The Research On GaN-based Ultra-wideband Power Amplifier

Since the Federal Communications Commission(FCC)released the ultra-wideband(UWB)technical standard,UWB wireless communications have officially entered the field of vision.UWB technology has more and more investment in scientific research due to its advantages of high transmission rate,low power loss and strong anti-interference ability.Power amplifiers are an indispensable part of the RF front-end.How to achieve UWB and high-efficiency power amplifiers is part of this study.On the other hand,if the wideband transmitter contains the operating frequency band of other devices,the signal of the wideband transmitter will interfere with the RF front end operating at the same frequency or in a wide frequency band.In order to prevent the radio frequency interference from UWB equipment,protect the normal operation of the remaining equipment,and finally realize the UWB power amplifier with integrated notch,this thesis mainly makes the following research and design:1 Introduced the broadband design technology of UWB power amplifier,and discussed the design method of UWB power amplifier.Analysis and research on the design indicators of UWB power amplifiers.At the same time,according to the method of improving the efficiency of power amplifier,the high-efficiency power amplifier bandwidth expansion technology is compared and analyzed.Finally,a high-efficiency UWB power amplifier is designed in the third chapter.This power amplifier works at 0.8-3GHz,the output power and highest drain.efficiency reached 42.6dBm and 68.9% respectively.The average output power is greater than 40 dBm and the average efficiency is greater than 53%.2 For the interference from the UWB power amplifier frequency range with the working frequency band of other equipments,this thesis proposes an UWB power with integrated notch by studying the matching circuit of UWB power amplifier and combining the design theory of band-pass and band-stop filters.The amplifier,for wideband transmitters to interfere with WiFi and Bluetooth,integrates stopband rejection in the 0.8-3GHz operating band.The centerband of the stopband is 2.4GHz,which effectively suppresses the transmit power of 2.4GHz and avoids interference problems.The test results show that the UWB power amplifier has a minimum output power of 23 dBm and a passband output power of 39.6-42.6dBm.The stop band suppression effect is remarkable,and it can be well compatible with WLAN and so on.3 Based on the integrated notch UWB power amplifier,this thesis has made further research and proposed a notch reconfigurable UWB power amplifier.This power amplifier can adjust the center frequency of the notch by changing the varactor bias according to the specific application scenario.It is suitable for communication environment with different frequency suppression requirements for transmitters.It has features of strong compatibility,continuous adjustment and good suppression effect.Based on the design theory of UWB power amplifier,this thesis deeply explores the matching network design method of broadband power amplifier,and designs three kinds of UWB power amplifiers using CREE CGH40010 F transistor.The working efficiency of these broadband power amplifiers is more than 50%,the typical output power is 10 W.A solution for the broadband transmitter compatibility problem is proposed,and the design method of the UWB power amplifier with integrated notch is deeply analyzed.