A wideband millimeter wave six-port reflectometer using four diode detectors calibrated without a power ratio standard

An 18-40 GHz coaxial six-port reflectometer using four diode detectors calibrated without a power ratio standard is presented. The hardware configuration of the six-port junction, the linearization of the diode detectors, and the calibration of the six-port reflectometer are discussed. Absolute power measurements or a high-quality variable attenuator is not required during the linearization of the diode detectors. A comparison between experimental results obtained by the six-port reflectometer and a Hewlett Packard HP 8510C Automatic Network Analyzer on a 3-dB attenuator terminated by a short circuit is presented