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

Electronics Letters

650 GHz SIS mixer fabricated on silicon‐on‐insulator substrate

B.‐K. Tan, G. Yassin, Paul Grimes, Karl Jacobs

Published Sep 1, 2013• 9 citations
Publisher

Abstract

The successful operation of a 650 GHz unilateral finline superconductor–insulator–superconductor mixer with a wide IF bandwidth is reported. The mixer was fabricated using silicon‐on‐insulator (SOI) technology, with planar circuit on‐chip integration. The mixer was tested over the frequency range of 630–702 GHz, and the best recorded DSB noise temperature was 226 K. The measured RF and IF behaviour of the mixer agreed very well with the simulation predictions. This demonstrates that superconducting finline mixers fabricated on an SOI substrate can achieve state‐of‐the‐art performance, and yet are much more compact and highly reproducible, and hence suitable for large‐format arrays in astronomy instruments, at THz frequencies.

DOI
10.1049/el.2013.2491

Related papers

A 700 GHz unilateral finline SIS mixer fed by a multi-flare angle smooth-walled horn

Boon-Kok Tan, G. Yassin, Paul Grimes +5 more

We present the design of a broadband superconductor-insulator-superconductor (SIS) mixer operating near 700 GHz. A key feature of our design is the utilisation of a new type of waveguide to planar circuit transition comprising a unilateral finline taper. This transition is markedly easier to design, simulate and fabricate than the antipodal finline we employed previously. The finline taper and the superconducting circuitry are deposited on a 15 μm thick silicon substrate. The employment of the very thin substrate, achieved using Silicon-On-Insulator (SOI) technology, makes it easy to match the incoming signal to the loaded waveguide. The lightweight mixer chip is held in the E-plane of the waveguide using gold beam leads, avoiding the need for deep grooves in the waveguide wall. This new design yields a significantly shorter chip, free of serrations and a wider RF bandwidth. Since tuning and all other circuits are integrated on the mixer chip, the mixer block is extremely simple, comprising a feed horn and a waveguide section without any complicated mechanical features. We employ a new type of smooth-walled horn which exhibits excellent beam circularity and low cross polarisation, comparable to the conventional corrugated horn, and yet is easier to fabricate. The horn is machined by standard milling with a drill tool shaped into the horn profile. In this paper, we describe the detailed design of the mixer chip including electromagnetic simulations, and the mixer performance obtained with SuperMix simulations. We also present the preliminary measurements of the smooth-walled horn radiation patterns near the mixer operating frequencies.

Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE•Jun 22, 2010•5 citations

A millimeter unilateral finline SIS mixer with a wide IF bandwidth

Yangjun Zhou

Superconductor-Insulator-Superconductor (SIS) tunnel junction mixers are now commonly used in as- tronomical receivers at (sub)millimeter wavelengths because of their superb sensitivity, high dynamic range and stability of operation. Niobium SIS mixers operating at frequencies well below the super- conducting gap (∼680 GHz) have already achieved quantum limited sensitivity. Therefore to further enhance the receiver sensitivity, increasing the Intermediate Frequency (IF) bandwidth of SIS mixers has became crucial. This thesis focuses on the theoretical modeling, design and experimental verifi- cation of Nb SIS mixers operating around 230 GHz with a wide IF bandwidth of 1–15 GHz. These mixers were designed for a single baseline heterodyne interferometer (GUBBINS), which is being built to observe the Sunyaev-Zel’dovich effect in the Cosmic Microwave Background. The combination of wide IF bandwidth SIS mixers and complex analogue correlators will allow GUBBINS to feature high surface brightness sensitivity, that helps to distinguish the weak SZ effect from the background noise. The SIS mixer detector system was assembled inside the GUBBINS cryostat together with the IF electronics and RF/LO optical systems. Low noise temperatures of around 71 K were then measured in the GUBBINS system. The Nb SIS mixer we have developed uses a unilateral finline and fully integrated planar circuits deposited on a silicon substrate, to couple the electromagnetic radiation from the waveguide into the SIS junction. The finline mixer allows a broad-band RF coupling, an easy integration of the on-chip planar circuits and an easy-to-fabricate mixer block. To achieve a wide IF bandwidth, the output impedance of the SIS mixer was well matched to the input impedance of the amplifier by a multi-stage microstrip circuit. Additionally, the planar circuit of the SIS mixer was also designed to have a small lumped inductance and capacitance. The SIS mixer chip was extensively simulated by rigorous electromagnetic software (HFSS) and the S-parameter was exported to a quantum mixing package SuperMix to produce a full-wave model of the mixer. Experimental testing yielded a best noise temperature of 50 K with an average noise temperature of 75 K over an RF bandwidth of 160 GHz– 260 GHz. We have performed thorough experimental and computational investigation of the IF system in particular the constraints on the bandwidth caused by the lumped element capacitance of the mixer chip and the matching of the output impedance of the mixer to the IF amplifier. Our conclusion is that a bandwidth of 1–15 GHz could be achieved using our mixer design, subject to the performance of the amplifier. Finally, a variable temperature load system was successfully developed and tested inside the cryostat, to avoid the losses from the room-temperature optics. We have showed that the noise temperature of the SIS detector could be reduced by as much as 15 K by testing the mixer using a variable temperature load inside the cryostat.

