Discrete gate bias modulation of a class-G modulated RF power amplifier

In this paper the combination of class-G supply modulation with discrete level gate bias modulation is investigated. Previous work with class-G supply modulation revealed that the supply voltage switching causes sharp discontinuities in gain and phase of the modulated baseband signal. Now it is found that either the gain or phase discontinuity can be compensated by applying dynamic gate modulation synchronously with the class-G modulation. Furthermore, reducing the gain discontinuity allows generating the control signal for the supply modulator by an envelope power detector. This enables to realize a highly efficient class-G system as a simple plug-in solution for the standard single-input single-output (SISO) PAs in a digital predistortion linearized system.