SP Probe vs S11, S22 of the whole circuit.

[ashesh223]

I've the RX and TX circuit of an RFIC. I used the SP probe node at different parts of the circuit example, between the RX/ TX port and the impednace matching circuit, Balauna and the impedance matching circuit.

Now, I'm seeing that the SP probe's S-parameters are higher at the different points, but as a whole circuit, S11 and S22 are getting in range, i.e., -15 to -18 db.

My question is,
Is it important to have the SP Probe, S11 & S22 all need to be below -15?
For the RX and TX section, is it like S11 or S22 that should be in priority?

Thanks in advance!

 

[BigBoss]

Depends on what you wanna see and desire. Drawing a sketch may help us to understand the case.