gain match
What is "power match" & "gain match" ?
Where can I find the detailed illustration ?
Thank you very much.
Usually the gain match is done at the input of a PA to get the required gain.
Power match is done in interstage and load matching, and they are more impedance transformations to get the required output power.
http://rfwireless.rell.com/pdfs/AN_721_D.pdf
In power amplifier is useful to do power match. If you do gain match (and so conjugatelly match at the input and output port) it is possible to see that you dont get the P1dB of the device. If you want the P1dB you have to do a power match. See Cripps for techniques to power match the amplifier
regards
Am I right for my thought,
Gain match on PA input => using conjugate match
Power match on PA ouput => match according to Load pull data for max power
Please advice. Thanks.
Yes, this is the way.
For PA matching you have to do both. If you are doing only power matching is possible the gain of your PA to be below to the required gain. More than this, PA input match is very important for linear PAs, otherwise you get gain enhancement (different gain for different input power levels).
Yes, matching can make the device unstable. Plotting the stability circles can help to avoid this. Usually conjugate matching will create these problems. Also by matching both input and output this complicates the situation more as the effective input and output reflection coefficients change.
The other point, yes gain match on input, power on output. The S12 is usually low enough so that the input match does not have to be readjusted when the power match is applied. Note the stability point though.
Brendan