Create a FOM Measurement

All Python examples in this topic create a FOM measurement with the following attributes:

Sweep the Source (input) from 1 GHz to 2 GHz
Sweep the Receivers (output) from 2 GHz to 3 GHz
You provide an LO at 1 GHz

import pyvisa as visa

# Change this variable to the address of your instrument
VISA_ADDRESS = 'TCPIP0::localhost::inst0::INSTR'

# Create a connection (session) to the instrument
resourceManager = visa.ResourceManager()
session = resourceManager.open_resource(VISA_ADDRESS)

# Command to preset the instrument and deletes the default trace, measurement, and window
session.write("SYST:FPR")

# Create and turn on window 1
session.write("DISP:WIND1:STAT ON")

# Create a measurement with parameter
session.write("CALC1:MEAS1:DEF 'S21'")

# Displays measurement 1 in window 1 and assigns the next available trace number to the measurement
session.write("DISP:MEAS1:FEED 1")

# Set the start and stop frequencies
session.write("SENS1:FREQ:START 1e9")
session.write("SENS1:FREQ:STOP 2e9")

# Set the receivers to be 2e9 -> 3e9
# See SENS:FOM:RNUM? to find the range number for a specific name
session.write("SENS1:FOM:RANG3:FREQ:OFFS 1e9")

# Turns frequency offset on and enable the freq offset settings

session.write("SENS1:FOM ON")

The following example can be run ONLY on a VNA with FOM (opt S93080A). It uses the internal 2nd source for the fixed LO frequency.

import pyvisa as visa

# Change this variable to the address of your instrument
VISA_ADDRESS = 'TCPIP0::localhost::inst0::INSTR'

# Create a connection (session) to the instrument
resourceManager = visa.ResourceManager()
session = resourceManager.open_resource(VISA_ADDRESS)

# Command to preset the instrument and deletes the default trace, measurement, and window
session.write("SYST:FPR")

# Create and turn on window 1
session.write("DISP:WIND1:STAT ON")

# Create a measurement with parameter
session.write("CALC1:MEAS1:DEF 'S21'")

# Displays measurement 1 in window 1 and assigns the next available trace number to the measurement
session.write("DISP:MEAS1:FEED 1")
session.write("SENS1:FREQ:START 1e9")
session.write("SENS1:FREQ:STOP 2e9")

# set the receivers to be 2e9 -> 3e9
session.write("SENS1:FOM:RANG3:FREQ:OFFS 1e9")

# setup the 2nd source frequencies
session.write("SENS1:FOM:RANG4:COUP 0")
session.write("SENS1:FOM:RANG4:FREQ:START 1e9")
session.write("SENS1:FOM:RANG4:FREQ:STOP 1e9")

# turn off coupling
session.write("SOUR1:POW:COUP 0")

# set LO power to 10dBm
session.write("SOUR1:POW3 10")

# turn ON port 3, our LO signal
session.write("SOUR1:POW3:MODE ON")
session.write("SENS1:FOM:STAT ON")

Create a FOM Measurement

See Also