APPLICATION OF A COUPLED-INTEGRAL-EQUATIONS TECHNIQUE TO RIDGED WAVE-GUIDES

Cut-off frequencies of all TE and TM modes of a ridged rectangular wav e guide are accurately determined using a coupled-integral equations t echnique (CIET). The technique analyzes both symmetric and asymmetric situations in one step. Basis functions, which include the edge condit ions and mirror images in the waveguide walls, are used in the moment method solution of the integral equations. One or two basis functions are found sufficient to accurately determine the spectrum. The limitin g case of a zero-thickness metallic ridge is also presented. Results f rom the present technique are compared with available data; excellent agreement is documented.