The array rawCalData must contain valid calibration data obtained by reading the EEPROM and rawCalData calData and deviceAttributes must have memory allocated Allocating memory for the input and output parameters in C and calling the function Similarly allocated memory must be de allocated when no longer used or when the program quits SC5304A Operating amp Programming Manual 44 Declaring calibrationData t calData deviceAttribute t devAttr u
56. er spurious free dynamic range commonly known as the SFDR In traditional radio terminology the SFDR strictly refers to the third order effects of nonlinearity whose products are generally close to the carrier signal and are very difficult to filter out In analog to digital conversion the SFDR term takes on a different definition referring to the ratio of the input signal strength to all the spurious products appearing within the Nyquist band These later spurious signals may be caused by harmonics inter modulation and digital quantization These two dynamic ranges are instantaneous in that the signal and the noise or spurs are observed at the same time On the other hand the measurement dynamic range specifically referring to SNRDR is not instantaneous The user may enable RF attenuation to receive signals levels much greater than the instantaneous compression point or enable the preamplifier to detect signals below the instantaneous noise density level The measurement dynamic range is thus much greater than the instantaneous equivalent The SC5304A was designed with a focus on a high dynamic range not just low in noise or just having high compression points It was designed as a receiver for signal analyzers which require that it handle larger signals well For weak signals the RF preamplifier should be enabled The design ensures the SFDR dynamic range specification is met when the RF signal level at the input mixer is 20 dBm and the IF
57. er supply Fuse Never access the fuse with the unit powered on Before attempting to remove the fuse for any reason switch off power to the unit and disconnect the power cord The fuse holder located on the rear panel of the unit contains a user replaceable fuse for protection against shorts and surges To access the fuse place a flat blade screwdriver in the slot on the face of the fuse holder and turn counter clockwise 90 degrees The center will pop out slightly allowing removal of the fuse clip Remove the fuse from the fuse clip and install a new one in its place Place the clip back into the holder Insert a flat blade screwdriver into the slot and push in with a slight pressure until the clip is flush with the fuse holder body Turn clockwise 90 degrees to lock the fuse clip in place N Replace fuse with same type and rating The SC53044A fuse type and rating are Power Connection Power is provided to the device through a standard IEC C 14 style power entry connector as shown in 5x20 mm glass 500 mA 250 VAC Time Lag Figure 2 An internal switching power supply allows for a range of input voltages from 88 264 VAC with line frequencies ranging from 47 63 Hz A power cable for use in North America is provided in the shipping kit Individual customers may have to replace this cable with one appropriate for use in their country Ensure that a properly grounded power cable is used at all times Bypassing the gro
58. fter the cause of action accrues SignalCore Incorporated shall not be liable for any delay in performance due to causes beyond its reasonable control The warranty provided herein does not cover damages defects malfunctions or service failures caused by owner s failure to follow SignalCore Incorporated s installation operation or maintenance instructions owner s modification of the product owner s abuse misuse or negligent acts and power failure or surges fire flood accident actions of third parties or other events outside reasonable control SC5304A Operating amp Programming Manual 1 Copyright amp Trademarks Under the copyright laws this publication may not be reproduced or transmitted in any form electronic or mechanical including photocopying recording storing in an information retrieval system or translating in whole or in part without the prior written consent of SignalCore Incorporated SignalCore Incorporated respects the intellectual property rights of others and we ask those who use our products to do the same Our products are protected by copyright and other intellectual property laws Use of SignalCore products is restricted to applications that do not infringe on the intellectual property rights of others SignalCore signalcore com and the phrase preserving signal integrity are registered trademarks of SignalCore Incorporated Other product and company names mentioned herein are trad
59. fty frequency points that span the operational frequency range of the SC5304A Data is read in concatenation of rows For example all the frequency values are read in first then the preamplifier gain values followed by the zero attenuation setting gain etc There are a total of 1650 values read that must be read from the EEPROM to form the full set of calibration Table 9 Example of the RF calibration data and its format Frequency MHz 3 5 10 500 4 3875 3900 Preamp Gain 20 564 20 643 20 456 20 003 19 654 19 231 Gain 33 223 33 423 33 213 33 102 i 29 980 29 450 RF ATTEN 1dB 0 988 0 955 1 093 0 973 5 2 1 008 0 995 RF ATTEN2dB 1 921 2 001 2 045 2 056 1 932 2 051 RF ATTEN 30dB 29 645 29 854 30 065 29 588 29 260 29 572 Frequency Correction On power up The SC5304A automatically applies the calibration value to the on board reference DAC that controls the TCXO which is the primary frequency reference of the device The user may choose to reprogram the DAC with the 16 bit code obtained from the EEPROM at starting address 0x54 or with another value by writing the REFERENCE DAC register 0x17 Gain Correction The SC5304A has seven dynamic variables that affect its gain namely pre amplifier state on off IF attenuator settings RF attenuator setting filter path inversion gain input frequency and temperature Correction of gain needs to take into account five main fac
60. g Manual 55 8 Sideband phase noise as specified is based on measured sideband noise which includes both phase noise and amplitude noise contributions Sideband noise is specified for the downconverter tune mode is set to NORMAL See the user manual for further information how to set the device to NORMAL or FAST TUNE modes These results are obtained with input signal levels of 0 dBm at the mixer no RF attenuation and the output IF level was set to 3 dBm The source is an ultra low noise 100 MHz OCXO with noise floor of 176 dBc Hz The 1000 MHz and 3500 MHz signals were multiplied up from the same OCXO The floor of the multiplied up 3500 MHz signal was about 143 dBc Hz so a phase locked YIG oscillator was used to complete the measurement for offset frequencies greater than 500 KHz The YIG oscillator noise floor was better than 160 dBc Hz In FAST TUNE mode the noise damping capacitor across the YIG tuning coil is disengaged and as a result the close in phase noise degrades LO related sideband spurious signals 10 1 10 Sideband spurious signals are results of the local oscillators in the DEVICE Sources of sideband spurious signals in the synthesized local oscillators are primarily due to fractional N spurious products in PLL DDS noise sources and inter modulation between oscillators within the multiple loop PLL synthesizers Fractional N and DDS spurious products affect spectral region below 200 kHz and inter modulation products
