Submillimeter-wave scattering parameter measurements with a sampled-line six-port reflectometer

The experimental investigation of a reflectometer for measuring return loss magnitude and phase at submillimeter wavelengths is presented. The reflectometer, which is designed as a proof-of-principle demonstration, is based on the sampled-transmission line architecture and its design and operation are described. The instrument is a relatively simple implementation of the six-port network analyzer introduced by Engen and consists of a section of rectangular waveguide and an ensemble of Schottky diode power detectors. Design considerations for the instrument are presented and measurements in the 270 GHz to 285 GHz range are discussed.