TD1262L/C 数字化扫频仪
Contents
1. Hox CIAT Sweepmode Graph Manager VFO Wattmeter Calculations Impedanzanpassung Graph1 Graph2 Graph3 Graph4 5 Load Graph Load Save Graph cuum ce ca ez or calor calor ce Adivate Channel 1 2 1 2MW1f 2T 11 2F 1T 2T 1 2 Show Graph v Active Active Active Active Active Active Graph 1 25 05 2015 18 16 45 Graph 2 25 05 2015 18 17 44 Graph 3 25 05 2015 18 18 49 Graph 4 empty Kurve 5 leer Kurve 6 leer 31 WinNWT4 4 09 07 FW 1 19 V10 hfm9 Measurement EM Jil Active Version 4 11 09 Graph Manager Version 4 09 07 32 3 traces selected for presentation for a 500MHz diplexer Low High pass and Isolation red X axis 250 0 MHz X axis 250 0 MHz The Graphical Manager is quite handy for measuring e g diplexers As the first graph for this diplexer specifiied as 0 500MHz 800 1300MHz showed many spurious responces in the 35 to 500MHz region As the NWT4000 deliver squarewave signals as the output signal the 3 and 5 harmonics or even higher orders passes unattended throught the higpass filter By inserting a 500MHz black trace or 600MHz red trace low pass filter only the 3 harmonics of 250MHz is visible and the true resonce of the the diplexer below 600MHz found 33 3 Linear scan settings unsupported2. ul gt 71 NWT500 AD9858 not in production oo 4 E gt b3 23 7 oooo 5 fale usp 4 RO L E E rJ Reap LIE L4 d E LS ceu PER pini 2116 50195 R54 J NHTSOO uss Hn unn fee 2 72 BG7TBL 2 d dz bs 9 gt 2 01 NWTS500 PLL DDS not in production 9 799 2 9 vi um pem l T 73 NWT3000 not in production 2 aia b nmi 7 LEA 35993193302 inva I JR 4 74 NWT70 USB ALC not in production WP n o un r 7 A mE ANT FARE CI 41 f d 4 TT ME nal i O LJ 3 Oo OOOD Fili R48 4 51824850 15767 B 21 2 MT 52 6 RIG 1817 1 52 75 NWT150 EXT RS232 ALC not in production Ir OSIZOZ1HN 2016362 H ae poja sj iw 774
3. 79 6 According to the prompt short circuit input output by connection a SMA male male test cable between input and output and when completed click on Send Ot v1 0 RHE wew fenjin com 7 Insert 40dB attenuation and when done click on Send Ot 1 0 RHE wew fenjin com t and output then input 3355553 59395999999 Insert 400E attenator between input and output then input 8 Calibration complete 80 gt b DE v 1 0 aer ir EQ Fenjin com Enter amplifiler calibration Short input and output then input POPPE OPPO IPO PRODI PE Insert attenator between input and output then input DOPED POPP PPP PPP Amplifiler calibration a axis 500 0 MHz 81 Appendix 4 2 Frequency calibration 1 Prepare a 1GHz frequency counter warm up time enough NWT4000 electric power up for 30 minutes 2 Enter VFO mode output 1GHz WinHWI4 V 4 11 09 F 1 19 10 hfa9 hfc CONI E je File Settings Graph C Set IF for Sweeping vFO Frequency x4 for 1 0 Mixer Frequenzvervielfachung x 10 MHz kHz Hz gt 0 go gj 808 3 Used frequency counter test nwt4000 output frequency 82 4 Options 4 11 09 1 19 10 hfe hfc CONI Z2 Graph sweep Measurement Help Firmware Update in Hz Attenuator 0 50 dB Set IF f
4. eap interrupt rus Frequency zoom Protie default 5 2 8 The frequency tag set of cursors Select with Curcor in the drop down list either 1 2 3 4 or 5 and on the Graphical Display with a click of the left mouse button where the marker is desired to be positioned On the Graphics Display area will be displayed an inverted triangle and in the text area the marker frequency and corresponding amplitude will be shown By a right click on the Graphical display you may delete a single or all markers The Cursor can also be selected by tapping the corresponding number on the PC keyboard as a shortcut to the frequency tag setting Y axis Scale and Shift Ymax 20 oh1 dB min dB 80 zh2 dB Cursor Online Progress Im Select the 1 5 Icon the drop down list 26 2 4200 2 4100 2 4300 2 4 2 4700 Left mouse button Cursor setting Right mouse button Menue only after the left mouse button Operation with the keyboard Return Cursor setting Space SingleSweep with cursor being set the active cursor M is the middle of theSweepWindow Up Cursor in the middle and Magnifrying Glass Single Sweep Down Cursor in the middle and Magnifying Glass Single Sweep Left Cursor 5 Pixel left Right Cursor 5 Pixel right 1 Switch to Cursor
5. Note Some type of equipment do not have this function and are not supported by NWTAOO0 family of products 4 SWR 4 1 SWR Measurements Enter SWR mode For SWR measurement an external br dge is required Connect the bridge The bridge input is connected to the NWT scanner RF output The bridge output is connected with the NWT scanner RF input See later for the calibration method used Select the SWR measurement Mode Mode Ymax dE 0 Zh1 dB Sweepmode y Sweepmode 98 90 Zh2 dB Cursor SWR Ant Impedance 7 Online Progress Spectrumanalyser Spectr Freq shifll Test mode select 4 2 SWR Frequency settings Set the frequency and log the same scanning pattern Enter the start endpoints frequency frequency continuous or single measurement can be read directly of the SWR The need for accurate calibration for measuring needed 4 3 SWR Calibration With bridge properly connected and the output of the bridge either shorted or open select Sweep Channel1 Calibration With bridge none terminated the calibration is started by clicking on OK The number of samples automatic changed to 9999 and after a while you are asked to save the calibration under a descriptive name Then at any time you can recall the calibration by select Channel 1 in the menu shown and choose the calibration file previously saved 34 Sweep Measurement Help Sweep Single Stop Channel 1 Calibration 1 Channel 2 Ca
6. From Front SMA 20cm cable dBm De From Front SMA vial dB attenuator 20cm cable 4 5 00 08 1 00E 09 1 50E 09 2 00 09 2 50 09 3 00 09 3 S0E 09 4 00 09 4 50E 09 5 00 09 Interesting to see the peak at 1 1GHz which is reflections inside the PCB of the 4000 2 as well a 5 cm SMA male male cable can create 1 5dB attenuation at 2 8GHz Also observe that when using an external 20cm SMA male male cable that standing waves develops above 1GHz and how 10dB attenuator is stabilizing the frequency response with the 20cm cable present 10 3 Saving a single or several Wattmeter measurement In case you want to measure a number of Wattmeter levels e g at 100MHz the output of an oscillator for various supply voltages or as in this example the levels for a step attenuator at various attenuations and later import these data into a spreadsheet you can add each measurement to a table and when finished save the table to a file File Settings Graph Sweep Measurement Help 9 Sweepmode Graph Manager VFO Wattmeter Calculations Impedanzanpassung 3 5 dBm 148 mV 442 1 uW HHHHBHHHBBHHUBHBUHBHUHHUHHUHHHHUBHHHHBHHBUBHUHBBHBBHEHBU 31137 5 275 MHz 15 2dB Attenuation dB Hang 1 0 10 MHz 0 0dB Y o Y Hang Frequenzvervielfachung x 10 MHz kHz Hz Attenuator 0 50 dB VFO on off 53 As there is inserted 10dB attenuator in
7. 0063 1 0113 0056 1 3767 1585 1 3290 1413 1 2880 1259 1 2528 1 2222 1000 1 0101 0050 1 0090 0045 1 0080 0040 1 0071 1 0063 1 1057 0891 1 1720 0794 1 1524 0706 1 1347 0631 1 1192 0362 1 1055 0501 1 0935 0447 1 0829 0398 1 0738 0355 1 0653 0318 67 Appendix 3 Sweep equipment history 70 NWT150 in production 68 NWTS500 DDS AD9957 in production i Rem Ji 282 de 79099 91 THINS trac tO ont 019 ou tiii 655 gn mns 6712 8210 t JT f 69 NWT4000 1 NWT4000 2 in production t Y 40 50 9 i 07 vba ef 9 L n TT Te 18010 1 129 iT esesepenanel P ook lt 6 0 Lr EH Mu we p tolo ee oe pem gt 7 s gt x sie 722 en PN t s gto 70 NWT500 AD9958 not in production e e e posa T A 6607014 e 9h SUS S e a 2 24 Hii gt PU 0125 C118 mm n r yee y 5 T 4E ru 106 4 T PE OD w 5 i OX M MOSES papi T Tou z
8. 4 6 4 6 4 4 4 4 4 2 4 2 4 0 4 0 3 8 3 8 3 6 3 6 3 4 3 4 3 2 3 2 3 0 3 0 2 8 2 8 2 6 2 6 2 4 2 4 2 2 2 2 2 0 2 0 1 8 1 8 1 6 1 6 1 4 1 4 1 2 1 2 1 0 1 0 SHY X axis 25 0 MHz The measured antenna curve Kuhl 4 09 07 FW 1 19 V10 hfm9 hfc Sweepmoade Setup Start 300000000 Stop Freq Hz 499999975 Stepsize Hz fionso25 Samples Interrupt ues 1 000 10000 Profie defaut The text area shows the standing wave maximum minimum SWR 11 3 301 005025 n Graphical Display gt GHz 2 900 3 000 3 500 4 000 2 250 2 750 3 250 3 750 4 250 2 0 3 5GHz 10dBi antenna Black trace direct at base Red trace via 4m low loss cable 2 0 4 8 4 8 Cursor 1 2480 966000 MHz 4 4 SWR 1 4105 4 4 4 2 4 2 in i 2978 79 7 3 8 SWR 1 2708 a 3 6 3 6 3 4 Cursor 3 3 4 3 2 3483 780110 MHz 32 30 SWR 1 5485 30 2 8 Cursor 3 2 8 2 6 3750 716240 MHz 2 6 2 2 SWR min 1 08 3132 674930 MHz 2 2 2 0 5 SWR max 4 24 2079 359390 MHz 5 1 8 UL M LN Y M ae af AU ull x W 1 2 1 0 x axis 250 0 MHz E Another case of a 3 5GHz 10dBi vertical antenna with and without 4m feed line cable 4 5 Bridge performance investigation Is is also posssible to examine the Bridge for proper operation to be used for SWR measurements Run
