A Waveguide-to-Microstrip Transition for a mm-Wave Mixer Test Jig

Many space missions operating above 100 GHz are using heterodyne receivers, which require Schottky diodes. The development of Schottky diode devices is important, not only for space instruments but also for the emerging terrestrial applications in millimeter wave imaging. So far the Schottky diode characterisation has been done on test carrier substrates, where the discrete diodes are mounted. The diodes are characterised by S-parameter measurements, direct current measurements and capacitance measurements. However it would be important to test the diodes in the actual operating environment of the diodes in final application, so that different Schottky diodes can be compared properly. The purpose is to develop a waveguide mixer test jig for characterisation of different Schottky diodes at the G-band frequencies.