My question is whether I need interstage filtering between two 900MHz
saturated amplifiers in an FM (FSK) transmitter. One stage is the driver
amplifier outputting about +15dBm, and the other stage is the PA, outputting
+30dBm. I want to keep parts count and insertion losses down, but do I need
such filtering to keep mixing products to a minimum, or is the standard TX
output bandpass filter all that I need in an FM system?

Many Thanks!

Mike