Efficient Linearization of Microwave Power Amplifiers

摘要

The growing use of multiple-carrier, complex (multi-level, multi- phase), spectrally efficient waveforms such as quadrature-amplitude-modulation (QAM) and code division multiple access (CDMA) in communication systems is placing a growing demand on the power efficiency and linearity of microwave power amplifiers. Continuing reliance on vacuum electronics amplifiers such as traveling-wave tube amplifiers (TWTA) in space-based transponders and ground terminals requires tube designers to constantly develop new techniques to improve the efficiency and linearity of devices. To satisfy performance requirements, there is an increasing trend of designers incorporating preor post-linearization modules with the power amplifiers to improve overall system efficiency and linearity.1 Signal predistortion is a simple and effective linearization technique that has been used successfully for both solid-state power amplifiers (SSPA) and TWTAs.