Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Log inSign up
Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Blog
Job Board
Q3AS

© 2026 Aqora Quantum S.A.S.

TermsPrivacyLegal Notice

IEEE International Conference on Terahertz Electronics (THz)

Low-noise and wideband hot-electron superconductive mixers for THz frequencies

Boris S. Karasik, Anders J. Skalare, Rolf A. Wyss, William R. McGrath, B. Bumble, B. LeDuc, Jeff B. Barner, Alan W. Kleinsasser

Published Nov 27, 2002• 5 citations
Publisher

Abstract

Superconductive hot-electron bolometer (HEB) mixers have been built and tested in the frequency range 1.1-2.5 THz. The mixer device is a 0.15-03 /spl mu/m microbridge made from a 10 nm thick Nb film. This device employs diffusion as a cooling mechanism for hot electrons. The double sideband noise temperature was measured to be /spl les/3000 K at 2.5 THz and the mixer IF bandwidth is /spl ap/9-10 GHz for a 0.1 /spl mu/m long device. The local oscillator (LO) power dissipated in the HEB microbridge was 20-100 nW. Further improvement of the mixer characteristics can be potentially achieved by using Al microbridges. The advantages and parameters of such devices are evaluated The HEB mixer Is a primary candidate for ground based, airborne and spaceborne heterodyne instruments at THz frequencies. HEB receivers are planned for use on the NASA Stratospheric Observatory for Infrared Astronomy (SOFIA) and the ESA Far Infrared and Submillimeter Space Telescope (FIRST). The prospects of a submicron-size YBa/sub 2/Cu/sub 3/O/sub 7-/spl delta// (YBCO) HEB are also discussed. The expected LO power of 1-10 /spl mu/W and SSB noise temperature of /spl ap/2000 K may make this mixer attractive for various remote sensing applications.

DOI
10.1109/thz.1998.731649

Related papers

Low-noise and wideband hot-electron superconductive mixer for terahertz frequencies

Boris S. Karasik, Anders J. Skalare, William R. McGrath +7 more

Superconductive hot-electron bolometer (HEB) mixers have been built and tested in the frequency range from 1.1 THz to 2.5 THz. The mixer device is a 0.15 - 0.3 micrometer microbridge made from a 10 nm thick Nb film. This device employs diffusion as a cooling mechanism for hot electrons. The double sideband noise temperature was measured to be less than or equal to 3000 K at 2.5 THz and the mixer IF bandwidth is expected to be at least 10 GHz for a 0.1 micrometer long device. The local oscillator (LO) power dissipated in the HEB microbridge was 20 - 100 nW. Further improvement of the mixer characteristics can be potentially achieved by using Al microbridges. The advantages and parameters of such devices are evaluated. The HEB mixer is a primary candidate for ground based, airborne and spaceborne heterodyne instruments at THz frequencies. HEB receivers are planned for use on the NASA Stratospheric Observatory for Infrared Astronomy (SOFIA) and the ESA Far Infrared and Submillimeter Space Telescope (FIRST). The prospects of a submicron-size YBa2Cu3O7-(delta ) (YBCO) HEB are discussed. The expected LO power of 1 - 10 (mu) W and SSB noise temperature of approximately equals 2000 K may make this mixer attractive for various remote sensing applications.

Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE•Nov 13, 1998•1 citation

Hot-electron superconductive mixers for THz frequencies

William R. McGrath, Boris S. Karasik, Anders J. Skalare +3 more

Superconductive hot-electron bolometer (HEB) mixers have been built and tested in the frequency range from 1.1 THz to 2.5 THz. The mixer device employs diffusion as a cooling mechanism for hot electrons. The double sideband receiver noise temperature was measured to be approximately equals 2750 K at 2.5 K at 2.5 THz; and mixer IF bandwidths as high as 9 GHz are achieved for 0.1 micrometers long devices. The local oscillator power dissipated in the HEB microbridge was in the range 20- 100 nW. Further reductions in LO power and mixer noise can be potentially achieved by using Al microbridges. The advantages and parameters of such devices are evaluated. A distributed-temperature model has been developed to properly describe the operation of the diffusion-cooled HEB mixer. The HEB mixer is a primary candidate for ground based, airborne and spaceborne heterodyne instruments at THz frequencies.

Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE•Apr 29, 1999•9 citations

A low-noise 2.5 THz superconductive Nb hot-electron mixer

Boris S. Karasik, Michael C. Gaidis, William R. McGrath +2 more

We report on the development of a quasioptical Nb hot-electron bolometer mixer for a 2.5 THz heterodyne receiver. The devices are fabricated from a 12 nm thick Nb film, and have a 0.30 /spl mu/m/spl times/0.15 /spl mu/m in-plane size, thus exploiting diffusion as the electron cooling mechanism. The rf coupling was provided by a twin-slot planar antenna on an elliptical Si lens. A specially designed 2.5 THz system, using a CO/sub 2/-pumped FIR laser as local oscillator (LO), with rf hot/cold loads enclosed in vacuum to avoid atmospheric absorption, was used in the experiment. The experimentally measured double sideband (DSB) noise temperature of the receiver was as low as /spl les/3000 K, with an estimated mixer noise temperature of /spl ap/750 K. These results demonstrate the operation of the diffusion-cooled bolometer mixer above 2 THz.

