Surface wave diffraction by a truncated inhomogeneous dielectric slab recessed in a conducting surface

The study of surface wave diffraction by a truncated dielectric slab recessed in a perfectly conducting surface is of importance in designing flush-mounted dielectric covered antennas. The incident surface wave gives rise to waves diffracted and reflected by the junction at the termination of the dielectric. A strong reflected surface wave is undesirable in certain situations in that it may cause a problem in matching antenna impedances. One way to reduce the reflected surface wave is to use an inhomogeneous dielectric near the junction. If the inhomogeneous dielectric near the junction is lossy, a substantial reduction of the reflected surface wave can be achieved as demonstrated in the present study. Owing to the added complexity by including inhomogeneous dielectrics, this diffraction problem is solved using an integral equation numerical approach.