Mode selection and boundary conditions using MAFIA in frequency-domain.

摘要

The field solvers of the 3D code MAFIA in the frequency domain are R3 and E3: the former generates an eigenvalue equation, and the latter solves this equation for eigenfrequencies and eigenvectors (fields). They are usually expensive to use. In order to save memory space and CPU time, one may employ a part of a structure in calculations if there are certain symmetries that are embedded in the geometry. In this case, one must run R3 and E3 several times with different boundary conditions if one wants to get a complete set of modes of the whole structure. However, sometimes only some modes are of interest to the authors (e.g., TM(sub 01)) and they may then specify the appropriate boundary conditions for a part of a structure to obtain these modes. There are two types of boundary conditions that one may choose from in R3: either a zero tangential E-field, denoted by integer 1, or a zero tangential H-field, denoted by integer 2. This note will use a circularly cylindrical cavity as an example to discuss the relation between mode selection and boundary conditions when using a part of the cavity.