A 225 Watt, 1.8-2.7 GHz Broadband Doherty Power Amplifier with Zero-Phase Shift Peaking Amplifier

Abstract

A new method for designing a broadband Doherty power amplifier has been developed. Using the proposed method, the dominant parasitic components of the power devices are effectively compensated. The peaking device is directly connected to the Doherty power combining node without using the quarter wavelength delay line of the conventional Doherty amplifier. The proposed method is applied to a dual input 225 W peak output power Doherty amplifier. The measured average drain efficiencies (DE) are 42.7-47.6% using a 10 MHz bandwidth 7.5 dB peak-to-average power ratio (PAPR) test signal whilst maintaining better than −50 dBc adjacent channel power ratio (ACPR) after linearization.