Accuracy considerations and FMCW operation of a six-port device

The application of a six-port device in a frequency modulated continuous wave sensor system is presented. Two completely different modes of operation are combined in the distance sensor to achieve an outstanding performance. A frequency sweep is accomplished and evaluated using the uncalibrated six-port device without degrading the final distance accuracy. The obtained distance accuracy is determined by the phase measurement accuracy of the calibrated six-port operating at 35 GHz. Influences of the six-port parameters with respect to the phase accuracy are treated.