Research On Design Technique Of Ku-band GaN Class-E Power Amplifier

The rapid development of information industry has put forward a higher request of smaller size、higher frequency and broader band-width of power amplifier.GaN has a character of broad wide band gap, high thermal conductivity, high saturated electron velocity and higher critical breakdown electric field,which provides GaN HEMT a big output power density, high breakdown voltage and high input/output impedance.These advantages make GaN HEMT a broad prospects in high frequency, high temperature,high efficiency and broadband high power device applications. The ideal efficiency of class E power amplifier can reach 100%. At low radio frequencies class E power amplifier has a higher efficiency and better linearity than other types of power amplifier.However, class E power amplifier seldom works under high frequency before.With the development of semiconductor technology, the class E power amplifier is implemented in higher and higher frequency.Due to the need for low power consumption in communication, aerospace, etc, the realization of the class E power amplifier under the higher frequency became the research hot spot.In this thesis, the efficiency and wide-band characteristics of GaN class E power and internal-matched method are studied. At first, On account of the higher the parasitic capacitance of GaN HEMT devices, using the compensation of the microstrip structure to reduce the influence of parasitic parameters in the Ku band class E power amplifier design.Then, designing a 400 um grid wide GaN class E power amplifier using compensation microstrip.The output power is measured to be more than 30 dBm,the power Gain is greater than 7dB,and drain efficiency greater than 40% in 13.7GHz~14.2GHz. On the basis of this early work,I designs the 4-way power synthesis power amplifier using 2.4 mm wide grid GaN HEMT.The simulation results show that the power amplifier in power added efficiency is more than 43%, the output power is greater than 45 dBm in 13.2~14.2GHz when the input power is 39 dBm.The Peak PAE was 44%, and the maximum output power greater than 40 w,maximum power density is greater than 4w/mm. Using high K material and bondwire to make the whole amplifier 17.2 mm * 22 mm in size, meeting the requirements of the miniaturization.