Frequency selective surfaces (FSSs) are spatial filters widely employed in high-performance applications like hybrid radomes for radars and antennas. While planar geometries are widely studied, less attention has been devoted to conformal ones, where we must consider the influence of both the lattice geometry and the shape and size of the individual elements. In the planar case, periodicity first impacts on the general reflecting properties of the surface, while the shape and the size of the individual element affect its detailed both spatial and frequency filtering behaviour. In particular, the frequency response is dictated mainly by the scattering by the individual element and attains its maximum at resonance conditions. We mean to numerically investigate whether the same also occurs for non-planar surfaces and curved elements, for both cylindrical and conical surfaces. We compare the results of the general frequency behaviour of FSS both made of strips in free space and slots cut in a perfectly conducting material. The effect of the lattice geometrical parameters is also appreciated. The main conclusions are that also for curved elements a frequency selective behaviour can be appreciated and the interaction with the single elements plays an important role, when mutual coupling is not strong.
Part of the book: Wave Propagation Concepts for Near-Future Telecommunication Systems