3D frequency selective surface for stable angle of incidence

A three-dimensional frequency selective surface (3D-FSS) that provides stability for an angle of incidence and miniaturised unit cell size is presented. The proposed 3D-FSS is easy to fabricate and is implemented using via holes in a multilayer printed circuit board structure. Frequency transmission characteristics for different angles of both TE and TM polarisations are presented through simulations. The proposed structure was fabricated so as to verify the simulation results. The comparisons between the simulation and the measured results show good agreement. The results also show that the proposed 3D-FSS can provide better frequency stability for different incidence angles and polarisations as well as miniaturised unit cell size.