A closely located dual-band FSS with frequency stability for multi-frequency communication

A novel angular independent dual-band FSS for multi-frequency communication is discussed in this letter. The proposed FSS with closely spaced response is consist of improved cross-shaped metal strips and a dielectric substrate. The unit cell size of the proposed FSS is 0.13λ×0.13λ where λ corresponds to the wavelength of the first resonant frequency. The proposed FSS exhibits dual stop band characteristics at 2.5 GHz and 3.5 GHz providing -15 dB bandwidth of 298 MHz and 290 MHz. Both bands are closely spaced providing the frequency ratio of f
_H
(upper resonant frequency value) to f
_L
(lower resonant frequency value) of 1.40. It also exhibits angular stability up to 60° for both TE mode and TM mode because of its symmetry.