Millimeter-wave mixers with Schottky diodes, for superheterodyne spaceborne radiometers-review and predictions

Millimeter-wave (MMW) mixers employing Schottky diode (SD) devices are the only mixers implemented, to date, for spaceborne superheterodyne radiometry applications. Spaceborne missions impose high technical standards on such radiometers, lending special significance to MMW mixers employed for such applications. This paper reviews milestones in the developments of SDs and circuit technologies for spaceborne MMW mixers. It also suggests possible and desired future developments necessary to maintain and extend the dominance of mixers with SDs even to submillimeter-wave (SMMW) frequencies