61. ge or elevated spurious levels in these ranges may not pose an application concern The lowest tunable frequency is 0 MHz DC However for input frequencies below 1 MHz the AC coupling capacitors in the circuit limit attenuate the signal significantly On the upper end of the spectrum the input low pass filter will attenuate the signal rapidly as the frequency increases above 3 9 GHz Calibration stored on the device EEPROM does not account for these out of range frequencies so applying any correction using the stored calibration is not valid SC5304A Operating amp Programming Manual 15 SC5304A PROGRAMMING INTERFACE Device Drivers The SC5304A is programmatically controlled by writing to its set of configuration registers and its status read back through its set of query registers The user may choose to program directly at the register level or through the API library functions provided These API library functions are wrapper functions of the registers that simplify the task of configuring the register bytes The register specifics are covered in the next section Writing to and reading from the device at the register level through the API involves calls to the sc5304a RegWrite and sc5304a RegRead functions respectively Writing to the device at the raw register level is independent of the host operating system and is suitable for embedded applications There are many USB drivers available that can be used to directly access the register
62. ibration intervals are used When used with or in a range defines performance met by approximately 8096 of all instruments manufactured This data is not guaranteed does not include measurement uncertainty and is valid only at room temperature standardized to 25 C Characterizes product performance by means of average performance of a representative value for the given parameter e g nominal impedance This data is not guaranteed and is valid only at room temperature standardized to 25 C Characterizes expected product performance by means of measurement results gained from individual samples Specifications are subject to change without notice For the most recent product specifications visit www signalcore com SC5304A Operating amp Programming Manual 52 Spectral Specifications RE anput range 17 1 MHz to 3 9 GHz IF output center frequency essent tnn tttn tent tante ttn ttt tent tatto tts tta tent to sotto 70 MHz IF output polarity O uoo Non Inverted Inverted IF Bandwidth 3 dB Final JF filter Dy Passed ite itti e gt 20 MHz Final IF filter enabled 54 0404 000000 essent gt 18 MHz 5 5 5 lt IF frequency MHz Figure 6 Typical output IF response of filter option
63. ication SC53044A calibration data is stored in the RF module metal housing Therefore changing or replacing interface adapters will not affect unit calibration However SignalCore maintains a calibration data archive of all units shipped Archiving this data is important should a customer need to reload calibration data into their device for any reason SignalCore also uses the archived data for comparative analysis when units are returned for calibration Should any customer need to reload calibration data for their SC5304A SignalCore offers free support through support signalcore com SignalCore will provide copy of the archived calibration data along with instructions on how to upload the file to the SC5304A The SC5304A requires no scheduled preventative maintenance other than maintaining clean reliable connections to the device as mentioned in the Getting Started section of this manual There are no serviceable parts or hardware adjustments that can be made by the end user SC5304A Operating amp Programming Manual 50 SC5304A ACCESSORIES Port Accessories SignalCore offers between series adapters for changing connectivity on all RF I O ports to suit specific requirements SignalCore s RF coaxial terminations provide a resistive power termination wherever it is needed with minimum reflection They are recommended to properly terminate unused ports to ensure the lowest noise installation Order Number Description 710
64. ice should handle the subsequent configuration data The configuration data likewise needs to be ordered MSB first that is transmitted first For configuration commands an output buffer of five bytes long is sufficient To ensure that a configuration command has been fully executed by the device reading a few bytes back from the device will confirm a proper command write because the device will only return data upon full execution of a command A map of the configuration registers for the SC5304A is provided in Table 2 Details for writing the registers are provided in the next section Reading the Device Registers Directly Valid data is only available to be read back after writing one of the query registers With the exception of registers 0x24 FETCH CAL EEPROM BULK and 0x25 FETCH USER EEPROM BULK where sixty four bytes of valid data are returned only the first two bytes of the device IN endpoints contain valid data When querying the device the MSB is returned as the first byte A map of the query registers for the SC5304A is provided in Table 3 Details for reading the registers are provided in the next section Using the Application Programming Interface API The SC5304A API library functions make it easy for the user to communicate with the device Using the API removes the need to understand register level details their configuration address data format etc Furthermore the user does not need to understand the different transfer
65. ing the filter reduces the delay to about 100 ns which may be preferred in some applications Following the band pass filter are the IF attenuators IF3 Atten1 and IF3 Atten2 These IF attenuators control the IF gain of the device and set the desired output IF level at the IF output port The recommended output level is O dBm However the level may be set to other values that suit the particular application Finally a low pass filter suppresses the harmonics of the IF signal It is important that the IF harmonics are kept as low as possible because they appear in band as higher order images SC5304A Operating amp Programming Manual 11 when digitized The harmonics are typically below 90 dBc at the IF In applications where this may not be acceptable external analog filtering is recommended Local Oscillator Description The signal path circuit is separate from the local oscillator generation circuits to maximize isolation between the RF IF signals and the local oscillators except for the LO injection paths into the mixers Although the both circuits reside within the same module well designed shielding and circuit layouts ensures leakages between them are keep to a minimum The first local oscillator LO1 is an agile tunable phase lock synthesizer The synthesizer tunes from 4675 MHz to 8575 MHz a tuning range of 3900 MHz The minimum step size is 1 Hz and is accomplished through a multiple phase locked loop and DDS hybrid architecture
