基于GaN器件的固态射频电源应用研究

随着电力电子技术的发展,射频电源由电子管电源发展成现在的晶体管射频电源。氮化镓GaN(gallium nitride)作为第三代宽禁带半导体材料的典型代表,具有宽禁带、高临界击穿场强、高电子饱和漂移速度以及高导通的AlGaN/GaN异质结二维电子气2DEG(two-dimensional electrons gas)等优点。GaN功率器件与硅(Si)功率器件相比,具有导通阻抗低,输入、输出电容小等特性,这些特性使得GaN功率器件高开关速度、低损耗。在E类功率射频电源的基础上,采用GaN功率器件设计制作了一款开关频率为4 MHz、功率可调的全固态射频电源实验样机。通过电路的设计和优化,样机的输出功率为21.4 W时,效率达到了96.7%;同时,采用专为射频电源生产的Si功率器件替换掉样机上的GaN器件,实验数据验证了GaN器件开关速度快、损耗低,可大幅度提高射频电源的效率。

Research on Applications of Solid-state RF Power Supply Based on GaN Devices

With the development of power electronics technology, RF power has been developed from the tube power supply to the current transistor RF power supply. Gallium nitride (GaN) is a typical representative of the third generation of wide bandgap semiconductor materials due to its excellent properties such as wide gap, high critical electric field, high electron saturation drift velocity and highly conductive AlGaN/GaN heterojunction two-dimensional electrons gas (2DEG). Compared with silicon (Si) power devices, GaN power devices have lower on-resistance and smaller input and output capacitance. These characteristics make GaN power devices show high switching speed and low loss.Based on the E-type power RF power supply, a 4 MHz, power-adjustable all-solid-state RF power supply experimental prototype was designed and manufactured using GaN power devices. Through the design and optimization of the circuit, the efficiency of the prototype is 96.7% when the output power of the prototype is 21.4 W. And the GaN device on the prototype is replaced by the Si power device that produces the RF power supply. The experimental data verified that the GaN device has a fast switching speed and low loss, which can greatly improve the efficiency of the RF power supply.