A Compact 8-to-16 GHz GaN Nonuniform Distributed PA With Double Feeding Line Matching Structure Presenting 43.2% Average PAE

This letter focuses on improving power added efficiency (PAE) of high-power nonuniform distributed power amplifier (NDPA). A double feeding line matching (DFLM) structure is proposed, where a double-T-type and a <tex-math notation="LaTeX">π </tex-math>-type DFLM networks are inserted into drain transmission-line (TL) and gate TL of classical designs, respectively. These optimize load/source impedance for each transistor, improving the output power and PAE. The NPDA monolithic microwave integrated circuit (MMIC) is fabricated with a commercial 0.25- <tex-math notation="LaTeX">μ </tex-math>m gallium nitride (GaN) process. The measurement results show that the proposed NDPA achieves output power of 37.6-to-40.2 dBm, and PAE of 37.6%-to-50.3% at 8-to-16 GHz, with the chip area of merely 3.5 mm2. The proposed NPDA outperforms the state-of-the-art broadband power amplifier (PA) in PAE with a much smaller chip area.