Efficient Method of Moments Analysis of Linear Cavity-Backed Slot Arrays with a Reduced Number of Basis Functions

This work deals with the efficient analysis of linear arrays of cavity-backed slot antennas. The considered array elements can be a single or multiple slots radiating in the presence of a rectangular cavity. A spectral method of moments (MoM) is used to estimate the impedance and the patterns of the slot array. The method is rendered computationally efficient by considering, for each slot, only two basis functions that suitably describe the magnetic current distribution. The first basis function is derived by solving the auxiliary problem where only the cavity walls parallel to the slot axes are considered. The second basis function is obtained by solving the problem of a closed rectangular cavity excited by a magnetic current distributed on the slot region. The proposed method allows to simulate entire finite arrays in a few seconds per frequency point and can be exploited to aid the design and optimization of cavity-backed slot arrays.