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 <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$68-86 \text{GHz}$</tex> with a gain of over 25 dB, a <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$P_{\text{SAT }}$</tex> 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 <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$(P_{\text{SAT }}&gt;30 \text{dBm})$</tex> and wideband (bandwidth <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$&gt;15 \text{GHz})$</tex> PAs in the E-band.