利用场耦合理论研究微波谐振腔

Investigation of RF cavity by coupling theory

根据 Maxwell方程 ,微波腔中的实际微波场可以按微波腔的模式展开 ,从而确定微波腔的工作特性 (如 :工作频率、场分布等 ) ,但是实际微波腔的模式很难求解。从 Maxwell方程出发 ,根据微波腔的具体边界 ,将微波腔分成 :规则形状微波腔和非规则部分 ,建立实际微波腔模式同规则形状微波腔模式之间的场耦合方程 。

According to Maxwell theory, the RF field in the RF cavity can be expressed by the modes of the cavity. And the characterizes of the cavity is determined by these modes, such as the frequencies and the fields. Because of sophisticated shapes of cavities, it's very difficult to calculate the modes of an actual cavity by using the usual methods. An actual RF cavity is divided into two parts: the normal part (such as normal cylindrical cavity) and the abnormal parts. According Maxwell theory, there exists a coupling equation between the modes of the normal part and the modes of the cavity. In another words, the modes of the cavity can be expressed by the modes of the normal part. And by solving the coupling equation, frequencies and fields of the cavity's modes can be calculated. Utilizing this method, the C-band reentrant cylindrical cavity is calculated, the calculated frequency of the working mode is very close to the measured value.