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

Journal of Applied Physics

Harmonic mixing in a superconductor-insulator-normal metal tunnel junction receiver

Lawrence M. Chernin, R. Blundell

Published Feb 15, 1991• 9 citations
Publisher

Abstract

We have investigated the theoretical performance of a subharmonically pumped Pb/Bi/In-oxide-Ag superconductor-insulator-normal metal mixer and found excellent receiver noise performance for signal frequencies above the gap frequency, Δ/h, if the junction is biased at zero volts. This type of mixer needs no pair current suppression and can use local oscillator power more efficiently than a fundamental mixer.

DOI
10.1063/1.348665

Related papers

Fundamental and harmonic mixing at 500 GHz using a superconductor-insulator-normal metal junction

Lawrence M. Chernin, R. Blundell, Edward Tong +1 more

We have demonstrated fundamental and harmonic mixing using a PbInAu/InOxPbOx/Ag superconductor-insulator-normal metal tunnel junction mixer designed to operate over the 450–550 GHz frequency range. Direct mixing experiments at up to 1.8 times the gap frequency of the tunnel junction have shown that the mixer works in both fundamental and second harmonic modes, with the highest conversion from the fundamental mode obtained at bias voltages near the gap voltage and the highest conversion from the harmonic mode obtained at zero bias. The measured mixer conversion curves are consistent with our five-port model simulations based on Tucker’s quantum mixer theory [IEEE J. Quantum. Electron. QE-15, 1234 (1979)].

Journal of Applied Physics•Oct 15, 1992•4 citations

Harmonic mixing in a superconducting tunnel junction

Edward Tong, Lawrence M. Chernin, R. Blundell

A theoretical analysis of harmonic mixing in a quasiparticle tunnel junction at Vbias=0 shows that harmonic mixing for submillimeter frequencies is a viable alternative to fundamental mixing. It is also shown that the signal gain from the first harmonic above the pump frequency to the intermediate frequency is independent of the embedding admittance at the pump frequency. In fact, we show that the five-port model reduces to the three-port model as a result of the inversion symmetry of the I-V curve and, moreover, no large-signal analysis is necessary. Full simulations of harmonic mixing using a five-port model confirm these results. The simulations have been done for the case of a superconductor-insulator-normal junction in which there is no pair current interference. For this type of harmonic mixer we show that the local oscillator (LO) power requirement can be less than a fundamental mixer operating at the same signal frequency, which is particularly useful in circumventing the problems of high-frequency LO power generation.

Journal of Applied Physics•Oct 15, 1990•8 citations

High-frequency limits of superconducting tunnel junction mixers

Dag Winkler, T. Claeson

We have investigated high-frequency limits of superconducting quasiparticle mixers from experiments on Al/Al-oxide-In/Al (or Ag) tunnel junctions, and from calculations based on Tucker’s quantum theory of mixing (QTM). The small superconducting energy gap of Al enabled us to study mixer performance at around the junction gap frequency, fg =(Δ1+Δ2)/h≊87 GHz, of superconductor-insulator-superconductor (SIS) mixers, and at twice the junction gap frequency for S-I-normal metal (SIN) mixers ( fg =Δ1/h) with available millimeter wave sources. Because of the low transition temperature of Al (Tc ≊1.3 K), a dilution refrigerator was used for providing temperatures below 1 K. The best mixer conversion efficiency was obtained for a low-resistance (∼34 Ω) six-junction array SIS mixer operated at f/fg ≊1 (in this case 73 GHz). The coupled single sideband conversion gain (with no image rejection) was −13.8 dB and the available conversion gain was estimated to −8.4 dB. Complicating nonequilibrium phenomena made it difficult to compare the performance of these relatively high-current-density mixers to the QTM. However, good agreement between calculated and corresponding measured conversion efficiencies and dynamic resistance values was obtained for the low-current-density mixers. Noise due to switching between rf-induced Josephson steps and interference from Josephson mixing could be quenched by a magnetic field. Several high-frequency limits are considered in this paper (such as Josephson switching noise, nonequilibrium phenomena, pair breaking, and energy gap limitations). Our results indicate that submillimeter wave SIS mixer receivers are likely to perform well, at least up to their gap frequencies, i.e., the THz region for large gap superconductors. Our QTM calculations showed that conversion gain larger than unity should be possible up to twice the gap frequency. Above this frequency the conversion loss will increase rapidly.

Journal of Applied Physics•Dec 1, 1987•35 citations

A Superconducting Tunnel Junction Receiver for 230 GHz

Edmund C. Sutton

The performance of superconducting tunnel junctions as high-frequency receivers is discussed. Low-noise mixing in superconductor insulator-superconductor (SIS) quasi-particle tunnel junctions has been seen for frequencies up to 400 GHz. Such mixers have the significant advantage of small local-oscillator power requirements. A receiver has been constructed which has a single-sideband (SSB) receiver noise temperature of 305 K at 241 GHz.

IEEE Transactions on Microwave Theory and Techniques•Jan 1, 1983•58 citations

Observation of subharmonically pumped mixing with gain using SIS junctions

S. E. G. Slusky, R. Trambarulo, Linus A. Fetter

We have observed subharmonically pumped, switched mode mixing in superconductor-insulator-superconductor (SIS) junctions. Experiments were performed at signal frequencies of 14.4 and 16.8 GHz using PbIn-oxide-Pb junctions approximately 1 μm × ½ μm The best single sideband power conversion seen was 2.0 ± 0.5 dB gain. The lowest single sideband mixer temperature measured was 48 ± 47K. This is the first superconducting mixer to combine the advantages of subharmonic pumping with single sideband gain and low noise.

