MODE-COUPLING IN A PLANAR CIRCULAR WAVEGUIDE ARRAY

By means of an integral-equation approach, expressions are derived for all mode coupling occurring in a finite, planar circuit waveguide array. Modes coupling in the aperture of each waveguide yield terms dependent upon contour integrals. These are placed in a suitable form for numerical integration. A new asymptotic formula is obtained for the coupling between modes in separate waveguides. Theoretical results are presented for the TE//1//1 mode admittance of flanged circular waveguide and for two wavegides coupling in the H-plane. These results are shown to correlate satisfactorily with previously published experimental data.