Ceramic Ribbons as Waveguides at Millimeter Wavelengths

Theoretical calculations verified by experiments have shown that suitably designed ribbons made of alumina can serve as low-loss dielectric waveguides for electromagnetic radiation at frequencies from 30 to 300 GHz. Prior to this development, low-loss waveguides for this frequency range were unknown. The achievable attenuation factor for an alumina-ribbon waveguide is less than 10 dB/km; as such, it is less than a hundredth of that of a typical ceramic dielectric rod waveguide, less than 1/200 of that of a customary metallic waveguide, and less than 1/300 of that of a microstripline at a frequency of 100 GHz.