A Broadband CMOS Doherty Power Amplifier with Asymmetric-Transformer-based Output Matching Network

Abstract

This paper presents a 60-GHz Doherty power amplifier with asymmetric-transformer-based output matching network in 65-nm CMOS process. To achieve a high output-power-transfer efficiency with a high reliability, the proposed Doherty output matching network is implemented with fully-EM simulated transformer with a high-Q custom capacitor. The output matching parameters of the main and auxiliary PA are asymmetrically tuned to simultaneously match the optimum load-impedance at a high power. As a result, the PA achieves a peak gain of 12.7 dB and a 3-dB bandwidth of 55 to 69 GHz. The PA also achieves a peak P1dB of 16.3 dBm, a peak PAEldB of 19.6 % and a peak PAE6-dBOBO of 8 % in the overall frequency band. The PA is implemented with a compact size area of 0.21 mm2 and the dc quiescent power consumption is only 104.4 mW.