分析了具有反射器的8 mm波段相對論繞射輻射振蕩器，其高頻系統為周期盤荷慢波結構，并且在電子注的輸入端加有圓柱形同軸反射器。利用HFSS軟件計算S11參數來確定反射器的結構尺寸。對該結構進行了PIC模擬，分析了該結構中注波互作用的非線性過程和反射器對該器件性能的影響。研究發現存在一個最佳反射器的位置，使注波互作用的效率高、頻譜好。
關 鍵 詞 相對論繞射輻射振蕩器; 反射器; HFSS軟件; 粒子模擬

Abstract A 8-millimeter-wave-band relativistic diffraction generator with a coaxial reflector is studied on this paper. High frequency system of the device is a slow-wave structure with a combination of rectangles and semicircles. A coaxial reflector is situated at the upstream entrance of the slow-wave structure. The parameter of reflector is obtained by calculating the S11 parameter by the software HFSS. The non-linear process of beam-wave interaction with the reflector is investigated on particle-in-cell (PIC) simulation. The result shows that there is the best location of the reflector, which makes the device have a maximum efficiency and single operation frequency.
Key words relativistic diffraction generator; reflector; HFSS software; particle-in-cell simulation