A hybrid UTD-MM analysis of the radiation from a composite slot-blade cavity-backed antenna on realistic aircraft configurations

A hybrid method which combines the uniform geometrical theory of diffractio n (UTD) with a numerical moment method (MM) technique is presented for the analysis of the radiation from a composite slot-blade cavity-backed antenna located on realistic aircraft configurations. The excitation of the antenn a is due to a delta gap generator in a thin-wire probe feed that is placed inside a rectangular cavity. The MM procedure is used to solve coupled inte gral equations that are formulated for the unknown equivalent electric curr ent distribution on the blade and the unknown equivalent magnetic current d istribution over the slot, when this slot-blade antenna configuration resid es on an infinite ground plane. The UTD is next used to efficiently and acc urately calculate the radiation from these equivalent current distributions for the slot-blade antenna combination when the latter are now located on realistic aircraft geometries instead of a flat ground plane. Calculated ra diation patterns of the composite slot-blade cavity-backed antennas placed on a Boeing 737 commercial, airplane and an F-16 fighter aircraft are prese nted to illustrate the utility of this hybrid approach.