Compact Load Network Having a Controlled Electrical Length for Doherty Power Amplifier

Kuhyeon Kwon; Woojin Choi; Jaekyung Shin; Yifei Chen; Young Chan Choi; Sooncheol Bae; Hyeongjin Jeon; Jiwon Hwang; Seungmin Woo; Young Yun Woo; Kang-Yoon Lee; Keum Cheol Hwang; Youngoo Yang

doi:10.1109/ACCESS.2022.3187087

IEEE Access (Jan 2022)

Compact Load Network Having a Controlled Electrical Length for Doherty Power Amplifier

Kuhyeon Kwon,
Woojin Choi,
Jaekyung Shin,
Yifei Chen,
Young Chan Choi,
Sooncheol Bae,
Hyeongjin Jeon,
Jiwon Hwang,
Seungmin Woo,
Young Yun Woo,
Kang-Yoon Lee,
Keum Cheol Hwang,
Youngoo Yang

Affiliations

Kuhyeon Kwon: ORCiD; Department of Electrical and Computer Engineering, Sungkyunkwan University, Suwon, South Korea
Woojin Choi: ORCiD; Department of Electrical and Computer Engineering, Sungkyunkwan University, Suwon, South Korea
Jaekyung Shin: ORCiD; Department of Electrical and Computer Engineering, Sungkyunkwan University, Suwon, South Korea
Yifei Chen: Department of Electrical and Computer Engineering, Sungkyunkwan University, Suwon, South Korea
Young Chan Choi: ORCiD; Department of Electrical and Computer Engineering, Sungkyunkwan University, Suwon, South Korea
Sooncheol Bae: Department of Electrical and Computer Engineering, Sungkyunkwan University, Suwon, South Korea
Hyeongjin Jeon: Department of Electrical and Computer Engineering, Sungkyunkwan University, Suwon, South Korea
Jiwon Hwang: ORCiD; Department of Electrical and Computer Engineering, Sungkyunkwan University, Suwon, South Korea
Seungmin Woo: Department of Electrical and Computer Engineering, Sungkyunkwan University, Suwon, South Korea
Young Yun Woo: Samsung Electronics Company Ltd., Suwon, South Korea
Kang-Yoon Lee: ORCiD; Department of Electrical and Computer Engineering, Sungkyunkwan University, Suwon, South Korea
Keum Cheol Hwang: ORCiD; Department of Electrical and Computer Engineering, Sungkyunkwan University, Suwon, South Korea
Youngoo Yang: ORCiD; Department of Electrical and Computer Engineering, Sungkyunkwan University, Suwon, South Korea

DOI: https://doi.org/10.1109/ACCESS.2022.3187087
Journal volume & issue: Vol. 10
pp. 70440 – 70446

Abstract

Read online

The load network of the carrier amplifier for the conventional Doherty power amplifier (DPA) consists of an impedance matching circuit, an offset line, and a $\lambda $ /4 transmission line (TL), so that the overall electrical length of the network can easily exceed the minimum value of 90°. Then for appropriate impedance modulation, it should be 270° with an additional 180°. This excessive electrical length of the load matching network limits the bandwidth at either the low-power or peak-power level. In this paper, a compact quasi-lumped $\lambda $ /4 impedance transformer (ITF) having simultaneous multiple functions of impedance matching and load impedance modulation with a controlled electrical length of 90° is presented. The proposed load network includes the internal components of the transistor, the simplest high-pass network using a shunt inductor, and a low-pass L-C network. Using the optimized value of the shunt inductor, the electrical length of the load network can be adjusted to 90°, while other components are accordingly changed to match the optimum load impedance. To verify the proposed load network, a DPA was designed and implemented using 10 W GaN-HEMTs for both carrier and peaking amplifiers. Using a 5G New Radio (NR) signal with signal bandwidth of 100 MHz and peak-to-average power ratio (PAPR) of 7.8 dB, a drain efficiency (DE) of 47 - 54.2%, and adjacent channel leakage power ratio (ACLR) of −27.9 - −23 dBc were achieved at an average output power level of 35.8 - 36.3 dBm for the frequency band of 3.4 - 3.8 GHz.

Published in IEEE Access

ISSN: 2169-3536 (Online)
Publisher: IEEE
Country of publisher: United States
LCC subjects: Technology: Electrical engineering. Electronics. Nuclear engineering
Website: https://ieeexplore.ieee.org/xpl/RecentIssue.jsp?punumber=6287639

About the journal

Abstract

Keywords