Linearity of X-band class-E power amplifiers in EER operation

Multifunctional RF front ends need to transmit different types of signals while maintaining efficiency and signal quality. This paper addresses efficient transmitter power amplifiers (PAs) for signals with varying peak-to-average ratios, requiring simultaneous efficiency and linearity. Linearity characterization of class-E high-efficiency PAs operating in envelope elimination and restoration (EER) mode is discussed. Specifically, a 67%-efficient 10-GHz MESFET PA is characterized in terms of its AM-AM, AM-PM conversion and intermodulation products. Measurements of intermodulation distortion are compared with harmonic-balance simulations using TriQuint's Own Model provided by the device manufacturer. It is shown experimentally and through simulations that the amplifier in the EER mode has improved linearity while maintaining high-efficiency operation.