Electromagnetic radiation from structures consisting of combined body of revolution and arbitrary surfaces

A formulation is developed to treat radiation from structures consisting of a body of revolution (BOR) in the presence of multiple arbitrarily shaped three-dimensional objects. An electric field integral equation is set up on the surface of the combined structure. The resulting integro-differential equation is solved using the method of moments. On the BOR, harmonic entire domain expansion functions are used for the circumferential dependence, while overlapping subdomain functions are used to model the axial curvature. The arbitrarily shaped portions of the structure are modeled using triangular surface patches. The resulting system matrix has a partial block diagonal nature, which provides a more economical solution for structures that have some rational symmetry. Numerical results are presented and compared to measurements of a unique cavity-backed patch fed antenna