9. 76 NWT70 RS232 EXT in production 2010 11 10 60 1 7 3411941 17 NI OLS 1X3 Appendix 4 NWT4000 Sweep flatness and frequency calibration 1 NWT4000 sweep calibration steps Appendix 4 1 Flatness calibration ATTENTION If curves is not flat or the linearity from 10dB to 0 dB is too compressed then insert two 3dB attenuation to input and output both when instrument is used and when calibrated as described below Then the linearity from 0dB down to 70dB is very accurate The dynamic range is of course reduced by 6dB Alternatively a single 6dB attenuator can be used and if so then place on the output not to reduce the sensitivity when used as spectrum analyzer 1 Connect power and connect USB to PC Power on for 30 minutes 2 Opened COM assiter and select COM port You may remove the Chinese characters by renaming editing the file name DATAS COM software em A la TestCom ini 2013 12 27 13 52 Notepad Docu 1 KE SE 1852 assiter exe 2003 11 18 11 38 52 KB 3 Select COM port baudrate hex ASCII code 0 E BE www njin com 2777 78 4 Open COM port input 8F 60 1 0 wee fenjin com PP 5 Click on Send 10 Fenjin com
10. CH1 65dB hfm Attenuator Chann 1 Lin defsonde 1lin FA Atten Chann 2 Log defsonde 2 15 n the mode selection box under sweepmode only sweepmode SWR and Impedance Z is supported The remaining selection cannot be used as they are Made Sweepmaode MSweepmode SWR M swrR_ant Impedance Spectrumanalyser SpectrFreq shift Attenuation and Frequency Zoom cannot be used Display shift OK for the dB Y Axe Interrupt uS rest time for each sample ERE Frequency Zoom Attenuation MES Interrupt uS 0 OdB 50dB dB M 2x Zoom 4 RUM 2 _ Displ shift For the Graph Manager all functions supported For VFO Attenuator 0 50dB Set IF for Sweeping and IF setting has no function dB Attenuator 0 50 dB SetiFforSweeping F 0 Hz For Wattmeter the VFO on off does not stop the output but allows to type remarks and save these Do not save in the application path but under a folder of your choice as else hidden for later retrieval calculations and Impedanzanpassung impedance matching are with no comment 2 Logarithmic Y scale sweep frequency settings 2 1 Select the sweep frequency mode Mode M Math Corr Channel Math Corr Channel Select the sweep frequency mode 2 2 Set the frequency parameter Enter the start frequency the end frequency scanning numbers number of samples for a scan There are two kinds of scanning modes a continuous
11. analyzer is OK Check USB driver check external DC power supply check USB cable check software setting about what port number is allocated to the sweeper in control panel system hardware settings When responsive then Disconnect input and output The curve is displayed in the bottom of the display area Connect input and output with shielding cable The curve is displayed in the top of the display area If these two displays curves are normal then the sweeper is OK 60 4 Can the sweeper test a duplexer and how 10 test A duplexer is a filter The NWT sweep analyzer input is connected to the output of the duplexer antenna connector and the NWT OUT connected to the Low or High antenna connector the unused connector terminated with 50 ohm The high and ow frequency response thus measured as shown below MOBILE DuUuUPLExER Duplexer for UHF band GSM band duplexer 61 Graphical Display a axis 50 0 MHz GSM band duplexer curve 5 How to test antenna Used a SWR bridge or a three port connector SWR bridge test Swr bridge RF output 62 RF OUT ST 581 GND ET SWR bridge 2 ANTENNA faic RF OUT RF IN ST 581 GND Diagram When using the SWR bridge you can measure in the transmission sweep mode as a qualitative measurement but you need to pay attention frequency sweep analyzer can only use the RF Output of the Bridge not the Bridge band detection o
12. can measure 100 2 12 1 Prepare a 1GHz frequency counter allow enough warm up time for NWT4000 electric power up for 30 minutes NWT3000 4000 1 4000 2 used 1GHz calibration for others models use 10MHz calibration 12 2 Enter VFO mode output 1GHz 10MHz WinHWI4 4 11 09 FW 1 19 V10 hfm9 hfc CONI2 eL File Settings dB Attenuator 0 50 dB Set IF for Sweeping x4 for O Mixer Frequenzvervielfachung x 10 MHz kHz 2 4 020202 Input 1GHz 10MHz 3 Use frequency counter to test nwt4000 output frequency Test output frequency in this case 999 990 330MHz 56 4 Enter option LUE EET 4 11 09 FW 1 19 10 hfa9 hfc COMI settings a n PE I E VFO Wattmeter Calculations Impedanzanpassung dB Attenuator 0 50 dB Set IF fc VFO Fre Frequenzvervielfachung x 10 1 5 151 l Enter OPTION Input frequency counter frequency with units in Hz press OK then the frequency calibration is complete result as shown below 57 Basic_data Sweep SA 1 SA 2 General Galibrationfrequency Math correction only Attenuator Startfrequency Hz 100000 stopfrequency Hz 150000000 Channels DDS Clockfrequency One Chann DDS Clock HZ 999990330 SWR Iteration Not Active PLL Ma
13. measure Now select Wattmeter and apply a signal source with known dBm amplitude to the 4000 Input port You may also chose the signal source to be the NWT4000 output but insert preferably 20dB attenuator the signal path however at least to avoid the compression in the mixer logarithmic detector of the internal circuitry as described earlier page 16 under sweep calibration Observe the dBm reading is pretty 49 wrong as the Wattmeter not yet calibrated Below the dBm read out is a drop down list which indicated is is possible to compensate for variation in the sensitivity of internal detection circuitry across the 35MHz to 4 4GHz range but as seen the list is initially for a quite different product so the calibration needed both to edit the drop down list and the sensitivity and the procedure described below File Settings Graph Sweep Measurement Help LECHA SEER IAAL Sweepmode Graph Manager VFO Wattmeter Calculations Impedanzanpassung dBm 92 3 mV 170 4 uW 398 110 10 MHz 0 0d8 v Attenuation dB o Hang 110 10 2110 20 MHz 0 848 3120 50 MHz 1 098 4150 100 MHz 2 048 5 100 150 MHz 2 598 6 150 200 MHz 3 008 71200 300 MHz 4 088 81300 400 MHz 6 008 9 400 500 MHz 9 048 101 NN o r Hang kHz Hz Attenuator 0 50 dB When for Wattmeter we click on Measurement the drop down
14. 1 with Return Set the Cursor 2 Switch to Cursor 2 with Return Set the Cursor 3 Switch to Cursor 3 with Return Set the cursor 4 Switch to Cursor 4 with Return Set the cursor 5 Switch to Cursor 5 with Return Set the Cursor 0 Delete all Cursors Single Sweep Like Button W Cantinuous Sweep like Button 5 5top Like Button 10 0 MHz Inverted triangle marker displayed File Settings Graph Sweep Measurement Help Sweepmaode Setup Start Freq Hz 2400000000 Stop Freq Hz 2475049600 Stepsize Hz 75200 Samples 9 interruptus 00 Displ shit o Profie default Frequenzvervielfachung x 10 Channel 1 2 89dB Cursor 2 2412 107200 MHz Cursor 4 2424 515200 MHz Channel 1 5 81dB Attenuation dB 50dB M gt Cursor 5 2450 158400 MHz Channel 1 5 81dB Math Corr Channeli v Channel 1 max 2 5108 2432 56 1600MHz min 74 1508 2474 748800MHz Math Corr Channel2 Frequency of the 5 screen markers displayed and the signal level in dBm 27 2 9 The Y settings in the Graphical Display The Y axis scaling function The Ymax signal level on the Graphical display is selected in the drop down list Standard level is 20dB but OdB more relevant for the NWT4000 family Ymin signal level on the Graphical display is also selected in a drop down list generally choose 90dB Fine adjustment in 1dB st