•Jan 1, 2013•0 citations

A 650 GHz Unilateral Finline SIS Mixer Fed by a Multiple Flare-Angle Smooth-Walled Horn

Boon-Kok Tan, G. Yassin, Paul Grimes +3 more

We report the design and successful operation of an superconductor-insulator-superconductor (SIS) mixer operating near the superconducting gap of niobium. A key feature of this design is the employment of a unilateral finline taper to transform the waveguide modes to microstrip signals. This transition is easy to design since it can be rigorously modeled, and also easy to fabricate being a single-layer structure. We will show that unilateral finline mixers have important advantages at THz frequencies since they exhibit wideband operation at both radio frequency (RF) and intermediate frequency (IF), allow elegant on-chip integration of the mixer circuits and result in an extremely simple mixer block that does not require a backshort or any mechanical tuners. The mixer we describe below is fed by a multiple flare-angle smooth-walled horn which exhibits beam pattern characteristic comparable to the conventional corrugated horn and yet is much easier to fabricate. In this paper, we shall present a brief discussion of the testing of the multiple flare-angle horn and detailed description of the design and testing of the mixer, covering ~100 GHz bandwidth centered at 650 GHz. In particular, we will present full electromagnetic de sign description of the mixer chip including the superconducting effects, and the heterodyne properties of the mixer using quantum mixing theory. Mixer performance tests that we carried out from 595 to 702 GHz gave a best receiver noise temperature of 145 K at 600 GHz, corrected for a 75 μm beam splitter. Finally, we performed a thorough analysis of the mixer performance, comparing the experimental results with theoretical models. Our investigation demonstrated that unilateral finline mixers fed by a multiple flare-angle horn can yield performance comparable to conventional designs, hence are suitable for large format mixer array at THz frequencies.

IEEE Transactions on Terahertz Science and Technology•Dec 13, 2011•17 citations

Balanced superconductor–insulator–superconductor mixer on a 9 µm silicon membrane

M. Westig, K Jacobs, J Stutzki +3 more

We present a 380-520 GHz balanced superconductor-insulator-superconductor (SIS) mixer on a single silicon substrate. All radio-frequency (RF) circuit components are fabricated on a $9 μ$m thick membrane. The intermediate frequency (IF) is separately amplified and combined. The balanced mixer chip, using Nb/Al/Al$_{2}$O$_{3}$/Nb SIS junctions, is mounted in a tellurium copper waveguide block at 4.2 K using Au beam lead contacts. We find uncorrected minimum receiver double-sideband noise temperatures of 70 K and a noise suppression of up to 18 dB, measured within a 440-495 GHz RF and a 4-8 GHz IF bandwidth, representing state-of-the-art device performance.

arXiv:1105.1956•Superconductor Science and Technology•Jul 1, 2011•32 citations

A 220 GHz finline mixer with ultra-wide instantaneous bandwidth

BK Tan, Faouzi M. Boussaha, Christine Chaumont +1 more

We describe the design and fabrication of a 220 GHz superconductor-insulator-superconductor (SIS) mixer with ultrawide IF bandwidth. The mixer is fabricated on a 100 µm thick quartz substrate, with planar circuit on-chip integration. The RF power is coupled to the tunnel junction via a unilateral finline taper and a slotline-to-microstrip transition. We used a double-stub tuning network to tune out the junction’s parasitic capacitance at a broad RF bandwidth, and matched the output impedance of the mixer to the input impedance of the IF amplifier (50 Ω) from 4–18 GHz using a 6-stage IF impedance-transformer. We have fabricated these devices and have measured good DC current-voltage (IV) characteristic curves. The heterodyne mixing performance of these devices is currently being measured, and we expect to present the results in the forthcoming ISSTT conference in March.

