Low-noise 320-360 GHz cryogenically cooled waveguide Schottky diode mixer
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 electroformed 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 6 dB, 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.
- Publication:
-
Electronics Letters
- Pub Date:
- November 1986
- DOI:
- 10.1049/el:19860895
- Bibcode:
- 1986ElL....22.1305W
- Keywords:
-
- Cryogenic Cooling;
- Low Noise;
- Mixing Circuits;
- Schottky Diodes;
- Submillimeter Waves;
- Waveguides;
- Noise Measurement;
- Noise Temperature;
- Radio Astronomy;
- Systems Engineering;
- Electronics and Electrical Engineering