15. 20 979 344170 MHz Channel 1 82 30dB 30 Cursor 3 30 1477 493360 MHz Channel 1 81 5208 0 Cursor 4 40 1982 627990 MHz Channel 1 80 75dB 50 Cursor 5 50 2978 489730 MHz Channel 1 77 64dB 60 J B dB 38 L316 min 84 63dB 1372 711760MHz a axis 500 0 MHz You may edit first line label prior to einblenden as seen on the next image below Graphical Display H GHz 1 000 2 000 4 000 0 dB 10 10 Calibration test direct TX to RX 20 Cursor 1 35 000000 MHz Channel 1 1 92dB C3 cursor 2 30 979 3170 MHz Channel 1 2 51dB 40 Cursor 3 40 1477 493360 MHz Channel 1 2 1298 20 Cursor 4 50 1982 627990 MHz Channel 1 2 1298 760 Cursor 5 50 2978 489780 MHz Channel 1 0 1898 U Channel 1 a max 0 0248 3290 651630MHz min 3 2888 14339 9466 20MHz B B 22 Above measurement done with two 5cm long male SMA SMA cables connected from the PCB SMA connector to a front panel with female female SMA adaptors used as the TX and RX connections As previous described the NWT4000 2 has best dynamic range if mounted in a plastic case Below plot shows a calibration performed without these two 5cm MSA SMA cables and the female female adaptors thus directly at the PCB SMA adaptors and the dynamic range even better manintaning 80 to 4 4 GHz To utilized the NMT4000 2 to the extreme two male female SMA adaptor might be a possibl
16. 900 MHz fl 2415 556800 MHz f2 2465 456400 MHz Shape Faktor 1 830882 50 50 4 60 60 70 70 80 80 90 90 X axis 25 0 MHz 24 Graphical Display _ 5 x MHz 21 40 21 60 21 80 00 21 30 21 50 21 T 21 90 20 20 dB dB 10 10 NE cee 9 1 10 10 20 zll 30 30 40 40 50 50 60 B TU 80 80 1 100 0 kHz A single scan curve the curve is a curve of a 21 6M filter 2 6 Saving of Graphical screen The Grapical Screen can be saved and re loaded by clicking on Graph The format is hfd and saving can happen to a folder at your choice File Settings Graph Sweep Mea B 2 Load Graph Save Graph Sweepmade 25 2 7 The below mentioned function about frequency zoom is not supported by the NWT4000 series and only mentioned for reference 2 times zoom settings For a measurement the available frequency scaling functions are magnified 2 times reduced 2 times fast frequency response measurement device The button 2 times Continuous magnification operation bond was reduced 2 times operation Sweepmode Setup Bandwidth Start Freq 21181919 Stop Freq Hz 22011 587 Single Stepsize Hz 4119 Markerlines Samples 200 Inverse
17. General Calibrationfrequency Math correction only Attenuator Startfrequency Hz 35000000 FA Atten Stopfrequency Hz 4400000000 Channels One Chann DDS Clockfrequency DDS Clock HZ 999999800 SWR Iteration Mot Active PLL Math Corr Serial Interface Interface Default Filename Chann 1 Log defsondet Chann 1 Lin detsondein Chann 2 Log defsonde2 Frequencylimits max Sweep Hz 4400000000 Frequency mulitiply 10 Note the settings for start and stop frequency where stop is negative Note also the max sweep setting If One Chann tickmark in Channels is removed then you have two channel operation e g quite handy to have two different calibrations in actions Also select Math Corr to allow SWR itteration 1 1 Functions not supported for NWT1400 in the WinNWT software by DL4JAL The WinNWT software developed by DL4JAL was for another project and has a number of function not supported by the 4000 family of products These are Inthe Settings Options a number of fields are not supported Only Basic data Sweep is supported SA 1 SA 2 General has no functions Basic_data Sweep 1 SA 2 General Attenuator has function Channel 1 Lin not supported only Log Remark file name for Channel 1 and Channel calibration files can be entered in the text field so in use when program started here CH1 6dB hfm Default Filename Chann 1 Log
18. Wattmeter Functions 10 2 Wattmeter calibration 10 3 Saving a single or several Wattmeter measurement 11 1 VFO signal level on the output 11 2 VFO frequency setting 12 Frequency calibration Appendix 1 FAQ page48 page48 page52 page54 page53 page55 page59 Appendix 2 return loss reflection coefficient voltage standing wave conversion tables Appendix 3 Sweep equipment history Appendix 4 NWT4000 Sweep flatness and frequency calibration Appendix 4 1 Flatness calibration Appendix 4 2 Frequency calibration page66 page67 page77 page77 page81 Overview NWT4000 2 Sweep Features 35 2 4400 2 35MHz 4400MHz range fast and accurate measurement Dynamic range gt 0dB Software calibration function to reduce the system error Directly display 3dB 6dB 60dB bandwidth Curves of maximum minimum value display with cursor VFO output Power meter function SWR measurement SWH measurement of Antenna with coax feed line simulation NB not supported by NW T4000 Impedance measurement spectrum Analyzer 35MHz 4 4GHz Print of measurement data and curve Overview NWT series digital virtual frequency sweeper is a high intelligent RF frequency analyzer The equipment is composed of MCU RF detection RF generator s and the circuit board contains the linear detection log detection completely analyzing systems for amplitude versus frequency characteristics
19. guide 1 1 Functions not supported for NWT1400 in the WinNWT software 2 1 and 2 2 Logarithmic Y scale sweep frequency settings 2 3 Sweep Calibration 2 4 Blending cursor data into the trace image and saving it 2 5 Typical display of sweep measurements 2 6 Saving of Graphical screen 2 7 unsupported zoom function 2 8 The frequency tag set of cursors 2 9 The Y settings in the Graphical Display 2 10 Bandwidth display settings 2 11 Multi curve display management 3 Linear scan settings not supported 4 1 SWR measurements 4 2 SWR Frequency settings 4 3 SWR Calibration 4 4 SWR Measurements examples 4 5 Bridge performance investigation 5 1 SWR Ant function not supported 6 1 Numerical Impedance measurements 6 2 Selection of impedance measurement mode 6 3 Reading from chart the numerical impedance values 7 1 Filter test method 1 7 2 Filter test method 2 7 3 RF transformer measurement method 1 7 4 RF transformer measurement method 2 7 5 An antenna measurement method 7 6 The small capacitance inductance measuring method 7 7 Amplifier amplitude frequency characteristics measuring 7 8 Notch filter test 9 1 Spectrum Analyzer functionality page 4 page 6 page 8 page 9 page11 14 15 17 page20 page23 page24 page25 page25 page27 page28 page30 page33 page33 page33 page33 page36 page37 page39 page39 page39 page40 page41 page41 page42 page43 page43 page44 page44 page46 page46 10 1
20. measurements you need to insert a 50 ohm resistor in series with the DUT This means if the bridge is terminated with 50 ohm the reading is 0 ohm Do not measure impedances directly as impedances below 50 ohm also will give positive readings SWR calibration required if not already performed prior to measurement of the DUT For the SWR calibration procedure see section 4 3 6 2 Selection of impedance measurement mode After calibration select the impedance measurement mode Impedance z Mode selection of impedance measurement model After selection read the prompt and then ignore 40 6 3 After measurement read directly from the chart the numerical impedance values During measurement a 50 ohm resistor in series with bridge and DUT required Graphical Display iol x 20 0 30 0 40 0 50 0 2 hm A axis 5 0 MHz Z Ohm Measurement of a 65 ohm resistance 4 7 Measuring a device connection methods 7 1 Filter test method 1 The following diagram is suitable if the filter input and output impedance is 50 ohm if the filter impedance has mismatch the measurements are prone to error in passband bandwidth and big fluctuation of measurement inaccuracy might exist SS ESOS CIA GMD Methods 1 suitable for filters with input and output impedance of 50 ohm 7 2 Filter test method 2 If the filter does not need the 50 ohm impedance
21. series it can be compensated for by the Attenuation dB setting Select for each measurement Write to Table File Settings Graph Sweep Measurement Help y Set Font Channel 1 Calibration ERES Channel 2 Calibration 3 6 culatians Impedanzanpass umm 438 1 uW Set Attenuation to default 3 137 5 275 MHz 15 298 Edit Channel 1 calibration Edit Channel 2 When finish with the measurements select Save Data and chose the location for saving and provide a file name WInNWTA V 4 11 09 FW 1 19 V10 hfm8 hfc E 4 k k Kurt k Saved data C Search Saved data Organize New folder H E Homegroup Mame Date modified Type B Kurt This PC Libraries messtab txt 30 05 2015 10 02 Text Document messtab cal txt 30 05 2015 10 09 Text Document w lt gt File name ATT Levels txt w Save as type Textdatei txt wi Hide Folders The format of the data in the saved file is semicolon seperated and directly to import in e g Excell Settings dBm uw 3 6 dBm 148 0 mV 438 1 uW 3 6 dBm 148 0 mv 438 1 10 14 1dBm 44 3 mV 39 3 uW 2 dBm 2 T uW 20 23 6 dBm 14 8 mV 4 4uW 23 6 dBm 0 mV 4 UW i 5 20 33 4 dBm 48 4525 nw 49 5 due d amp wvo 40 42 9dBm 1 6mV 51 2 amp As neither the frequency nor step number is inc
