Three-dimensional frequency selective structure with wide passband and sharp roll-off

In this paper, a new three-dimensional frequency selective structure (3D-FSS) is presented, which is periodical in both X, Y and Z directions with brick-wall-shaped 3D unit cell. The proposed structure exhibits excellent frequency response, which passband is ultra-wide with the half power bandwidth varies from 12.1GHz to 17.9GHz, with relative bandwidth of 40%. At the same time, the frequency response has the merits of sharp roll-off, wide out of band rejection, as well as insensitivity within 50 degrees for both TE and TM modes. Furthermore, the impaction of key parameters of the unit cell is investigated. The passband of designed 3D-FSS can be adjustable to various applications by changing mentioned key parameters. Such a 3D-FSS is a good candidate of dielectric filled radomes using in aircraft.