Highly Efficient Power Amplifier Based on Harmonic-Controlled Matching Network

This study presents a highly efficient power amplifier (PA) based on a compact harmonic-controlled matching network (HCMN). The proposed HCMN with three-stage band-stop matching network (BMN) can simultaneously match to the optimum power matching impedance at fundamental and second harmonic frequencies and suppress second harmonic signals caused by nonlinearity without an additional filter. For verification, the proposed PA was designed, fabricated, and measured. The implemented PA was a compact size of 53.3 mm x 40 mm. The measurement results show that the output power is 36-38.6 dBm, and the drain efficiency (DE) is 68.2%-74.3% in the frequency range of 2.9-3.3 GHz. The proposed PA also achieves the low second harmonic level of -44.1 to -67.1 dBc in the frequency range of 2.9-3.3 GHz.