Properties of Surface Metal Micromachined Rectangular Waveguide Operating Near 3 THz

Single-mode TE10 rectangular waveguides operating near 3 THz have been demonstrated. The waveguides have internal dimensions of 75 μm × 37 μm (WR-0.3) and are fabricated using an additive gold electroplating process on a silicon substrate. The impact of photoresist removal holes was minimized by full-wave design of the hole and matching structures. Waveguides were measured at three frequencies from 2.56 to 3.11 THz and demonstrated loss as low as 1.3 dB/mm at 3.11 THz, corresponding to a loss per wavelength of 0.12 dB/λ. This paper summarizes the design, fabrication, and measurement of these micromachined waveguides operating near 3 THz.