On a reciever, I'm using a MMIC LNA at VHF (2m), and while it's quite clear to
me why I need to match at the amplifier's input -- to minimize VSWR and get as
much of the signal from the antenna into the system -- it's not quite to clear
to me just how important output matching is. The S22 parameters for this LNA
are very close to an open circuit with a little capacitance -- I expect the
output looks back into a drain or something else that's a reasonably decent
current source at RF, and you see that shunted by parasitic capacitances.

So... how important is it that I bother to build a matching network at the
output? (I'll be "outputting" to another ~50 ohm input.) It doesn't really
seem that important, and building something like an L-match with de-Q-ing
resistor drops the gain a couple dB anyway.

I know that for a transmitter output matching is important so that reflections
from poor or non-existant terminations don't blow up the output amplifier, but
for low-level signals as in a receiver it wouldn't seem to matter so much?

Thanks,
---Joel Kolstad