Hi Tom,

That's a most informative post; thanks.

At work we have a design that uses these:
http://datasheets.maxim-ic.com/en/ds...71-MAX2373.pdf -- right after an
antenna and a matching network. Too bad that Maxim didn't choose to provide
any clues on what antenna impedance it would like to see for the lowest
nose -- I just matched it to 50ohms. (And truth be told, we have a slightly
wretched antenna to work with anyway... the main reason it's workable at all
is due to the antenna designer -- and outside firm -- sticking a 160ohm
resistor in parallel across the input leads.)

---Joel