High-efficiency, high-linearity envelope tracking power amplifier for mobile UHF applications

In next generation mobile military applications, where competing constraints like high linearity and high efficiency is required to allow for energy savings and signal integrity, envelope tracking offers a promising solution. The representative signal used throughout the paper is a 5 MHz single-carrier uplink WCDMA signal with 3.3 dB peak to average power ration (PAPR) centered around 300 MHz. In this paper, we demonstrate high efficiency and linearity at high output power (85W and 150W) using a mobile UHF signal waveform. Efficiencies greater than 60% with at least 20 dB of gain while meeting ACPR requirements were achieved. In the case with 85 W output power, a single push-pull power amplifier was used in conjunction with one drain modulator. While in the 150W output power configuration, a dual modulator approach was used.