Optimized geometry pyramidal absorber for normal incidence case

To improve accuracy of the EMC measurements in anechoic chambers, a new absorber shape is presented in this study that results in a lower reflection coefficient than the commonly used pyramidal shape for the normal incidence case of the plane electromagnetic wave. This new profile shape is obtained based on a pyramidal absorber by using genetic algorithm. The return loss characteristics of the proposed absorber structure which is illuminated by a TE polarized plane wave have been obtained using well-known simulation software for normal incidence case. Comparisons of the simulation results of the conventional wedge and proposed absorber are presented. The results show that new absorber shape provides better absorption characteristics than a conventional wedge across almost all frequency ranges for normal incidence case.