Concurrent dual-band power amplifier with second harmonic controlled by gate and drain bias circuit

A concurrent second harmonic controlled 1.7/2.14GHz dual-band GaN power amplifier (PA) for base station is designed, fabricated and tested in this paper. The influence of 2nd harmonic on PAE (Power Added Efficiency) for dual-band PA is discussed. A novel bias line structure is proposed to control the 2nd harmonic in the gate and drain side for dual-band operation. To the best knowledge of authors, it is the first time that 2nd harmonic is considered in the input of a dual-band PA. The structure of harmonic control circuit is realized by the bias lines at gate and drain integrated with resonators for dual-band operation. By applying this structure, the complexity of this amplifier is reduced to minimize the loss of the circuit, and also the dimension of the PA. The finial PA circuit measured PAE is 58.4% with 36.7 dBm maximum output power at 1.7 GHz, and 59.9% PAE with 39.7 dBm output power at 2.14 GHz. The gain at maximum PAE is 9.8 dB and 10.5 dB at 1.7 and 2.14GHz, respectively.