A high-power wideband digital Doherty power amplifier for Wi-Fi 6

doi:10.3969/j.issn.1000-5641.2026.02.004

Abstract

Abstract:

In this study, we propose a class-G high-power broadband digital Doherty power amplifier (DPA) for Wi-Fi 6 applications, operating from 5.125 to 7.125 GHz. The proposed DPA is based on a polar architecture that combines Doherty load modulation with class-G amplification to achieve optimal efficiency, and it is fabricated using a 22-nm complementary metal-oxide-semiconductor (CMOS) process. At the output, a λ/4 transmission line-integrated transformer-based combining network minimizes insertion loss and enables watt-level output with an 8-bit amplitude modulation module. The results of post-layout simulations showed a saturated output power of 29 dBm, a peak power-added efficiency (PAE) of 23%, and 6- and 12-dB back-off PAEs of 22% and 13%, respectively. For an 80-MHz 256-quadrature amplitude modulation (256-QAM) signal, the DPA delivers an average output power of 21 dBm with an error vector magnitude (EVM) of –30 dB. It also achieves a phase error of less than 6° across a 2-GHz bandwidth via a compact fully differential broadband quadrature input network with an 8-bit phase modulation module. Thus, the proposed DPA meets the wideband, high-efficiency and high-linearity requirements of Wi-Fi 6 systems.

Key words: digital power amplifier, Doherty, power combiner, power back-off (PBO) efficiency, Wi-Fi 6

CLC Number:

TN432

Kangjie ZHAO, Can LIU, Runxi ZHANG. A high-power wideband digital Doherty power amplifier for Wi-Fi 6[J]. J* E* C* N* U* N* S*, 2026, 2026(2): 35-47.

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Table 1

References 14

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Reference	Process/ nm	Architecture	Freq./GHz	PSat/ dBm	Peak SE/%	PBO SE	P_avg/dBm	Modulation	EVM/dB	VDD/V
This work	22	Digital IQ Doherty	5.125~7.125	29	23	22% @6dB/ 13% @12dB	21 @256-QAM/ 21.8 @64-QAM	64-QAM/ 256-QAM	–30	0.9/3.3
JSSC 2020^[3]	28	Digital Polar	5~6	27	–	26% @6dB	21 @1024-QAM	1024-QAM	–35	1.4
ISSCC 2020^[4]	55	Analog	2.4/5~6	28.5/29	–	–	20	1024-QAM	–35	3.3
ISSCC 2022^[5]	40	Digital IQ	5~7.125	28	28.5	15% @6dB	17.8 @5G 1024-QAM	1024-QAM	–35	1.2
ISSCC 2024^[11]	28	Digital IQ	0.8~2.4	28.3	41	–	24.2 @64-QAM 22.5 @64-QAM	64-QAM	–28	1.1/2.2

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