High frequency analysis of irregularly contoured planar tapered phased arrays

The formulation presented in Martini et al. (2003) for equiamplitude excitation, is extended to the case of weakly tapered illumination. A similar extension has been carried out using numerical techniques based on the Fourier transform theory. Here an efficient formulation is achieved through the following steps. First, by applying the Poisson summation formula, the contributions of each constituent linear array are represented in terms of equivalent continuous tapered lines. Then, the radiation from each tapered line is evaluated after approximating its current distribution by a linear combination of a suitable number of equiamplitude linearly phased excitations. The coefficients of this expansion are defined to match the characteristics of the actual tapering associated to the dominant asymptotic contributions. Finally, each linear array field is represented in terms of truncated single-indexed conical Floquet waves and tip-diffracted spherical waves.