On the Effect of Absorbing Materials on Electromagnetic Waves with Large Relative Bandwidth

Coats of absorbing material over metallic surfaces can substantially reduce the energy of a returned radar signal. This paper analyzes the effect of such coatings on radar signals with large relative bandwidths close to 1, rather than the conventional relative band- widths in the order of 0.01 or less. Normal incidence of the wave, and absorption due to ohmic losses are assumed. The purpose of the paper is strictly to draw attention to the significance of a change from small to large relative bandwidths, since the decades of work on the reflection of sinusoidal waves with various angles of incidence by targets with various shapes, constructed with a variety of materials, cannot be duplicated for nonsinusoidal waves with less than corresponding decades of effort.