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

Optimization of a 115 GHz waveguide mixer based on an HTS Josephson junction

Oliver Harnack, Marian Darula, Jens Scherbel, J.-K. Heinsohn, M. Siegel, D. Diehl, P Zimmermann

Published Nov 1, 1999• 25 citations
Publisher

Abstract

A waveguide mixer based on a Josephson junction made from a high-temperature superconductor (HTS) has been analysed at frequencies of 90 GHz and 115 GHz. The mixer consisted of a single-grain-boundary bicrystal junction which was integrated with a bow-tie antenna and a microstrip filter structure fabricated on an MgO substrate. Two different designs of mixer block were tested. Using the first design the best noise performance was measured at a local oscillator (LO) frequency of about 90 GHz. At the projected LO frequency of 115 GHz significant deterioration of performance was observed. A computer simulation of the mixer chip and substrate channel structure was performed using the 3D simulation program HFSS. Sufficient RF signal rejection by the filter structure was confirmed at 90 GHz. After a simulation cycle at 115 GHz the substrate channel in the mixer block was modified. Using this second design we measured a double-sideband mixer noise temperature of 1090 K at 10 K operating temperature which is the best performance of an HTS Josephson mixer to date obtained at this frequency and temperature.

DOI
10.1088/0953-2048/12/11/346

Related papers

Waveguide-Type SIS Receiver Using All-NbN Technique

M. TAKEDA

This paper describes the first experimental results for a waveguide-type all-NbN superconductor-insulator-superconductor (SIS) heterodyne mixer on an MgO substrate designed to operate over the gap frequency of Nb. The mixer consists of an NbN/MgO/NbN junction, which has a length of one wavelength at 880GHz as a tuning circuit, an NbN/MgO/NbN microstrip as a λ/4 impedance transformer, and an RF choke filter. The mixer chip was designed using a high-frequency-structure simulator. Its return-loss and embedding-impedance characteristics were examined using a 180-times-scaled mixer model. By optimizing the cutting and polishing processes for the MgO substrate, we were able to fabricate the mixer chip with an accuracy of less than 5 μm. We succeeded in mounting the chip on a mixer block and in estimating the receiver noise temperature. The uncorrected minimum double-sideband receiver noise temperature was 740 K at 824 GHz. A comparison of the receiver noise temperature in a quasi-optical SIS mixer fabricated on the same wafer as the waveguide mixer showed that input noise was the major contributor to receiver noise in the waveguide mixer.

IEICE Transactions on Electronics•Feb 1, 2006•5 citations

Low-noise integrated balanced SIS mixer for 787–950 GHz

Yasunori Fujii, Takafumi Kojima, Álvaro González +5 more

Abstract We developed a low-noise, compact, balanced superconductor–insulator–superconductor (SIS) mixer, operating in the 787–950 GHz radio frequency range. A waveguide mixer block was designed to integrate all the key components, such as a radio frequency (RF) 90° hybrid coupler, two identical SIS mixer chips, bias-tees, and an intermediate frequency power-combiner. The RF waveguide 90° hybrid coupler consists of branch lines with wide slots optimized by numerical simulation, for ease of fabrication. The balanced mixer was installed into a cartridge type receiver, originally developed for the Atacama Large Millimeter/submillimeter Array Band 10 (787–950 GHz). The receiver demonstrated double sideband noise temperatures of approximately 200 K for most of the band, without any correction for loss in front of the receiver. The local oscillator noise rejection ratio was estimated to be more than 15 dB within the measured frequency range.

Superconductor Science and Technology•Nov 30, 2016•13 citations

Noise properties of HTS Josephson mixers at 345 GHz and operating temperatures at 20 K

Jens Scherbel, Marian Darula, Oliver Harnack +1 more

The authors report on the mixing properties of high-temperature superconductor bicrystal Josephson junctions at 345 GHz and high-operating temperatures. A variable backshort and E-plane tuner enabled the control of impedance matching between the junction and the RF environment. The local oscillator frequency and intermediate frequency were 345 and 1.4 GHz, respectively. The double-side band (DSB) mixer noise temperature and the conversion efficiency were determined using the hot/cold method. The authors observed that the noise temperature was strongly dependent on the matching conditions. The lowest noise temperatures were observed for tuner positions supporting the formation of a subharmonic step which appeared between the zeroth and first Shapiro step. At T = 20 K they obtained a lowest DSB mixer noise temperature of 1003 K and a conversion efficiency of -1.2 dB. They have investigated the dependence of the noise temperature on the operating temperature in detail. The impact of resonances on the device performance will be discussed.

