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arXiv · 2512.05846

Design of a High-Power and High-Efficiency GaN-HEMT VCO Based on an Inverse Class-F Amplifier

Junlin Mi·Ruinan Fan·Liping Yan·Yuhao Feng·Changjun Liu
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Abstract

This letter proposes a high-power and high-efficiency GaN-HEMT voltage-controlled oscillator. The VCO consists of a coupled-line coupler, an inverse class-F amplifier, and a novel frequency-tunable stepped-impedance resonator. Using a harmonic control circuit and a parasitic parameter compensation circuit, the power amplifier operates in the inverse class-F state to achieve high efficiency. The feedback circuit uses a coupled-line coupler instead of the traditional coupling capacitor to control feedback power precisely. The measurement results show that the VCO with an oscillation frequency of 2.41-2.45 GHz achieves a maximum conversion efficiency of 74.5% at 2.44 GHz and an output power of 40.2 dBm. It is a candidate for the microwave source in a wireless power transmission system.

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Junlin Mi, Ruinan Fan, Liping Yan, Yuhao Feng, Changjun Liu. 2025-12-05. Design of a High-Power and High-Efficiency GaN-HEMT VCO Based on an Inverse Class-F Amplifier. https://doi.org/10.1109/lmwt.2024.3514739

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