High-Efficiency Power Amplifier with a Multiharmonic Tuning Network

One high-efficiency power amplifier (PA) with a novel multiharmonic tuning (HT) network is presented. The second and third harmonic impedances are simultaneously controlled with a simple offset double-sided parallel strip line (DSPSL)-based output-matching network. Based on the above strategy, high PA efficiency can be achieved by mapping the fundamental and harmonic impedances to the optimum positions, while PA linearity can be improved through third harmonic suppression. The offset DSPSL is used to realize the transmission lines with extremely high impedance ratio in the multiharmonic trapping circuit. For demonstration, a PA using Cree CGH40010 GaN HEMT is designed with up to third harmonic control. The fabricated PA achieves peak power-added efficiency (PAE) and drain efficiency (DE) of 78.2% and 82.3%, respectively, while delivering 39.2-dBm output power at 1.8 GHz. Besides, the output third-order intercept point (OIP3) of the PA has an improvement of 3 dB.