Far-ir heterodyne radiometric measurements with quasioptical Schottky diode mixers

Abstract

We have made heterodyne radiometric measurements with GaAs Schottky diode mixers, mounted in a corner-reflector configuration, over the spectral range 170 μm to 1 mm. At 400 μm, system noise temperatures of 9700 K DSB (NEP=1.4×10−19 W/Hz) and mixer noise temperatures of 5900 K have been achieved. This same quasioptical mixer has also been used to generate 10−7 W of tunable radiation suitable for spectroscopic applications.

Millimeter and submillimeter wave absorption by atmospheric pollutants and constituents

“…With waveguide mixers and GaAs Schottky diodes, good performance has been obtained at frequencies up to 300 GHz. Promising results have also been obtained for frequencies up to about 1000 GHz employing open structures and whisker antennas (28). Very low noise operati~n has been obtained at frequencies up to 450 GHz using Josephson junction mixers.…”

“…Although these sources are essentially non-tunable, they have been employed in situations where accidental coincidences exist between the laser frequency and the molecular transition being investigated. In addition, Fetterman et al (28), for example, have shown that tunable submillimeter frequencies (at power levels up to about l0-7 W) can be obtained by mixing the laser output with lower frequency microwaves using Schottky barrier diodes.…”

Plasmonic Rectenna for Efficient Conversion of Light into Electricity

“…It has been demonstrated that optical antennas can couple electromagnetic radiation in the visible in the same way as radio antennas do at their corresponding wavelength, three kinds of the metallic nanostructures with OR effect in the visible/near-infrared wavelength range had been located: whisker diodes [24,25], Schottky diodes [26,27] and metal-insulator-metal tunneling diodes [28,29]. Meanwhile, for the application in the solar cell technology, Bailey originally proposed that broadband rectifying antennas can be used for direct conversion of solar energy to DC power [30], the first patent on solar rectification was issued to Marks [31].…”

Fundamentals of Terrestrial Millimeter-Wave and THz Remote Sensing

“…To force the antenna pattern into one direction of space and thereby improve the directivity, the wire is mounted in a corner-cube reflector. 19 Historically, because of its broadband nature and small reactance, the cat whisker antenna played a key role in the development of THz technology as the demonstration vehicle for Schottky diodes, resonant-tunneling diodes, and other THz semiconductor devices.…”