ngks79 Post subject: Two peak curve on S22 when measure return loss
Posted: Sun Apr 23, 2006 10:33 pm Lieutenant Joined:
Sun Apr 09, 2006 8:48 pm Posts: 2 Location: Penang Good day
everybody, currently, i doing PA evaluation board measurement.
i just wanna to know why on the return loss of S22 have 2 peak curve
occur? is it because there have 2 resonane circuit on the board? if
yes, where is that 2 resonance circuit forming on the board?
(on output of this board's circuit diagram, there have 2 capacitor placed
in parallel.(one is act as DC bolck and another one is short to ground.).
And so have some capacitive decoupling circuit) Thanks
Top Jeanalmira Post subject: Posted: Tue Jun 13,
2006 10:50 pm General Joined: Tue Mar 15, 2005 11:43
pm Posts: 65 Location: Singapore Hi : I am not very
sure about your question. But I assumed that it's kinda valley on yout
S22 measurement. First, the S22 will go much lower at your operating
frequency which means it has the best return loss in the operating frequency.
Regarding 2nd valleys appearance, I guess it most likely the
resonance frequency appears. It can be caused by the capacitive coupling
somewhere in the circuit. I am not very sure about this either. Please
feel free to correct me if I'm wrong. Cheers, Jean
Top karthik Post subject: Posted: Wed Jun 14, 2006
12:18 am Colonel Joined: Tue Apr 11, 2006 8:13 pm
Posts: 34 Is your PA enclosed in a metal housing? Could there be
cavity modes? Posted
11/12/2012
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