Research Of All Solid-state RF Power Supply Based On GaN Wide Bandgap Semiconductor Devices

Power devices based on silicon materials are limited by the forbidden band width of silicon materials,and their performance is increasingly difficult to meet the requirements of high operating frequency,high efficiency and high-power density of solid-state RF power supplies.Gallium Nitride?GaN?,a wide-bandgap semiconductor material,has superior physical properties than silicon materials,and its power devices have lower on-resistance and smaller input-output capacitance.These features enable GaN devices to have faster switching speeds.The higher the switching frequency,the smaller the volume of passive components?such as capacitors,inductors,and transformers?in the system,resulting in the overall volume of the solid-state RF power system.On the other hand,the loss of the power device can be reduced,thereby simplifying or even eliminating the heat sink and reducing the volume of the system.Therefore,GaN power devices are more suitable for solid-state RF power systems,improving system efficiency and power density.This paper focuses on the design and fabrication of all solid-state RF power supplies using GaN power devices.Firstly,the physical properties of GaN semiconductor materials,the performance of GaN devices and their advantages in high frequency power converters are analyzed.Using the Class-E power converter topology,Transphorm's cascode GaN device TPH3202PD is used as the power switching device.The component parameters of each functional circuit module are derived according to the design requirements,which lays a theoretical foundation for the simulation and prototype production of the design scheme.basis.Then PSPICE is used to simulate the solid-state RF power supply main circuit system based on TPH3202PD device,and the simulation circuit parameters are optimized to meet the design specifications,thus verifying the feasibility of the scheme.According to the simulation results,an all-solid-state RF power supply prototype with a switching frequency of 4MHz and adjustable power is designed and manufactured.Through the design and optimization of the prototype circuit,the efficiency of the prototype reaches 96.9%,and the power density can reach 227.8×10^-3 W/cm³.At the same time,the two prototypes based on GaN devices are used to solve the problem that the output power of a single solid-state RF power module cannot meet the high-power demand through the power synthesis method.Secondly,using the same circuit topology,a comparative experimental study was carried out using IXYS's RF Si MOSFET device IXFH6N100F.Under the same working conditions,the prototype based on the IXFH6N100F device has an efficiency of 78.5% and a power density of 71.3×10^-3 W/cm³,which proves that the GaN device can greatly improve the efficiency and power density of the solid-state RF power supply.