1.7/2.6 GHz high-efficiency concurrent dual-band power amplifier with dual-band harmonic wave controlled transformer

A 1.7/2.6 GHz high-efficiency concurrent dual-band power amplifier (DBPA) with a dual-band harmonic wave controlled transformer is demonstrated. The proposed dual-band transformer, which transfers the fundamental and the second harmonic impedances of each frequency, is directly transmission line implemented with the help of an optimisation algorithm. The measurement results show that the proposed DBPA has performances of 70 and 64% power added efficiency with an 11 dB gain and a 41 dBm output power at 1.7 and 2.6 GHz, respectively. Its average drain efficiency is more than 42% and the adjacent channel leakage ratios are lower than -46 dBc at both frequencies with the digital predistortion adjustment for a 5 MHz WCDMA signal input.