The Researches On Key Technology Of Microwave Solid-state Power-combining

The research and application trend of microwave technology is developing to higher frequency.The following basic characteristics is belong to microwave.The range of microwave frequency is broad,that is from 300 MHz to 300 GHz,which can meet the requirements of high-speed data transmissions and high-capacity communications.Microwave power amplifier is a necessary key technology in the field of microwave technology.At present,all kinds of power amplifiers are still in a state of development.From the perspective of system application a single microwave power amplifier,especially a power amplifier that working at higher frequencies,is difficult to meet the requirements of the output power of the system.Therefore,the microwave power combining technologies become the necessary technical means to improve the system output power.At present,the development of microwave monolithic integrated circuits in China get rapid development,but the output power of monolithic microwave monolithic integrated circuits(MMICs)is still greatly limited by the development of processes and the semiconductors.The researches of high frequency power combining technologies,especially which at the frequency of millimeter wave become particularly important.The first chapter gives a brief overview of microwave technology and power combining technologies at home and abroad.The second chapter introduces the basic principles of solid-state power synthesis.The third chapter mainly discusses the non-resonant circuit power combining in waveguide within W-band and introduces the design methods and results verifications of four-way power combining,two-way power combining and twelve-way power combining.From the test results,it can be seen that the dual-probe power-combining back-to-back network has an insertion loss of less than 2.52 dB and a return loss greater than 13.7 d B in 90 GHz-95 GHz.The insert loss of four-way ring loops network is better than 2.56 dB,the return loss of which is greater than 12 dB from 90 GHz to 95 GHz.The fourth chapter mainly introduces the power combiner of wideband planar circuits,and gives out the theory and design method of multi-channel Wilkinson power combiner and multi-channel T-shaped power combiner.Finally,the results are verified.From the test results,it can be seen that the two-way Wilkinson power combiner network has insertion loss better than 2 dB from 8 GHz to 16 GHz and return loss greater than 10 d B in the same frequency range.The four-channel Wilkinson power combiner network has an insertion loss better than 4 d B in 8.1 GHz-17.5 GHz,and return loss greater than 9 dB in the same frequency range.The insertion loss of four-way T-shaped power-combining network are better than 4 dB and return loss greater than 9 dB from 8 GHz to 18 GHz.The fifth chapter and the sixth chapter are additional chapters.Aiming at the need of modern microwave systems,a novel broadband directional coupler and a new type of ultra-wideband band pass filter are proposed in the fourth chapter and the fifth chapter respectively.Microwave directional coupler is widely used as a microwave device in various microwave systems.Conventional directional couplers require a larger spatial volume to achieve a wider bandwidth.In order to solve this problem,chapter five presents a novel miniaturized full Ka band directional coupler based on a novel aperture array.The broadband,good in-band coupling flat-ness and excellent return loss are achieved by using the proposed novel aperture array in the common broad wall of two paralleled waveguides.For verification purpose,a prototype of the proposed directional coupler has been designed,fabricated and measured.The experimental results show that the return loss and isolation of the proposed coupler are better than 28 and 30 dB,respectively,and coupling strength varies from-20.35 to-19.23 d B over the full waveguide bandwidth.The length of the coupling region is only 8.5 mm.As a kind of traditional microwave devices,microwave ultra-wideband band pass filters are widely used in microwave systems.A novel planar ultra-wideband(UWB)bandpass filter(BPF)using radial-stub-loaded resonator is proposed,where the resonator consists of three radial stubs,one located in the middle and two symmetrically at both sides.This radial-stub-loaded structure situates the first four resonant modes in the UWB passband(3.1~10.6 GHz)and makes the fifth resonant mode far away from this passband.To enhance the coupling degree,two interdigital coupled feed lines are utilized in this UWB filter.Finally,a UWB BPF with wide upper-stopband and sharp upper rejection skirt has been realized and its design steps have been also presented.The measured and full-wave simulated results of the proposed filter are in good agreement.