STRIPLINE-FED ARBITRARILY-SHAPED PRINTED-APERTURE ANTENNAS

A full-wave analysis method is presented for modelling the radiation p roperties of a stripline-fed planar printed-aperture antenna element, In this formulation, both the finite length of stripline and the finit e aperture may be of any arbitrary shape since their equivalent electr ic and magnetic currents are modeled with triangular patch basis funct ions, Galerkin's method is applied to numerically solve the coupled mi xed-potential integral equation (MPIE). Exact spatial-domain Green's f unctions are used to account fur all radiation, surface-wave, and mutu al-coupling effects, Interactions between the stripline feed and the r adiating aperture are rigorously included. Numerical analysis is prese nted for the following nonrectangular shapes: an exponentially tapered slot, an annular slot, an annular slot with opposing stabs, and a mon ofilar Archimedean spiral slot element, Results are shown for input re turn loss, radiation patterns, and axial ratio for the circularly pola rized elements.