Diffraction and reflection of a plane electromagnetic wave in a right-angle corner with impedance walls

Abstract

We study the behavior of an electromagnetic field in a right-angle interior wedge-shaped region with impedance faces. This geometry is a useful model for a variety of applications in radar and wireless communication technologies. An exact solution of the general problem for an arbitrary-angle wedge with tensor impedance boundary conditions excited by an incident plane electromagnetic wave is specialized to the case of a 90° wedge with diagonal tensor impedances. We present explicit expressions for the geometrical optics portion of the field and show that they are continuous inside the region only if a compatibility condition on the face impedances is met. In general the geometrical optics fields are discontinuous at the direction of incidence and the edge-diffracted field gets excited in the region to make the total field continuous. Numerical results illustrate the edge-diffracted field as a function of observation angle for several impedance combinations, showing the overall increase as the impedance compatibility condition is increasingly not met.