A Compact Wideband Low-loss On-chip Power Combiner for High-efficiency GaN mm-wave Power Amplifiers

This article presents a generalized, compact, wideband, low-loss four-way on-chip distributed power combiner designed for high-power and high-efficiency mm-wave power amplifiers (PAs). The measured results of the proposed combiner show a significant improvement in the matching bandwidth compared to the traditional distributed matching networks (DMNs) while maintaining the same overall area. As a demonstrator, a four-stage, four-way power-combining E-band
PA covering 68 - 86 GHz with a gain of over 25 dB, a PSAT of 33.3 dBm, and an associated PAE of 21.9% is presented. To the authors’ best knowledge, this work achieves the highest PAE and gain for high-power (PSAT > 30 dBm) and wideband (bandwidth > 15 GHz) PAs in the E-band.