66. instead SC5304A Operating amp Programming Manual 24 WORKING WITH CALIBRATION DATA The device EEPROM on board has capacity for 16k bytes data The EEPROM stores both device information and calibration data which the user may choose to use to correct for conversion gain Users are not required to use the onboard calibration to compensate for the gain errors associated with temperature attenuator settings frequency pass band ripple and filter path selection Alternatively users can perform their own system calibration to remove these errors if the unit is integrated into a larger system whose external factors affect the gain significantly Furthermore the calibration data provided are raw measured data and it is in the discretion of the user to decide on the appropriate methods of applying the calibration For example the user may choose to fit the measured data to a polynomial and use the polynomial coefficients to compute the necessary correction Alternatively the user may choose to perform correction through the use of interpolation The methods outlined in this section only serve as guides on how to use the calibration data for correction and these are the methods used by SignalCore in deriving published specifications that indicate the use of calibration The function sc5304a CalcGain utilizes the methods outlined here and may be used to compute the device gain for any particular setting of the device Table 5 EEPROM memory map of
67. instead of calling the above 2 functions status scb304a GetCalData devHandle devAttr calData 5 5304 Operating amp Programming Manual 45 Function Definition Input Output Description Example sc5304a CalcAutoAttenuation int sc5304a_CalcAutoAttenuation unsigned int frequency float inputRfLevel float inputMixerLevel bool preampEnable float nominallfOutLevel bool if3Filter1Enable float temperature calibrationData_t calData attenuator_t attenuator unsigned int frequency input RF frequency in Hz float inputRfLevel input RF level in dB float inputMixerLevel input mixer level in dB bool preampEnable preamplifier enabled float nominallfOutLevel nominal IF out level in dB bool if3Filter1Enable Enable Filter 1 path in IF3 float temperature current device temperature calibrationData t calData structured calibration data for the device attenuator t attenuator attenuation settings for RF IF1 and final IF3 attenuators SC5304A CalcAutoAttenuation returns the set of attenuation settings for all the attenuators that will configure the SC5304A for best dynamic range operation based on user input parameters such as frequency mixer level etc The values are calculated to maintain a good balance between the signal to noise dynamic range and the linearity dynamic range The input parameters are based on those of traditional spectrum analyzers The SC5304A downconverter is designed f
68. is that the SNR will degrade The LO1 leakage signal will appear as DC when the IF is digitized and converted to baseband By design setting the IF frequency at 4675 MHz allows sufficient frequency separation from the highest RF frequency so that the IF1 filter despite its non ideal roll off response can suppress the RF signal by more than 100 dB The first IF is then down converted to the second IF of 675 MHz by mixing with the second LO LO2 Similarly as with the first IF section the second IF IF2 section is also well filtered and amplified Keeping isolation between the second and third mixers is important to ensure spurious signals generated within the device are kept significantly low when compared to the primary signal of interest Finally the second IF is converted to the third and final IF by mixing with the third LO LO3 Located in this stage are the primary band pass filters that define the bandwidth of the device The final IF filters are selectable between two filters of different bandwidths centered at 70 MHz The standard bandwidths for these filters are 5 MHz 10 MHz 20 MHz and 40 MHz These surface acoustic wave SAW filters provide excellent filter response The user may choose to use one of these two filter paths as a bypass that is no band pass filter in the path One reason for bypassing the final IF filter is to improve the group delay through the device with the filters enabled the delay is approximately 1 us Bypass
69. level is at O dBm This requires a total IF attenuation of 10 dB for a typical device gain of 30 dB preamplifier disabled This setting is typical for broadband signals with more than a few MHz of real time bandwidth SC5304A Operating amp Programming Manual 14 For applications where the SNR must be maximized such as examining the close in characteristics of a sine tone the input mixer should be set to accept 0 dBm power and the IF set at dBm or higher This is a likely setting for making phase noise measurements of an RF signal assuming the specified phase noise of the SC5304A is low enough for measuring that particular signal It is important to first set the necessary attenuators before injecting a O dBm level signal to the mixer otherwise heavy saturation of the mixer or the output amplifiers may cause degradation or even possible failure of the receiver over time The SC5304A is designed for a nominal output IF level of 0 dBm ensuring the IF signal is about 3 4 dB below the full scale value of many 50 2 analog to digital data converters ADCs Depending on the application the user will need to set the appropriate gain of the device via attenuation and hence the output level to suit the particular application For broadband signals it is recommended that the IF output level be about 7 dB below the full scale value of a digitizer because of possible high crest factors that may saturate the digitizer For sine tone or narrowb
70. lue y For example Table 10 lists the input and output parameters to obtain the gain G f 1000 MHz T Table 10 Parameters to a Spline interpolation Frequency MHz X 3 5 19 5 En 950 1050 3875 3900 Measured Gain Y 33 223 33 423 33 213 ES 32 652 32 482 29 980 29 450 fix 1000 G f y 32 453 From experience having a large X and Y array of points does not necessarily provide the best interpolated value due the nature of trying to fit a function over many points and over many octaves of frequency Better results are obtained from a set of localized calibrated points around the point of interest The function scb304a CalcGain uses six localized X points to compute the interpolated point Using localized points the example on Table 10 is re tabulated in Table 11 Similarly frequency dependent preamplifier gain and RF attenuation may be derived SC5304A Operating amp Programming Manual 29 Table 11 Localized parameters to a Spline interpolation Frequency MHz X 850 900 950 1050 1100 1150 Gain Y 32 681 32 673 32 652 32 482 32 419 32418 fix 1000 GCF Tg y 32 532 To find the change in gain with respect to change in temperature involves a couple of steps first determine the array values of AG f T where f is the frequency point at which a measurement was made and then as a second step use interpolation to determine the AG f T at some frequenc
