Effects of a resistively coated dielectric strip on the TM-polarized resonant backscatter behavior of a slotted conducting rectangular shell

The performance of a resistively coated dielectric strip used to suppress the first TM-type resonant backscatter associated with a two-dimensional slotted conducting rectangular shell is analyzed in this paper using the moment method technique. Results obtained indicate that almost perfect resonance damping performances are attained when a finite-dimensioned resistively coated dielectric strip with dielectric constant Epsilon(sub r) = 4 - j0.4 and film resistance R(sub s) = 188.5 ohms is placed: (1) at the slot (which directly faces the normally incident TM-polarized plane wave), (2) on the interior perimeter of the shell adjacent to the slot, or (3) at the center of the back wall of the shell. Poorer damping performances are observed, however, when the resistively coated dielectric strip is placed at other positions and/or with the same or higher film resistance. Finally, it is also shown that in general the knowledge of the waveguide theory can be used advantageously in the placement of the resistively coated dielectric strip for achieving best resonance damping performance.