How to measure IQ mismatch using a Vector Network Analyzer?

[neo]

iq mismatch

How to measure IQ mismatch using a Vector Network Analyzer?
I have a Agilent 89600.
Any tips, thanks

 

[vfone]

what is iq mismatch

Agilent 89600 is not a Vector Network Analyzer (VNA). Is a Vector Signal Analyzer (VSA).

I/Q gain imbalance results in an asymmetric constellation, and I/Q offset errors result in a constellation whose center is offset from the reference center.

The best way to verify most I/Q impairments is to magnify the scale of the constellation and look at the EVM metrics.

 

[neo]

i q mismatch measurement

i noticed some datasheet plots a static I/Q mismatch data, e.g., the static phase error shows that 3sigma phase error is less than 0.5°, or something like that, how can they do that?

 

[henryhd]

i q mismatch

But EVM can be affected by any other factor,such as nonlinear...IQ unbanlance result in DC offset ,and can be shown in constellation..

Added after 3 minutes:

it can be got by 9dB surplus compaired to P_1dB for nonlinear component

Added after 2 minutes:

if you want EVM less than 0.5°