The integration of superconductor digital electronics together with superconducting sensors can enable smart multi-channel sensor arrays. Applications of such sensors range from basic astrophysical research to advanced security screening devices. The main advantage of superconducting sensor interfaces is the very low power consumption in combination with a very low noise level; both are required in order to keep the excellent superconducting sensor performance without distortions. The FLUXONICS Foundry technology has been optimized with respect to electronic interfaces circuits for analogue sensor readout and signal multiplexing. In this work, we describe this new interface technology and present a comparison with our standard RSFQ technology.
The integration of superconductor digital electronics together with superconducting sensors can enable smart multi-channel sensor arrays. Applications of such sensors range from basic astrophysical research to advanced security screening devices. The main advantage of superconducting sensor interfaces is the very low power consumption in combination with a very low noise level; both are required in order to keep the excellent superconducting sensor performance without distortions. The FLUXONICS Foundry technology has been optimized with respect to electronic interfaces circuits for analogue sensor readout and signal multiplexing. In this work, we describe this new interface technology and present a comparison with our standard RSFQ technology.
Technological processes for the fabrication of low- and high-Tc Josephson junctions, aimed for certain applications, are described. On the one hand, the integration of low-Tc superconductor digital electronics with superconducting sensor arrays enables input signal processing with quantum limited resolution at millikelvin temperatures. We describe this mixed signal superconductor technology for analogue sensor readout and signal multiplexing for operating temperatures down to 300 mK. On the other hand, by making use of modern high-Tc Josephson junction technology, sensitive magnetometers, which require a modest cooling power, can be developed. Examples of the application of the mentioned processes are shown.
Superconducting Rapid Single Flux Quantum (RSFQ) circuits have the ability to perform digital operation with clock signals in the microwave frequency range. The clock signal can be either generated on-chip via Josephson oscillators, or injected externally through microwave lines. We have investigated several configurations to digitize and process on-chip microwave signals for space-based applications, based on the European FLUXONICS Foundry with a niobium-based technology that can opearate at clock frequencies in the 30-40 GHz range. This presentation will focus on the main features of the technology, the expected performances for specific applications and the current status of experimental results of several circuits measured at 4K. It will also feature prospects and expectations, based on circuits already designed and in preparation.
Advancement of superconductor digital electronics, especially Rapid Single Flux Quantum (RSFQ) logic circuit is described. Ultra short pulse of a voltage generated across a Josephson junction and release from charging/discharging process for signal transmission in RSFQ circuits enable us to reduce power consumption and gate delay. The power-delay products (PDPs) of RSFQ integrated circuits (ICs) are 4 or 5 orders of magnitude smaller than those of semiconductor ICs. The fabrication process technology and the related designing technology have been advanced, and RSFQ ICs have been applied to software-defined radio receivers, superconductor detector array systems, and supercomputers. Recently, several kinds of energy-efficient single flux quantum circuit have been proposed to obtain further advantage to semiconductor devices. The PDPs of these circuits become at least 1 order smaller than those of conventional RSFQ circuits.
The article describes the activities aimed at bringing superconductive high-speed electronics towards maturity.Integrated circuits based on the effects in superconducting materials have become feasible for some years already.The main focus lies on the so-called Rapid Single-Flux-Quantum (RSFQ) electronics which allows the combination of high operation frequencies (well above 20 GHz) with very low energy consumption when logical states are changed.Thus, this circuit technology exhibits a promising potential for realising energy-efficient modules for signal processing and computing.Recently, a dedicated design infrastructure has been developed in Europe.Closely associated is a foundry for digital RSFQ integrated circuits so that the fabrication of integrated circuits is viable.In the contribution, the basic features of the RSFQ circuit design are addressed with special emphasis on implementation on the wafer scale.
Ultrafast switching speed, low power, natural quantization of magnetic flux, quantum accuracy, and low noise of cryogenic superconductor circuits enable fast and accurate data conversion between the analog and digital domains. Based on rapid single-flux quantum (RSFQ) logic, these integrated circuits are capable of achieving performance levels unattainable by any other technology. Two major classes of superconductor analog-to-digital converters (ADCs) are being developed - Nyquist sampling and oversampling converters. Complete systems with digital sampling at rates of /spl sim/20 GHz and above have been demonstrated using low-temperature superconductor device technology. Some ADC components have also been implemented using high-temperature superconductors. Superconductor ADCs have unique applications in true digital-RF communications, broadband instrumentation, and digital sensor readout. Their designs, test results, and future development trends are reviewed.
Interface circuits are the key components that enable the hybrid integration of superconductor and semiconductor digital electronics. The design requirements of superconductor-semiconductor interface circuits vary depending on the application, such as high-performance classical computing, superconducting quantum computing, and digital signal processing. In this survey, various interface circuits are categorized based on the working principle and structure. The superconducting output drivers are explored, which are capable of converting and amplifying, e.g., single flux quantum (SFQ) voltage pulses, to voltage levels that semiconductor circuits can process. Several trade-offs between circuit- and system-level design parameters are examined. Accordingly, parameters such as the data rate, output voltage, power dissipation, layout area, thermal/heat load of cryogenic cables, and bit-error rate are considered.