Question: How to measure matching?

[brian39]

How to measure matching?

There is a matching circuit between SAW filter and LNA on a PCB. when

needs measuring the matching of this circuit . How to measure ? It works

GSM900 band , i think only power to measure after SAW filter and before

LNA with Spectrum Analyzer, is right? Pls give me a correct way.

 

[mr_ghz]

Hi brian39,

To measure the correct matching, you have to use a network analyzer connected after your SAW filter and to measure the S11 parameter.
This gives you the return loss (reflected power) which should be as small as possible (better than -10dB is often OK). The phase information can be used to optimize the matching network.
If you don't use the phase info and you don't have a network analyzer you can also measure the return loss with a directional coupler, a frequency generator and a spectrum analyzer or powermeter.

Bye

 

[brian39]

Thank u !

/ Warning#9 - No thanks at elektroda! /