IEEE Transactions on Magnetics•Jan 1, 1981•3 citations

Pushing the operating range of SIS mixers into the THz regime

T. M. Klapwijk, Pieter Dieleman, M. W. M. de Graauw

In recent years, responding to the need of the astronomical community, superconductor - insulator - superconductor (SIS) mixers have been developed to operate at THz frequencies. Best results are obtained by using niobium-based tunnel junctions with well-matched low-loss normal metal striplines, which are found to be less lossy than niobium striplines operated above the gap frequency of niobium (700 GHz). Niobium nitride tunnel junctions with a magnesium oxide tunnel barrier, although having reasonable-quality current - voltage characteristics, have been found to be unsuitable owing to excess shot noise resulting from pinholes in the barrier.

Superconductor Science and Technology•Dec 1, 1997•5 citations
We have investigated the theoretical performance of a subharmonically pumped Pb/Bi/In-oxide-Ag superconductor-insulator-normal metal mixer and found excellent receiver noise performance for signal frequencies above the gap frequency, Δ/h, if the junction is biased at zero volts. This type of mixer needs no pair current suppression and can use local oscillator power more efficiently than a fundamental mixer.
We have demonstrated fundamental and harmonic mixing using a PbInAu/InOxPbOx/Ag superconductor-insulator-normal metal tunnel junction mixer designed to operate over the 450–550 GHz frequency range. Direct mixing experiments at up to 1.8 times the gap frequency of the tunnel junction have shown that the mixer works in both fundamental and second harmonic modes, with the highest conversion from the fundamental mode obtained at bias voltages near the gap voltage and the highest conversion from the harmonic mode obtained at zero bias. The measured mixer conversion curves are consistent with our five-port model simulations based on Tucker’s quantum mixer theory [IEEE J. Quantum. Electron. QE-15, 1234 (1979)].
A theoretical analysis of harmonic mixing in a quasiparticle tunnel junction at Vbias=0 shows that harmonic mixing for submillimeter frequencies is a viable alternative to fundamental mixing. It is also shown that the signal gain from the first harmonic above the pump frequency to the intermediate frequency is independent of the embedding admittance at the pump frequency. In fact, we show that the five-port model reduces to the three-port model as a result of the inversion symmetry of the I-V curve and, moreover, no large-signal analysis is necessary. Full simulations of harmonic mixing using a five-port model confirm these results. The simulations have been done for the case of a superconductor-insulator-normal junction in which there is no pair current interference. For this type of harmonic mixer we show that the local oscillator (LO) power requirement can be less than a fundamental mixer operating at the same signal frequency, which is particularly useful in circumventing the problems of high-frequency LO power generation.
We have investigated high-frequency limits of superconducting quasiparticle mixers from experiments on Al/Al-oxide-In/Al (or Ag) tunnel junctions, and from calculations based on Tucker’s quantum theory of mixing (QTM). The small superconducting energy gap of Al enabled us to study mixer performance at around the junction gap frequency, fg =(Δ1+Δ2)/h≊87 GHz, of superconductor-insulator-superconductor (SIS) mixers, and at twice the junction gap frequency for S-I-normal metal (SIN) mixers ( fg =Δ1/h) with available millimeter wave sources. Because of the low transition temperature of Al (Tc ≊1.3 K), a dilution refrigerator was used for providing temperatures below 1 K. The best mixer conversion efficiency was obtained for a low-resistance (∼34 Ω) six-junction array SIS mixer operated at f/fg ≊1 (in this case 73 GHz). The coupled single sideband conversion gain (with no image rejection) was −13.8 dB and the available conversion gain was estimated to −8.4 dB. Complicating nonequilibrium phenomena made it difficult to compare the performance of these relatively high-current-density mixers to the QTM. However, good agreement between calculated and corresponding measured conversion efficiencies and dynamic resistance values was obtained for the low-current-density mixers. Noise due to switching between rf-induced Josephson steps and interference from Josephson mixing could be quenched by a magnetic field. Several high-frequency limits are considered in this paper (such as Josephson switching noise, nonequilibrium phenomena, pair breaking, and energy gap limitations). Our results indicate that submillimeter wave SIS mixer receivers are likely to perform well, at least up to their gap frequencies, i.e., the THz region for large gap superconductors. Our QTM calculations showed that conversion gain larger than unity should be possible up to twice the gap frequency. Above this frequency the conversion loss will increase rapidly.
We have observed subharmonically pumped, switched mode mixing in superconductor-insulator-superconductor (SIS) junctions. Experiments were performed at signal frequencies of 14.4 and 16.8 GHz using PbIn-oxide-Pb junctions approximately 1 μm × ½ μm The best single sideband power conversion seen was 2.0 ± 0.5 dB gain. The lowest single sideband mixer temperature measured was 48 ± 47K. This is the first superconducting mixer to combine the advantages of subharmonic pumping with single sideband gain and low noise.
In recent years, responding to the need of the astronomical community, superconductor - insulator - superconductor (SIS) mixers have been developed to operate at THz frequencies. Best results are obtained by using niobium-based tunnel junctions with well-matched low-loss normal metal striplines, which are found to be less lossy than niobium striplines operated above the gap frequency of niobium (700 GHz). Niobium nitride tunnel junctions with a magnesium oxide tunnel barrier, although having reasonable-quality current - voltage characteristics, have been found to be unsuitable owing to excess shot noise resulting from pinholes in the barrier.