Create and Cal a VMC Measurement


The following example program sets up a 1-stage mixer, then performs a VMC calibration using an N4691-60004 ECal module.

By removing the comments ( ' ) at the start of the BLUE code, it can also do the following:

See Also

Converter Object

VMCType Object

Example - Perform a VMC Mixer Characterization ONLY

 

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

dim NASWEPT: NASWEPT = 0

dim NAFIXED: NAFIXED = 1

dim LOWSIDE: LOWSIDE = 0

dim HIGHSIDE: HIGHSIDE = 1

dim MIXEROUT: MIXEROUT = 2

dim pna: set pna = CreateObject("AgilentPNA835x.application")

pna.reset

' Create a VMC channel

' Other valid measurement strings are: "S11", and "S22"

pna.CreateCustomMeasurementEx 1, "Vector Mixer/Converter","VC21",1

' Setup Stimulus

dim chan: set chan = pna.activechannel

dim cv: set cv = chan.Converter

chan.NumberOfPoints = 11

chan.IFBandwidth = 1000

cv.InputStartFrequency = 3.6e9

cv.InputStopFrequency = 3.9e9

cv.LOFixedFrequency(1) =  1e9

cv.LOPower(1) = 10

cv.OutputSideband = LOWSIDE

cv.Calculate MIXEROUT

cv.LOName(1) =  "Port 3"

cv.Apply()

DoBasicVMCCal (chan.channelNumber)

 

sub DoBasicVMCCal( channel )

dim myMixerCharFile: myMixerCharFile = "C:\Program Files(x86)\Keysight\Network Analyzer\Documents\MyMixerS2P.s2p"

 

' construct a VMC calibration object

dim calmanager: set calmanager = pna.GetCalManager

dim guidedCal: set guidedCal = calmanager.CreateCustomCalEx( channel )

dim vmc: set vmc = guidedCal.CustomCalConfiguration

 

' Initialize the cal object.

' Choose to respect or ignore the Preference: Cal: Auto Save to User Calset

' if you set this true, the behavior will be dependent on the setting

' of the preference.

dim useCalSetPreference: useCalSetPreference = false

vmc.Initialize channel, useCalSetPreference

 

' Define the DUT connectors and kits at ports 1 and 2 of the VNA

vmc.ConnectorType (1) = "APC 3.5 female"

vmc.ConnectorType (2) = "APC 3.5 male"

' Use Mechanical cal kits

vmc.CalKitType(1) = "85033D/E"

vmc.CalKitType(2) = "85033D/E"

' To use an ECal module instead, comment out the above two lines

' and uncomment the appropriate lines below:

' Your ECal module must already be connected

' via USB to the VNA.

' vmc.CalKitType(1) = "N4691-60004 ECal"

' vmc.CalKitType(2) = "N4691-60004 ECal"

' Non-factory characterizations are specified as follows:

' vmc.CalKitType(1) = "N4691-60004 User 1 ECal"

' When two or more ECal modules with the same model number are connected

' also specify the serial number as follows:

' vmc.CalKitType(1) = "N4691-60004 ECal 01234"

' When Disk Memory ECal user characterizations are used,

' specify both the User char and the serial number as follows:

' vmc.CalKitType(1) = "N4691-60004 MyDskChar ECal 01234"

'

MsgBox("Cal kits defined for Ports 1 and 2")

 

' By default, VMC requires the measurement of a Calibration Mixer.

' To determine the conversion loss of the calmixer, the cal wizard

' will add a step to perform a 1 port cal at the output of the mixer.

' The following commands opt to perform the mixer

' characterization using a cal kit.

' Do both characterization and full 2-port cal

vmc.CharacterizeMixerOnly = False

' Define the DUT connectors for the output of the characterization mixer

' Use (logical) Port 3. If it is already used by the DUT,

' then specify port 4.

vmc.ConnectorType(3) = "APC 3.5 male"

' Specify the mechanical cal kit for port 3

vmc.CalKitType(3) = "85033D/E"

 

' To avoid performing the 1-port cal steps, provide the wizard with a

' mixer characterization file. Uncomment the following two lines to

' specify the characterization file.  This is an .S2P file.

' vmc.CharFileName = myMixerCharFile  ' this file will be read

' vmc.LoadCharFromFile = true     

 

' By default, auto orientation of the ecal module is performed

' Uncomment the following lines to manually orient the ecal

' vmc.autoorient = false

' for 2-port portion, ecal port A connected to VNA port 1

' vmc.EcalOrientation2Port(1) ="A1,B2"

' for mixer char, ecal port A connected to cal mixer output

' vmc.EcalOrientation1Port(1) = "A1"   

         

' the main calibration loop

' a description for the connection instructions is read

' and then the standard is acquired

dim steps, connectionPrompt

steps = vmc.GenerateSteps

wscript.echo "Number of Steps = " + cstr(steps)

if (steps > 0)  then  ' otherwise an error condition occurred

for i = 1 to steps

 connectionPrompt = vmc.GetStepDescription( i )

 wscript.echo connectionPrompt

vmc.AcquireStep( i )

next

vmc.GenerateErrorTerms

end if

end sub