An efficiency-improved inverse class-F2,3 power amplifier design using a novel metamaterial-based harmonic control circuit

Abstract

In this article, an efficiency-improved inverse class- F 2 , 3 (class- F 2 , 3 - 1 ) power amplifier (PA) is designed and implemented using a novel harmonic control circuit (HCC) based on a metamaterial structure. It is proposed to utilize a bi-band, compact microstrip resonant cell (CMRC) inspired by the split ring resonator (SRR) that behaves like an HCC, to control concurrently the second and third harmonics. The main objective is to demonstrate the potentiality and versatility of SRRs for suppression of unwanted harmonics in microwave PAs, shaping voltage and current waveforms, miniaturization (due to subwavelength operation of SRRs), as well as improving the performance of the PA. The recommended architecture is validated by the design, fabrication and testing of a metamaterial-based class- F 2 , 3 - 1 PA utilizing a commercial 10 W GaN-HEMT device. The proposed PA yields a power added efficiency (PAE) of 78 %, a drain efficiency (DE) of 83.3 %, a saturated output power of 41 dBm, and a gain of 16.8 dB at 3.5 GHz.