利用HFSS仿真软件对螺旋线行波管中衰减器的衰减量分布情况进行了模拟分析。由于直接模拟螺旋线行波管中不同涂碳层厚度下衰减器的衰减分布情况难度大,计算量大,涂碳厚度不易模拟,因此,本文利用等效替换的方法进行了模拟计算,通过对单根夹持杆进行波导测试,获得S21,找到不同S21下的等效体电率或损耗角正切,并将他们对应的这些材料替换到行波管内,计算相应的衰减常数,得出不同位置下的衰减常数。
This paper analyses the distribution of the attenuation in attenuator which is in helix traveling wave tubes by HFSS.Because it is difficult to direct simulate the attenuation distribution which is in attenuator of the TWT with different thickness carbon layers,so the method of equivalent replacement is used to simulation.The S21 parameter is achieved by the measurement of waveguide with single rod.Then the equivalent conductivity and loss tangent are calculated.The materials with the corresponding conductivity and loss tangent are used to calculate the attenuation constant in TWT.This study is helpful to the estimation of attenuation distribution of attenuator in helix traveling wave tubes,and it also contributes to the further research on the beam-wave interaction in helix traveling wave tubes.