Double channel mechanically tunable terahertz filter based on parallel plate waveguide cavities

Abstract

Theoretical and experimental works were carried out on a double channel mechanically tunable terahertz filter integrated with parallel plate waveguide cavities. The filter includes two rectangular grooves on upper and bottom plates of waveguide, respectively. The filter frequencies can be quasilinearly tuned by altering the overlap length between two rectangle grooves on metal plates. From the experiment, we found low (high) resonant frequency can be adjusted from 0.417(0.346) THz to 0.399(0.374) THz when the overlap length is altered from 0 to 500 µm, respectively. The Q values can reach 46 with the resonant frequency (0.41THz), overlap length (220 µm) and waveguide spacing (650 µm). Theoretical results show good agreement with experiment.