SYSTEMATIC CHARACTERIZATION OF THE SPECTRUM OF UNILATERAL FINLINE

Knowledge of the higher-mode spectrum of finline is necessary for the treatment of discontinuities. A rigorous approach to the problem of the spectrum of unilateral finline is presented on the basis of a variational solution in the space domain and transverse equivalent network considerations. This method is termed transverse resonance diffraction. Having satisfied the correct edge condition a priori, the analysis produces highly accurate dispersion characteristics calculated at each spot frequency for the fundamental and higher-order modes with matrices of very low order. By exploiting the quasi-analytical character of the model, it is possible to derive a systematic and complete characterization of the spectrum in terms of mode families. Simple-to-use wide-band approximations to the dispersion characteristics are also obtained which are suitable for evaluation by a desktop calculator.