71. ng Manual 58 Conversion Gain 5 5 c o Gain No attenuation preamp disabled Gain No attenuation preamp enabled 2000 Frequency MHz Figure 10 Typical RF conversion gain response 9 25 C IF Response Final IF filter enabled Gain dB Final IF filter by passed 70 IF frequency MHz Figure 11 Typical IF amplitude response 9 25 9 RF to IF group delay 80 of IF bandwidth Ilium C 1 us typical IF Filter bypassed anite entente rtt vec toe oue eee 100 ns typical IF Phase Linearity 80 of IF bandwidth 09 JE Filter path rt ertet RH Ru et 8 deg IE Filter bypassed a u e ces ters rt site reb rie peras tes REL Rep RE te cie 8 deg IF Phase Linearity deviation rate 2 deg MHz SC5304A Operating amp Programming Manual 59 o o G Ideal measured 70 IF frequency MHz Figure 12 Phase deviation over 20 MHz 13 There are 3 IF attenuators in total each having 30 dB of attenuation There are 2 attenuators in the final stage and 1 attenuator in the first IF stage after the first mixer How to effectively use them to optimize for performance is outlined in the DEVICE user manual 14 These are typical gain specifications The gain of the device is calibrated and stored in the device calib
72. ng bit 1 high enables the device to export a 10 MHz signal through the ref out port Asserting high bit 1 and bit 2 exports a 100 MHz signal Adjusting the Reference Clock Accuracy The frequency precision of the SC5304A s 10 MHz TCXO is set by the device internally The device writes the factory calibrated value to the reference DAC on power up This value is an unsigned 16 bit number stored in the EEPROM see the calibration EEPROM map The user may choose to write a different value to the reference DAC by accessing the REFERENCE DAC 0x17 register This register has two data bytes to hold the 16 bit word Setting Spectral Inversion in the IF The default IF spectral polarity is the same as that of the RF input However should there be a need to invert the IF spectrum with respect to the RF spectrum the register IF INVERT SETTING 0x1D is used for that purpose This register contains one data byte Setting bit O high will enable inversion Storing Data into the User EEPROM Space There is an on board 16k byte EEPROM available to the user to store user data information such as user calibration settings etc Writing to the user accessible EEPROM space is accomplished through the register WRITE USER EEPROM 0x23 This register has three data bytes bytes 2 and 1 contain the address of the EEPROM byte O is the byte value to be written NOTE The user must add a 5 millisecond delay between consecutive writes There is no delay required in r
73. nsigned char rawCal allocate memory for raw calibration rawCal unsigned char malloc sizeof char CALEEPROMSIZE Allocate memory the user may use malloc instead of calloc devAttr gt calDate unsigned int calloc 4 sizeof unsigned int devAttr gt manDate unsigned int calloc 4 sizeof unsigned int calData gt rfCal float calloc RFCALPARAM sizeof float for i 0 i lt RFCALPARAM i calData rfCal i float calloc RFCALFREQ sizeof float calData gt ifAttenCal float calloc IFATTENUATOR sizeof float for i 0 i lt IFATTENUATOR i calData ifAttenCal i float calloc IFATTENCALVALUE sizeof float calData gt ifFilOResponseCal float calloc IFRESPONSEPARAM sizeof float for i 0 i lt IFRESPONSEPARAM i calData gt ifFilOResponseCal i float calloc IFRESPONSEFREQ sizeof float calData gt ifFillResponseCal float calloc IFRESPONSEPARAM sizeof float for i 0 i lt IFRESPONSEPARAM i calData gt ifFillResponseCal i float calloc IFRESPONSEFREQ sizeof float calData gt tempCoeff float calloc TEMPCOPARAM sizeof float for i calData gt tempCoeff i float calloc TEMPCOFREQ sizeof float read in raw calibration int status scb304a GetRawCal devHandle rawCal Calling the function to structure the calibration data status sc5304a_convertRawCalData rawCal devAttr calData alternatively
74. nverted mode gain IF3 Filter1 Gain Correction 0x790 This is a float that contains the change in IF gain when the device is switched to the IF3 FILTER1 path The default gain in the IF is the FILTERO path gain IF Attenuator Calibration 0x798 This is a 3x30 float matrix containing the calibrated attenuation values of the three IF attenuators Data is read in row by row Each attenuator has 30 attenuation steps and each row correspond to one attenuator The first row is the attenuation values of IF3 ATTEN2 the second row contains the values or IF3 1 and the third row contains the values of IF1 ATTEN Table 8 is an example of the data and its format Since the IF bandwidth is typically less than 40 MHz wide and centered at a fixed frequency it is sufficient to perform the calibration at the center IF as attenuation variation is insignificant over its range Table 8 An example of IF attenuation calibration IF3_Attenuator 2 0 973 1 927 2 948 3 912 28 630 29 634 SC5304A Operating amp Programming Manual 27 IF3_Attenuator1 0 989 1 970 2 998 3 989 28 890 29 874 IF1_ Attenuator 0 995 2 028 3 038 4 023 28 868 29 854 RF calibration Ox9F8 This is a 33x50 float matrix Table 9 is an example of the data and format for the RF calibration data RF calibration contains data for preamplifier gain gain with zero RF and IF attenuation and attenuation values of the RF attenuator for fi
75. ollowing pages To program in C C SignalCore defines the following constants and types which are contained in the C header file sc5304a h These constants and types are useful not only as an include file for developing applications using the sc5304a libraries but also for writing device drivers independent of those provided by SignalCore Constants Definitions 2 D parameters for storing calibration data define RFCALPARAM 33 rows of caldata define RFCALFREQ 50 frequency points define IFATTENUATOR 3 total number of IF attenuators define IFATTENCALVALUE 30 attenuation steps 1 30 dB define IFRESPONSEPARAM freq amp phase define IFRESPONSEFREQ 51 freq points over the bandwidth define TEMPCOPARAM 3 freq coeff 1 coeff 2 define TEMPCOFREQ 8 freq points Attenuator assignment Hdefine IF2ATTENUATOR2 0 define IF2ATTENUATOR1 1 Hdefine RFATTENUATOR 2 Hdefine IFLATTENUATOR 3 Hdefine CALEEPROMSIZE 15168 define USEREEPROMSIZE 16384 Tune mode parameters define FASTTUNEENABLE 1 define DISABLEDFINEMODE 0 1 MHz tuning steps PLL implementation define PLLFINEMONDE 1 25 KHz tuning steps PLL implementation define DDSFINEMODE 2 1 Hz tuning steps DDS implementation ERROR Set define SUCCESS 0 define DEVICEERROR 1 define TRANSFERERERROR 2 define INPUTNULL 3 define COMMERROR 4 define INPUTNOTALLOC 5 define EEPROMOUTBOUNDS 6 define INVALIDARGUMENT 7 d
76. on without the need for sharp cut off pre select band pass filters Having high image rejection makes the SC5304A suitable for SC5304A Operating amp Programming Manual 8 applications such as spectral monitoring broadband spectral analysis and others where the spectral environment cannot be controlled The SC5304A exhibits very low phase noise of 107 dBc Hz at 10 kHz offset on a 1 GHz RF carrier with a typical noise floor of 150 dBm Hz The noise floor can be further reduced below 165 dBm Hz by enabling the internal preamplifier With gain control between 60 dB to 50 dB a measurement signal to noise dynamic range greater than 180 dB is achievable Using high reverse isolation devices and sharp cutoff filters LO leakages and other spurious contents at the input connectors are well below 120 dBm Inter stage LO leakages are also kept very low through sophisticated circuit and shielding design to ensure that spurious in band signals remain less than 80 dBc The excellent spurious free dynamic range is achieved using low noise linear amplifiers low loss mixers and high performance solid state attenuators State of the art solid state attenuators have improved linearity over earlier designs Their attenuation level changes settle under a microsecond and for applications that involve frequent range changing they offer a vastly superior lifetime over mechanical attenuators The real time bandwidth is shaped primarily by the final 70 MHz IF
