rf transceiver measurement question

[saw86]

Hello everyone

I have LNA mixer ıf amplifier and ıf filter on the pcb and I want to measure signal power,return loss, inertion loss on the pcb what is the best solution for this. Should I put directional coupler every spot or any other method to measure signal

Thanks in advance

 

[jiripolivka]

Depends upon what you really need. Do you need to measure the indicated parameters on each of the components, or he complete receiver?

To start, you should know the design parameters of each of the indicated components. All should have a common impedance for testing, e.g. 50 Ohms. The IF filter has its insertion loss and return loss, the IF amplifier will exhibit a gain in addition to it. Mixers have three ports to define the return loss, and a conversion loss under a nominal LO input.

The best solution for all above tests is to have a test setup capable to measure these parameters over the frequency band(s) of interest. Directional couplers are good in reflectometers that indicate return loss over a band, but one needs a signal generator or a sweeper as well as a calibrated wideband detector or power meter.