Comparison of Micromachined Dielectric and Metallic Waveguides for THz applications

The paper considers micromachined dielectric and metallic waveguides for THz applications. Analytical analysis and simulation of losses for ideal structures are provided. Effect of fabrication nonidealities, such as surface roughness is also considered. In dielectric waveguide, the dielectric losses are the main loss mechanism, and Silicon tan8 is low above 1 THz, but increases rapidly at lower frequencies. The loss in metallic waveguides increases with increasing frequency. For ideal structures, the Silicon dielectric slot waveguide shows lower loss over 1.2 THz than the metallic waveguide. The effect of rough metal surface in the metallic waveguide increases the loss, making the dielectric waveguide interesting at even lower frequencies.