77. or best balanced dynamic range with 20 dBm power at the input mixer and 0 dBm nominal power at the IF output port Each attenuator must have memory allocated before calling this function SC5304A_ConvertRawCalData must be called or valid structure calibration data must be entered before calling this function Code showing how to properly use this function SC5304A Operating amp Programming Manual 46 Declaring Attenuator t atten float deviceTemp call a function to return the device temperature function to 5 5304 GetTemperature amp deviceTemp unsigned int rfFreq 1000000000 1 0 GHz float rfLevel 2 0 expecting 0 dBm input signal float mixerLevel 20 set the mixer level requirement bool preamp 0 since input level is O dB no need for a preamp float ifLevel 0 to obtain a level clost to 0 dBm at the IF bool filterPath 0 use the default filter path in the IF float temp deviceTemp Calling the function int status scb304a CalcAutoAttenuation rfFreq rfLevel mixerLevel preamp ifLevel filterPath temp atten Function sc5304a CalcGain Definition int sc5304a CalcGain unsigned int frequency bool preampEnable bool iflnvertEnable bool if3Fil1Enable attenuator t atten float temperature calibrationData t calData float conversionGain Input unsigned int frequency input RF frequency in Hz bool preampEnable preamplifier enabled bool iflnvertEnable enable IF s
78. pectral inversion attenuator t atten attenuation settings float temperature temperature value of the device in degrees Celsius calibrationData t calData calibration data for the device Output float conversionGain calculated calibrate conversion gain for current settings Description 5 5304 CalcGain calculates the calibrated gain based on the current user settings SC5304A Operating amp Programming Manual 47 Function sc5304a CalclfResponseCorrection Definition int sc5304a CalclfResponseCorrection float offsetFrequencies unsigned int nPoints bool ifFil1PathEnable calibrationData t calData ifResponseCorrect t correctedlfResponse Input float offsetFrequencies floating point number 1 D array unsigned int nPoints number of points in the 1 D array bool ifFillPathEnable IF filter 1 path enable calibrationData t calibrationData calibration data for the device Output float correctedifResponse Description SC5304A CalculatelfResponseCorrection determines the IF correct response for the set of IF offset frequencies These offset frequencies may be the frequency components of an FFT of the acquired data being offset from its center frequency To obtain the offset frequencies one can simply subtract the frequencies from the IF center frequency For example if a digitizer sampling at 100 MHz is used to digitize the 70 MHz IF signal with bandwidth of 3 MHz the center of the digitized signal is 30 MHz 1 5
79. phase spurious signals below the levels published in the product specification The DDS mode also tunes to exact frequencies however it requires many more computing cycles and additional register level writes in order to set a new frequency Comparing times the device requires up to 175 microseconds to compute and change to a new frequency in PLL only modes but requires up to 350 microseconds in the DDS tuning mode At first glance it may seem that these differences would directly impact frequency tuning times However tuning times are predominantly set by the physical parameters of the YIG oscillator Computation and register writes typically account for less than 2596 of the total tune time of a 10 MHz step change in frequency It is important to note that although the synthesized frequencies are exact frequencies there are observable random phase drifts in the downconverted signals These drifts are due to PLL non idealities rather than a frequency error in the DDS tuning circuit Having exact frequency synthesis is important for many applications Published phase noise and spurs specifications are based on the 1 Hz DDS mode Setting the SC5304A to Achieve Best Dynamic Range When discussing dynamic range there are two distinct quantities which are specified First is the compression to noise density per Hz dynamic range commonly referred to in SignalCore literature as the signal to noise ratio dynamic range SNRDR Second is the third ord
80. r lock and settling times between frequency changes Please refer to Appendix A for more information regarding Fast Tune mode The second mode Fine Tune mode has three options 1 MHz PLL 25 kHz PLL and 1 Hz DDS Selection of these options requires setting the first two bits of the data byte to O 1 and 2 respectively See the Frequency Tuning Modes section for more information For example to set the device for Fast Tune and a 1 Hz tuning step resolution the command bytes would be 0x13 0x06 Selecting the IF Filter Path The IF FILTER SELECT 0x15 register has one data byte that selects between two installed IF filters IF3 FILTERO and IF3_FILTER1 Setting bit high will select IF FILTER1 The exact bandwidths of the filters depend on the available installed options and are stored in the device calibration EEPROM SC5304A Operating amp Programming Manual 19 Setting the Reference Clock Behavior The REFERENCE SETTING 0x16 register has one data byte which sets the reference clock behavior of the device The default state of this register is 0x00 which disables the export of the internal reference clock and disables phase locking to an external source Asserting bit O high enables the device to lock to an external clock source However the device will not attempt to phase lock until it successfully detects the presence of a clock source at the ref in port Asserting bit 1 low disables export of the internal clock Asserti
81. ration EEPROM 15 Minimal gain is specified when all attenuators are set to their maximum values and the RF pre amplifier is disabled 16 Maximum gain is specified when all the attenuators are set to 0 dB 17 Correction stored in the calibration EEPROM must be applied properly Users are not obligated to use the calibration provided they could devise their own method of calibration and correction should they choose to User method of calibration and application may improve on the accuracies specified 18 For broadband signal operation it recommended that users apply in situ amplitude and phase equalization to the received signal to minimize amplitude and phase errors caused by the DEVICE Phase deviation at offset frequencies from the center frequency of 70 MHz is stored in the calibration EEPROM The calibration may be applied as a first order correction SC5304A Operating amp Programming Manual 60 Dynamic Range Specifications Spurious response 19 Residual spurious signals 20 sienten 100 dBm LO related spurious signals 9 tss 80 dBc Image Pe Cet OM C lt 100 dBc rejection 23 E 115 dBc o 5 5 o a 999 1001 Frequency Figure 13 Spectrum showing low LO related spurious signals at for input signal 1000 15 MHz 19 Spurious respon