22. 00 2 output is measured to be 2 36dBm with a Hewlett Packard powermeter 437B and 8481A power sensor As the output of the NWT4000 2 is squarewave the theoretical fundamental is 0 707 or 3 01dB lower in level then 5 37dBm As we 20dB inserted in the signal path and measures 7 dBm with the Wattmeter then the theoretical compensation to apply is 20 7 7dB 12 3dB The picture above to the right shows a compensation of 15 20 which is derive when using the signal from a Marconi 2022A Wavegenerator with an accurate measured sinusoidal output of OdBm using the HP437 8481 seem like the NWT4000 2 output is not following the theoretical condition and the third and higher harmonics are lower than theoretical levels explaining the difference It appear the difference is only 1dB As the output impedance from the NWT4000 deviating somewhat from 50 ohm it is contributing to some mismatch as well Anyway when using the Marconi 2022A wave generator up to 1GHz with accurate measured output and the output from the NWT4000 2 from 1GHz to 4 4GHz where output measured with the HP437A as well the compensation derived as shown in the below image across the frequency band The NWT4000 2 VFO is covering 2 2GHz to 4 4GHz and sub band created by division of 2 4 8 14 32 These limits entered in the edited list However above 2 2GHz further sub band created according to the measured levels drop off as seen in a Graph further down All the dat
23. 188 GND GND Amplifier test method 45 DERN NEGERI SEAE a UN A RE RR m a N S gie Power amplifier test 1 pie Power amplifier test 2 46 7 8 Notch filter test For a trap LC parallel circuit available method for testing shown where a dip seen in the sweep mode when connected between RF OUT and HF IN Tor GND GND LC parallel notch filter measurement connection method 9 Spectrum Analyzer 9 1 Spectrum Analyzer functionality The Spectrum Analyzer is a simple spectrum analyzer which is utilizing one of the PLL s in the NWT4000 2 Quite simply the spectrum analyzer is no less than the sweeper where the signals to be analyzed is applied to the Input Port The PLL delivering signal for the receiver mixer receiver PLL is running with a fixed offset from the wanted frequency of 260 2 to facilitate the sweeper is measuring on the right frequency The PLL being input to the RX mixer beats with the RX input signal and generates an IF signal on either side of the input frequency but not being on the required frequency The IF signal is passing through a low pass filter from 15KHz to 300KHz and being detected in the Logarithmic detector for presentation The other PLL on the TX side is doing nothing when we are analyzing the spectrum Below is shown an input signal of 100MHz from the Mar
24. NWT4000 2 RF DIGITAL SWEEPER amp ANALYZER USER MANUAL Manufacturer WUTONG ELECTRONIC site http bg7tbl taobao com TEL 86134 2795 9750 1630 2767 Email bg7tbl 2126 com version V2 0 date 2014 10 20 This document is based on the original manual from the supplier edited and updated by Kurt Poulsen OZ70U The document and applied editing and updates devoted entirely to document the NWT4000 2 25MHz 4 4GHz unit using 2xADF4351 PLL s but will also be useful for the NWT4000 2 and NWT4000 1 series going from 138MHz to 4 4GHz using 2xADF4350 PLL s However the latest NWT4000 2 where the SMD connector are on top of the PCB and not at the edge has improved screening and far better dynamic range Watch our when building it into a case to use a plastic case Using a metal case will most likely give elevated noise floor by several dB in the GHz region Watch out that you do not purchase the version in a case with two SMA connectors and a Green LED in between believing it is a NWT4000 version as it most likely will only have 1 PLL ADF4350 for 138MHz version and ADF4351 for 25MHz version and thus only is a signal generator and spectrum analyzer not being able to sweep the frequency response of devices May 2015 edition List of content Overview NWT4000 1 and NWT4000 2 Instrumental composition and technical characteristics Conditions of use The basic design 1 The hardware connection reference and software
25. The amplitude frequency characteristics can be fast and accurate measurement of RF devices in the 35MHz 4400MHz range NWT series of digital virtual measurement scanner will by way of man machine dialogue display of the numbers on the screen and can also print out the measurement data and the curves The instrument has the function of self checking through the host computer and related devi ces perform self calibration so that more accurate measurement can be done computing power and perform signal generator function NWT series digital virtual frequency sweeper can be widely used within radio television communication and other fields The measured object includes RF Devices like coaxial cables amplifiers combiners amplifier modules filters attenuators splitters loads antennas power dividers and tuners NWT series of digital virtual frequency units are sweepers equipped with microwave integrated circuits and digital integration technology controlled by the high performance CPU being a software instrument and has the advantages of simple operation reliable and easy to use by amateurs RF developers television equipment manufacturers and being the best choice for RF measurement research institute Instrumental composition and technical characteristics Instrument NWT Series sweep instrument 1PCS USB cable 1PCS AC 100 240V to DC 12V power supply 1PCS DISC 1PCS SWR BRIDGE OPTION not included 1PCS 40db ATT OPTION n
26. a from the editing is automatic saved in the current selected sweep calibration file when clicking on Save in below screen 51 Wattmeter Error Text in the ComboBox 34 375 68 75 MHz 15 2dB 68 75 137 5 MHz 15 5dB 137 5 275 MHz 15 2dB 275 550 MHz 15 1dB 0 55 1 1GHz 14 9dB 1 1 2 2 GHz 15 2dB 2 2 2 5 GHz 15 2dB 2 5 2 8 GHz 15 5dB 2 8 3 3 GHz 16 0dB 3 3 4 4 GHz 16 5dB The editing thus results in new visual drop down list File Settings Graph Sweep Measurement Help BE Sweepmode Graph Manager VFO Wattmeter Calculations Impedanzanpassung 22 9 dBm 16 0 mV 9 1 uW 1 34 375 68 75 MHz 15 Attenuation dB 0 7 Hang 1 34 375 MHz 15 2dB 2 68 75 1 MHz 15 5dB 3 137 5 275 MHz 15 2dB 4 275 550 MHz 15 1dB 5 0 55 1 1 GHz 14 9dB 6 1 1 2 2 GHz 15 2dB 7 2 2 2 5 GHz 15 2dB 0 Hang 8 2 5 2 8 GHz 15 5dB 9 2 8 3 3 GHz 16 0dB gx 10 10 3 3 4 4 GHz 16 5dB kHz Hz ru fo 3 3 53 o jo do 3Jo do If you do not have a wave generator then use the settings in the table It is better than nothing done 52 1 50 2 00 2 50 3 00 3 50 4 00 4 50 0 00E 00 NWT4000 2 35 4400MHz Output dBm Inside PCB dBm i Plot Area A From SMA Front 5cm cable dBm
27. a sweep for the bridge from input to output and also for the bridge coupler output with the Bridge output terminated with open short and 50 ohm 38 Graphical Display GHz 2 000 3 000 4 000 1 500 2 500 3 500 Aces cui dB dB 10 10 Performance measurement 20 of 1 4GHz Bridge 20 Cursor 1 30 50719 30 Channel 177969 40 Cursor 2 4 991 181070 MHz Channel 1 36 86dB 30 30 Cursor 3 3988 755960 MHz Channel 1 26 86dB Channel 1 37 05dB Channel 1 1 2 max 96 2808 2195 982530MHz 3 4 min 97 2598 4389 154050MHz X axis 500 0 MHz The 4000 output fitted with a 10dB attennuator to stabilize the output impedance closer to 50 ohm Black trace input to output Red trace output terminated with short and green with open and thus with full reflection Blue trace when output terminated with 50 ohm and thus no reflection The span from terminated with 50 ohm and short open is better than 30dB yelding adequate span for SWR measurements 39 5 SWR Ant mode 5 1 SWR antenna measurement with coax feed line This function is not compatible with the NWT4000 family SWR Ant SWF Range default Attenuation 100m 3 CableLength 100 Setting the cable parameters Wrong results obtained if used 6 Impedance Z 6 1 Numerical Impedance measurements You need to use the bridge to measure the numerical impedance During the
