An AM-PM Compensation of Cross-Coupled Capacitance Neutralization Technique in a Differential Power Amplifier

Takuma TORII
Masaomi TSURU

Publication
IEICE TRANSACTIONS on Electronics   Vol.E105-C    No.10    pp.492-500
Publication Date: 2022/10/01
Publicized: 2022/04/11
Online ISSN: 1745-1353
DOI: 10.1587/transele.2022MMP0003
Type of Manuscript: Special Section PAPER (Special Section on Microwave and Millimeter-Wave Technologies)
Category: 
Keyword: 
power amplifiers,  GaN,  phase compensation,  K-band,  

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Summary: 
In this study, AM-PM compensation of the cross-coupled capacitance neutralization technique is discussed. Cgd neutralization leads to AM-PM compensation of a power amplifier with negligible change of AM-AM characteristics. AM-PM compensation was confirmed via circuit analysis and measurements. The formulation analysis showed that AM-PM compensation can be derived via gm variation against input power with capacitance neutralization. A differential power amplifier with capacitance neutralization was fabricated with GaN high-electron-mobility transistors. The AM-PM characteristic of the fabricated differential power amplifier was measured at 17.7 GHz. It showed AM-PM reduction of 22° at compared to a single-phase power amplifier without capacitance neutralization at output power of 35 dBm.