82. reading the temperature sensor requires sending serial clock and data commands from the processor The process of sending clock pulses on the serial transfer line may cause unwanted spurs on the RF signal as the serial clock potentially modulates the local oscillators Furthermore once the SC5304A stabilizes in temperature repeated readings will likely differ by as little as 0 25 C over extended periods of time Given that the gain to temperature coefficient is on the order of 0 1 dB C gain changes between readings will be negligible Reading Calibration EEPROM Data To read a single byte from an address in the device EEPROM write the FETCH CAL EEPROM register with the address in the two data bytes followed by reading back 2 bytes of data The data is returned on the last byte byte 1 byte O contains invalid data The EEPROM maximum address is Ox3FFF Reading above this address will cause the device to retrieve data starting from the lowest addresses For example addressing 0 4000 will return data stored in address location 0x0000 calibration EEPROM map is discussed in detail in the Working With Calibration Data section For faster reading of the entire calibration EEPROM the FETCH CAL EEPROM BULK 0x24 register should be written with the starting address of the 64 byte memory read Data is return in 64 byte chunks where the first byte corresponds to the starting memory address There are 237 chunks of 64 byte data All calibration d
83. rs the noise figure of the system is proportional to their accumulated losses if the attenuators were placed before the amplifier The trade off for better sensitivity is the lack of attenuation adjustment for larger signals when the amplifier is enabled The user will need to provide good judgment when enabling the preamplifier SC5304A Operating amp Programming Manual 9 ZHD 6 E aSN 222 8 185 v einpojy 3 9IXd T b jeu L A 7 7 22 pL amp eg ZHN OL 76 N T 4 ul Jeu gt JA J0sueg eiod dwa OXOL 2 Noy 1 ZHN 00 ZHN OL Y fS N 8 N uoneiqieo N V Tid
84. rum once digitized can easily be re inverted mathematically SC5304A Operating amp Programming Manual 53 RF tuning Resolution 2 P 1Hz Lock and settling times 1 ms settled to 0 5 settled to 0 1 ppm settled to 0 5 ppm m o E 49 Fast Tune Mode Enabled 100 Tuning Step MHz Figure 7 Typical frequency settle time vs tuning step with 3600 MHz being the final frequency 3 To give the user flexibility the DEVICE has 4 resolution modes 2 coarse modes and 2 fine modes The coarse modes using fractional N PLL allow 1 MHz and 50 kHz steps while the fine modes using PLL and DDS provide less than 1 Hz resolution See the DEVICE user manual for further information Lock and settled to lt 1 ppm of final frequencies of 2500 MHz and step size of 10 MHz For final frequencies 500 MHz the settle time applies to accuracy with 500 Hz of the final frequency for a 10 MHz step See figure X for example of other tuning step settling times When fast tune mode is enabled the noise damping capacitor across the main YIG tuning coil is disengaged resulting in an increase of the rate of current flow through the coil and settle to a steady state quicker Lock time begins when the full tuning word command is received by the device Frequency reference 5 Technology iunii picante
85. s Maximum of two IF filter options are available Standard product filter has 20 MHz bandwidth and bypass path 1 RF input below 1 MHz suffers from amplitude roll off and calibration is not valid below this lower end frequency In the frequency range below the specified IF bandwidth 15 MHz the first LO leakage appears inside the IF band This LO leakage will appear as DC when the RF is converted to baseband in the final analysis Furthermore because the LO appears inside the IF band it will inter modulate with the input RF signal to produce higher order in band spurious signals that may degrade signal integrity It is recommended to attenuate the RF signal before the mixer by applying RF attenuation or attenuate after the first mixer by applying attenuation Suppressing the RF amplitude up front of the downconverter path will reduce the spurious signal levels The IF output polarity refers to the conversion polarity of the downconverter When the polarity is inverted the spectral content of at the output is inverted with respect to the input this process is commonly known as spectral inversion or spectral flipping The choice depends on the application For digitizers that are sampling the IF in the even order Nyquist zones that naturally inverting spectra having the IF polarity inverted will produced non inverted baseband and vise versa However this is only a convenience in this application case because inverted spect
86. s above the limit requirement in SJ T11363 2006 CE European Union EMC amp Safety Compliance Declaration The European Conformity CE marking is affixed to products with input of 50 1 000 VAC or 75 1 500 VDC and or for products which may cause or be affected by electromagnetic disturbance The CE marking symbolizes conformity of the product with the applicable requirements CE compliance is a manufacturer s self declaration allowing products to circulate freely within the European Union EU SignalCore products meet the essential requirements of Directives 2004 108 EC EMC and 2006 95 EC SC5304A Operating amp Programming Manual 2 product safety and comply with the relevant standards Standards for Measurement Control and Laboratory Equipment include EN 61326 and EN 55011 for EMC and EN 61010 1 for product safety Recycling Information All products sold by SignalCore eventually reach the end of their useful life SignalCore complies with EU directive 2002 96 EC regarding Waste Electrical and Electronic Equipment WEEE Warnings Regarding Use of SignalCore Products a 2 PRODUCTS FOR SALE BY SIGNALCORE INCORPORATED ARE NOT DESIGNED WITH COMPONENTS NOR TESTED FOR A LEVEL OF RELIABILITY SUITABLE FOR USE IN OR IN CONNECTION WITH SURGICAL IMPLANTS OR AS CRITICAL COMPONENTS IN ANY LIFE SUPPORT SYSTEMS WHOSE FAILURE TO PERFORM CAN REASONABLY BE EXPECTED TO CAUSE SIGNIFICANT INJURY TO A HUMAN IN ANY APPLICATION INCLUDING
87. s of the device WinUSB libusb 1 0 libusb win32 libusbx and NI VISA are a few examples The SC5304A API is provided as a dynamic linked library sc5304a dll or shared library libsc5304a so This is based on the libusb 1 0 driver and is available for both Windows and Linux operating systems For more information on the libusb driver visit www libusb org For the Windows platform libusb 1 0 relies on WinUSB at the kernel level For libusb 1 0 to function properly on Windows platforms WinUSB must be installed on the host For LabVIEW support on Windows operating systems the LabVIEW sc5304a llb is provided on the software installation CD and is based on the NI VISA driver platform For Windows Vista or later operating systems the NI VISA driver uses WinUSB at the kernel level For these systems installing just the NI VISA driver will provide support for both NI VISA and libusb 1 0 drivers However on Windows XP systems NI VISA does not rely on WinUSB so the user must choose to install the NI VISA driver for LabVIEW programming or the libusb 1 0 driver for C CC VBASIC and other languages that can call C C style DLLs The user should only install one driver the host to reduce driver load confusion by the operating system For other operating systems or embedded systems users will need to access the registers through their own proprietary USB driver or through one of the drivers mentioned above Should the user require