28. ate In any case it is recommended to use the latest published version 4 11 09 of WINNWT from below link as several more and improved features available http www dl4jal eu hfm9 htm That version used for this documents screendump 12 2 x WinHWT4 en WindWT4 ileskAFUSWinHWTA winnwti exe app 15 Progean Filez AFUVinHWTA Original Chinese startup settings remark the app cn qm extension to winnwt4 exe winnwt4_11_09 exe Properties General Shortcut Compatibility Security Details n winnwt4 11 Target type Application Target location WinNW Target SG AFUNSWinNW Td winnwt exe app en qm Start in C Program Files x856 AFUSWinNWTA Shortcut key None The line G Program Files AFU WinNW T winnwt4 exe app cn qm Changed to G ProgramFiles AFU WinNW T winnwt4 exe app_en qm available close and restart the program and the English menu is available The use of English version recommended but Chinese cn Spanish es Hungary hu Netherland nl Polish pl and Russian ru language may be chosen The native German language requires no extension after winnwt4 exe the required before and after the path as shown 1 3 Setting COM port Insert the USB into the computer Because USB driver is already installed in the device manager you will find the c
29. c VFO Fre Frequenzvervielfachung x 10 l l l l 5 Input frequency counter frequency with unit Hz press OK frequency calibration complete 83 Basic_data Sweep SA 2 General Calibrationfrequency Math correction only Attenuator Startfrequency Hz 100000 FA Atten Stopfrequency Hz 150000000 Channels DDS Clockfrequency One Chann DDS Clock HZ 999990330 SWR Iteration NotActive PLL Math Corr serial Interface Interface Default Filename Chann 1 Log defsonde1 Chann 1 Lin detsondelin Chann 2 Log defsonde Frequencylimits max Sweep Hz 200000000 Frequency mulitiply 10 Special tricks if your counter does not go to 1GHz If you counter does cover 100MHz then use a gate time of 10sec to read the frequency with at least 10Hz resolution set the VFO to 100MHz and write down the measured frequency e g 99 99931MHz Then write down the frequency as if it was 10x higher with 1 Hz resolution 84 e g 999999310Hz and set the VFO to 1GHz and enter 999999310 into the DDS PLL Clock Hz in the Settings Options menu point Then the frequency is calibrated to within 1kHz at 4 4GHz When measuring the 100MHz output after calibration You may experiment with the 1 Hz settings to get closer to 100M Hz Most likely you will hit the correct frequency with less than 50Hz error 85
30. ced to 8V to reduce temperature of the 5V regulators cooling fin which else being quite hot The power connector shall be with positive center 10 TT 11 32 7 Bottom view with latest improved screening 11 The hardware connection reference map The software guide Software installation and configuration Dependent your operating system the USB driver might be installed automatic Let the computer search on the Internet and it might take several minutes Otherwise find on the supplied disk relevant drivers If not installed automatic then Install USB driver by running ftdi ft232 drive exe for WIN7 WIN8 or use inf file install driver 74 amp ftdi 232 drive exe Double click install USB driver 1 1 WINNWT Install WINNWT software winnwt 4 exe WINNWT4 Setup DLAIAL 17 winnwt 4 09 07 update exe Setup second After installing the WINNWT the attribute shortcuts on the desktop can be modified to support a number of languages as described below Right click on the shortcut and select properties and perform the modification as described However you may experience problem installing the software supplied on the Disk due error messages Copy the two zip files to your hard disk and unzip those and remove the Chinese character in the folders filenames That worked for me to install the 4 09 version and the 4 09 07 upd
31. coni 2022A Wavegenerator stepped down in 10dB steps which discloses the Offset between the two PLL s Graphical Display MHz 99 50 100 00 100 50 REM 2 2 0 dB Spectrum analyzer Offset dB 10 1 10 99 738000 MHz Channel 1 82 69dB 20 20 Channel 1 max 40 95dB 99 6g2000MHz 30 min 83 08dB 99 2620 00 2 30 40 40 50 50 60 60 70 70 80 A B 90 90 5 250 0 kHz 47 Spectrum of the 100MHz signal when 6dBm 16dBm and 26dBm applied to the input lt is clarly seen that all sort of spurous signal generated and mesurement of the signal generators harmonics not possible First by comparing the 16 and 26dBm sweeeps we can trust the measurements of 2 3 4 and 5 Harmonics X axis 50 0 MHz X axis 50 0 MHz X axis 50 0 MHz 48 10 Wattmeter 10 1 Wattmeter Functions The Wattmeter when calibrated is a superb tool as being a selective Wattmeter only measuring the frequency the VFO is tuned to with a bandwidth 300KHz to either side of the VFO frequency and then suppressing harmonics and other signal which could create false readings Tools are provided to compensate for the slight drop off sensitivity above 2 5GHz Before selection the Wattmeter remember to select the calibration file for sweep as calibration data for Wattmeter is stored in the sweep calibration file Please also do the sweep calibration first before the Wattmeter calib
32. ecommend to initially using the software on the supplied disc called COM assiter exe It performers an excellent flat calibration of you particular hardware and the result is saved into the hardware However the levels from 10dB to OdB is nonlinear due to about 498 compression in the internal reception mixer and or logarithmic detector The 40dB level is calibrated and consequently the 10 20 and 30dB level are not fully accurate It applies also for all levels below 40dB This problem can be eliminated by inserting a 6dB attenuator in the Output path mounted on the SMA TX output at all times but this however reduces the dynamic range by As the WInNWT software also have calibration routines which is allowing the top level calibration to be performed at a user selected lower level this 6dB attenuator is only used during calibration within the WinNWT software and removed after calibration Then the full dynamic range is available with the only limitation that OdB level is compressed to about 3dB but from 10dB and downwards everything is perfect If the device tested has an insertion loss above 3 4dB then the compression has no effect If not so then use att permanently and accept the 6dB loss of dynamic range and create a different calibration The WinNWT software can save as many calibration files as you wish so just find you own Way The initial calibration being the platform the WinNWT calibrations is described in the documen
33. ep is also selectable axis Scale and Shift Ymax dE Zh1 dB o Ymin dB 90 Zh2 dB axis Scale and Shift Ymax dE o Zh1 dB 2 4 20 Cursor 3 2 Online Progress 4 1 2 3 E E co 4 Y axis scaling function To magnify the top area of a trace you may change the settings to Ymax 0dB and Ymin 20dB Note that because of the limited resolution of the MCU AD conver sion the curve may appear stepped jagged as seen below x axis 10 0 MHz Select back to Ymax 0dB and Yminz 90dB 28 Graphical Display RN MHz 49 550 49 570 49 590 49 610 0 49 540 1 49 560 49 580 49 500 49 520 dB A 99 sample 10Hz steps dB 10 Cursor 1 10 49 549940 MHz 20 Channel 1 2 8908 20 49 562270 MHz 30 Channel 1 39 3888 30 Cursor 3 49 599840 MHz Channel 1 5 4208 50 50 Cursor 4 ZEE 43 6040 70 MHz 60 Bid Channel 1 40 56dB 60 70 Bie max 2 89dB 49 550270MHz 70 EI miri 48 3208 49 568540MHz m Did B3dB 3 280 kHz 80 0 15106 63 80 Fa f1 49 548100 MHz fm 49 549740 MHz E m f2 49 551380 MHz Maxis 10 0 Measurement of a 49 55MHz Quartz Crystal 2 10 Bandwidth display settings The measured curve can directly have in the Graphical Display the 3dB 6 and 60dB bandwidth shown as lines and the data shown in the text field with additional Q value and rectangular coefficient Tick ma
34. isplay management Graphic Manager Get Active channel Show Graph After a measurement the curve can be stored and controlled by the Graphical Manager The current trace is acquired by a click on the Get button Then tick the active channel number and tick Active for Showing Graph File Settings Graph Sweep Measurement Help 3 Sweepmode Graph Manager VFO Wattmeter Calculations Impedanzanpassung Graph1 Graph2 Graph3 4 5 6 Load Graph Load Save Graph cM Gm GM o ee cx espe cx ca os ca e Channel 1 2 2T 1 2 1 2 1 21 10 2 Show Graph Active Active Active Active Active Active Graph 1 25 05 2015 18 16 45 Graph 2 25 05 2015 18 17 44 Graph 3 25 05 2015 18 18 49 Graph 4 empty Kurve 5 leer Kurve 6 leer WinNWT4 4 09 07 FW 1 19 V10 hf aK Sweepmode Graph Manager VFO Wattmeter Calculations Graphi Graph Graph 3 Graph 4 Load Graph i Load Load Load ee oom gat ern coor oes ci caf Leo e Activate Channel F if mi mf miu miu mi j mf Show Graph Active Active Active Active Version 4 11 09 Graph Manager Version 4 09 07 File Settings Graph Sweep Measurement Help
