Title :
Low-noise 320-360 GHz cryogenically cooled waveguide Schottky diode mixer
Author :
Woestenburg, E.E.M. ; Nieuwenhuis, L.
Author_Institution :
Radio Observatory Dwingeloo, Dwingeloo, Netherlands
Abstract :
Construction details and results of noise measurements on a cryogenically cooled Schottky diode mixer for the 320-360 GHz range are given. Critical mixer parts are electro-formed or machined on a precision lathe. The system double-sideband noise temperature is close to 400 K over a 30 GHz range with a lowest temperature of 385 K at 335 GHz. The mixer uses a tunable contacting backshort and has a total RF/IF double-sideband conversion loss of about 6dB, including input lens and diplexer losses. Corrected for input losses and second-stage contribution, a mixer double-sideband noise temperature of 271 K has been calculated at 335 GHz. This mixer has shown reliable and reproducible performance during five cooldowns to 15 K.
Keywords :
Schottky-barrier diodes; electron device noise; mixers (circuits); radiotelescopes; solid-state microwave devices; 15 K; 320 to 360 GHz; 385 K; James Clerk Maxwell Telescope; RF/IF double-sideband conversion loss; SMMW; THF; construction details; cooldowns; cryogenically cooled Schottky diode mixer; diplexer losses; electroformed; input lens; low noise mixers; noise measurements; precision lathe; reproducible performance; submm; system double-sideband noise temperature; tunable contacting backshort; waveguide Schottky diode mixer;
Journal_Title :
Electronics Letters
DOI :
10.1049/el:19860895
