Gan High Efficiency Power Amplifier Design Technology Research

With the development of wireless communication systems, the power amplifier’s performance of efficiency and power has become increasingly demanding. High-efficiency power amplifier is becoming a research hotspot in recent years. The third-generation semiconductor material, wide bandgap GaN HEMT, is very suitable for application in high-efficiency electronic devices. Because it has some advantages of big power density, high breakdown voltage and high electron saturation drift velocity.This article briefly describes GaN HEMT devices and the design basis of power amplifiers. Under this background, the following work is taken:1、This paper analyse the designed principles of Class F amplifier. With the company of Cree CGH40010GaN HEMT, a class F power amplifer is designed, which design target is that the center frequency is2.14GHz and the bandwidth is100MHz. the1/4λ short-circuit branch line which is series-connected with the drain and the1/12λ open-circuit branch line from the output circuit can implement the second harmonic short-circuit and the third harmonic open-circuit, thus approximate square-wave voltage waveform and a half sine wave current waveform can be seen at the output of the transistor. The test results show that the maximum efficiency of the amplifier is up to55.47%. These efforts to improve power amplifier efficiency for wireless communication systems provide some help.2、Through the simulation methods and design techniques of defect ground structure (DGS) is analysed, The results show that the cycle asymmetric spiral DGS structure can achieve the inhibition of the second and fourth harmonic and realize the breakover of third and fifth harmonic. Therefore it can be applied to the inverse class F power amplifier input-output circuit, in order to achieve the inverse class F power amplifier miniaturization and high performance.3、A inverse class F power amplifier based on the cycle asymmetric spiral DGS structure is designed, in order to solve the shortcomings of narrow bandwidth. This amplifier’s center frequency is2.14GHz. With in the bandwidth of300MHz, the power added efficiency is greater than71%and its maximum is78.3%. The test results show that the maximum efficiency of the amplifier is up to58.87%. Verified by measuring, the results is better than the traditional inverse class F power amplifier. The experimental results show that the results have important guiding significance to improve the bandwidth of the inverse class F power amplifier.