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Create and Cal Noise Figure with External Switches

This example program creates a Noise Figure that uses external switches, then calibrates the measurement.

This VBScript program can be run as a macro in the VNA. To do this, copy the code into a text editor file such as Notepad and save on the VNA hard drive as NF.vbs. Learn how to setup and run the macro.

See the Noise figure commands.

See Other SCPI Example Programs

' This section gets the VNA application

' starts the scpi parser, and presets the VNA

windowNum = 1

channelNum = 1

set pna=CreateObject("AgilentPNA835x.Application")

set scpi = pna.ScpiStringParser

' Create noise figure measurement

scpi.Parse "SYST:FPR"

scpi.Parse "DISP:WIND ON"

'Put only 1 trace S11 before the cal, because the switch needs to start in the S-parameter position:

scpi.Parse "CALC:CUST:DEF 'MyMeas', 'Noise Figure Cold Source', 'S11'"

scpi.Parse "DISPlay:WINDow1:TRACe1:FEED 'MyMeas'"

scpi.Parse "CALC:PAR:SEL 'MyMeas'"

pullEcal = "85052D"

'pullEcal = "N4691D ECal MY59410340"

 

' configure channel

ConfigureChannel

ConfigureNoiseSettings

' perform calibration

SetupCalAttributes_Insertable

FinishCalibration

 

' ----- Support subroutines ------

' Configure noise channel

sub ConfigureChannel

  scpi.Parse "SENS:FREQ:START 1GHz"

  scpi.Parse "SENS:FREQ:STOP 2.5GHz"

  scpi.Parse "SENS:SWEEP:POINTS 21"

  scpi.Parse "SENS:BWID 1.0E3"

  scpi.Parse "SENS:SWE:DWEL:SDEL .2"

  'increase the power for the Ecal during calibration

  scpi.Parse "SOUR:POW -15"

  

end sub

' Configure noise-specific channel settings

sub ConfigureNoiseSettings

  scpi.Parse "SENS:NOIS:REC NORM"     'Use std PNA receiver

  scpi.Parse "SENS:NOIS:AVER:STAT ON"   ' turn averaging ON

  scpi.Parse "SENS:NOIS:AVER 100"            ' noise averaging       

  scpi.Parse "SENS:NOIS:BWID 1.2MHz"        ' noise bandwidth

  scpi.Parse "SENS:NOIS:TEMP:AMB 301"   ' ambient temperature, in Kelvin

'The two next SCPI commands are here to assign pin to drive external switches

scpi.Parse "CONTrol:CHANnel:INTerface:CONTrol:STATE 1"

scpi.Parse "SENSe:NOISe:CONTrol:HANDler:PIN22:FUNCtion 'NF_SOURCE'"

scpi.Parse "SENSe:NOISe:CONTrol:HANDler:PIN23:FUNCtion 'NF_SOURCE_INVERTED'"

end sub

 

sub   SetupCalAttributes_Insertable

   scpi.Parse "SENS:CORR:COLL:GUID:CONN:PORT1  'APC 3.5 female'"

   scpi.Parse "SENS:CORR:COLL:GUID:CONN:PORT2  'APC 3.5 female'"

   scpi.Parse "SENS:CORR:COLL:GUID:CKIT:PORT1 '" & pullEcal & "'"  ' port 1 calkit

   scpi.Parse "SENS:CORR:COLL:GUID:CKIT:PORT2 '" & pullEcal & "'"  ' port 2 calkit

 

  scpi.Parse "SENS:NOISE:CAL:METHOD 'Scalar'"

 'Only power Meter can be use here as we are using STD receiver

  scpi.Parse "SENS:NOISE:CAL:RMEThod 'PowerMeter'"

   scpi.Parse "SENS:CORR:COLL:GUID:INIT"

end sub

 

sub FinishCalibration

' Build the connection list and acquire the calibration

   steps = scpi.Parse("SENS:CORR:COLL:GUID:STEPS?")

   for i = 1 to steps

     str = scpi.Parse("SENS:CORR:COLL:GUID:DESC? " & i)

     msgbox  str

     scpi.Parse "SENS:CORR:COLL:GUID:ACQ STAN" & i

   next

   scpi.Parse "SENS:CORR:COLL:GUID:SAVE 0"

 

   scpi.Parse "SOUR:POW -30"

   wscript.echo "Calibration complete"

end sub