Method of Moments Analysis of Slotted Substrate Integrated Waveguide Arrays

A method of moments analysis is described for substrate integrated waveguide slot arrays. The array structure is modeled as a parallel plate waveguide on which via holes and slots are created. The field into the waveguide is expressed by the sum of the parallel plate's contribution and the field scattered by the metallic through holes, with both contributions expressed by means of an expansion in terms of vectorial cylindrical eigenfunctions. The slots are modeled as unknown equivalent magnetic current distributions which are found by solving an integral equation derived from the continuity of the field on the slot surface. Antenna arrays already presented in the literature will be analyzed, and the results compared with HFSS simulations. It will be shown that the proposed method is efficient and gives results in excellent agreement with the most common simulation tools.