35. ity to get the Input and Output to penetrate the case on the top and let the cooling fin be exposed to the ambient The black trace for Input and Output directly connected shows below 3GHz up to 2dB loss off signal amplitude due to mentined compression in the internal mixer and or logarithmic detector If the DUT has insertion loss more than 2 dB it has no effect Ju Graphical Display ES GHz 1 000 2 000 3 000 4 000 i E AT 4 E i E ee V 0 dB dB 10 Direct PCB output SMA to input SMA calibration 10 Cursor 1 20 56 868850 MHz 20 Channel 1 0 98dB 30 Cursor 2 30 3302 8556530 MHz Channel 1 1 5998 40 doen 40 Cursor 3 2506 180050 MHz 50 Channel 1 0 18dB 50 Cursor 0 4076 363480 MHz 60 Channel 1 0 221 70 70 Channel 1 max 0 82dB 3603 996320MHz 0 min 2 3908 1067 209720MHz 80 90 an x axis 500 0 MHz 23 2 5 Typical display of sweep measurements 1 000 0 500 a axis 500 0 MHz WiFi Filter single Channel GHz 2 3750 2 4250 2 4750 2 5250 2 3500 2 4000 2 4500 2 5000 10 10 WiFi Filter single Channel 20 Cursor 1 20 2436 799200 MHz Channel 1 2 70dB 30 Channel 1 30 max 2 51dB 2451 789200MHz 80 5508 2363 052000MHz B3dB 25 852 MHz 0 Q 94 28 f1 2424 374400 MHz fm 2437 300200 MHz f2 2450 226000 MHz B6dB 27 254 MHz f1 2423 572800 MHz 2 2450 827200 MHz 49
36. libration 44 Select Channel 1 Select Channel 2 Setting SWR Infinite Returnloss bridge Open or Shorted Store Channel 1 calibration Store Channel 2 calibration Saving data in calibrationfile 5ave data now ow In the shown example below the Bridge used is a Narda bidirectional coupler model 3022 specified for 1 to 4GHz and selected frequency setting 1 to 4 4GHz When running a SWH sweep the number of samples is e g changed to 999 for a faster sweep as the Calibration always uses 9999 samples It will be seen that above 2 5GHz a slight ripple exist due to reflection between NWT4000 TX output and Bridge input By inserting 1098 attenuator in the TX output this ripple is removed red trace and the TX out now closer to 50 ohm for all frequencies Graphical Display GHz 2 000 3 000 4 000 1 500 2 500 3 500 5 0 5 0 4 8 4 8 4 6 4 6 4 4 4 4 4 2 4 2 4 0 SWR Bridge terminated with 50 ohm 4 0 3 8 TX Out fitted with 1008 attenautor 38 3 6 result seen in red trace 3 6 3 4 SWR min 1 01 1000 340070 MHz 3 4 32 SWR 1 09 4046 687130 MHz 3 2 3 0 iere buie tu teg 3 0 2 8 2 8 2 6 2 6 24 2 4 2 2 2 2 2 0 2 0 1 8 1 8 1 6 1 6 1 4 1 4 1 2 1 2 1 0 gu e s rre o ege E ec er I ge 1 0 SWV X axis 500 0 MHz SWW 35 Mode SWR Range default PM 49999 e n max SWR 2 0 max SWR 3 0 max SWR 3 0 max SWR 5 0 max SWR 6 0 90 Black trace without any atte
37. list allow a number of selections DO NOT CHOOSE Channel 1 Calibration as 4000 does support this procedure of the WinNWT software We will instead choose the Edit Channel 1 calibration as perform the calibration manually and edit the prompting as well in the compensation drop down list in a couple of steps File Settings Graph Sweep Measurement Help Set Font Channel 1 Calibration Channel 2 Calibration culations Impedanzanpassung Write to Table UM 170 4 uW Set Attenuation to default 398 k ang Edit Channel 1 calibration Edit Channel 2 When chosing the Edit Channel 1 calibration the initial setting is seen below next to result the final settings to be explained in the next steps 50 Wattmeter Error Text in the ComboBox Deviation in dB Text in the ComboBox 0 10 MHz 0 048 34 375 68 75 MHz 15 298 15 20 10 20 MHz 0 848 68 75 137 5 MHz 15 5dB 20 50MHz 1 0dB 137 5 275 MHz 15 2dB 50 100 MHz 2 0dB 275 550 MHz 15 1dB 15 10 100 150 MHz 2 5dB 0 55 1 1GHz 14 9dB 14 90 150 200 MHz 3 0dB i 1 1 2 2 GHz 15 2dB 15 20 200 300 MHz 4 088 2 2 2 5GHz 15 2dB 15 20 300 400 MHz 6 088 2 5 2 8GHz 15 5dB 400 500 MHz 9 0dB 2 8 3 3GHz 16 0dB 16 00 3 3 4 4 GHz 16 5dB NN NN F arar a The input to the NWT4000 2 when delivered from the NWT40
38. luded in the data left picture such information must be added manually right image 54 11 The VFO mode 11 1 VFO signal level on the output The output is documented in section 10 2 page 52 as the level into 50 ohm 11 2 VFO frequency setting The frequency setting is quite simple to understand and need no further explanation They 15 selextion possiblity for five quick access frequencies which in combination with the tick in VFO Frequnecy x4 for I Q Mixer as VFO a SDR radio where the output frequency is 4 times higher then the setting can be quite handy for quick band changes The minimum frequency steps are dependant of the frequency and the dicvision rate in the PLL going from 1 1 1 2 1 8 1 16 1 32 to 1 64 for the lowest band From 2 2GHz to 4 4GHz they are 1KHz From 1 1GHz to 2 2GHz they are 500Hz from 550MHz to 1100MHz thety are 250Hz From 275 to 550MHz they 125Hz From 137 5MHz to 275MHz they are 62 5Hz From 68 75MHx to 137 5 mhz they are 31 25Hz From 34 375MHz to 68 75MHz they are 15 635Hz That os not entirely the thruth because the PLL is binary and not exactly in 1KHz steps Sweepmode Graph Manager VFO Wattmeter Calculations Impedanzanpassung t00000000 in Hz 098 Attenuator 0 50 dB Set IF for Sweeping VFO Frequency x4 VQ Mixer Frequenzvervielfachung x 10 MHz KHZ Hz 041440105 03010 23 12 Frequency calibration Note Read appendix 4 if you counter only
39. matching then matching transformers introduced After matching the curve and filter measurements was accurate Resistance matching can also be used but the matching method introduces very large insertion loss E ES RETE SERA S HPB POT 3ESDER fe FHEPFESR PUES Re SEA EUR see SKA Tg GND XE E FEES sabe inh 5 C elo 71 89 1 Tit T2 RFH H GND aspi 50 714 Ae u SMA aN SORRA ON Method of impedance matching this method can measure the insertion loss 42 7 3 RF transformer measurement method 1 PP Pedi 1 a ARpA HHBE Hoste trr BBL fa Seok Eee eae 1235 5 Il RF GHD RF transformer measurement method 1 7 4 RF transformer measurement method 2 2152 APRS a SORT at OOKFR 68 Sp FEB OOK ER ar a GND RF transformer measurement method 2 43 7 5 An antenna measurement method For NWT series of frequency sweep meter you need an additional external bridge for antenna SWR measurements A reference circuit are as follows WESKERIN ANTENNA BORA RF OUT NWT4000 REIN NWT4000 diagram of SWR bridge Because the bridge needs to be a precision device not easy to make yourself you are recommended to buy a finished bridge The finished bridge
40. mode VFO Wattmeter Calculations Impedanzanpassung Graph1 Graph2 Graph3 Graph4 5 6 30 30 Load Graph Save Graph craoncoor e ez es 2 e eer ea e esp Adivate Channel T 2 1T 2 2T 1T 1 2T 1T 2 50 Show Graph Active Active Active Active Active Active 50 As can be seen below the linearity is quite excellent and the noise floor pretty low 20 1 000 0 500 a axis 500 0 MHz 2 4 Blending cursor data into the trace image and saving it It is possible to blend cursor data into the trace image First of all press the numeric key from 1 to 5 on the keybord and click on the frequency position where you want the particulator cursor number to be placed When so done select in the main menu File opeichern als Bild store as image When next screen promt apears enable tickmark Info einblenden and with X and Y position place the information where you want it You may also change letter size with Schriftgroesse When you click on the Bild speichern you can save the image to harddisk incl the data information as shown below File Settings Graph Sweep a Prnt BER Save as PDF Speichern als Bild X Position Y Pasition Exit 35 000000 MHz 21 Graphical Display H G Hz 1 000 2 000 3 000 4 000 label 10 Cursor 1 10 35 000000 MHz Channel 1 82 11dB 20 Cursor 2
