LAUSR

A novel millimeter-wave frequency selective surface (FSS) is presented for demultiplexing four atmospheric remote sensing bands with varying bandwidth (3–20 GHz) and frequency separation (50–195 GHz). The unit cell (670 μm × 670 μm) is a circular metal mesh loaded with a monopole integrated concentric ring on a 175-μm-thick quartz substrate designed to reject 50–60 GHz (B₁), 87–91 GHz (B ₂), and 148–151 GHz (B₃), and transmit 175–195 GHz (B₄) for transverse electric (TE) and transverse magnetic (TM) polarizations at oblique incidence (25^°−35 ^°). Transmission response of the cascaded FSS measured using a continuous-wave terahertz source showed insertion loss of 15 dB and higher in the reflection windows (B₁, B₂, and B₃) and less than 0.5 dB in the transmission window (B₄) for TE and TM polarizations at 30° incident angle.