Signal pre-distortion and bandwidth requirements for sequential power amplifiers.

This paper presents a linearization approach for Sequential Power Amplifiers (SPAs) through pre-distortion. The signal characteristics and pre-distortion waveforms for the main and peaking amplifiers are derived mathematically. The pre-distortion approach is validated experimentally by measurement of the reconstructed signals. It is found that the signal characteristics results in an at least three fold bandwidth of the signal. Rules for bandwidth restriction in the individual PA channels are given and the effect of a reduced bandwidth on the average efficiency of SPAs is shown.