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

Superconductor Science and Technology

A 345 GHz waveguide mixer using an array of four Nb-Al-Al2O3-Nb SIS junctions

Cornelia E. Honingh, M. M. T. M. Dierichs, H. Schaeffer, T. M. Klapwijk, T de Graauw

Published Nov 1, 1991• 1 citation
Publisher

Abstract

An array of four Nb-Al-Al 2 O 3 -Nb SIS junctions in series is used as the mixing element in a waveguide mixer at 345 GHz. The area of one junction is 4 mu m 2 and its normal state resistance is about 12 Omega , yielding at 345 GHz, omega RC approximately 5. The receiver noise temperature below 550 K is between 330 and 375 GHz with best results around 350 K measured with a hot- and cold-load calibration. The conversion loss calculated from the hot/cold measurements ranges from 10.5 to 12.5 dB. The mixer noise temperature is around 200 K, with an instantaneous bandwidth of 2 GHz.

DOI
10.1088/0953-2048/4/11/036

Related papers

Comparison of measured and predicted performance of a SIS waveguide mixer at 345 GHz

Cornelia E. Honingh, G. Delange, M. M. T. M. Dierichs +5 more

The measured gain and noise of a SIS waveguide mixer at 345 GHz have been compared with theoretical values, calculated from the quantum mixer theory using a three port model. As a mixing element, we use a series array of two Nb-Al2O3-Nb SIS junctions. The area of each junction is 0.8 sq microns and the normal state resistance is 52 omega. The embedding impedance of the mixer has been determined from the pumped DC-IV curves of the junction and is compared to results from scale model measurements (105 x). Good agreement was obtained. The measured mixer gain, however, is a factor of 0.45 plus or minus 0.5 lower than the theoretical predicted gain. The measured mixer noise temperature is a factor of 4-5 higher than the calculated one. These discrepancies are independent on pump power and are valid for a broad range of tuning conditions.

•Jan 1, 1992•1 citation

Low noise broadband fixed tuned SIS waveguide mixers at 660 and 800 GHz

Cornelia E. Honingh, Sybille Haas, D. Hottgenroth +2 more

We present measurements and simulations of mixer performance around 660 GHz and around 800 GHz. We use Nb-Al/sub 2/O/sub 3/-Nb tunnel junctions with areas of 0.9 /spl mu/m/sup 2/ and 0.7 /spl mu/m/sup 2/, and RA-products of 14.5 /spl Omega/(/spl mu/m)/sup 2/ and 13 /spl Omega/(/spl mu/m)/sup 2/ for 660 GHz and 800 GHz. Both junctions have an integrated tuning structure made of niobium that consists of a series resonant stub and a quarter lambda transformer. The waveguide mixerblock has no additional adjustable tuning elements. It contains just a waveguide cavity and a substrate channel across it. A horn is carefully adjusted to the cavity and flanged to the block. The measured receiver noise temperatures from 630-690 GHz are below 190 K with a best value of 120 K at 655 GHz. From 780-820 GHz they are below 950 K with a best value of 780 K at 792 GHz. When the operating temperature is reduced from 4.2 K to 2.5 K, a reduction in noise temperature from 830 K to 660 K is observed at 810 GHz. The mixer performance is simulated using the quantum theory of mixing. The simulated performance shows a fairly good agreement with the measured one.

IEEE Transactions on Applied Superconductivity•Jun 1, 1997•21 citations

Performance of a two-junction array SIS-mixer operating around 345 GHz

Cornelia E. Honingh, Gert J. de Lange, M. M. T. M. Dierichs +3 more

The authors have made a detailed study of the gain and noise of a SIS (superconductor-insulator-superconductor) heterodyne receiver at 345 GHz. An array of two Nb-Al/sub 2/O/sub 3/-Nb SIS junctions in series are used as the mixing element. The array is operated in a waveguide mount with a backshort and an E-plane tuner. The best receiver noise temperature achieved is 140 K DSB (double sideband). The embedding impedances were determined by fitting theory to the measured pumped curves. High-quality fits were obtained, providing the first detailed test of the Tucker-theory at frequencies above 300 GHz. The impedances found by this method are in very good agreement with impedances measured in a scale model at 3.3 GHz. From these embedding impedances, the gain and noise of the mixer were calculated over a full bias range using the Tucker theory in the three-port low-IF approximation. The measured dependence of mixer gain and noise on bias voltage, pump power and embedding impedance is in good agreement with theory. However the absolute values show discrepancies that appear to be independent of the bias parameters of the mixer.>

