An Accurate Millimeter Wave Loss and Delay Measurement Set

A point-by-point millimeter wave loss and delay measurement system has been built which combines large dynamic range with high accuracy. Up to 80 db loss and 100 nanoseconds envelope delay can be measured in the 50-60 Gc/s range. The accuracy for 0-40 db loss measurements is /spl plusmn/0.05 db, while beyond that accuracy is progressively diminished to /spl plusmn/0.8 db at 80 db. Delay accuracy for low loss devices (0-20 db) is /spl plusmn/0.2 /spl mu/sec over the entire 100 /spl mu/sec range. High accuracy and large range are attained with a substitution heterodyne measurement scheme using rapid RF and IF comparison switching along with calibrated IF loss and delay standards. In addition, high gain, narrow band, IF amplification and differential null detection is employed. Both measurement functions are incorporated into one system with manual waveguide switching and preset IF programs to facilitate conversion from loss to delay.