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IEEE MTT-S International Microwave Symposium digest

Ultra-wide IF bandwidth — The next frontier for SIS receivers

Edward Tong, Paul Grimes, Jonathan Weintroub, R. Blundell

Published May 1, 2015• 2 citations
Publisher

Abstract

Tucker's theory of quantum mixing can be extended to model distributed series connected SIS mixers, which offer a lower capacitance and a higher dynamic range. These mixers have wider IF bandwidth than single junction mixer. Coupled with the emerging ultra-wide band technologies in low noise amplifier and fast digital signal processing, they open a new frontier of ultra-wide band receivers. We report on the development of the wideband SIS receivers for the Submillimeter Array, designed with Tucker's theory.

DOI
10.1109/mwsym.2015.7166804

Related papers

Design and Performance of a 3-Junction Series Distributed SIS Mixer for Wide IF Applications

Edward Tong, Paul Grimes, A. Barbier +2 more

Series distributed superconductor-insulator-superconductor mixers have been used to provide very wide instantaneous bandwidth of operation. In this paper, we explore a design based on a 3-junction array in which the junctions themselves form part of the RF tuning network of the mixer. We have developed mixers based on these designs for use in the 200 and 300 GHz bands. Receivers incorporating these wideband mixers demonstrate very low noise temperature. At a local oscillator frequency of 300 GHz, the lowest measured intermediate frequency noise temperature is about 42 K and the usable intermediate frequency bandwidth extends from 6 to 16.5 GHz. Both the design theory and experimental results are presented.

IEEE Transactions on Applied Superconductivity•Dec 20, 2012•12 citations

Development of Submillimeter SIS Mixers and Broadband HEMT Amplifiers

Jonas Stasys Zmuidzinas

The goal of this project is to develop and demonstrate a new generation of superconducting tunnel junction (SIS) receivers with extremely wide instantaneous (intermediate-frequency, or IF) bandwidths, of order 12 GHz. Such mixers would allow rapid submillimeter wavelength spectral line surveys to be carried out with SOFIA, and could potentially be used for future submillimeter space missions such as SAFIR. There are two major components which are being developed: (1) SIS mixers with broad (12 GHz) IF bandwidths; and (2) low-noise, broadband microwave, (6-18 GHz) amplifiers, which amplify the IF output from the SIS mixer. The work on these components is discussed in two sections

•Oct 5, 2004•0 citations

A Fixed-Tuned SIS Mixer with Ultra-Wide-Band IF and Quantum-Limited Sensitivity for ALMA Band 3 (84-116 GHz) Receivers

S.-K. Pan, Anthony R. Kerr, M.W. Pospieszalski +13 more

Abstract- This paper describes an 84-116 GHz Nb/Al-oxide/Nb SIS mixer with multi-octave IF bandwidth and quantum-limited sensitivity. The mixer can be integrated with a three-stage 4-12 GHz HFET preamplifier or fitted with a coaxial connector for operation with an external isolator and IF amplifier. An 84-116 GHz receiver using the mixer with an integrated 4-12 GHz HFET preamplifier has a double sideband noise temperature of 16-20 K ( 3 to 4 h</kB) over most of the IF band. Analysis of the mixer-preamp using Tucker=s theory shows good agreement with measurements. The mixer is easy to build and is being used as a building block for the Band 3 sideband-separating receivers for the Atacama Large Millimeter Array (ALMA)**. With minor modifications, this mixer design can be scaled to other ALMA bands. I

•Jan 1, 2004•22 citations

Theoretical SIS mixer research

M. J. Feldman

Theoretical research has been conducted to elucidate the basic physics behind the properties of superconductor-insulator-superconductor (SIS) tunnel junction receiving devices. The properties of SIS mixers using nonideal junctions and finite LO power, were determined by analytic expansion of the equations of the quantum theory of mixing, and also by computer simulations of SIS receivers over the entire range of experimental parameters. The result is a new coherent and intuitive picture of SIS mixer behavior. Many of the outstanding mysteries and questions about SIS receivers are resolved, and this contributes greatly to the design and interpretation of SIS mixer experiments. Other calculations show how to achieve sub-quantum noise temperatures in the phase sensitive SIS mixer, an important step towards realization of ultra-low- noise detectors. A simplified model casts doubt on the superlative experimental results reported for the rf-series dc-parallel biased array SIS mixer. Superconductivity; SIS mixer; Submillimeter-wave detection.

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Analyzing and improving the IF bandwidth performance for 345 GHz SIS mixer

Chen Peng, Boxun Wang, Liping Zuo +5 more

Abstract The wide intermediate frequency (IF) bandwidth is a core performance metric for terahertz heterodyne receivers, and a wide-IF superconductor–insulator–superconductor (SIS) mixer is key to achieving this. This paper presents the simulation-based design, optimization, and performance analysis of a 345 GHz superconducting SIS mixer developed for wide-IF applications. The mixer employs a parallel-connected twin-junction tuning structure and integrates a dedicated IF impedance matching circuit, achieving wideband impedance matching between the mixer output port and low-noise amplifier. The design is based on two tunnel junction technologies, AlO x and AlN, with critical current densities of 1 kA·cm −2 and 25 kA·cm −2 , respectively. We systematically studied the effects of different junction materials and junction areas on the RF and IF bandwidth performance of the SIS mixer. It is found that for AlN-barrier junctions with diameters of 0.6 μ m and 0.8 μ m, the receiver’s IF noise temperature slowly decreased as the IF frequency increased at a high local oscillator frequency. Furthermore, we incorporated the calculated IF output port impedance into the mixer model for correction and introduced an integrated IF circuit approach, overcoming the original IF bandwidth limitation. Simulations show that the newly designed mixer achieves the stringent sensitivity and bandwidth requirements across the 320–370 GHz range, delivering an IF bandwidth of 4–22 GHz and a receiver noise temperature of 39–73 K. Notably, the −3 dB IF bandwidth is improved by more than 1.5 times compared to conventional AlO x -based designs. These findings provide new design guidelines and quantitative criteria for next-generation wide-IF receivers and other high-frequency applications requiring a wide IF bandwidth.

