ANALYSIS AND DESIGN OF PLANAR WAVEGUIDE SLOT ARRAYS USING SCATTERING MATRIX APPROACH

Abstract

A scattering matrix approach to the analysis and design of planar waveguide slot arrays is described in this paper. The new method employs the scattering matrix for TE10 and TE20 (to the waveguide axis) modes of isolated slot in the broad wall of a rectangular waveguide, rather than the admittance of the slot derived from approximate shunt or series lumped element model for the slot. The method fully accounts for the external mutual coupling due to the TE10 and TE20 modes on the slot, and can be easily extended to include higher order waveguide modes. Fur-thermore, it takes into account the deviation of the slot aper-ture from the sinusoidal distribution that is normally as-sumed with a nearly resonant slot. Numerical results dem-onstrating the viability of the scattering matrix approach, including an example for the design of a 2 x 3 planar array of longitudinal slots, are presented