A 1.4-THz Superconducting HEB Mixer for DATE5

W. Zhang, Wei Miao, Kang Zhang, S. C. Shi

Published Jan 1, 2012• 1 citation

Abstract

Purple Mountain Observatory as well as its collaborators is proposing to build a 5-m THz telescope (DATE5) at Dome A, Antarctic. Two THz heterodyne receivers, with one at 1.4 THz, are being considered as its first generation instrument. Here we report on the development of a 1.4-THz superconducting hot-electron bolometer (HEB) mixer for DATE5, which adopts a twin-slot antenna design. The direct-detection spectral (FTS) response of the 1.4-THz superconducting HEB mixer, with the HEB device fabricated at MSPU, has been measured, giving a frequency coverage of 0.8~1.5THz. And the measured FTS response appears in good agreement with the simulated one. Preliminary noise- temperature measurement at a lower frequency of 0.85 THz shows a receiver noise temperature of 1500 K. The estimated performance at 1.4 THz should be less than 1000 K in terms of the measured FTS response. Detailed simulation and experimental results will be presented.

Related papers

Investigation of high-sensitivity superconducting HEB mixers for Antarctic astronomy

Kangmin Zhou

China is now building an astronomical observatory including a THz telescope at Dome A on the Antarctic plateau. The development of superconducting HEB (Hot Electron Bolometer) mixers, the best choice for coherent detection at frequencies beyond 1 THz, becomes increasingly crucial. We present in this manuscript the investigation of high-sensitivity superconducting HEB mixers using quasi-optical technology in the THz region. The main results of this study are as follows: 1. We measured the dielectric constant of high-resistivity silicon at 77 K and 295 K by a vector measurement system. The measured permittivity is adopted to simulate the far-field beam pattern of a quasi-optical superconducting HEB mixer. 2. We measured the far-field beam pattern of a superconducting HEB mixer by both near-field heterodyne measurement system and far-field direct detection measurement system. The measured results accord well with the simulation. We also investigated the effect of HEB bias voltages and bath temperature on the far-field beam-pattern. 3. We successfully developed a high-sensitivity superconducting HEB mixer at 1.3 THz. The uncorrected measured double-sideband noise temperature is 600 K, which is a state-of-the-art result at this frequency. We systematically characterized heterodyne performances such as RF noise, conversion gain and noise bandwidth. We also measured the frequency response and calibrated it with a new method. Furthermore, we investigated the performance of this superconducting HEB mixer integrated with different elliptical lenses. 4. Finally, we measured the noise performance and the frequency response of a HEB mixer coupled to a 0.1-1.5 THz spiral antenna, the frequency dependence of the noise temperature has also been characterized. This study has provided a further understanding of superconducting HEB mixers and allowed the realization of a HEB mixer with state-of-the-art sensitivity at 1.3 THz. Hence the results of this study can find good use in the 5 m terahertz telescope (DATE5) at Dome A.

Sep 30, 20150 citations

Performance of a 1.4 THz Twin-Slot Superconductivity Hot Electron Bolometer Mixer

Daowei Wang, Kangmin Zhou, Yuan Ren +3 more

Three observation bands are planned for the Dome A Terahertz Explorer (DATE5), with the superconducting hot-electron bolometer (HEB) served as the mixer for the H200 band ( 200 μm wavelength). In this paper, the performance of a twin-slot antenna coupled superconducting NbN HEB mixer is fully characterized at 1.34 THz. The measured uncorrected receiver noise temperature is 500 K and the intermediate frequency (IF) noise bandwidth is about 3 GHz. Moreover, the receiver stability is characterized by measuring the Allan variance time.

International Conference on Microwave and Millimeter Wave Technology (ICMMT)May 1, 20180 citations

Superconducting hot electron bolometer as mixer for far-infrared heterodyne receivers

Heinz‐Wilhelm Hübers, Alexei D. Semenov, Heiko Richter +6 more

Heterodyne receivers for applications in astronomy need quantum limited sensitivity. In instruments which are currently under development for SOFIA or Herschel superconducting hot electron bolometers (HEB) will be used to achieve this goal at frequencies above 1.4 THz. We present results of the development of a phonon-cooled NbN HEB mixer for GREAT, the German Receiver for Astronomy at Terahertz Frequencies, which will be flown aboard SOFIA. The mixer is a small superconducting bridge incorporated in a planar feed antenna and a hyperhemispherical lens. Mixers with logarithmic-spiral and double-slot feed antennas have been investigated with respect to their noise temperature, conversion loss, linearity and beam pattern. At 2.5 THz a double sideband noise temperature of 2200 K was achieved. The conversion loss was 17 dB. The response of the mixer was linear up to 400 K load temperature. The performance was verified by measuring an emission line of methanol at 2.5 THz. The measured linewidth is in good agreement with the linewidth deduced from pressure broadening measurements at millimeter wavelength. The results demonstrate that the NbN HEB is very well suited as a mixer for far-infrared heterodyne receivers.

Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIEFeb 1, 20030 citations

Heterodyne receiver for 3-5 THz with hot-electron bolometer mixer

Heinz‐Wilhelm Hübers, Alexei D. Semenov, Heiko Richter +5 more

Heterodyne receivers for applications in astronomy and planetary research need quantum limited sensitivity. In instruments which are currently build for SOFIA and Herschel superconducting hot electron bolometers (HEB) will be used to achieve this goal at frequencies above 1.4 THz. The local oscillator and the mixer are the most critical components for a heterodyne receiver operating at 3-5 THz. The design and performance of an optically pumped THz gas laser optimized for this frequency band will be presented. In order to optimize the performance for this frequency hot electron bolometer mixers with different in-plane dimensions and logarithmic-spiral feed antennas have been investigated. Their noise temperatures and beam patterns were measured. Above 3 THz the best performance was achieved with a superconducting bridge of 2.0 x 0.2 μm2 incorporated in a logarithmic spiral antenna. The DSB noise temperatures were 2700 K, 4700 K and 6400 K at 3.1 THz, 4.3 THz and 5.2 THz, respectively. The results demonstrate that the NbN HEB is very well suited as a mixer for THz heterodyne receivers up to at least 5 THz.

Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIEOct 8, 200411 citations

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 SPIENov 13, 19981 citation

Terahertz Superconducting Hot Electron Bolometer Heterodyne Receivers

J. R. Gao, Merlijn Hajenius, Zhenyu Yang +4 more

We highlight the progress on NbN hot electron bolometer (HEB) mixers achieved through fruitful collaboration between SRON Netherlands Institute for Space Research and Delft University of Technology, the Netherlands. This includes the best receiver noise temperatures of 700 K at 1.63 THz using a twin-slot antenna mixer and 1050 K at 2.84 THz using a spiral antenna coupled HEB mixer. The mixers are based on thin NbN films on Si and fabricated with a new contact-process and-structure. By reducing their areas HEB mixers have shown an LO power requirement as low as 30 nW. Those small HEB mixers have demonstrated equivalent sensitivity as those with large areas provided the direct detection effect due to broadband radiation is removed. To manifest that a HEB based heterodyne receiver can in practice be used at arbitrary frequencies above 2 THz, we demonstrate a 2.8 THz receiver using a THz quantum cascade laser (QCL) as local oscillator.

IEEE Transactions on Applied SuperconductivityJun 1, 200728 citations