An Ultrawideband Three-Dimensional Bandpass Frequency Selective Surface

A new ultrawideband frequency selective surface(FSS) is proposed, which exhibits six resonances to achieve a flat passband. It consists of a three-dimensional (3-D) configuration. However, unlike many other 3-D FSSs, the proposed structure can be assembled through simple steps involving single-layer printed circuit board (PCB) fabrication only. Its unit-cell consists of a wire-loop conducting pattern, printed on a dielectric substrate. The pattern excites four resonances while two resonances are contributed by the dielectric. These six resonances are properly tuned and coupled to form an ultrawide frequency band from 7.53 to 29.45 GHz. It translates to a
$-$
3 dB bandwidth of 119
$\%$
. Our design guidelines and discussions are validated through both simulation and measurement results.