Minimum Power Input Control for Class-E Amplifier Using Depletion-Mode Gallium Nitride High Electron Mobility Transistor

You-Chen Weng,Chih-Chiang Wu,Wei-Hua Chieng,Edward Chang

doi:10.3390/en14082302

You-Chen Weng, Chih-Chiang Wu + Show 2 more

Open Access

https://doi.org/10.3390/en14082302

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Journal: Energies	Publication Date: Apr 19, 2021
Citations: 11	License type: CC BY 4.0

Affiliation: National Yang Ming Chiao Tung University

Abstract

In this study, we implemented a depletion (D)-mode gallium nitride high electron mobility transistor (GaN HEMT, which has the advantage of having no body diode) in a class-E amplifier. Instead of applying a zero voltage switching control, which requires high frequency sampling at a high voltage (>600 V), we developed an innovative control method called the minimum power input control. The output of this minimum power input control can be presented in simple empirical equations allowing the optimal power transfer efficiency for 6.78 MHz resonant wireless power transfer (WPT). In order to reduce the switching loss, a gate drive design for the D-mode GaN HEMT, which is highly influential for the reliability of the resonant WPT, was also produced and described here for circuit designers.

Highlights

Class-E power amplifiers perform well in wireless power transfer (WPT) applications [1] because of their simple topology as well as high efficiency under zero voltage switching (ZVS) and zero voltage derivative switching (ZVDS) conditions
The charge pump gate drive presented by Ishibashi [20] is useful for driving the depletion (D)-mode GaN HEMT in a class-E amplifier
Based on the equivalent circuit, the characteristics of a fabricated D-mode GaN HEMT and the parameter of a compatible charge pump gate driver for the D-mode GaN HEMT were included in analyses to improve practicability

Summary

Introduction

Class-E power amplifiers perform well in wireless power transfer (WPT) applications [1] because of their simple topology as well as high efficiency under zero voltage switching (ZVS) and zero voltage derivative switching (ZVDS) conditions. Based on the equivalent circuit, the characteristics of a fabricated D-mode GaN HEMT and the parameter of a compatible charge pump gate driver for the D-mode GaN HEMT were included in analyses to improve practicability. The fabrication conditions and parameters of the D-mode GaN HEMT are introduced in Section 2.1 in order to explain the design for a gate drive compatible with wireless power transfer.

Materials and Methods

Design of Charge Pump Gate Drive for D-Mode GaN HEMT

Class-E Amplifier Circuit

Maximum Power Transfer