Micromachined terahertz waveguide band-pass filters

Three waveguide band-pass filters are designed based on three different resonant cavity structures, operating at WR-2.2 (0.33~0.5THz), WR-1.5 (0.5~0.75THz) and WR-1.0 (0.75~1.1THz) frequency band separately. Terahertz filters are all fabricated using the deep reactive ion etching (DRIE) silicon micromachining technique. For more accurate designs, the conductivity of the metal film with the roughness surface is investigated in the terahertz frequency band, using the HB and the modified Huray model. The measurements are performed using the vector network analyzer (VNA) with corresponding frequency extenders. Measured insertion losses within pass band are about 1.9dB, 2dB and 3.4dB respectively, which are in good agreement with simulations and therefore verifies the accuracy of the analysis above.