A technique for analyzing radiation from conformal antennas mounted on arbitrarily-shaped conducting bodies

This paper presents an efficient method to solve the problem of radiation from conformal aperture and microstrip antennas mounted on arbitrarily-shaped conducting bodies. The method, based on the surface equivalence and reciprocity principles, uses a combination of the Finite Difference Time Domain (FDTD) and Method of Moments (MoM) techniques to substantially improve the computational efficiency of the radiation pattern calculation. When the geometry and location of the radiating element are modified, only a small portion of the overall analysis requires re-simulation. This leads to a significant improvement in computational efficiency over presently-used techniques, and can substantially improve design efficiency when included in an optimization loop. The technique is first validated by solving two canonical problems, namely a thin slot which is oriented either axially or azimuthally on an infinitely long, perfectly conducting cylinder. These patterns are then compared to those produced by the same slots mounted on finite length cylinders. Finally, patterns are computed for a cavity-backed elliptical patch antenna mounted on an infinite-length PEC cylinder and compared to patterns computed by an alternate method.