Electromagnetic transmission through a small radome of arbitrary shape

A simple moment solution is presented for the problem of electromagnetic transmission through a small radome of arbitrary shape. The radome is excited by either a plane wave (receive mode) or an elementary dipole inside the radome (transmit mode). The equivalence principle is used to replace the radome by a set of equivalent electric and magnetic surface currents radiating into an unbounded medium. A set of coupled integral equations involving the surface currents is obtained by enforcing the boundary conditions on the tangential components of the total electric and magnetic fields. The method of moments is used to solve the integral equations. The surfaces of the radome are approximated by planar triangular patches and linearly varying vector functions are used for both expansion and testing functions. In the receive mode, the total field inside the radome is computed along a number of straight lines and in the transmit mode the far transmitted field is computed. A spherical and a Von Karman radome are studied. The computed results are in excellent agreement with the exact or other available published data.