41. nuator in the TX path and red trace with 10dB attenuator inserted The bridge output is 20dB below input signal and as there is ample sensitivity in the RX so this 10dB attenuator does not harm Please observe the SWR range can be changed with the drop down list SWR 1 0173 Cursor 3 3988 755960 MHz SWR min 1 02 803 607190MHz SWR max 1 09 4053 685380 MHz Graphical Display 3 000 4 000 12 4 4 SWR Measurements examples fl Graphical Display E GHz 2 000 3 000 4 000 1 500 2 500 3 500 5 0 5 0 4 8 Multiband whip antenna for 5 900 and G5M 1800 4B 4 6 Cursor 1 4 6 4 4 882 9655370 MHz 4 4 4 2 SWR 2 1089 42 iie Cursor 2 2 3 8 951 5019 Hz 3 8 3 6 SWERE 2 99 3 6 3 4 LI 3 4 UMS Cursor 3 gt 32 1753 119 730 3 2 3 0 SWR 1 6583 3 0 2 8 2 8 2 6 Cursor 3 2 6 NN 2073 338070 iir 2 4 SWR 1 6687 2 4 2 2 2 2 2 0 SW min 1 14 1852 477910 MHz 2 0 1 8 AWR max 5 41 3703 967700 1 8 i E 1 6 1 6 1 4 1 4 1 2 1 2 1 0 1 0 SWW X axis 500 0 MHz SWW The GSM900 band between marker 1 and 2 has too low a resonance and then too high SWR but GSM1800 inside marker 3 and 4 quite OK The picture below is a measurement of a UHF low band antenna The resonant point at about 430M SWR about 1 1 The related limit values are to read in the text area Graphical Display Bl x MHz 350 0 400 0 450 0 325 0 375 0 425 0 475 0 5 0 5 0 4 8 4 8
42. orresponding COM port and the allocated port number 13 gt Network adapters Other devices jg Mass Storage Controller b EE Portable Devices 3 Ports COM amp LPT USB Serial Port Print queues k The port number to remember in this case is COM4 When installing the driver on different computers the COM port number will be differ ent In WINNWT software Settings Options select the corresponding COM port and click OK Basic data Sweep SA 1 SA 2 General Calibrationfrequency Math correction only Attenuator Exit Startfrequency Hz 35000000 FA Atten Stopfrequency Hz 4400000000 Channels cn EE DDS Clock HZ 999999800 SWR Iteration NotActive No PLL Math Corr Serial Interface Interface Default Filename Chann 1 Log detsonde1 1 Lin defsondetlin Chann 2 Log defsonde2 Frequencylimits max Sweep Hz 4400000000 Frequency mulitiply 10 Select COM port Choose the correct com port and if successful you will see the hardware firmware version Otherwise check the connection and incorrect settings X Sweepmode Graph Manager VFO Wattmeter Calculations Impedanzanpassung Correct prompt after selection of the correct COM port 14 When using NWT3000 NWT4000 1 or NWT4000 2 you must set frequency multiply to 10 rate in Settings Options Basic_data Sweep SA 1 SA 2
43. ot included 1PCS 6db ATT OPTION not included 1PCS NWT4000 2 The version with improved screening as shown above was purchase from cart100 http www cart100 com Product 40865867643 6 Technical characteristics comparison chart to other products by WUTONG ELECTRONIC The basic parameters type frequency step line att NWT25 EX 2k 25M 1Hz 70dB 12V 0 4A 0 50dB no USB AN NWT70 EX 50 85 1 2 gt 0dB 0 0 7VRM 12V 0 4A 0 50dB yes S NWT70 USB 50k 85M 1Hz 70dB 0 0 7VRM USB 5V 0 4A 0 50dB NO S NWT150 EX 50k 300M gt 70dB 0 0 7VRM 12V 0 4A 0 50dB S NWT150 USB 50k 300M 1Hz gt 0dB 0 0 7VRM USB 5V 0 4A 0 50 8 NO o no NWT500 DDS 50k 500M 1Hz gt 60dB 0 0 7VRM 12V 0 5A 0 50dB NWT500 PLL 50k 500M 1082 gt 6088 0 0 7VRM 12V 0 5A 0 50dB DDS NWT3000 138 3000 gt 50dB USB 5V 0 4A NWT4000 1 138 4400 gt 6598 12V 0 5A M Note All the sweepers input port has maximum power 10dBm not to exceed this power level otherwise it may cause damage to the detection device requiring return to factory for repair Ifa need exist to apply power level of more than 10dBm use external attenuator The system accuracy Frequency accuracy can be calibrated to the smallest step accuracy Frequency stability Power measurement error 2dB The physical characteristics a typical example amongst all types Dimensions L W H 113 5 92 5 30 a t
44. pictures are as follows gro e SWR BRIDGE 750 5MHz 2000 Me ZRB 2 Swr bridge In below diagram is shown a frequency sweep with logarithmic Y scale in sweep mode measuring an antenna connected to the bridge output and a dip seen where the antenna has resonance just like when measuring in the SWR mode X axis 50 0 KA VHF antenna measurement curve with a bridge 44 7 6 The small capacitance inductance measuring method SLOWS CEA ee AL eS SAC 1 Re 1008 1008 gt GHD Testing of unknown L or C 7 7 Amplifier amplitude frequency characteristics measuring method If it is a small power amplifier and the output power is less than 10dBm you can directly connect to the sweeper s RF OUT and IN without to destroy NMW4000 series However as seen before the INPUT saturates for a lesser amplitude so attenuator needed If the power amplifier needs to be used with the directional coupler or attenuator for signal attenuation then enter the attenuators in the detection circuit RF IN During measurements you need to pay attention to the amplifier and load impedance matching For the power amplifiers you need to pay attention to frequency scan range which should not be too broad otherwise the amplifier impedance changes standing wave increase and easy to cause damage DB OK sal Er 7772 for
45. ration File Settings Graph Sweep Measurement Help J gt Kurt gt hfm9 gt Swee 5 2 5 2 K i Organize New folder ingle Sweepmode Grapl B Calculations Impedan E Wome stop Favorites 8 Setu no label CST ne 4 Autodesk 360 Saved data EM eq Hz 35000000 Desktop CH1 6dB and 10dB hfm Channel 1 Channel 2 Calibration H 4399972560 max 87 14dB 35 0000 q Hz 4399972560 Downloads CHI 6dB hfm min 87 14dB 35 00000 Select Channel 1 iCloud Drive CH1 6dB 2xcoax hfm Select Channel 2 Samples 999 iCloud Photos Y lt errupt uS 0 File name CH1 6dB hfm ispl shift o In this case the Select Channel 1 filename is CH1 6dB hfm chosen where the file Store Channel 1 calibration Store Channel 2 calibration name indicates the sweep calibration performed using a 6dB and 4088 attenuator as the NWTWin software facilitates to obtained a superb GB linearity You might have saved the sweep calibration in the default file name defsonde1 hfm gt Kurt gt hfm9 Organize v New folder X Favorites Na Autodesk 360 Coax coupler 1 4GHz hfm Desktop defsondel hfm 8 Downloads defsondellin hfm iCloud Drive defsonde2 hfm iCloud Photos Y lt File name CH1 6dB hfm 10 2 Wattmeter calibration Note For NWT4000 1 and 4000 2 the VFO must be set to the frequency to
46. rk the required function in the Bandwidth selection box A tick in Markerlines toggles all the marker line presentations in the Graphical display on and off Handwidth Markerlines Inverse Bandwidth selection 6dB 60dB and 3dB Q tick the software will display the measured curves 3dB bandwidth and value On above image the value calculated for a 49 55MHz quartz crystal and below for the WiFi filter remark the 60dB on the high side of the curve is way off because the notch is not 6088 deep enough some 564GB relative top level at marker 1 29 x axis 10 0 MHz The measured curve File Settings Graph Sweep Sweepmode m Manager VFO Display of 3dB bandwidth Q value and related Channel 1 54 i5dE m parameters Cursor 4 bandwidth and 60dB bandwidth is similarly 2423 746620 MHz Channel 1 8 5208 MM rectangular coefficient Cursor Pr Markerlines are used to display the dotted line Channel 1 bandwidth in the Graphical Display area for better max 2 514 2431 842400MHz min 74 34dB 2474 964820MHz dB 25 360 MHz recognition of bandwidth parameters te Se din B3aB Inverse is used for trap measurement 12 2450 009090 MHz cdb Inv None 26 9716 fl 2423 746620 MHz f2 2450 662460 MHz B6DdB 49 649 MHz 1 2415 650840 12 2465 299450 MHz Shape Faktor 1 844587 30 2 11 Multi curve d
47. scanning where the number of samples max 9999 are being scanned until final sample to stop scanning is measured 16 Another is the single scanning where only one scanning performed for the number of samples For changing frequency settings scanning numbers number of samples and other parameters you must click on Stop before change settings The scan delay for each point sample of the output frequency are long latency for power measurement Enable the Math Corr Channel1 and Channel2 if enabled Y scale and Shift can only be set provided the scan is stopped Attenuation is not applicable for the NWT4000 models File Settings Graph Sweep Measurement Help Sweepmode Graph Manager VFO Wattmeter Calculations Impedanzanpassung ell ae Continuous Start Freq Hz 35000000 Stop Hz 4400026820 6dB 60dB Shape Single 4 Stepsize Hz 436590 Markerlines Samples pg Inverse Stop lt Interrupt uS o Frequency Zoom o 2x Zoom Profile default Frequenzvervielfachung x 10 defsonde1 hfm defsonde2 hfm axis Scale and Shift Ymax dE 10 Zh1 dB o Ymin dB 90 Zh2 dB 0 r Math Corr Channeli Malh Com Channel Cursor 1 Online Progress Other possible settings to be explained in later sections of this document 17 2 3 Before starting measurement the Instrument should be calibrated It is r
