Performance evaluations of microwave power amplifiers with single‐ and multi‐carrier quadrature amplitude modulations

This article presents the performance evaluations of microwave power amplifiers (PAs) for different kinds of quadrature amplitude modulation (QAM) schemes including π/4‐DQPSK and 16‐QAM for single‐carrier formats and orthogonal frequency division multiplexing (OFDM) for multi‐carrier configuration, by using the time‐domain signal processing technique and the hybrid Volterra analysis. The influences due to various peak‐to‐average power ratios (PAPRs) of the modulation signals for the PA performances such as output powers, adjacent channel power ratios (ACPRs), and error vector magnitudes (EVMs) are shown with experimental verifications. A figure‐of‐merit of PAs based on linearity and efficiency is presented to establish a criterion for choosing the best working condition.