Three-way Doherty power amplifier for efficient amplification of wideband signals with extended PAPR

Abstract

This paper deals with three-way Doherty power amplifiers (3W-DPAs) as a viable solution for wideband high-efficiency amplification of multi-standard signals. A methodology is presented to design a 3W-DPA with maximal bandwidth. This methodology was successfully applied to design a 30-W GaN 3W-DPA with a measured average drain efficiency of 55% at an output back-off of up to 9 dB, over the frequency range of 0.73-0.98 GHz. The 3W-DPA was driven with a four-carrier wideband code division multiple access (WCMDA) signal with 20-MHz bandwidth and 11.7-dB peak-to-average power ratio (PAPR) at 830 MHz. Power added efficiencies of 47% was measured at 32 dBm average output power, with an adjacent channel leakage ratio (ACLR) of -48 dBc after linearization.