Analysis and Design of Highly Efficient Wideband RF-Input Sequential Load Modulated Balanced Power Amplifier

Research output: Journal Publications and Reviews (RGC: 21, 22, 62)21_Publication in refereed journalpeer-review

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Author(s)

  • Jingzhou Pang
  • Yue Li
  • Meng Li
  • Yikang Zhang
  • Zhijiang Dai
  • Anding Zhu

Related Research Unit(s)

Detail(s)

Original languageEnglish
Article number8966560
Pages (from-to)1741-1753
Journal / PublicationIEEE Transactions on Microwave Theory and Techniques
Volume68
Issue number5
Online published22 Jan 2020
Publication statusPublished - May 2020

Abstract

The analysis and design of an RF-input sequential load modulated balanced power amplifier (SLMBA) are presented in this article. Unlike the existing LMBAs, in this new configuration, an over-driven class-B amplifier is used as the carrier amplifier while the balanced PA pair is biased in class-C mode to serve as the peaking amplifier. It is illustrated that the sequential operation greatly extends the high-efficiency power range and enables the proposed SLMBA to achieve high back-off efficiency across a wide bandwidth. An RF-input SLMBA at 3.05-3.55-GHz band using commercial GaN transistors is designed and implemented to validate the proposed architecture. The fabricated SLMBA attains a measured 9.5-10.3-dB gain and 42.3-43.7-dBm saturated power. Drain efficiency of 50.9-64.9/46.8-60.7/43.2-51.4% is achieved at 6-/8-/10-dB output power back-off within the designed bandwidth. By changing the bias condition of the carrier device, higher than 49.1% drain efficiency can be obtained within the 12.8-dB output power range at 3.3 GHz. When driven by a 40-MHz orthogonal frequency-division multiplexing (OFDM) signal with 8-dB peak-to-average power ratio (PAPR), the proposed SLMBA achieves adjacent channel leakage ratio (ACLR) better than -25 dBc with an average efficiency of 63.2% without digital predistortion (DPD). When excited by a ten-carrier 200-MHz OFDM signal with 10-dB PAPR, the average efficiency can reach 48.2% and -43.9-dBc ACLR can be obtained after DPD.

Research Area(s)

  • 5G, High efficiency, Load modulated balanced power amplifier (LMBA), Sequential power amplifier (SPA), Wideband

Citation Format(s)

Analysis and Design of Highly Efficient Wideband RF-Input Sequential Load Modulated Balanced Power Amplifier. / Pang, Jingzhou; Li, Yue; Li, Meng; Zhang, Yikang; Zhou, Xin Yu; Dai, Zhijiang; Zhu, Anding.

In: IEEE Transactions on Microwave Theory and Techniques, Vol. 68, No. 5, 8966560, 05.2020, p. 1741-1753.

Research output: Journal Publications and Reviews (RGC: 21, 22, 62)21_Publication in refereed journalpeer-review