Design of a Compact GaN Power Amplifier With High Efficiency and Beyond Decade Bandwidth

• Published in: IEEE microwave and wireless components letters Vol. 32; no. 12; pp. 1439 - 1442
• Main Authors: Zhou, Han, Perez-Cisneros, Jose-Ramon, Langborn, Bjorn, Eriksson, Thomas, Fager, Christian
• Format: Journal Article
• Language: English
• Published: IEEE 01.12.2022
• Subjects: decade bandwidt; Decade bandwidth; Energy efficiency; GaN; HEMT; Inductors; Integrated circuit modeling; power amplifier (PA); Prototypes; Transistors; Transmission line measurements; Wideband; wideband matching networks; Wireless communication
• ISSN: 1531-1309; 1558-1764; 1558-1764
• DOI: 10.1109/LMWC.2022.3186805

This letter presents a power amplifier (PA) design and network synthesis approach to achieve wideband and efficient performance with a very compact circuit size. A design method is presented in detail to convert a canonical filter-based high-order matching network to the proposed matching configuration with transistor parasitic and packaged elements absorption, and a compact passive network footprint. As a proof of concept, a prototype GaN HEMT PA is implemented. Starting from a fourth-order output network filter, the inductances and capacitance of the filter elements are re-organized to model, and thus absorb the output parasitics of the transistor, leading to a compact footprint with only four transmission lines. The measured results show that the prototype PA achieves an output power of 41.9-44.3 dBm and a 55%-74% drain efficiency, over a record-high decade bandwidth (0.35-3.55 GHz).