IEEE Transactions on Applied Superconductivity•Jun 1, 1997•32 citations

Noise and Bandwidth Measurements of Diffusion-Cooled Nb Hot-Electron Bolometer Mixers at Frequencies Above the Superconductive Energy Gap

Rolf A. Wyss, Boris S. Karasik, William R. McGrath +2 more

Diffusion-cooled Nb hot-electron bolometer (HEB) mixers have the potential to simultaneously achieve high intermediate frequency (IF) bandwidths and low mixer noise temperatures for operation at THz frequencies (above the superconductive gap energy). We have measured the IF signal bandwidth at 630 GHz of Nb devices with lengths L = 0.3, 0.2, and 0.1 micrometer in a quasioptical mixer configuration employing twin-slot antennas. The 3-dB EF bandwidth increased from 1.2 GHz for the 0.3 gm long device to 9.2 GHz for the 0.1 gm long device. These results demonstrate the expected 1/L squared dependence of the IF bandwidth at submillimeter wave frequencies for the first time, as well as the largest EF bandwidth obtained to date. For the 0.1 gm device, which had the largest bandwidth, the double sideband (DSB) noise temperature of the receiver was 320-470 K at 630 GHz with an absorbed LO power of 35 nW, estimated using the isothermal method. A version of this mixer with the antenna length scaled for operation at 2.5 THz has also been tested. A DSB receiver noise temperature of 1800 plus or minus 100 K was achieved, which is about 1,000 K lower than our previously reported results. These results demonstrate that large EF bandwidth and low-noise operation of a diffusion-cooled HEB mixer is possible at THz frequencies with the same device geometry.

Softwaretechnik-Trends•Jan 1, 1999•20 citations

Aluminum Sub-Micron Superconducting Hot-Electron Bolometer Mixer

Irfan A. Siddiqi, A. Verevkin, D. E. Prober +5 more

We report on microwave measurements of superconducting aluminum hot-electron bolometers (Al HEBs). Diffusion-cooled Al HEB mixers are ideal candidates for space-borne and terrestrial remote-sensing 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 HEBs. Mixer measurements were made at an LO frequency ~30 GHz LO, with an IF in the range 0.1-7.3 GHz. For T < 0.8 K, a magnetic field H=0.1-0.3T was applied to suppress the superconductivity in the contact pads, and partly in the bridge. For a 0.6 μm long Al HEB, we measure an IF bandwidth of 4 GHz, a conversion efficiency η = -8dB, and a mixer noise temperature Tm ! 4K, DSB (Tmixer=Toutput noise/2η). These results are shown to be in quantitative agreement with simple theoretical predictions.

Softwaretechnik-Trends•May 1, 2000•3 citations

Noise and conversion efficiency of aluminum superconducting hot-electron bolometer mixer

Irfan A. Siddiqi, A. Verevkin, D. E. Prober +5 more

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 /spl gsim/10 GHz, and a noise temperature lower than that of Nb and NbN HEB mixers. Mixer measurements were made at an LO frequency /spl sim/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 /spl mu/m long device, we measure an IF bandwidth of 4 GHz, a conversion efficiency /spl eta/=-8 dB, and a mixer noise temperature T/sub M//spl gsim/4 K, DSB (T/sub mixer/=T/sub output noise//2/spl eta/). These results are shown to be in quantitative agreement with simple theoretical predictions.

