Some ideas I hear about RF amps are to decouple each stage with a series resistor and a cap across the stage. The resistor is chosen to drop a small voltage and the cap to have a low reactance. Next, use a low noise device in the first stage and also separate the stages across the board to avoid positive feedback. Another trick is to align any tuned inductors at 90 degree angles to minimize feedback. Also use double sided PB board to provide a good ground plane. Another trick is to shift the phase 180 degrees with a unity gain stage to further reduce feedback if necessary depending on layout. Is there some limit to the overall gain of a small signal RF amp, or does it depend on the noise generated by the circuit itself? I don't have much experience with low noise devices. What devices are recommended (transistors, op- amps)?
-Bill