IEEE Transactions on Microwave Theory and Techniques•Apr 1, 1993•14 citations

A low noise 410-495 GHz Nb/Al/sub 2/O/sub 3//Nb SIS waveguide mixer

Gert J. de Lange, Cornelia E. Honingh, M. M. T. M. Dierichs +5 more

The noise and gain of a heterodyne waveguide mixer using Nb/Al/sub 2/O/sub 3//Nb superconducting tunnel junctions were measured in the 400-500-GHz frequency range. Three different arrays of two junctions in series are analyzed. The minimum receiver noise temperature is 120 K DSB at 480 GHz, measured with an array having integrated tuning stubs. The authors compare data of the pumped I-V curves with the Werthammer-Tucker theory and demonstrate an excellent agreement at frequencies up to 500 GHz. For an array without integrated tuning stubs. a mixer noise temperature of 90+or-30 K and a DSB mixer gain of -12.5+or-0.6 dB were measured. A comparison of the measured gain versus bias voltage with the quantum theory of mixing shows good qualitative agreement, indicating the applicability of this theory to Nb tunnel junctions up to 500 GHz. The noise temperature of an array with a lower gap voltage is 220 K at 495 GHz. This frequency is 85% of the reduced gap frequency, indicating that Nb superconductor insulator-superconductor (SIS) mixers can be used up at least the gap frequency of 680 GHz.>

IEEE Transactions on Applied Superconductivity•Mar 1, 1993•13 citations

275–500-GHz Wideband Waveguide SIS Mixers

Takafumi Kojima, M. Kroug, Álvaro González +5 more

We have successfully demonstrated low-noise and wideband SIS mixers for the 275-500-GHz radio-frequency (RF) band, aiming to cover Atacama Large Millimeter/submillimeter Array band 7 (275-373 GHz) and band 8 (385-500 GHz) simultaneously. The waveguide SIS mixers integrate a multisection impedance transformer with a parallel-connected-twin-junction or single-junction circuits based on Nb/AlN/Nb trilayers with a critical current density of 31 kA/cm2. In order to achieve the targeted broadband performance, we designed an asymmetric one-side waveguide probe placed across a reduced height waveguide with dimensions 100 μm × 580 μm. The shape of the waveguide probe was optimized to have nearly constant impedance at around 35 Ω in the desired RF range. For evaluation of the receiver performance, we have established a dual-band noise temperature measurement system. The system implements a broadband corrugated horn antenna and a 15-dB RF/local oscillator (LO) waveguide coupler based on WR-2.3 (290 μm × 580 μm) waveguide size. The target bandwidth is too wide for typical LO sources at these high frequencies, and, therefore, we applied a dual-band LO injection system utilizing two different LO sources and an LO diplexer. The IF chain uses a cryogenic isolator and a low-noise amplifier with a typical noise temperature of 2.1 K over the 4-8-GHz range. The measured double sideband receiver noise temperature is two to three times the quantum noise at all LO frequencies for both the twin-junction and the single-junction circuits.

