Design of a wideband highly efficient GaN HEMT power amplifier for multiband applications

A distributed basic matching network (MN) designed method that can achieve multioctave bandwidth and highly efficient power amplifier (PA) for multiband applications is presented in this letter. The distributed network unit with a left-rotating T-type structure is employed to construct the wideband MN, whose topology and circuit parameters are acquired through optimization. Finally, the impedance realized by the designed MN falls into the target impedance region obtained by using multi-harmonic bilateral pull technique in the desired frequency band. For the proof of the method, a broadband highly efficient PA has been designed, fabricated, and measured using commercialized GaN high electron mobility transistors (HEMT). The measured results show that the implemented PA achieves a bandwidth of 137.8% from 0.7 to 3.8 GHz. The drain efficiency is between 59% and 70% with an output power of greater than 39 dBm and a gain ranging from 9 to 12.1 dB.