DTIC ADA472943: Genetic Algorithm Optimization of Multilayer Jaumann Absorbers. Oblique Incidence

Beschreibung

Multilayers of spacers and resistive sheets can produce wide bandwidth microwave absorbers. Absorber bandwidth increases with the number of resistive sheets and the resistance profile through the absorber determines its performance. Absorber design requires an optimisation tool. In this paper absorber design is optimized using the Genetic Algorithm for oblique angles of incidence. The influence of incident angle on absorber bandwidth is studied for 1 to 7-layer absorbers, high permittivity spacers and protective layers. It was found that the bandwidth at normal incidence remains fairly constant to an angle of about 30 degrees. Absorber performance was maintained out to large incident angles if the absorber was designed at the large angle, though at a cost of a thicker absorber.