High-Power Ka/Ku Dual-Wideband GaN Power Amplifier With High Input Isolation and Transformer-Combined Load Design

• Published in: IEEE microwave and wireless components letters Vol. 31; no. 1; pp. 49 - 51
• Main Authors: Tao, Hongqi, Wang, Jiawen, Wang, Yi, Ma, Dongdong, Cao, Hanzhang, Wu, Wen, Huang, Tongde
• Format: Journal Article
• Language: English
• Published: IEEE 01.01.2021
• Subjects: Broadband; Dual band; dual-band amplifiers; Gallium nitride; GaN monolithic microwave integrated circuit (MMICs); high power; Impedance; Loading; power amplifiers (PAs); Power generation; Transistors; Wireless communication
• ISSN: 1531-1309; 1558-1764
• DOI: 10.1109/LMWC.2020.3032569

A high-power dual-wideband GaN power amplifier (PA), which features a filter-based input diplexer and a transformer-combined load, has been proposed in this study. The diplexer realized by low-/high-pass filters presents a high dual-band isolation (>15 dB) and can arbitrarily select the location of the two widely spaced bands. Instead of using a diplexer in the output matching network (OMN), a transformer-combined load design has been proposed to simplify the OMN design. The transformer can effectively minimize the loading effect from each other branch, but does not obviously influence the optimal output impedance. The designed PA can operate in either <inline-formula> <tex-math notation="LaTeX">Ku </tex-math></inline-formula>-or <inline-formula> <tex-math notation="LaTeX">Ka </tex-math></inline-formula>-band mode. In the <inline-formula> <tex-math notation="LaTeX">Ku </tex-math></inline-formula>-band mode, an output power more than 40 dBm and a power-added efficiency (PAE) more than 35% are obtained at 13.5-18 GHz. In the <inline-formula> <tex-math notation="LaTeX">Ka </tex-math></inline-formula>-band mode, the output power more than 30 dBm and the PAE more than 17.5% are obtained at 33-38 GHz. The gain in the <inline-formula> <tex-math notation="LaTeX">Ku </tex-math></inline-formula>- and <inline-formula> <tex-math notation="LaTeX">Ka </tex-math></inline-formula>-band modes is more than 30 and 13 dB, respectively.