ABSTRACT
Coupling slots between adjacent cavities can break the axial symmetry of the electromagnetic fields in these structures. An on-axis coupled structure (biperiodic structure or BPS) is an illustrative example. The coupling elements between adjacent cells of biperiodic structures are usually made as narrow azimuthal slots cut in the irises. It is obvious that the modeling of a coupling element reduces to choosing a method of obtaining a specific expression. An efficient method of modeling narrow azimuthal slots of BPSs lies in their representation in the form of a lossless strip line that is short-circuited at the ends. This chapter considers this model as well as a simpler model based on representing coupling slots in the form of a radiating antenna. It also considers coupling slots between BPS cells by representing these narrow azimuthal slots in the form of a lossless strip line short-circuited at its ends.