Journal of Physics D Applied Physics•Oct 6, 2026•0 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
Tucker's theory of quantum mixing can be extended to model distributed series connected SIS mixers, which offer a lower capacitance and a higher dynamic range. These mixers have wider IF bandwidth than single junction mixer. Coupled with the emerging ultra-wide band technologies in low noise amplifier and fast digital signal processing, they open a new frontier of ultra-wide band receivers. We report on the development of the wideband SIS receivers for the Submillimeter Array, designed with Tucker's theory.
Series distributed superconductor-insulator-superconductor mixers have been used to provide very wide instantaneous bandwidth of operation. In this paper, we explore a design based on a 3-junction array in which the junctions themselves form part of the RF tuning network of the mixer. We have developed mixers based on these designs for use in the 200 and 300 GHz bands. Receivers incorporating these wideband mixers demonstrate very low noise temperature. At a local oscillator frequency of 300 GHz, the lowest measured intermediate frequency noise temperature is about 42 K and the usable intermediate frequency bandwidth extends from 6 to 16.5 GHz. Both the design theory and experimental results are presented.
The goal of this project is to develop and demonstrate a new generation of superconducting tunnel junction (SIS) receivers with extremely wide instantaneous (intermediate-frequency, or IF) bandwidths, of order 12 GHz. Such mixers would allow rapid submillimeter wavelength spectral line surveys to be carried out with SOFIA, and could potentially be used for future submillimeter space missions such as SAFIR. There are two major components which are being developed: (1) SIS mixers with broad (12 GHz) IF bandwidths; and (2) low-noise, broadband microwave, (6-18 GHz) amplifiers, which amplify the IF output from the SIS mixer. The work on these components is discussed in two sections
Abstract- This paper describes an 84-116 GHz Nb/Al-oxide/Nb SIS mixer with multi-octave IF bandwidth and quantum-limited sensitivity. The mixer can be integrated with a three-stage 4-12 GHz HFET preamplifier or fitted with a coaxial connector for operation with an external isolator and IF amplifier. An 84-116 GHz receiver using the mixer with an integrated 4-12 GHz HFET preamplifier has a double sideband noise temperature of 16-20 K ( 3 to 4 h</kB) over most of the IF band. Analysis of the mixer-preamp using Tucker=s theory shows good agreement with measurements. The mixer is easy to build and is being used as a building block for the Band 3 sideband-separating receivers for the Atacama Large Millimeter Array (ALMA)**. With minor modifications, this mixer design can be scaled to other ALMA bands. I
Theoretical research has been conducted to elucidate the basic physics behind the properties of superconductor-insulator-superconductor (SIS) tunnel junction receiving devices. The properties of SIS mixers using nonideal junctions and finite LO power, were determined by analytic expansion of the equations of the quantum theory of mixing, and also by computer simulations of SIS receivers over the entire range of experimental parameters. The result is a new coherent and intuitive picture of SIS mixer behavior. Many of the outstanding mysteries and questions about SIS receivers are resolved, and this contributes greatly to the design and interpretation of SIS mixer experiments. Other calculations show how to achieve sub-quantum noise temperatures in the phase sensitive SIS mixer, an important step towards realization of ultra-low- noise detectors. A simplified model casts doubt on the superlative experimental results reported for the rf-series dc-parallel biased array SIS mixer. Superconductivity; SIS mixer; Submillimeter-wave detection.
Abstract The wide intermediate frequency (IF) bandwidth is a core performance metric for terahertz heterodyne receivers, and a wide-IF superconductor–insulator–superconductor (SIS) mixer is key to achieving this. This paper presents the simulation-based design, optimization, and performance analysis of a 345 GHz superconducting SIS mixer developed for wide-IF applications. The mixer employs a parallel-connected twin-junction tuning structure and integrates a dedicated IF impedance matching circuit, achieving wideband impedance matching between the mixer output port and low-noise amplifier. The design is based on two tunnel junction technologies, AlO x and AlN, with critical current densities of 1 kA·cm −2 and 25 kA·cm −2 , respectively. We systematically studied the effects of different junction materials and junction areas on the RF and IF bandwidth performance of the SIS mixer. It is found that for AlN-barrier junctions with diameters of 0.6 μ m and 0.8 μ m, the receiver’s IF noise temperature slowly decreased as the IF frequency increased at a high local oscillator frequency. Furthermore, we incorporated the calculated IF output port impedance into the mixer model for correction and introduced an integrated IF circuit approach, overcoming the original IF bandwidth limitation. Simulations show that the newly designed mixer achieves the stringent sensitivity and bandwidth requirements across the 320–370 GHz range, delivering an IF bandwidth of 4–22 GHz and a receiver noise temperature of 39–73 K. Notably, the −3 dB IF bandwidth is improved by more than 1.5 times compared to conventional AlO x -based designs. These findings provide new design guidelines and quantitative criteria for next-generation wide-IF receivers and other high-frequency applications requiring a wide IF bandwidth.
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.