Compact three-dimensional terahertz resonators based on periodically corrugated metallic slit waveguides

We present a compact terahertz filter design realized as a short inhomogeneous Bragg grating formed by variation in the slot width of a three-dimensional (3D) metallic slit waveguide. By introducing a phase-shift into the grating, a narrowband 3D waveguide transmission resonator is created. The functionality of the filter as well as the influence of parameter variations on the performance of the device are analyzed by detailed numerical 3D simulations. By tapering the depth of the grooves in the modulated region the radiation loss is minimized. The simulation results are verified by measurements of the transmission characteristic of a realized structure and show excellent agreement. (C) 2010 American Institute of Physics. [doi:10.1063/1.3462382]