Approximate solution for the scattering of an E-polarized wave from a concentrically loaded slit cylinder

An approximate solution to the problem of scattering from a concentrically loaded slit cylinder has been derived. For simplicity a perfectly conductive loading is considered, but extension to an impedance loading through the application of an impedance boundary condition is straightforward. The cylinder is an infinite one made of a perfect conductor with an infinite axial slot, and the loading is also an infinite coaxial cylinder. The incident wave is E-polarized with respect to the axis of the cylinders, and the angle of incidence is arbitrary. A modal expansion approach has been adopted, but an approximate expression for the field in the slot has been proposed. Thus, the dual infinite series has been avoided. This approximate expression is similar to the one used in static case. Based on this approximation, the scattered field outside the cylinder, the field penetrated into the cavity, and the bistatic cross section have been evaluated.<>