Distributed matching network design for broadband power amplifiers

This paper presents a distributed matching network design method for the realization of broadband high-efficiency power amplifiers (PAs). Source-pull and load-pull simulations are employed to determine the optimal input and output impedances of a GaN transistor across 0.3-2.3 GHz. With the optimal source and load impedances across the desired bandwidth, the proposed method can be used to compute and optimize the distributed matching network directly without requiring close-form initial element values. This method will enable a PA to achieve high power added efficiency (PAE) over an ultra-wide bandwidth. A low-pass matching network is applied to implement the optimal impedances over the band. The measured results of the PA indicate a power gain of better than 10 dB and a typical output power of 20 W. The PAE is 59%-69% across a 153% bandwidth. The measurement demonstrates the excellence of the proposed method.