I am working on the buffer operation @ 2.5GHz and 5GHz. The 1dB compression point is 10dBm. I tried to increase overdrive voltage or gm to improve the P1dB, however, it stops at 8dBm. I do not know how to improve it. Any one can give me some idea. Right now, i am using cascode topology, loading a inductor. Is there any other topology has better linearity?
In fact the nonlinearity of a transistors whichever is bipolar or MOS, depends on mostly operating point.
But...
Every active device has own "optimum operating point" for lowest nonlinearity.To provide lowest nonlinearity from a system, every critical active device should be set in working optimum operating point for less nonlinearity (generally lower power operating condition), however by multiplying these devices the wanted power can be obtained.
So briefly, small amount of power cells should be combined that work at optimum nonlinear condition.