48. se they can be replaced by 6 10 dB attenuators or even higher dB levels but the disadvantage is loss of dynamic range 10 Some component curves tested with the NWT4000 2 equipment Graphical Display a axis 500 0 MHz HP 5086 7051 LPF Graphical Display a axis 500 0 MHz Mini NHP 700 HPF 65 40 50 80 Graphical Display WiFi Filter single Channel Cursor 1 2435 799200 MHz Channel 1 2 70dB Channel 1 max 2 510 2431 789200MHz min 80 554 2363 052000MHz B3dB 25 852 MHz Q 24 28 f1 2424 374400 MHz fm 2437 300200 MHz 2 2450 226000 MHz 27 254 MHz 1 2423 572800 MHz f2 2450 827200 MHz B60dB 49 900 MHz f1 2415 556800 MHz f2 2465 456400 MHz Shape Faktor 1 830882 A axis 500 0 MHz at mlm i a TE a a C C E I EE M X axis BPF24 806A 25 0 MHz 66 REACTEL 1 1 1 15G BPF 40 50 60 80 90 Appendix 2 return loss reflection coefficient voltage standing wave conversion tables RATA VSWR dB VSWR p 17 3910 8013 1 0580 0282 8 7242 7943 1 0515 0251 5 8480 7079 1 0458 0224 4 4194 6310 1 0407 0200 3 5008 5623 1 0382 0178 3 0005 5012 2 0146 4467 2 3229 3981 2 0999 3548 1 9250 3162 1 0322 0158 1 0287 0141 1 0255 0126 1 0227 0112 1 0202 0100 1 7840 2818 1 6709 2512 1 5709 2239 1 4985 1995 1 4326 1778 1 0180 0089 1 0180 0079 1 0143 0071 1 0127
49. t Calibration step UK pdf published same public places as this document The documentation also added as Appendix to this document It also contains a frequency calibration method which works nicely and allows 1KHz setting at 4 4GHz but that stability not maintained over time or temperature changes The frequency calibration is performed at 1GHz and the measured output frequency just entered in the WinNWT DDS PLL clock field as seen previously above on page 12 as 999999800HZ Tricks a possible to use a 100MHz counter as described in said document and the Appendix WinNWT calibration performed as follows Select Channel 1 Calibration and subsequently Logarithmic Channel Lin does not apply for NWT4000 hardware 18 File Settings Graph Sweep Measurement Help im amp Sweep Single Sweepmode Grapl T Channel 1 Calibration Channel 2 Calibration Select Channel 1 Select Channel 2 Sample Lin Store Channel 1 calibration P WD Select Channel Linear or Logarithmic Channel Insert a 40dB attenuator in the Transmit path at the SMA Output and click OK Subsequent you are promptedd to insert a OdB attenuator or select differently a user defined att here stepped down to 6dB The sweep is performed automatic with 9999 samples Setting second dB line Channel 1 A Setting the 40dB line Insert 40dB Attenuator Connect Output of the NWT to the Input or Insert a small at
50. tenuaton Enter Attenuation or set to Default Only when automatic Attenuator is mot present amp EN C cm Then you are asked to save the calibration or not if not then only in force as long the NWT4000 switched on o Saving data in calibrationfile 5ave data now A file name selected here CH1 6dB hfm k Kurt k hfrn9 Search hfm3 Organize New folder yr p Date modified Autodesk 360 CH1 6dB hfm 21 05 2015 01 23 File Desktop CH2 6dB hfm 19 05 2015 00 25 HFM File Downloads Coax coupler 1 4GHz hfm 20 05 2015 17 28 File 19 When accepted by a click on OK the trace is jumping to it correct position 6dB If Y scaling change to 0 and 10dB we see it bang on small image below axis 500 0 MHz If we enter the 40dB att and run a single scan we will see it is flat on 40dB from 35MHz to 4 4GHz If we connect the Output and Input directly and run a sweep we see the degree af compression in the mixer Below 2GHz it is about max 2 5dB and above 2GHz it is reduced to less than 1 dB By clicking on Graph Manager we can maintain the sweep by clikcing on Get and enable tickmark Active Channel 1 and Active as shown Thus we can have up to 6 traces for ch1 on the screen in addtion to the current run sweep Graphical Display GHz 1 000 2 000 3 000 4 000 File Settings Graph Sweep Measurement Help e aa e pm Sweep
51. th Carr serial Interface Interface Default Filename Chann 1 Log defsonde1 Chann 1 Lin defsondeiin Chann 2 Log defsonde2 Frequencylimits max Sweep Hz 900 Frequency mulitiply Input test frequency Frequency reading has changed Frequency calibration complete 58 The user should pay attention to 1 Read the manual at first 2 NWT series digital virtual frequency sweeper is a precision instrument and has been vibration tested splash proof and corrosion resistant 3 Do not short circuit signal the output port as easy to cause internal damage to parts 4 During testing do not use a soldering iron in the device under test 59 Appendix 1 FAQ 1 What is this device used for A sweeper is a frequency characteristic tester it is a test set which test devices for frequency and amplitude characteristics as curves such as test of a LC tank s frequency and amplitude curve 2 What is the difference of a NWT sweeper and a CHINA TYPE CRT sweeper A NWT serial sweeper is a digital sweeper with small frequency steps connected to a PC via USB which performs the calculation of data and present the curves It can act as VFO signal generator as a power meter and are lighter than the old sweeper NWT4000 1 4000 2 can be used as a simple spectrum analyzer CRT sweep 3 NWT sweeper is connected to the PC but non responsive How to know the sweep
52. utput Graphical Display a axis 100 0 MHz 63 SWR bridge test of UHF antenna with three port connector Use a three port connector replacing the SWR bridge and you can test an antenna but only for a qualitative test just a showed above SMA three port 6 Attention when using the Sweep analyzer When connected to the computer and the DUT then you need to pay attention that grounding is good to prevent too high level input to the detection circuitry otherwise it will damage the detecting element 7 Power supply from the USB port is inadequate what to do According to USB2 0 protocol the current is 0 5A which should be enough If the USB power is not enough check USB cable connection is good or change to a high quality USB cable change to a USB 3 0 port current is 0 9A or use an externally powered USB HUB 8 The impedance 15 not matched creating problems how to solve If there is an impedance mismatch power is not 100 transmitted and reflection will cause the measured parameters gain fluctuation insertion loss bandwidth and other parameters being incorrect then you can consider using external transformers or resistors as impedance matching then measure again 9 need to improve the NWT input and output impedance precision how to do Insert an inline attenuator in the instruments input and output terminals attenuator 64 normally of 3 dB will be adequate but if you want to have more preci
53. ypical example Weight 75g a typical example Working temperature 0 to 40 Installation and storage Conditions of use NWT series digital virtual frequency sweepers are using USB or external DC 12V power supply and need to be kept away from strong radiations high power switching power supply high power RF emission Operation temperature 0 40 degrees centigrade Preheating NWT series digital virtual frequency sweepers are most accurate after 30 minutes preheating prior to measurement Storage Clean up the NWT series digital virtual frequency sweeper container filled with desiccant can be stored at ambient temperature 10 to 50 C The basic design Hardware configuration 1 1 Theory WA ATT ATT ATT RF OUT j SIGNAL GENERATOR REIN 2518 11 RF RECEIVE The block diagram only for reference some sweepers does not have att and amplifier NWT4000 2 contains addition circuitry such as two PLL signal generators but does not contain any attenuators or Amplifier 1 2 Hardware connect With the DC 12V and RS232 USB connected external devices are connected to the SMA connectors If the power supply method is via USB as for other type of products you only need to connect the USB plug but the NWT4000 2 uses external DC 12V supply NOTE The supply must we a clean source and voltage can be redu
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