High-Efficiency Power Amplifier Featuring a Csrr-Like Multi-Harmonic Tuning Network

Abstract

This paper presents a high-efficiency power amplifier (PA) designed for sub- 6 GHz 5 G applications, featuring an advanced multi-harmonic tuning network (HTN) inspired by complementary split-ring resonator (CSRR) geometries. The proposed PA architecture enables synchronized refinement of second- and third-harmonic impedance conditions, significantly enhancing both efficiency and linearity. By embedding the CSRRbased multi-HTN within the output matching network, precise harmonic termination is achieved, leading to improved waveform shaping. Implemented with a 10 W GaN HEMT transistor, the PA operates over the <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$3.3-3.7 \text{GHz}$</tex> band, achieving a drain efficiency of <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$64 \%-75.9 \%$</tex> and a peak output power of <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$38.2-42.5 \text{dBm}$</tex> at saturation. These results highlight the effectiveness of the proposed design for next-generation wireless communication systems.