Analysis of microwave resonators using transmission line modelling

Dielectric loaded cavities are used widely in such diverse applications as communications systems and microwave heating. Generally, they may have nontrivial geometries with multiple lossy dielectrics, feed points, etc., making detailed analytical study intractable. The paper presents a numerical modelling analysis, based on the transmission line modelling (TLM) method, of a realistically dimensioned generic resonator structure. The benefits to be gained in the understanding of the behaviour of the resonator structure from this type of approach are highlighted. Comparisons of experimental results with those obtained using the TLM show very good agreement for the location of the resonances, identification of mode interaction and the magnitude of the voltage standing wave ratio (VSWR) in the resonator feed point. This establishes TLM as a valuable diagnostic aid and preprototype design tool for dielectric loaded resonant cavities