Flexible circular waveguides at millimeter wavelengths frommetallized Teflon tubing

Flexible waveguides for use at millimeter wavelengths have been fabricated by deposition of metallic film onto the composite-modified inside surface of Teflon tubing. The attenuation characteristics in the range 80 to 115 GHz show losses on the order of 0.1 dB/cm. Bending, twisting, and rotating to the limit of plastic mechanical stability (curvature radius typically >8 cm) have a negligible effect on the attenuation, and bend angles ⩽45° produce relatively small changes in the insertion phase