Reseach On Wide Band Gap Semiconductor High Efficiency Power Amplifier

As a third-generation semiconductors,the GaN high mobility transistor(GaN HEMT) is the most representative material in the wide bandgap semiconductors.GaN HEMT has many advantages such as high two-dimensional electron gas(2DEG) density,high breakdown voltage,high power density,high electron saturation drift velocity,it is very suitable for the production of high-power, high-efficiency, high-frequency devices.As we all know,switch mode power amplifier has been a certain degree of recognition in the design of high-efficiency power amplifier,such as class-E,class-F and class-F-1.Research is constantly on their depth.In this paper, there are discussed that the principle of class-E,class-F,class-F-1 power amplifier and designing methods.For performance and characteristics of GaN HEMT, works and innovations carried out as follows:Based on domestic technology GaN HEMT devices,and for the GaN HEMT has a large parasitic capacitance Cds of the output,design a Ku-band 13.7GHz~14.2GHz Class-E power amplifier.The transistor gate width is 400μm.Measured output power is greater than 30 dBm, drain efficiency is greater than 40% and peak drain efficiency is greater than 46%.For characteristics that class-AB power amplifier has godd linearity but poor efficiency, and class-F power amplifier has high efficiency but poor linearity,based on independent design and develop GaN HEMT by a unit,designed an class AB/inverse-F multi-mode power amplifier,working frequency S-band 2.7GHz~3.5GHz.Measured output power is greater than 36 dBm, drain efficiency is greater than 55% and peak drain efficiency is greater than 72%.By adjusting the gate bias voltage of the power amplifier can control the operating state in class-AB or class-F-1 separately. In wireless communication systems, according to the actual situation,adjust the gate bias voltage to make it work in class AB operation state when need the power amplifiers providing high linearity;adjust the gate bias voltage to make it work in class F-1 operation state when need the power amplifiers providing high efficiency.This paper has guide meaning of designing high efficiency power amplifier with wide band gap semiconductor.