Novel Swastika-shaped tightly coupled resonator based metamaterial-FSS for radome applications

A novel metamaterial-FSS (frequency selective surface) is designed in this paper based on the theory of tightly coupled resonators for radome applications. The proposed metamaterial unit cell consists of a Swastika-shaped conductor on each side of the substrate which is shorted at the edges by introducing shorting strips. The structure exhibits negative permittivity and permeability behavior at distinct frequency region. The EM analysis of metamaterial-FSS is carried out using transmission line transfer matrix method and validated with the full-wave method. The structure exhibits bandpass characteristic with very high transmission efficiency (>90%) over the frequency range of 10.43–11.43 and sharp roll-off characteristics outside the band as compared to conventional FSS. In view of radome applications, the EM characteristics are further studied at oblique incidence, which is found to show stable EM characteristics w.r.t. angle of incidence and polarizations.