Envelope Distortion in EER Power Amplifier under VSWR Variation

Envelope elimination and restoration technique transmitters can amplify signals with a high peak-to-average power ratio while achieving an efficiency of 90% or more. However, there are many factors that can distort the signal. This article shows that one of these factors is the untuned load of the RF power amplifier, which causes distortion of the envelope voltage at the output of the modulation power supply. Using the example of an OFDM signal with QAM-16, it has been demonstrated that the BER performance can deteriorate by one or two orders.