88. sabled 5 100 MHz 1000 MHz 3600 MHz Noise floor dBm Hz 153 152 148 Noise figure dB 21 22 26 Preamplifier enabled 25 100 MHz 1000 MHz 3600 MHz Noise floor dBm Hz 167 166 164 Noise figure dB 7 8 10 Input Noise Density gt o 2 o 1500 2000 2500 3000 3500 4000 RF Input Frequency MHz Figure 14 Measured noise density of the average of 2 lots 24 Noise thermal is referred to the input of the downconverter 25 The downconverter is configured with 0 dB RF attenuation 0 dB attenuation and IF attenuators set the gain to 20 dB This setting is made to be consistent with the configuration for other specifications such as linearity and spurious responses so that the user may obtain a clearer picture of the performance of the downconverter The RF input is terminated with a matched 50 Q load 26 In spectrum analyzer and signal analyzer applications this is also commonly referred to as the Displayed Average Noise Level DANL This assumes that the digitizer used does not limit the performance of the downconverter SC5304A Operating amp Programming Manual 62 Input third order intermodulation IIP3 dBm 100 MHz 1 GHz 1 GHz 2 5 GHz 2 5 GHz 3 9 GHz Preamplifier disabled 209 16 17 17 5 20 18 5 20 Preamplifier enabled 2829 5 0 2 3 0
89. ses are unwanted signals appearing at the IF output All spurious products are treated as if they originate at the input port of the downconverter which is the common reference plane as the RF input 20 spurious signals are observed and reference to the RF input of the downconverter when the RF input is terminated with a matched load The RF and first IF IF1 attenuators are set to 0 dB attenuation and the final IF attenuators were adjusted to obtain a downconverter gain to 20 dB The preamplifier is disabled 21 LO related spurious signals are unwanted signals produced at the IF output due to inter modulation of all the downconverter local oscillators These spurious signals are measured relative to a RF signal present at the input Specification provided here is when the downconverter is configured for 20 dBm at the mixer and 0 dBm at the IF output and a total gain of 20 dB 22 Image rejection is the DEVICE ability to reject an image signal of the RF frequency that would otherwise produce the same result as the desired RF signal The image of the desired RF signal is calculated as RFimage RF 2IF where IF 4 675 GHz 23 IF rejection is the DEVICE ability to reject RF signals at any of the IF frequencies while the downconverter is tuned elsewhere Signal level at the mixer is 20 dBm and gain of 20 dB SC5304A Operating amp Programming Manual 61 Input Noise 15 C to 35 C ambient 4 Preamplifier di
90. temperature data is converted to Celsius a floating point type Taking the frequency dependence of the measured parameters into consideration Equation 2 may be rewritten as fT f To GU To Ars f To AG f T AGfu To Equation 3 AGiny 70 m Air To Note that the IF attenuation values do not need to be frequency dependent as discussed earlier Using the IF attenuator calibration is as simple as substituting the intended value with the calibrated value From Table 8 one would use 29 854 dB for an intended 30 dB attenuation The other 2 variables To To are also frequency independent as they are only referred to at the center of the IF band and their values are simply summed in the total gain equation Only those parameters that depend on frequency and or temperature are treated below To obtain calibrated gain values from the parameters that are a function of frequency interpolation is required to provide the best estimated values A natural cubic Spline interpolation is suggested for f To To and 70 The important input parameters for a cubic spline interpolation are the 2 arrays X and Y and an arbitrary point x The output of the interpolation is some interpolated value y based on the inputs X is the set of independent values Y is the set of X dependent values and x is an arbitrary independent value to obtain the interpolated va
91. ters that can be explored to optimize the device for any particular application The first set of parameters TUNE SPEED set the tuning and phase lock time as the frequency is changed TUNE SPEED consists of two modes Fast Tune mode and the Normal mode both of these modes directly affect the way the YIG oscillator is configured The Fast Tune mode deactivates a noise suppression capacitor across the tuning coil of the YIG oscillator and doing so increases the rate of current flow through the coil correspondingly increasing the rate of frequency change In Normal mode the capacitor is activated slowing down the rate of frequency change The advantage of activating the capacitor is that it shunts the noise developed across the coil decreasing close in phase noise Refer to Appendix A for specifications regarding tuning speed SC5304A Operating amp Programming Manual 13 The other set of control parameters FINE TUNE sets the tuning resolution of the device There are three modes 1 MHz 25 kHz and 1 Hz tuning step sizes The first two modes use only fractional phase detectors to tune the frequency of the LO1 synthesizer while the third mode enables the DDS to provide 1 Hz resolution The PLL only modes 1 MHz and 25 kHz provide the ability to realize exact frequencies with tuning as fine as 25 kHz Use of these modes offers several advantages lower phase spurs and less computational burden to set a new frequency These modes have the lowest
92. tlined above only applies to a signal that is centered in the 70 MHz IF band The device s Fine Tune mode 1 Hz is able to place any RF signal at the center of the IF so for narrow bandwidth signals typically less than a MHz applying the center IF gain correction and assuming no deviation from linear phase is sufficient However for a large bandwidth signal that spans several MHz it is important to apply gain and phase correction to the offset frequencies those that are offset from the center IF Although SignalCore performs calibration of the amplitude and phase over the SC5304A Operating amp Programming Manual 30 bandwidth of the IF filters available on the device calibration EEPROM it is recommended that the user perform in situ system equalization for digital broadband applications for improved performance Measured IF gain and phase error response is available for both filter paths the user simply needs to properly select the path of interest The measurement is made using a vector network analyzer in the frequency domain covered by fifty one evenly spaced frequency points The amplitude gain error values are measured with respect to the center frequency and are given in decibels while the phase error values are in radians The phase errors are deviations from linear phase Each set of calibrated points consists of a 3x51 floating point array see Table 7 as an example There are several ways to apply the frequency domain calibr