ORA review team•Jan 1, 2015•7 citations

Broadband 230 GHz finline mixer for astronomicalimaging arrays

G. Yassin, Rachael Padman, S. Withington +2 more

The authors report the successful operation of an antipodal finline quasi-particle SIS mixer at 230 GHz. The mixer is fed by a waveguide diagonal horn and uses planar circuit technology and integrated tuning. The mixer is tested over the frequency range 213–265 GHz and a receiver noise temperature of ~60 K DSB over the whole of this range is obtained. This work has shown that superconducting finline mixers have low noise and are easy to manufacture, and are therefore suitable for large-format imaging arrays.

Electronics Letters•Mar 13, 1997•13 citations
The successful operation of a 650 GHz unilateral finline superconductor–insulator–superconductor mixer with a wide IF bandwidth is reported. The mixer was fabricated using silicon‐on‐insulator (SOI) technology, with planar circuit on‐chip integration. The mixer was tested over the frequency range of 630–702 GHz, and the best recorded DSB noise temperature was 226 K. The measured RF and IF behaviour of the mixer agreed very well with the simulation predictions. This demonstrates that superconducting finline mixers fabricated on an SOI substrate can achieve state‐of‐the‐art performance, and yet are much more compact and highly reproducible, and hence suitable for large‐format arrays in astronomy instruments, at THz frequencies.
We present the design of a broadband superconductor-insulator-superconductor (SIS) mixer operating near 700 GHz. A key feature of our design is the utilisation of a new type of waveguide to planar circuit transition comprising a unilateral finline taper. This transition is markedly easier to design, simulate and fabricate than the antipodal finline we employed previously. The finline taper and the superconducting circuitry are deposited on a 15 μm thick silicon substrate. The employment of the very thin substrate, achieved using Silicon-On-Insulator (SOI) technology, makes it easy to match the incoming signal to the loaded waveguide. The lightweight mixer chip is held in the E-plane of the waveguide using gold beam leads, avoiding the need for deep grooves in the waveguide wall. This new design yields a significantly shorter chip, free of serrations and a wider RF bandwidth. Since tuning and all other circuits are integrated on the mixer chip, the mixer block is extremely simple, comprising a feed horn and a waveguide section without any complicated mechanical features. We employ a new type of smooth-walled horn which exhibits excellent beam circularity and low cross polarisation, comparable to the conventional corrugated horn, and yet is easier to fabricate. The horn is machined by standard milling with a drill tool shaped into the horn profile. In this paper, we describe the detailed design of the mixer chip including electromagnetic simulations, and the mixer performance obtained with SuperMix simulations. We also present the preliminary measurements of the smooth-walled horn radiation patterns near the mixer operating frequencies.
Superconductor-Insulator-Superconductor (SIS) tunnel junction mixers are now commonly used in as- tronomical receivers at (sub)millimeter wavelengths because of their superb sensitivity, high dynamic range and stability of operation. Niobium SIS mixers operating at frequencies well below the super- conducting gap (∼680 GHz) have already achieved quantum limited sensitivity. Therefore to further enhance the receiver sensitivity, increasing the Intermediate Frequency (IF) bandwidth of SIS mixers has became crucial. This thesis focuses on the theoretical modeling, design and experimental verifi- cation of Nb SIS mixers operating around 230 GHz with a wide IF bandwidth of 1–15 GHz. These mixers were designed for a single baseline heterodyne interferometer (GUBBINS), which is being built to observe the Sunyaev-Zel’dovich effect in the Cosmic Microwave Background. The combination of wide IF bandwidth SIS mixers and complex analogue correlators will allow GUBBINS to feature high surface brightness sensitivity, that helps to distinguish the weak SZ effect from the background noise. The SIS mixer detector system was assembled inside the GUBBINS cryostat together with the IF electronics and RF/LO optical systems. Low noise temperatures of around 71 K were then measured in the GUBBINS system. The Nb SIS mixer we have developed uses a unilateral finline and fully integrated planar circuits deposited on a silicon substrate, to couple the electromagnetic radiation from the waveguide into the SIS junction. The finline mixer allows a broad-band RF coupling, an easy integration of the on-chip planar circuits and an easy-to-fabricate mixer block. To achieve a wide IF bandwidth, the output impedance of the SIS mixer was well matched to the input impedance of the amplifier by a multi-stage microstrip circuit. Additionally, the planar circuit of the SIS mixer was also designed to have a small lumped inductance and