Doppler tomographic investigations of a lossy high impedance surface absorber at high incident angles

High impedance surfaces (HIS) have attracted a significant amount of attention in recent years, as they allow for the manipulation of surface currents on ground planes for antennas. These same structures, along with various similar resonant elements have been exploited to design near perfect narrow band absorbers. This class of absorbers has also been used to develop multi-resonant and broadband responses using lossy, high dielectric mediums (i.e. graphite, carbon, etc.). This paper investigates a high resolution, coherent Doppler tomographic (CDT) image of a simple lossy mushroom HIS structure, designed from structural composite materials. The resonating elements are investigated for their surface wave scattering properties and are shown to create complex scattering interactions within the HIS absorber. The HIS structure resonated at 6.2 GHz with a -10.48 dB reflection coefficient. A wideband analysis indicates that the overall scattering is reduced.