级联同轴腔体的传输特性研究

Transmission Characteristics of Coaxial Cascaded Cavities

提出了一种用于计算多节同轴腔体级联情况下的输入阻抗和终端瞬态电压的方法。构成整个结构的相邻同轴腔体半径是不同的,由此带来不连续性问题。在本征模展开的基础上,运用脉冲基函数离散化腔体不连续处的切向电场,并且结合腔体连接处电磁场的连续性条件,建立频域下的积分方程,从而求解腔体不连续续处的电场。同时对不同本征模个数选取带来的结果差异也进行了详细讨论。之后根据终端条件结合反傅立叶变换得到腔体的终端瞬态电压、电流响应。计算结果表明适当地截取有限个传输模式可以准确、快速地反映改腔体的传输特性。

This paper presents a method for computing input admittance and terminal voltage in a series of cascaded cavities. Each section of the total cavity has different radius cross - section, which will introduce discontinuity problem. The method used here builds upon the eigen modes expansion method and uses pulse basis function to discretize the tangential electric field at the aperture in order to construct integral equation combined with the continuity conditions. Thus, electric field at the aperture can be solved numerically. Furthermore, the impact of different number of modes is also discussed in the paper. Then according to the terminal condition, the time - domain terminal voltage and current can be obtained through inverse FFT. The result shows that selecting transmission modes appropriately can catch the transmission characteristics exactly and quickly.