Design and optimization of spoof surface plasmon polaritons based multi-octave power amplifier using PSO algorithm

Abstract

In this article, we explore how spoof surface plasmon polaritons (SSPP) theory can be applied to the design of active radio frequency (RF) power amplifiers (PAs). This work utilizes SSPP structures for the design of both input and output matching networks for a multi-octave PA. In order to perform proper impedance matching, the properties of SSPP unit structures are presented and analyzed. A description of the performance of the initial PA has been provided and discussed. Additionally, particle swarm optimization (PSO) is used to further enhance the performance of the PA circuit. In comparison with an embedded gradient method in a commercial tool, the PSO method results in a better optimization result. The fabricated PA is tested and the results indicate that in the frequency range of 0.5 GHz to 2.9 GHz, it achieves an output power of 40.4 dBm to 41.2 dBm, a power added efficiency of 60.5–65%, and an output gain exceeding 10 dB. Compared to recent work, the multi-octave PA in this work broadens bandwidth while maintaining high output power and PAE. To further verify the linearity of the SSPP-based PA, digital pre-distortion (DPD) is implemented. As a result of the DPD, the linearity of the SSPP PA was greatly enhanced.