An Efficient Hybrid Method for Analysis of Slot Arrays Enclosed by a Large Radome

Abstract

A hybrid method that combines the integral equation (IE) method and Physical Optics (PO) is proposed for efficient analysis of slot arrays enclosed in an electrically large radome. The integral equations are applied over the aperture of the slot antenna and the tip region of the radome by enforcing continuity of the tangential magnetic or electric field. Equivalent PO currents are assumed on the relatively smooth region of the radome walls, induced by the radiated fields from the antenna. The radiated fields due to the PO currents on the radome are coupled back to the integral equations to account for interactions between the radome and the antenna, as well as the interactions between the tip and other parts of the radome. This method leads to considerable reduction in memory and computational time, since PO is applied to a large part of the electrically large radome, with unknown currents defined only on the aperture of the slot antenna and the small tip region of the radome. Better efficiency can be attained if the integral equation is applied only to the slot aperture and the entire radome wall taken as the PO region, with acceptable degradation in accuracy.