Stable and compact multiband frequency selective surfaces with Peano pre-fractal configurations

This work presents a fractal design methodology for frequency selective surfaces (FSSs) with Peano pre-fractal patch elements. The proposed FSS structures are composed of periodic arrays of metallic patches printed on a single-layer fibreglass dielectric. The shapes presented by pre-fractal patches allow one to design compact FSSs that behave like dual-polarised band-stop spatial filters. On the other side, the space-filling and self-similarity properties of Peano fractals became possible various configurations for patch elements. An FSS parametric analysis is performed in terms of the fractal iteration-number and cell-size of pre-fractal patches. To validate the used methodology four FSS prototypes are built and tested in the range from 1.0 to 13.5 GHz. Experimental characterisation of the FSS prototypes is accomplished through three different measurement setups with commercial horns and circular monopole microstrip antennas. Results show that the proposed FSS presents most of the desired features for spatial filters: compact design, multiband responses, dual-polarisation, excellent angular stability and facility for reconfiguration.