IEEE Transactions on Terahertz Science and Technology•Oct 1, 2018•22 citations

A 275–425-GHz Tunerless Waveguide Receiver Based on AlN-Barrier SIS Technology

J. Kooi, A. Kovács, Matthew Sumner +7 more

We report on a 275-425-GHz tunerless waveguide receiver with a 3.5-8-GHz IF. As the mixing element, we employ a high-current-density Nb-AlN-Nb superconducting-insulating-superconducting (SIS) tunnel junction. Thanks to the combined use of AlN-barrier SIS technology and a broad bandwidth waveguide to thin-film microstrip transition, we are able to achieve an unprecedented 43% instantaneous bandwidth, limited by the receiver's corrugated feedhorn. The measured double-sideband (DSB) receiver noise temperature, uncorrected for optics loss, ranges from 55 K at 275 GHz, 48 K at 345 GHz, to 72 K at 425 GHz. In this frequency range, the mixer has a DSB conversion loss of 2.3 plusmn1 dB. The intrinsic mixer noise is found to vary between 17-19 K, of which 9 K is attributed to shot noise associated with leakage current below the gap. To improve reliability, the IF circuit and bias injection are entirely planar by design. The instrument was successfully installed at the Caltech Submillimeter Observatory (CSO), Mauna Kea, HI, in October 2006.

