A broadband active FSS absorber

In this paper, a broadband and tunable active frequency selective surface (FSS) absorber for EMC which is insensitive to the microwave signal incident angle was investigated. The periodic structure is composed of an array of conductive orthohexagonal loops,active devices are loaded at the center of the six sides of the periodic units. Reflection of the adaptive FSS absorber can be shifted in a broadband by active devices controlled by electric signals. Moreover, the thickness of the active FSS absorber is much smaller than the central incident wavelength. The investigated active FSS absorber shows that reflection loss below -20dB can cover a frequency bandwidth of 6 GHz.