Author(s): Cheng, PS (Cheng, Peisen); Wang, Q (Wang, Quan); Li, W (Li, Wei); Jia, YT (Jia, Yeting); Liu, ZC (Liu, Zhichao); Feng, C (Feng, Chun); Jiang, LJ (Jiang, Lijuan); Xiao, HL (Xiao, Hongling); Wang, XL (Wang, Xiaoliang)

Source: ELECTRONICS Volume: 10 Issue: 3 Article Number: 311 DOI: 10.3390/electronics10030311 Published: FEB 2021

Abstract: This paper proposes a broadband asymmetrical monolithic microwave integrated circuit (MMIC) Doherty power amplifier (DPA) using 0.25-mu m gallium-nitride process with a compact chip size of 2.37 x 1.86 mm(2) for 5G communication. It adopts an unequal Wilkinson's power divider with a ratio of 2.5:1, where 71.5% of the total power is transferred to the main amplifier for higher gain. Different input matching networks are used to offset phase difference while completing impedance conversion. This design also applies a novel topology to solve the problem of large impedance transformer ratio (ITR) in conventional DPA, and it optimizes the ITR from 4:1 to 2:1 for wider band. Moreover, most of the components of the DPA including power divider and matching networks use lumped inductors and capacitors instead of long transmission line (TL) for a smaller space area. The whole circuit is designed and simulated using Agilent's advanced design system (ADS). The simulated small-signal gain of DPA is 8-11 dB and the saturation output power is more than 39.5 dBm with 800 MHz band from 4.5 GHz to 5.3 GHz. At 6-dB output power back-off, the DPA demonstrates 38-41.3% power added efficiency (PAE), whereas 44-54% PAE is achieved at saturation power.

Accession Number: WOS:000614954500001

eISSN: 2079-9292

Full Text: https://www.mdpi.com/2079-9292/10/3/311