Re: Predistortion Amp
Well, If I were doing it I would build a circuit with two connectors for attaching a coaxial delay line to, and in the lab I would input my modulation to the predistorter, pass the resulting signal thru the transmitter, and look at 2tone 3rd order products on a spectrum analyzer. I would then tweek the delay line length until they were nulled over the biggest portion of their bandwidth.
In practical circuits, you would probably have both amplitude, phase, and delay line lengths to fool around width until you got it right.
If you want to calculate such a thing, you would need a non-linear simulation program that could simulate both the predistorter and transmit amplifier non-linearities accurately, and you would do the same as above.
If you are up on FFT processing in something like Mathcad or Matlab, you could simulate it all to a first order there, modeling the predistorter like a nonlinear diode I-V curve, etc. Would not be very accurate though.