Radar Absorbing Material Design

Low observable platforms have extremely low radar cross section specifications that cannot be achieved by shaping alone. The application of radar absorbing material is necessary, in which case the appropriate constitutive parameters and thickness must be selected. The universal design chart gives combinations of ?, and that provide zero specular reflection at normal incidence. Three different backing materials were used to generate the charts: (1) perfect electric conductor, (2) free space, and (3) graphite. One can pick the required values from the charts for an ideal zero reflection dielectric/magnetic layer. The extension to other materials is straightforward. Numerical simulations of coated plates were performed to estimate the effectiveness of the absorbing layers in reducing radar cross section. The reduction in monostatic radar cross section value is shown by plotting the radar cross section of the plate with and without radar absorbing material.