A 90°-Inclined Linearly Polarized Probe for Terahertz Mueller Imaging

A novel terahertz (THz) probe, consisting of a 90°-inclined linearly polarized (LP) component incorporated with a pyramidal-shaped TE₁₀ mode rectangular open-ended waveguide (OEWG), is introduced in this paper. The pyramidal feed, located beneath the substrate, is made of brass plated with gold. The radiation component, placed on tip of the OEWG, is achieved by standard printed-circuit and plated-through-hole techniques. Measurement results demonstrate that the proposed probe possesses an impedance bandwidth (VSWR ≤ 2) of better than 18.5% from lower than 270 to higher than 325 GHz. In the impedance bandwidth, the measured gain is from 7.2 to 8.2 dBi and all radiation patterns are relatively symmetric with relatively small back radiation and cross-polarization levels. The proposed probe is a potential component for Mueller imaging at THz frequencies.