A new mixer design for 140-220 GHz

A new Schottky-diode mixer is described which has low noise and conversion loss in the 140-220-GHz band. At 170 GHz mixer noise temperatures of 1100-1300 K [Single sideboard (SSB)] have been measured, with 6.2-7.2-dB SSB conversion loss. The design should be usable up to -300 GHz with appropriate scaling. The mixer has been successfully used in airborne radiometers on the NASA Convair 990 and C-141 aircraft.