A double layer FSS filter for sub-THz applications

This work presents the simulated and measured performance of single- and double-layer frequency selective surface filters for operation at sub-THz frequencies (250 GHz center frequency). They were composed of concentric square loops with a split as a unit cell resonator on top of a low dielectric permittivity, low thickness material (RT5880). Both a single layer filter and a cascaded two layer filter with varied distances were investigated. The simulated bandwidth for the cascaded filter was 27 GHz and 16 GHz and 9 GHz bandwidth measured with a THz-TDS and microwave system.