Calculation and Simulation of GaN FET Modulator for Envelope Elimination and Restoration Power Amplifier

The article is devoted to the development of efficiency calculating methodology, consistent with the simulation results for the GaN FET PWM modulator for Envelope Elimination and Restoration Power Amplifier. The proposed analytical methodology for losses accounting includes constant terms (relatively small losses in the gate driver), terms linearly dependent on the supply voltage (also relatively small), terms, quadratically dependent on the output voltage and terms, quadratically dependent on the supply voltage, having the largest absolute value at 1 MHz frequency. This clearly shows that the use of supply voltage step switching can provide a significant gain in average efficiency when amplifying OFDM signals with a large crest factor, the envelope of which has a Rayleigh distribution and is concentrated mainly in the small amplitudes region.