Six Port Consisting of Two Directional Couplers and Two Voltage Probes for Impedance Measurement in the Millimeter-Wave Range

The conventional reflectometer system is completed by two voltage probes which are separated by an average distance of λ/8. Because of the unavoidable errors of the millimeter-wave components, a calibration procedure is necessary, which is known from six-port theory. Some results in the frequency range from 26 to 40 GHz are presented.