Computer-Aided Testing of Mixers Between 90 and 350 GHz

Two computer-controlled measurement systems have been constructed to allow testing of millimeter-wave Schottky-barrier diode mixers in the frequency range from 90 to 350 GHz. A theoretical background to mixer measurement is presented and the design of the instruments and associated computer software is described. In a companion paper, a typical application of the measurement system to the testing and evacuation of a practical W-band, cryogenic, fixed-tuned Schottky diode mixer is used to demonstrate the performance and versatility of the instruments.