Research On High Power Microwave Pulse Compression Of X-band Five-fold Helically Corrugated Waveguide

The further development of high-power microwave technology has made higher and higher requirements for high-power microwave signal sources.How to obtain a microwave signal with a sufficiently large power capacity and a sufficiently high power amplitude has become a relatively bottleneck in the development of microwave technology.Microwave pulse compression has become an increasingly important research direction.The passive high-power microwave pulse compression system based on the helically corrugated waveguide can generate high-power microwaves in the X-band to reach the GW level power.And because of the advantages of simple and compact structure,large power capacity and easy realization of repeated operation,it has attracted more attention from universities and research institutions at home and abroad.Based on the detailed study of the helically corrugated waveguide structure,this paper designs an X-band five-fold helically corrugated waveguide pulse compressor.First,the dispersion characteristics of the helically corrugated waveguide are deduced by the impedance perturbation method and the coupled mode theory,and the coupling rules are analyzed in detail,and the coupling mechanism has a certain understanding.Using numerical analysis dispersion equation and traveling wave method software to simulate the dispersion characteristics,the results obtained are relatively consistent,which confirms the correctness of the theoretical derivation.Compared with the difference of the three-fold waveguide,the input mode of the five-fold helically corrugated waveguide is analyzed.According to the characteristics of the microwave in the elliptical waveguide that are affected by the long and short axis and the special structure of the four-fold helically corrugated waveguide,a TE₁₁-TE₃₁mode converter based on the four-fold helically corrugated waveguide is designed.The mode converter can effectively convert the linearly polarized TE₁₁mode into the circularly polarized TE₃₁mode in the frequency range required for pulse compression,and provide input for the pulse compressor.MAGIC is used to model the main structure of the helical corrugated waveguide pulse compression system,and the frequency modulation signal is designed to simulate the pulse compression process.The preliminary simulation results with an input power of 630MW,a pulse width of 70ns,an output power of 1.456GW,and a gain of 2.31 were obtained.On the basis of theoretical research and software simulation,the process of this compression method is optimized for the input pulse and the structural parameters of the helically corrugated waveguide.The simulation results with input power of 630MW,pulse width of 70ns,output power of 3.348GW,and gain of 5.31were obtained.