HYBRID SPECTRAL-SPATIAL METHOD FOR THE ANALYSIS OF PRINTED ANTENNAS

A technique is presented combining the advantages of the spatial and s pectral versions of the method of moments for a general electromagneti c problem involving a printed structure. The metalizations are of arbi trary shape and are described by a shape-conforming mesh with subdomai n basis functions. The technique is based on the extraction of the lea ding singular terms of the Green's function, in which space and freque ncy dependences are separated. The part of the impedance matrix associ ated with these terms is efficiently evaluated in the space domain, on ce for all frequencies. The eigenfunctions of these singular parts (ex pressed in terms of the subdomain basis functions) are then used as en tire-domain basis functions for the remaining regular part, whose asso ciated impedance matrix is evaluated in the spectral domain. This appe ars to be the generalization to arbitrary patch shapes of the use of e ntire-domain functions (like orthogonal polynomials or cavity modes) a nd drastically reduces the number of unknowns, showing potential for t he full-wave analysis of printed arrays.