93. tors As noted in the EEPROM Data Content sub section the pre amplifier gain through gain no attenuation no pre amplification RF attenuation and gain over temperature variation are calibrated over the span of the SC5304A frequency range These are the frequency dependent parameters that are combined with the IF attenuation to make the total gain calculation Let us start by writing the gain equation with no dependence on temperature or frequency and with the pre amplifier turned on We get the following equation Gaev Gpreamp GT AGiny Arf Air Equation 1 5 5304 Operating amp Programming Manual 28 Gaey is the total gain of the device Gpreamp is the gain of the pre amplifier G is the through gain is the attenuation of the RF attenuator is the gain change of IF3 FILTER1 path AGiny is the gain change in spectral inversion mode and Aj is the attenuation of the the IF attenuators If the preamplifier is off no inversion default filter path and no attenuation applied then G Writing Equation 1 with dependency on temperature we add on the temperature dependent gain factor AG T and obtain the following Gag T Gpreamp G To AGr To AGiny To ug Ars To Aig To Equation 2 AG T where is the temperature of the device and T is the fixed temperature at which calibration was performed The section Reading Temperature Data provides information on how unsigned raw
94. types of the USB interface For example to obtain the device temperature the user simply calls the function sc5304a_GetDeviceTemperature or calls sc5304a SetFrequency to set the device frequency The software API is covered in detail in the Software API Library Functions section SC5304A Operating amp Programming Manual 17 SETTING THE SC5304A WRITING CONFIGURATION REGISTERS DIRECTLY Configuration Registers The configuration registers to control the SC5304A are summarized in Table 2 The size of a command is based on the sum of the register address byte and the number of data bytes For example setting the frequency would require five bytes with the first byte being the register address Ox10 The user may send more data bytes than required for a command without incurring a device error Extra bytes will be ignored Table 2 Configuration registers Data Register Address Bytes Bit7 Bit 6 Bit 5 Bit4 Bit 3 Bit 2 Bit 1 Bit O Default INITIALIZE 0x01 7 0 Open Open Open Open Open Open Open Mode 0x00 Enable SET SYSTEM ACTIVE 0x02 7 0 Open Open Open Open Open Open Open SYSLED 0x00 POWER SHUT DOWN 0x05 7 0 Open Open Open Open Open Open Open Enable 0x00 7 0 Frequency Word 7 0 0x00 RF FREQUENCY 0x10 15 8 Frequency Word 15 8 0x00 23 16 Frequency Word 23 16 0x00 31 24 Frequency Word 31 24 0x00 ATTENUATOR SETTING 0x11 7 0 Attenuator Value 0x00 15 8 Attenuator 0x00 PREAMPLIFIER S
95. und connection can increase the risk of serious injury or death SC5304A Operating amp Programming Manual 7 SC5304A THEORY OF OPERATION Overview The SC5304A operates on the principle of heterodyning a process whereby an incoming RF signal is mixed with specific oscillator frequencies in stages producing both sum and difference frequency products At each stage the summed frequency product or image is removed through low pass filtering allowing the difference frequency product to continue through the signal path Repeating this process several times using carefully selected local oscillators LOs and well designed band pass filtering the original signal is translated or down converted in frequency low enough for inexpensive digitizers to acquire the signal with reasonable bandwidth The resultant output signal of a heterodyne downconverter is known as the intermediate frequency IF Using a tunable LO as the first mixing oscillator allows the downconverter to translate a broad range of frequencies to a common IF output When combined a tunable LO and extraction of the lower mixed frequency product creates an important and useful variant of the heterodyne process known as superheterodyning The SC5304A is a three stage superheterodyne downconverter that delivers superior image rejection over single stage conversion and offers both high signal to noise dynamic range and high spurious free dynamic range The RF input ranges from 1
96. y Improperly mated connections or dirty damaged or worn connectors can degrade measurement performance Clean out any loose dry debris from connectors with clean low pressure air available in spray cans from office supply stores If deeper cleaning is necessary use lint free swabs and isopropyl alcohol to gently clean inside the connector barrel and the external threads Do not mate connectors until the alcohol has completely evaporated Excess liquid alcohol trapped inside the connector may take several days to fully evaporate and may degrade measurement performance until fully evaporated N Tighten all SMA connections to 5 in Ib max 56 N cm max SC5304A Operating amp Programming Manual 5 Signal Connections RF IN IF OUT REF OUT REF IN This port accepts input signals from 1 MHz to 3 9 GHz to the downconverter The connector is N type female The nominal input impedance is 50 O Maximum input power is 27 dBm This port outputs the 70 MHz IF signal from the downconverter The connector is SMA female The nominal output impedance is 50 O This port outputs the internal 10 MHz or 100 MHz reference clock The connector is BNC female This port is AC coupled with a nominal output impedance of 50 This port accepts an external 10 MHz reference signal allowing an external source to synchronize the internal reference clock The connector is BNC female This port is AC coupled with a nominal input imped
97. y f Again natural cubic spline interpolation is recommended in the second step Let us outline a method to determine AG f T at frequency f there are a total of 8 frequency points for this calibration The calibration values retrieved from the EEPROM are second order polynomial coefficients fitted to measured data Writing the general form of the gain function using coefficients we have G fi T ao fi a4 fT a2 i T Equation 4 Here aj f is the jt order coefficient measured some frequency f The gain deviation at temperature T from the gain measured at the calibration temperature T can be written as AG fi T G fi T G fi To Equation 5 a fT a2 f T Using equation 5 and the temperature coefficients of Table 6 we obtain the following Table 12 Calculated gain changes at the measured frequency points Frequency MHz f 50 0 250 500 1000 1500 2500 2800 3800 AG f T 45 dB 0 340 0 343 0 351 0 348 0 354 0 351 0 355 0 357 After determining the set of gain deviations at some temperature T we apply spline interpolation to the set of AG f T values to obtain AG f T change in gain with respect to both temperature and frequency Using Table 12 and the convention developed here the Spline parameters are X f Y AG f T x f and y AG f T IF Response Correction The gain correction procedure ou

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