Characteristic Analyse And Simulation Of Clover-leaf Coupled Cavity Slow-wave Structure

Clover-leaf coupled cavity is a kind of slow-wave structure of high interaction impedance.The dimension of coupled cavity slow-wave structure is large,and the structure has an advantage in elimination of heat and can work under high pressure and gained high average power-output and pulse power-output.At present,coupled cavity slow-wave structure is used in high power traveling wave tube widely. Clover-leaf coupled cavity is first used in output section of Twystron in China.The dissertation analyses the characteristic of clover-leaf coupled cavity structure.The structure is periodic loaded circular waveguide transmission line. Compared with normal structure,it's interaction impedance is higher.Design principle and dimension of a kind of Clover-leaf coupled cavity are expounded.The mathematic analyse and the engineering design are very difficult for it's complex structure. The slow-wave characteristic can be simulated ,which avoids supposing condition when analysing model and advances precision of the results and saves manpower, time and money . Three-dimensional simulation codes Isfe13d, Mafia,HFSS are used to determine the dispersion and interaction impedance.Resonance method is used to simulate dispersion and perturbation technique is used to simulate interaction impedance.The results show that the average error of dispersion is less than 0.03 percent and the average error of interaction impedance is less than 8 percent.The simulation results are consistent with the measurement results,which means simulation is feasible to researching slow-wave structure.Based on analyse of the simulate results,the coupled cavity slow-wave structure is optimized primarily. Isfe13d is used to simulate different structure so that bandwidth becomes wider and interaction impedance becomes higher. These conclusions are available to design.