IEEE Transactions on Applied Superconductivity•Jun 1, 2002•24 citations

Noise and Conversion Efficiency of High-T c Superconductor Josephson Mixers

Oliver Harnack, S. Beuven, Marian Darula +4 more

We report on experimental studies of the noise performance and conversion efficiency of high-Te Josephson mixers at frequencies between 90 GHz and 550 GHz. The heterodyne mixing experiments have been performed by using YBa2Cu307_8 step-edge junctions and bicrystal junctions on MgO (E--9.6) substrates. We studied the Josephson mixer performance for the case of internal pumping (selfpumping) and external pumping. Receiver noise measurements in a waveg,uide setup for the case of external pumping at 90-94 GHz gave formally calculated double-side-band (DSB) mixer noise temperatures (Tm) of about 2000 K at physical temperatures of 10 K. Similar measurements in a quasioptical setup at 4.2 K and at operation frequencies of 430 GHz and 546 GHz yielded mixer noise temperatures of 1200 K and 1100 K, respectively. Using the internal pumped mode, i.e. mixing without external local oscillator signal, we also obtained clear IF response in hot/cold-measurements. The formally calculated Tm were between 580 K and 2300 K.

Softwaretechnik-Trends•Mar 1, 1998•1 citation

Characterizations of High-Temperature Superconducting Step-Edge Josephson Junction Mixer

Dan Dan Bai, Jia Du, Yu Sheng He

We report the experimental evaluation of a high-temperature superconducting (HTS) Josephson mixer. The mixer is fabricated from a HTS step-edge junction on MgO substrate. The mixer device operates as a lower side-band down-converter from a radio frequency between 6 and 10 GHz to a 1-2 GHz intermediate frequency under the action of a local oscillator. The experimental results of the current-voltage characteristics, optimal bias conditions, dynamic range, linearity, conversion gain, and the temperature dependence of the mixer are presented.

IEEE Transactions on Applied Superconductivity•Aug 15, 2014•6 citations

340 GHz Double-Sideband Mixer Based on Antenna-Coupled High-Temperature Superconducting Josephson Junction

Xiang Gao, Ting Zhang, Jia Du +1 more

Wireless communication and sensing are moving from microwave, millimeter-wave into the terahertz (THz) frequency regime to meet the fast growing demand of ultrahigh data-rate communications and super resolution imaging. Faced with severe atmospheric absorption attenuation and the lack of power efficient transmitting source at the higher band, ultrasensitive and cost-effective receiver frontend technology is required for advanced THz wireless systems. To date, the most sensitive heterodyne mixers, the key components of frontend receiver systems, are based on low-temperature superconducting materials that operate at liquid helium (4.2 K) temperature range, requiring expensive and bulky cryogenic cooling systems thus hindering them from commercial applications such as wireless communications and sensing. In this article, we present a 340 GHz double-sideband fundamental mixer based on thin-film antenna-coupled high-temperature superconducting (HTS) Josephson junction that operates at a much higher temperature range attainable with smaller and cheaper cryocoolers. Based on our innovative work in terms of advanced device circuit and on-chip antenna designs, accurate parametric simulation analyses, and Josephson junction parameter optimizations, the reported mixer exhibits a measured noise temperature of 470 and 780 K at operating temperatures of 20 and 40 K respectively at 340 GHz, a performance significantly higher than any HTS THz mixers reported to date.