IEEE Transactions on Microwave Theory and Techniques•Oct 1, 2007•38 citations
An array of four Nb-Al-Al 2 O 3 -Nb SIS junctions in series is used as the mixing element in a waveguide mixer at 345 GHz. The area of one junction is 4 mu m 2 and its normal state resistance is about 12 Omega , yielding at 345 GHz, omega RC approximately 5. The receiver noise temperature below 550 K is between 330 and 375 GHz with best results around 350 K measured with a hot- and cold-load calibration. The conversion loss calculated from the hot/cold measurements ranges from 10.5 to 12.5 dB. The mixer noise temperature is around 200 K, with an instantaneous bandwidth of 2 GHz.
The measured gain and noise of a SIS waveguide mixer at 345 GHz have been compared with theoretical values, calculated from the quantum mixer theory using a three port model. As a mixing element, we use a series array of two Nb-Al2O3-Nb SIS junctions. The area of each junction is 0.8 sq microns and the normal state resistance is 52 omega. The embedding impedance of the mixer has been determined from the pumped DC-IV curves of the junction and is compared to results from scale model measurements (105 x). Good agreement was obtained. The measured mixer gain, however, is a factor of 0.45 plus or minus 0.5 lower than the theoretical predicted gain. The measured mixer noise temperature is a factor of 4-5 higher than the calculated one. These discrepancies are independent on pump power and are valid for a broad range of tuning conditions.
We present measurements and simulations of mixer performance around 660 GHz and around 800 GHz. We use Nb-Al/sub 2/O/sub 3/-Nb tunnel junctions with areas of 0.9 /spl mu/m/sup 2/ and 0.7 /spl mu/m/sup 2/, and RA-products of 14.5 /spl Omega/(/spl mu/m)/sup 2/ and 13 /spl Omega/(/spl mu/m)/sup 2/ for 660 GHz and 800 GHz. Both junctions have an integrated tuning structure made of niobium that consists of a series resonant stub and a quarter lambda transformer. The waveguide mixerblock has no additional adjustable tuning elements. It contains just a waveguide cavity and a substrate channel across it. A horn is carefully adjusted to the cavity and flanged to the block. The measured receiver noise temperatures from 630-690 GHz are below 190 K with a best value of 120 K at 655 GHz. From 780-820 GHz they are below 950 K with a best value of 780 K at 792 GHz. When the operating temperature is reduced from 4.2 K to 2.5 K, a reduction in noise temperature from 830 K to 660 K is observed at 810 GHz. The mixer performance is simulated using the quantum theory of mixing. The simulated performance shows a fairly good agreement with the measured one.
The authors have made a detailed study of the gain and noise of a SIS (superconductor-insulator-superconductor) heterodyne receiver at 345 GHz. An array of two Nb-Al/sub 2/O/sub 3/-Nb SIS junctions in series are used as the mixing element. The array is operated in a waveguide mount with a backshort and an E-plane tuner. The best receiver noise temperature achieved is 140 K DSB (double sideband). The embedding impedances were determined by fitting theory to the measured pumped curves. High-quality fits were obtained, providing the first detailed test of the Tucker-theory at frequencies above 300 GHz. The impedances found by this method are in very good agreement with impedances measured in a scale model at 3.3 GHz. From these embedding impedances, the gain and noise of the mixer were calculated over a full bias range using the Tucker theory in the three-port low-IF approximation. The measured dependence of mixer gain and noise on bias voltage, pump power and embedding impedance is in good agreement with theory. However the absolute values show discrepancies that appear to be independent of the bias parameters of the mixer.>
The noise and gain of a heterodyne waveguide mixer using Nb/Al/sub 2/O/sub 3//Nb superconducting tunnel junctions were measured in the 400-500-GHz frequency range. Three different arrays of two junctions in series are analyzed. The minimum receiver noise temperature is 120 K DSB at 480 GHz, measured with an array having integrated tuning stubs. The authors compare data of the pumped I-V curves with the Werthammer-Tucker theory and demonstrate an excellent agreement at frequencies up to 500 GHz. For an array without integrated tuning stubs. a mixer noise temperature of 90+or-30 K and a DSB mixer gain of -12.5+or-0.6 dB were measured. A comparison of the measured gain versus bias voltage with the quantum theory of mixing shows good qualitative agreement, indicating the applicability of this theory to Nb tunnel junctions up to 500 GHz. The noise temperature of an array with a lower gap voltage is 220 K at 495 GHz. This frequency is 85% of the reduced gap frequency, indicating that Nb superconductor insulator-superconductor (SIS) mixers can be used up at least the gap frequency of 680 GHz.>
We have successfully demonstrated low-noise and wideband SIS mixers for the 275-500-GHz radio-frequency (RF) band, aiming to cover Atacama Large Millimeter/submillimeter Array band 7 (275-373 GHz) and band 8 (385-500 GHz) simultaneously. The waveguide SIS mixers integrate a multisection impedance transformer with a parallel-connected-twin-junction or single-junction circuits based on Nb/AlN/Nb trilayers with a critical current density of 31 kA/cm2. In order to achieve the targeted broadband performance, we designed an asymmetric one-side waveguide probe placed across a reduced height waveguide with dimensions 100 μm × 580 μm. The shape of the waveguide probe was optimized to have nearly constant impedance at around 35 Ω in the desired RF range. For evaluation of the receiver performance, we have established a dual-band noise temperature measurement system. The system implements a broadband corrugated horn antenna and a 15-dB RF/local oscillator (LO) waveguide coupler based on WR-2.3 (290 μm × 580 μm) waveguide size. The target bandwidth is too wide for typical LO sources at these high frequencies, and, therefore, we applied a dual-band LO injection system utilizing two different LO sources and an LO diplexer. The IF chain uses a cryogenic isolator and a low-noise amplifier with a typical noise temperature of 2.1 K over the 4-8-GHz range. The measured double sideband receiver noise temperature is two to three times the quantum noise at all LO frequencies for both the twin-junction and the single-junction circuits.
We report on a 275-425-GHz tunerless waveguide receiver with a 3.5-8-GHz IF. As the mixing element, we employ a high-current-density Nb-AlN-Nb superconducting-insulating-superconducting (SIS) tunnel junction. Thanks to the combined use of AlN-barrier SIS technology and a broad bandwidth waveguide to thin-film microstrip transition, we are able to achieve an unprecedented 43% instantaneous bandwidth, limited by the receiver's corrugated feedhorn. The measured double-sideband (DSB) receiver noise temperature, uncorrected for optics loss, ranges from 55 K at 275 GHz, 48 K at 345 GHz, to 72 K at 425 GHz. In this frequency range, the mixer has a DSB conversion loss of 2.3 plusmn1 dB. The intrinsic mixer noise is found to vary between 17-19 K, of which 9 K is attributed to shot noise associated with leakage current below the gap. To improve reliability, the IF circuit and bias injection are entirely planar by design. The instrument was successfully installed at the Caltech Submillimeter Observatory (CSO), Mauna Kea, HI, in October 2006.