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 Transactions on Microwave Theory and Techniques

A low noise 230 GHz heterodyne receiver employing 0.25- mu m/sup 2/ area Nb-AlO/sub x/-Nb tunnel junctions

J. Kooi, M. Chan, Tom G. Phillips, B. Bumble, Henry George LeDuc

Published May 1, 1992• 41 citations
Publisher

Abstract

The authors report recent results for a full-height rectangular waveguide mixer with an integrated IF matching network. Two 0.25 mu m/sup 2/ Nb-AlO/sub x/-Nb superconducting-insulating-superconducting (SIS) tunnel junctions with a current density of approximately=8500 A/cm/sup 2/ and omega RC of approximately=2.5 at 230 GHz have been tested. One of these quasiparticle tunnel junctions is currently being used at the Caltech Submillimeter Observatory in Hawaii. Detailed measurement of the receiver noise have been made from 200-290 GHz for both junctions at 4.2 K. The lowest receiver noise temperatures were recorded at 239 GHz, measuring 48 K DSB at 4.2 K and 40 K DSB at 2.1 K. The 230-GHz receiver incorporates a one-octave-wide integrated low-pass filter and matching network which transforms the pumped IF junction impedance to 50 Omega over a wide range of impedances.>

DOI
10.1109/22.137383

Related papers

A 547 GHz SIS receiver employing a submicron Nb junction with an integrated matching circuit

Pascal Febvre, William R. McGrath, P. D. Batelaan +4 more

A heterodyne receiver using an SIS (superconductor-insulator-superconductor) waveguide mixer with two mechanical tuners has been built and characterized over the frequency range of 460 GHz to 630 GHz. This receiver is designed for radioastronomy applications. The mixer uses high-current-density, 0.25- mu m/sup 2/, Nb/AlO/sub x//Nb SIS tunnel junctions with integrated superconductive RF circuits to tune the junction capacitance. A DSB (double sideband) receiver noise temperature as low as 200+or-17 K has been obtained at 540 GHz. In addition, negative differential resistance has been observed in the DC I-V (current-voltage) curve at 487-491 GHz.>

IEEE MTT-S International Microwave Symposium digest•Dec 30, 2002•4 citations

Quasi-optical submillimeter-wave SIS mixers with NbN/A1N/NbN tunnel junctions

Yoshinori Uzawa, Zhen Wang, Akira Kawakami

We report on low-noise heterodyne mixing with NbN/A1N/NbN tunnel junctions in the submillimeter-wave region for the first time. The receiver consists of the quasi-optical NbN SIS mixer with an integrated tuning circuit in which a radial short stub tuner is incorporated to resonate out the junction capacitance for RF matching and a balanced IF circuit for broadband IF matching. The prepared NbN SIS junction has a current density of 20 kA/cm 2 and is about 1 I1111 in diameter, supplying a small coC JRN product (o)CJRN = 3 at 300 GHz). The junctions showed good dc I-V characteristics, excellent submillimeter-wave responses and sensitive heterodyne mixing responses. From 254 to 350 GHz the average receiver noise temperature measured using by the standard Y-factor method was about 250 K (DSB) at 5 K. The lowest receiver noise temperature, 200 K (DSB), was obtained at around 303 GHz. Comparing NbN/A1N/NbN and Nb/A10x/Nb tunnel junction performance with the same tuning circuit showed that the frequency dependence of the receiver noise temperature agreed well in the two receivers. These results suggest that our well-controlled NbN SIS junctions can be used for terahertz mixer elements instead of Nb SIS junctions.

•Mar 1, 1996•2 citations

A 665 GHz Waveguide Receiver Using a Tuned 0.5 μm 2 Nb/AlO x /Nb SIS Tunnel Junction

J. Kooi, Mansun Chan, Henry George LeDuc +1 more

We report recent results on a 580-740 GHz SIS heterodyne receiver employing a tuned 0.50Am Nb/A10x/Nb SIS tunnel junction. The receiver has been successfully installed at the Caltech Submillimeter Observatory, Hawaii. Results of an untuned device in the same waveguide block were presented at the fifth International THz Conference. Since the mixer is meant to be operated near the superconducting gap frequency of niobium (2,L/h 690 GHz), special has been taken to minimize the absorption loss in the rf matching network. To this effect we propose the use of a RF matching network that constitutes a hybrid between the well know end-loaded stub and radial stub matching networks. We have measured uncorrected DSB receiver temperatures as low as 160K from 680to 702 Gliz, 200K at 725GHz and 120K from 585-640 GHz. The uncorrected mixer noise temperature at 702 Gliz is about 125K, of which 62K can be directly contributed to the front end optics loss. Mixer conversion loss at 702 GHz is 7dB, of which 0.9dB is due to the absorption loss in the Nb film. This results in a corrected mixer noise temperature of 63K, 1.7 times the quantum noise limit.

