A polarization independent compact multi-band Frequency Selective Surface

This paper presents the investigations on two patch type slot loaded Frequency Selective Surface (FSS). In the first design, patches of the FSS are designed with 0° rotations to one another while in the second design; adjacent patches are at 90° rotations to one another. In the latter design due to symmetrical nature of the design; the FSS becomes totally polarization independent for 90° rotations about any vertical axis, perpendicular to the FSS plane and passing through its centre and the design also reveals reduced patch size of the FSS with multiband characteristics. The proposed designs have been investigated theoretically using ANSOFT® software. In comparison to the conventional square patch Frequency Selective Surface (FSS) without slot, this slotted square patch FSS with second design can provide reduction in resonant frequency resulting in size reduction up to 94%. The second structure acts like a band reject filter with three bands having resonant frequencies of 5.93 GHz, 9.25 GHz and 13.8 GHz.