IEEE Transactions on Terahertz Science and Technology•Nov 11, 2019•33 citations
A waveguide mixer based on a Josephson junction made from a high-temperature superconductor (HTS) has been analysed at frequencies of 90 GHz and 115 GHz. The mixer consisted of a single-grain-boundary bicrystal junction which was integrated with a bow-tie antenna and a microstrip filter structure fabricated on an MgO substrate. Two different designs of mixer block were tested. Using the first design the best noise performance was measured at a local oscillator (LO) frequency of about 90 GHz. At the projected LO frequency of 115 GHz significant deterioration of performance was observed. A computer simulation of the mixer chip and substrate channel structure was performed using the 3D simulation program HFSS. Sufficient RF signal rejection by the filter structure was confirmed at 90 GHz. After a simulation cycle at 115 GHz the substrate channel in the mixer block was modified. Using this second design we measured a double-sideband mixer noise temperature of 1090 K at 10 K operating temperature which is the best performance of an HTS Josephson mixer to date obtained at this frequency and temperature.
This paper describes the first experimental results for a waveguide-type all-NbN superconductor-insulator-superconductor (SIS) heterodyne mixer on an MgO substrate designed to operate over the gap frequency of Nb. The mixer consists of an NbN/MgO/NbN junction, which has a length of one wavelength at 880GHz as a tuning circuit, an NbN/MgO/NbN microstrip as a λ/4 impedance transformer, and an RF choke filter. The mixer chip was designed using a high-frequency-structure simulator. Its return-loss and embedding-impedance characteristics were examined using a 180-times-scaled mixer model. By optimizing the cutting and polishing processes for the MgO substrate, we were able to fabricate the mixer chip with an accuracy of less than 5 μm. We succeeded in mounting the chip on a mixer block and in estimating the receiver noise temperature. The uncorrected minimum double-sideband receiver noise temperature was 740 K at 824 GHz. A comparison of the receiver noise temperature in a quasi-optical SIS mixer fabricated on the same wafer as the waveguide mixer showed that input noise was the major contributor to receiver noise in the waveguide mixer.
Abstract We developed a low-noise, compact, balanced superconductor–insulator–superconductor (SIS) mixer, operating in the 787–950 GHz radio frequency range. A waveguide mixer block was designed to integrate all the key components, such as a radio frequency (RF) 90° hybrid coupler, two identical SIS mixer chips, bias-tees, and an intermediate frequency power-combiner. The RF waveguide 90° hybrid coupler consists of branch lines with wide slots optimized by numerical simulation, for ease of fabrication. The balanced mixer was installed into a cartridge type receiver, originally developed for the Atacama Large Millimeter/submillimeter Array Band 10 (787–950 GHz). The receiver demonstrated double sideband noise temperatures of approximately 200 K for most of the band, without any correction for loss in front of the receiver. The local oscillator noise rejection ratio was estimated to be more than 15 dB within the measured frequency range.
The authors report on the mixing properties of high-temperature superconductor bicrystal Josephson junctions at 345 GHz and high-operating temperatures. A variable backshort and E-plane tuner enabled the control of impedance matching between the junction and the RF environment. The local oscillator frequency and intermediate frequency were 345 and 1.4 GHz, respectively. The double-side band (DSB) mixer noise temperature and the conversion efficiency were determined using the hot/cold method. The authors observed that the noise temperature was strongly dependent on the matching conditions. The lowest noise temperatures were observed for tuner positions supporting the formation of a subharmonic step which appeared between the zeroth and first Shapiro step. At T = 20 K they obtained a lowest DSB mixer noise temperature of 1003 K and a conversion efficiency of -1.2 dB. They have investigated the dependence of the noise temperature on the operating temperature in detail. The impact of resonances on the device performance will be discussed.
We report on experimental studies of the noise performance and conversion efficiency of high-Te Josephson mixers at frequencies between 90 GHz and 550 GHz. The heterodyne mixing experiments have been performed by using YBa2Cu307_8 step-edge junctions and bicrystal junctions on MgO (E--9.6) substrates. We studied the Josephson mixer performance for the case of internal pumping (selfpumping) and external pumping. Receiver noise measurements in a waveg,uide setup for the case of external pumping at 90-94 GHz gave formally calculated double-side-band (DSB) mixer noise temperatures (Tm) of about 2000 K at physical temperatures of 10 K. Similar measurements in a quasioptical setup at 4.2 K and at operation frequencies of 430 GHz and 546 GHz yielded mixer noise temperatures of 1200 K and 1100 K, respectively. Using the internal pumped mode, i.e. mixing without external local oscillator signal, we also obtained clear IF response in hot/cold-measurements. The formally calculated Tm were between 580 K and 2300 K.
We report the experimental evaluation of a high-temperature superconducting (HTS) Josephson mixer. The mixer is fabricated from a HTS step-edge junction on MgO substrate. The mixer device operates as a lower side-band down-converter from a radio frequency between 6 and 10 GHz to a 1-2 GHz intermediate frequency under the action of a local oscillator. The experimental results of the current-voltage characteristics, optimal bias conditions, dynamic range, linearity, conversion gain, and the temperature dependence of the mixer are presented.
Wireless communication and sensing are moving from microwave, millimeter-wave into the terahertz (THz) frequency regime to meet the fast growing demand of ultrahigh data-rate communications and super resolution imaging. Faced with severe atmospheric absorption attenuation and the lack of power efficient transmitting source at the higher band, ultrasensitive and cost-effective receiver frontend technology is required for advanced THz wireless systems. To date, the most sensitive heterodyne mixers, the key components of frontend receiver systems, are based on low-temperature superconducting materials that operate at liquid helium (4.2 K) temperature range, requiring expensive and bulky cryogenic cooling systems thus hindering them from commercial applications such as wireless communications and sensing. In this article, we present a 340 GHz double-sideband fundamental mixer based on thin-film antenna-coupled high-temperature superconducting (HTS) Josephson junction that operates at a much higher temperature range attainable with smaller and cheaper cryocoolers. Based on our innovative work in terms of advanced device circuit and on-chip antenna designs, accurate parametric simulation analyses, and Josephson junction parameter optimizations, the reported mixer exhibits a measured noise temperature of 470 and 780 K at operating temperatures of 20 and 40 K respectively at 340 GHz, a performance significantly higher than any HTS THz mixers reported to date.