The continuous spectrum of the inset dielectric guide and its application to waveguide transitions

The analysis of discontinuities in open waveguides, particularly strongly radiating discontinuities, requires a knowledge of the complete modal spectrum of the guide. The continuous spectrum of nonseparable open waveguides, a category which includes many useful high-frequency structures, may be developed from a characteristic Green´s function approach. The continuous hybrid spectrum of the inset dielectric guide (IDG), a structure that shows promise for both propagation and antenna applications, is presented as an example. As a verification, this spectrum is used in the analysis of strongly radiating rectangular waveguide to IDG transitions, and a good correlation with experimental data is achieved