Rapid progress in big data technologies results in the need for a drastic increase in wireless data transfer rates. To meet the demand, it is necessary to develop communication systems operating at carrier frequencies in the range 0.1–10 THz (so-called THz band). They can provide data transfer rates of more than 1 Tbps in in-door deployments. However, existing hardware solutions for THz transmitters/receivers usually rely on the use of hollow metallic waveguides, which already suffer from noticeable insertion losses of 0.24-0.31 dB/cm at 110 GHz. And these losses increase even more with further increase of operating frequency. Thus, use of metallic waveguides potentially compromises signal strength and sensitivity, increases design complexity and fabrication costs of a transceiver. One of the potential solutions is to use low-loss fully dielectric wave-guiding structures. In this work, we report on the development of a THz dielectric waveguide made from a high-resistivity Si substrate. A square lattice of openings is fabricated in the substrate via the Bosch process. Transmission and reflection spectra of the fabricated waveguide samples are measured over the frequency range 135–160 GHz. Similar to the simulation forecast, we measure insertion and return losses of 0.04 dB/cm and 20 dB at 150 GHz, respectively, which meet requirements of modern practical applications.
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