Ultra-wideband frequency selective surface at K and Ka band

In this work, an ultra-wideband FSS is designed with a hexagonal ring unit cell and a dual-FSS array structure to widen its bandwidth. The 3dB bandwidth is from 17.83 to 45.66 GHz, covering the entire K and KA band and the unit periodicity is about λ
0
/5.75 for the lowest passband. The designed FSS features low profile, flat passband, and stable performance regarding incident angle and polarization, providing a practical solution to encrypted wideband satellite communications and radome for radar cross section reduction.