Title :
Noise and conversion efficiency of aluminum superconducting hot-electron bolometer mixer
Author :
Siddiqi, Irfan ; Verevkin, Aleksandr ; Prober, Daniel E. ; Skalare, Anders ; Karasik, Boris S. ; McGrath, William R. ; Echternach, Pierre ; LeDuc, Henry G.
Author_Institution :
Dept. of Appl. Phys., Yale Univ., New Haven, CT, USA
fDate :
3/1/2001 12:00:00 AM
Abstract :
We report on microwave measurements of superconducting aluminum hot-electron bolometers (Al HEBs). Diffusion-cooled Al HEB mixers are good candidates for space-borne applications in the Terahertz frequency range since they are predicted to have small local oscillator (LO) power requirements, intermediate frequency (IF) bandwidths ≳10 GHz, and a noise temperature lower than that of Nb and NbN HEB mixers. Mixer measurements were made at an LO frequency ~30 GHz, with an IF in the range 0.1 to 7.3 GHz. For T<0.8 K, a magnetic field H=0.1-0.3 T was applied to suppress the superconductivity in the contact pads, and partly in the bridge. For a 0.6 μm long device, we measure an IF bandwidth of 4 GHz, a conversion efficiency η=-8 dB, and a mixer noise temperature TM≳4 K, DSB (Tmixer=Toutput noise/2η). These results are shown to be in quantitative agreement with simple theoretical predictions
Keywords :
aluminium; bolometers; hot carriers; microwave mixers; superconducting device noise; superconducting microwave devices; superconducting mixers; 0.1 to 0.3 T; 0.8 K; 30 GHz; 4 GHz; Al; IF bandwidth; LO power; aluminum superconducting hot electron bolometer mixer; conversion efficiency; diffusion cooling; magnetic field; microwave measurements; noise temperature; space-borne applications; terahertz spectroscopy; Aluminum; Bandwidth; Bolometers; Frequency; Magnetic field measurement; Magnetic noise; Microwave measurements; Mixers; Superconducting device noise; Superconducting microwave devices;
Journal_Title :
Applied Superconductivity, IEEE Transactions on