Softwaretechnik-Trends•Mar 1, 1996•1 citation

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

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 230 GHz low noise subharmonically pumped SIS mixer

K. C. Xiao, Hideo Ogawa, Akira Mizuno +1 more

A 230 GHz Low Noise Subharmonically Pumped (SHP) SIS mixer has been developed and tested at 115 GHz LO. The mixer has a two backshorts waveguide structure and employs an array of four 1.7 /spl mu/m/sup 2/ Nb/AlO/sub x//Nb SIS junctions in series with /spl omega/RnC/spl sim/3 at 230 GHz. Harmonic quantum mixing occurred over the whole experimental frequency range of 208-234 GHz (LO:114-117 GHz), with the corresponding DSB noise temperatures of lower than 150 K and a lowest value of 75 K at /spl sim/230 GHz. The present noise results are believed to be the lowest yet reported for a SHP mixer.

IEEE MTT-S International Microwave Symposium digest•Nov 7, 2002•2 citations
The authors report recent results for a full-height rectangular waveguide mixer with an integrated IF matching network. Two 0.25 mu m/sup 2/ Nb-AlO/sub x/-Nb superconducting-insulating-superconducting (SIS) tunnel junctions with a current density of approximately=8500 A/cm/sup 2/ and omega RC of approximately=2.5 at 230 GHz have been tested. One of these quasiparticle tunnel junctions is currently being used at the Caltech Submillimeter Observatory in Hawaii. Detailed measurement of the receiver noise have been made from 200-290 GHz for both junctions at 4.2 K. The lowest receiver noise temperatures were recorded at 239 GHz, measuring 48 K DSB at 4.2 K and 40 K DSB at 2.1 K. The 230-GHz receiver incorporates a one-octave-wide integrated low-pass filter and matching network which transforms the pumped IF junction impedance to 50 Omega over a wide range of impedances.>
A heterodyne receiver using an SIS (superconductor-insulator-superconductor) waveguide mixer with two mechanical tuners has been built and characterized over the frequency range of 460 GHz to 630 GHz. This receiver is designed for radioastronomy applications. The mixer uses high-current-density, 0.25- mu m/sup 2/, Nb/AlO/sub x//Nb SIS tunnel junctions with integrated superconductive RF circuits to tune the junction capacitance. A DSB (double sideband) receiver noise temperature as low as 200+or-17 K has been obtained at 540 GHz. In addition, negative differential resistance has been observed in the DC I-V (current-voltage) curve at 487-491 GHz.>
We report on low-noise heterodyne mixing with NbN/A1N/NbN tunnel junctions in the submillimeter-wave region for the first time. The receiver consists of the quasi-optical NbN SIS mixer with an integrated tuning circuit in which a radial short stub tuner is incorporated to resonate out the junction capacitance for RF matching and a balanced IF circuit for broadband IF matching. The prepared NbN SIS junction has a current density of 20 kA/cm 2 and is about 1 I1111 in diameter, supplying a small coC JRN product (o)CJRN = 3 at 300 GHz). The junctions showed good dc I-V characteristics, excellent submillimeter-wave responses and sensitive heterodyne mixing responses. From 254 to 350 GHz the average receiver noise temperature measured using by the standard Y-factor method was about 250 K (DSB) at 5 K. The lowest receiver noise temperature, 200 K (DSB), was obtained at around 303 GHz. Comparing NbN/A1N/NbN and Nb/A10x/Nb tunnel junction performance with the same tuning circuit showed that the frequency dependence of the receiver noise temperature agreed well in the two receivers. These results suggest that our well-controlled NbN SIS junctions can be used for terahertz mixer elements instead of Nb SIS junctions.
We report recent results on a 580-740 GHz SIS heterodyne receiver employing a tuned 0.50Am Nb/A10x/Nb SIS tunnel junction. The receiver has been successfully installed at the Caltech Submillimeter Observatory, Hawaii. Results of an untuned device in the same waveguide block were presented at the fifth International THz Conference. Since the mixer is meant to be operated near the superconducting gap frequency of niobium (2,L/h 690 GHz), special has been taken to minimize the absorption loss in the rf matching network. To this effect we propose the use of a RF matching network that constitutes a hybrid between the well know end-loaded stub and radial stub matching networks. We have measured uncorrected DSB receiver temperatures as low as 160K from 680to 702 Gliz, 200K at 725GHz and 120K from 585-640 GHz. The uncorrected mixer noise temperature at 702 Gliz is about 125K, of which 62K can be directly contributed to the front end optics loss. Mixer conversion loss at 702 GHz is 7dB, of which 0.9dB is due to the absorption loss in the Nb film. This results in a corrected mixer noise temperature of 63K, 1.7 times the quantum noise limit.
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.>
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.>
A 230 GHz Low Noise Subharmonically Pumped (SHP) SIS mixer has been developed and tested at 115 GHz LO. The mixer has a two backshorts waveguide structure and employs an array of four 1.7 /spl mu/m/sup 2/ Nb/AlO/sub x//Nb SIS junctions in series with /spl omega/RnC/spl sim/3 at 230 GHz. Harmonic quantum mixing occurred over the whole experimental frequency range of 208-234 GHz (LO:114-117 GHz), with the corresponding DSB noise temperatures of lower than 150 K and a lowest value of 75 K at /spl sim/230 GHz. The present noise results are believed to be the lowest yet reported for a SHP mixer.