Fast Impedance and Pattern Evaluation for Phased Arrays Made of Complex Elements Involving Finite Dielectric Material

Wideband antenna arrays are usually made of complex elements. The method of moments analysis of a single element, based on the surface equivalence principle, can involve of the order of thousand unknowns. In this context, the macro basis functions (MBF) approach becomes very useful to array analysis. In this paper, we show how this approach can be efficiently implemented to obtain the array impedance matrix, as well as all embedded element patterns. The method relies on multi- poles decompositions and FFT computations. Examples are given for a 10times10 array of tapered-slot antennas embedded in thin dielectric boxes. Validation points are provided at the element level (energy conservation), by comparison with a brute-force solution for a 4 x 4 array and by comparison of a 10times10 array solution with the infinite- array result.