A Broadband Fully Integrated Power Amplifier Using Waveform Shaping Multi-Resonance Harmonic Matching Network

Abstract

In this article, we propose a broadband fully integrated power amplifier (PA) using a waveform shaping harmonic matching network. A comprehensive theory is developed for the proposed multi-resonance harmonic matching network to derive design criteria for achieving wide bandwidth, low insertion loss, and optimum load impedances in the second- and third-harmonic frequency bands. Furthermore, it is shown that this network can be realized using a lower total inductance compared to a standard bandpass network which is an important feature in reducing chip area and fabrication cost. A fully integrated PA prototype is implemented using a 250-nm GaN-on-SiC process with 28-V supply. The PA provides 33.9-36.1dBm output power (at 2-3dB gain compression), 42-51% drain efficiency (DE), 38-48% power-added efficiency (PAE), and 10-12.2dB power gain, across 4.0-6.0GHz. The output-power 1-dB bandwidth is 3.6-5.6GHz (44.5%). For a 64-QAM signal with 8dB peak-to-average power ratio (PAPR) at 5.0GHz, the PA can provide 30.2dBm average output power and 32% average PAE with RMS error vector magnitude (EVM) of -34.0/-32.4/-28.4dB (2.0/2.4/3.8%) for 50/100/200MHz modulation bandwidth, without using digital predistortion (DPD). The maximum average output power and average PAE, under the linearity constraint EVM