IEEE Transactions on Applied Superconductivity•Mar 1, 2001•17 citations
Superconductive hot-electron bolometer (HEB) mixers have been built and tested in the frequency range 1.1-2.5 THz. The mixer device is a 0.15-03 /spl mu/m microbridge made from a 10 nm thick Nb film. This device employs diffusion as a cooling mechanism for hot electrons. The double sideband noise temperature was measured to be /spl les/3000 K at 2.5 THz and the mixer IF bandwidth is /spl ap/9-10 GHz for a 0.1 /spl mu/m long device. The local oscillator (LO) power dissipated in the HEB microbridge was 20-100 nW. Further improvement of the mixer characteristics can be potentially achieved by using Al microbridges. The advantages and parameters of such devices are evaluated The HEB mixer Is a primary candidate for ground based, airborne and spaceborne heterodyne instruments at THz frequencies. HEB receivers are planned for use on the NASA Stratospheric Observatory for Infrared Astronomy (SOFIA) and the ESA Far Infrared and Submillimeter Space Telescope (FIRST). The prospects of a submicron-size YBa/sub 2/Cu/sub 3/O/sub 7-/spl delta// (YBCO) HEB are also discussed. The expected LO power of 1-10 /spl mu/W and SSB noise temperature of /spl ap/2000 K may make this mixer attractive for various remote sensing applications.
Superconductive hot-electron bolometer (HEB) mixers have been built and tested in the frequency range from 1.1 THz to 2.5 THz. The mixer device is a 0.15 - 0.3 micrometer microbridge made from a 10 nm thick Nb film. This device employs diffusion as a cooling mechanism for hot electrons. The double sideband noise temperature was measured to be less than or equal to 3000 K at 2.5 THz and the mixer IF bandwidth is expected to be at least 10 GHz for a 0.1 micrometer long device. The local oscillator (LO) power dissipated in the HEB microbridge was 20 - 100 nW. Further improvement of the mixer characteristics can be potentially achieved by using Al microbridges. The advantages and parameters of such devices are evaluated. The HEB mixer is a primary candidate for ground based, airborne and spaceborne heterodyne instruments at THz frequencies. HEB receivers are planned for use on the NASA Stratospheric Observatory for Infrared Astronomy (SOFIA) and the ESA Far Infrared and Submillimeter Space Telescope (FIRST). The prospects of a submicron-size YBa2Cu3O7-(delta ) (YBCO) HEB are discussed. The expected LO power of 1 - 10 (mu) W and SSB noise temperature of approximately equals 2000 K may make this mixer attractive for various remote sensing applications.
Superconductive hot-electron bolometer (HEB) mixers have been built and tested in the frequency range from 1.1 THz to 2.5 THz. The mixer device employs diffusion as a cooling mechanism for hot electrons. The double sideband receiver noise temperature was measured to be approximately equals 2750 K at 2.5 K at 2.5 THz; and mixer IF bandwidths as high as 9 GHz are achieved for 0.1 micrometers long devices. The local oscillator power dissipated in the HEB microbridge was in the range 20- 100 nW. Further reductions in LO power and mixer noise can be potentially achieved by using Al microbridges. The advantages and parameters of such devices are evaluated. A distributed-temperature model has been developed to properly describe the operation of the diffusion-cooled HEB mixer. The HEB mixer is a primary candidate for ground based, airborne and spaceborne heterodyne instruments at THz frequencies.
We report on the development of a quasioptical Nb hot-electron bolometer mixer for a 2.5 THz heterodyne receiver. The devices are fabricated from a 12 nm thick Nb film, and have a 0.30 /spl mu/m/spl times/0.15 /spl mu/m in-plane size, thus exploiting diffusion as the electron cooling mechanism. The rf coupling was provided by a twin-slot planar antenna on an elliptical Si lens. A specially designed 2.5 THz system, using a CO/sub 2/-pumped FIR laser as local oscillator (LO), with rf hot/cold loads enclosed in vacuum to avoid atmospheric absorption, was used in the experiment. The experimentally measured double sideband (DSB) noise temperature of the receiver was as low as /spl les/3000 K, with an estimated mixer noise temperature of /spl ap/750 K. These results demonstrate the operation of the diffusion-cooled bolometer mixer above 2 THz.
Diffusion-cooled Nb hot-electron bolometer (HEB) mixers have the potential to simultaneously achieve high intermediate frequency (IF) bandwidths and low mixer noise temperatures for operation at THz frequencies (above the superconductive gap energy). We have measured the IF signal bandwidth at 630 GHz of Nb devices with lengths L = 0.3, 0.2, and 0.1 micrometer in a quasioptical mixer configuration employing twin-slot antennas. The 3-dB EF bandwidth increased from 1.2 GHz for the 0.3 gm long device to 9.2 GHz for the 0.1 gm long device. These results demonstrate the expected 1/L squared dependence of the IF bandwidth at submillimeter wave frequencies for the first time, as well as the largest EF bandwidth obtained to date. For the 0.1 gm device, which had the largest bandwidth, the double sideband (DSB) noise temperature of the receiver was 320-470 K at 630 GHz with an absorbed LO power of 35 nW, estimated using the isothermal method. A version of this mixer with the antenna length scaled for operation at 2.5 THz has also been tested. A DSB receiver noise temperature of 1800 plus or minus 100 K was achieved, which is about 1,000 K lower than our previously reported results. These results demonstrate that large EF bandwidth and low-noise operation of a diffusion-cooled HEB mixer is possible at THz frequencies with the same device geometry.
We report on microwave measurements of superconducting aluminum hot-electron bolometers (Al HEBs). Diffusion-cooled Al HEB mixers are ideal candidates for space-borne and terrestrial remote-sensing 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 HEBs. Mixer measurements were made at an LO frequency ~30 GHz LO, with an IF in the range 0.1-7.3 GHz. For T < 0.8 K, a magnetic field H=0.1-0.3T was applied to suppress the superconductivity in the contact pads, and partly in the bridge. For a 0.6 μm long Al HEB, we measure an IF bandwidth of 4 GHz, a conversion efficiency η = -8dB, and a mixer noise temperature Tm ! 4K, DSB (Tmixer=Toutput noise/2η). These results are shown to be in quantitative agreement with simple theoretical predictions.
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 /spl gsim/10 GHz, and a noise temperature lower than that of Nb and NbN HEB mixers. Mixer measurements were made at an LO frequency /spl sim/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 /spl mu/m long device, we measure an IF bandwidth of 4 GHz, a conversion efficiency /spl eta/=-8 dB, and a mixer noise temperature T/sub M//spl gsim/4 K, DSB (T/sub mixer/=T/sub output noise//2/spl eta/). These results are shown to be in quantitative agreement with simple theoretical predictions.