Design of high-efficiency compact Doherty power amplifier with harmonics suppression and wide operation frequency band

Abstract

A novel Doherty power amplifier (DPA) using a novel power divider with harmonics suppression and size reduction is proposed. The designed power divider suppresses eight unwanted harmonics. Moreover, the proposed divider reduces the circuit size and only occupies 41% in comparison with conventional divider. In the DPA structure two elliptical resonators are used instead of two long λ/4 transmission lines to size reduction. The AB and C classes power amplifiers are exploited as main and auxiliary amplifiers. The proposed DPA has good specifications such as wide bandwidth from 500 MHz to 1900 MHz with a fractional bandwidth of 116%. The DE, PAE and gain parameters of the designed DPA are 76%, 71%, and 19 dB, respectively.