capacitance. The SIS mixer chip was extensively simulated by rigorous electromagnetic software (HFSS) and the S-parameter was exported to a quantum mixing package SuperMix to produce a full-wave model of the mixer. Experimental testing yielded a best noise temperature of 50 K with an average noise temperature of 75 K over an RF bandwidth of 160 GHz– 260 GHz. We have performed thorough experimental and computational investigation of the IF system in particular the constraints on the bandwidth caused by the lumped element capacitance of the mixer chip and the matching of the output impedance of the mixer to the IF amplifier. Our conclusion is that a bandwidth of 1–15 GHz could be achieved using our mixer design, subject to the performance of the amplifier. Finally, a variable temperature load system was successfully developed and tested inside the cryostat, to avoid the losses from the room-temperature optics. We have showed that the noise temperature of the SIS detector could be reduced by as much as 15 K by testing the mixer using a variable temperature load inside the cryostat.
We report the design and successful operation of an superconductor-insulator-superconductor (SIS) mixer operating near the superconducting gap of niobium. A key feature of this design is the employment of a unilateral finline taper to transform the waveguide modes to microstrip signals. This transition is easy to design since it can be rigorously modeled, and also easy to fabricate being a single-layer structure. We will show that unilateral finline mixers have important advantages at THz frequencies since they exhibit wideband operation at both radio frequency (RF) and intermediate frequency (IF), allow elegant on-chip integration of the mixer circuits and result in an extremely simple mixer block that does not require a backshort or any mechanical tuners. The mixer we describe below is fed by a multiple flare-angle smooth-walled horn which exhibits beam pattern characteristic comparable to the conventional corrugated horn and yet is much easier to fabricate. In this paper, we shall present a brief discussion of the testing of the multiple flare-angle horn and detailed description of the design and testing of the mixer, covering ~100 GHz bandwidth centered at 650 GHz. In particular, we will present full electromagnetic de sign description of the mixer chip including the superconducting effects, and the heterodyne properties of the mixer using quantum mixing theory. Mixer performance tests that we carried out from 595 to 702 GHz gave a best receiver noise temperature of 145 K at 600 GHz, corrected for a 75 μm beam splitter. Finally, we performed a thorough analysis of the mixer performance, comparing the experimental results with theoretical models. Our investigation demonstrated that unilateral finline mixers fed by a multiple flare-angle horn can yield performance comparable to conventional designs, hence are suitable for large format mixer array at THz frequencies.
We present a 380-520 GHz balanced superconductor-insulator-superconductor (SIS) mixer on a single silicon substrate. All radio-frequency (RF) circuit components are fabricated on a 9μ9 μ9μm thick membrane. The intermediate frequency (IF) is separately amplified and combined. The balanced mixer chip, using Nb/Al/Al2_{2}2​O3_{3}3​/Nb SIS junctions, is mounted in a tellurium copper waveguide block at 4.2 K using Au beam lead contacts. We find uncorrected minimum receiver double-sideband noise temperatures of 70 K and a noise suppression of up to 18 dB, measured within a 440-495 GHz RF and a 4-8 GHz IF bandwidth, representing state-of-the-art device performance.
We describe the design and fabrication of a 220 GHz superconductor-insulator-superconductor (SIS) mixer with ultrawide IF bandwidth. The mixer is fabricated on a 100 µm thick quartz substrate, with planar circuit on-chip integration. The RF power is coupled to the tunnel junction via a unilateral finline taper and a slotline-to-microstrip transition. We used a double-stub tuning network to tune out the junction’s parasitic capacitance at a broad RF bandwidth, and matched the output impedance of the mixer to the input impedance of the IF amplifier (50 Ω) from 4–18 GHz using a 6-stage IF impedance-transformer. We have fabricated these devices and have measured good DC current-voltage (IV) characteristic curves. The heterodyne mixing performance of these devices is currently being measured, and we expect to present the results in the forthcoming ISSTT conference in March.
The authors report the successful operation of an antipodal finline quasi-particle SIS mixer at 230 GHz. The mixer is fed by a waveguide diagonal horn and uses planar circuit technology and integrated tuning. The mixer is tested over the frequency range 213–265 GHz and a receiver noise temperature of ~60 K DSB over the whole of this range is obtained. This work has shown that superconducting finline mixers have low noise and are easy to manufacture, and are therefore suitable for large-format imaging arrays.