Abstract: The present invention provides a superconducting device including a substrate, a first superconducting pattern formed on the substrate, an insulating pattern formed on the first superconducting pattern, and a second superconducting pattern formed at the uppermost level in the multilayered superconducting pattern. A barrier layer of a Josephson junction is formed on the lower side of, or within the second superconducting pattern. The second superconducting pattern constitutes a circuit element on the insulating pattern.

Abstract: A magnetic field sensor which can be used as an active antenna is disclosed that is capable of small size, ultrawideband operation, and high efficiency. The sensor includes a multiplicity of magnetic field transducers, e.g., superconducting quantum interference devices (SQUIDs) or Mach-Zehnder modulators, that are electrically coupled in a serial array. Dummy SQUIDs may be used about the perimeter of the SQUID array, and electrically coupled to the active SQUIDs for eliminating edge effects that otherwise would occur because of the currents that flow within the SQUIDs. Either a magnetic flux transformer which collects the magnetic flux and distributes the flux to the transducers or a feedback assembly (bias circuit) or both may be used for increasing the sensitivity and linear dynamic range of the antenna.

Abstract: A magnetic flux-enhanced control line for a superconducting flux flow transistor (SFFT). The SFFT includes a pair of superconducting electrodes which provide a voltage output, a region of weakened superconductor connecting the electrodes and a control line. The region of weakened superconductor carries a current I.sub.body and the control line carries a current I.sub.Control. The control line further has a portion thereof proximate the weakened region for providing a localized magnetic field through the weakened region as a function of I.sub.Control. The magnetic flux through the weakened region induces vortices therein which have a resistance r.sub.o. The proximate portion of the control line forms a tortuous current path whereby the magnetic flux through the weakened region is increased for increasing r.sub.o so that the output voltage of the transistor is increased without increasing I.sub.Control.

Abstract: An impedance-matching circuit assembly supplies a.c. power from an external a.c. source to Josephson devices. The assembly comprises resonant-line composed quarter-wave impedance conversion circuits, interconnected in a tree. The impedance-conversion circuits are assembled such that connected to the a.c. source is a circuit having a first-stage impedance, followed by two circuits having second-state impedances connected in parallel, to each of which are connected in parallel two circuits having third-stage impedances, each of which in turn is connected to supply input terminals of two of the Josephson devices.

Abstract: A switching circuit which comprises a digital circuit formed of a superconductor, a transmission line connected to the digital circuit through magnetic coupling, and a resistor element disposed in the transmission line for differentiating the output of the digital circuit.

Abstract: A DC powered integrated circuit includes a plurality of magnetic flux coupling type Josephson elements. First and second Josephson elements are connected in series to form a first element series circuit of Josephson elements. Third and fourth Josephson elements are connected in series to form a second element series circuit of Josephson elements. The first and second element series circuits are connected in series to form a huffle circuit, with a load inductance, three resistors and a DC current source.

Abstract: A superconducting threshold logic circuit comprises current switching circuits each having a Josephson device. Bias currents of the switching circuits are varied independently to change weights for input signals. A sum of the weighted input signals are inputted to another current switching circuit having a Josephson device in order to compare the sum with a threshold.

Abstract: A family of logic circuits using nonhysteretic superconducting quantum interference devices (SQUIDs) connected together to perform various functions using a common operating principle. Each circuit has an output line, first and second power supply lines having first and second voltage states, and input lines that can have one of the two voltage states. A pull-up circuit, having at least one SQUID, is connected between the output line and the first power supply line, and the input lines are coupled to the pull-up circuit in such a manner as to pull the output line to the first voltage state only if the input lines conform with a selected combination of voltage states. A pull-down circuit, also having at least one SQUID, is connected between the output line and the second power supply line, to pull the output line to the second voltage state only when input lines do not conform with the selected combination of voltage states.

Abstract: Active superconducting devices are formed of thin films of superconductor which include a main conduction channel which has an active weak link region. The weak link region is composed of an array of links of thin film superconductor spaced from one another by voids and selected in size and thickness such that magnetic flux can propagate across the weak link region when it is superconducting. Magnetic flux applied to the weak link region will propagate across the array of links causing localized loss of superconductivity in the links and changing the effective resistance across the links. The magnetic flux can be applied from a control line formed of a superconducting film deposited coplanar with the main conduction channel and weak link region on a substrate. The devices can be formed of any type to superconductor but are particularly well suited to the high temperature superconductors since the devices can be entirely formed from coplanar films with no overlying regions.

Abstract: A low-voltage CMOS interconnection circuit utilizing high-Tc superconducting tunnel junctions and interconnects for a very high speed interchip communication at low temperatures (4-77K). An improved driver produces very small current transients and has good immunity to noise from input voltage fluctuations, cross talk and simultaneous switching of drivers. An improved receiver includes a common gate CMOS receiver having a biasing stage and at least one amplifier stage and has the advantage of a large amplification and is self biasing.

Abstract: An Integrated Superconductor Sampling Oscilloscope may include a sampling gate utilizing superconductor devices such as a Josephson junction device as well as external circuitry for producing a visual representation of an input signal responsive to the output of the sampling gate. The oscilloscope may further comprise an attenuator for receiving the input signal, a trigger recognizer comprising superconductor devices which produces a pulse signal when the input signal from the attenuator exceeds a threshold level, a hold-off gate which produces an output signal when the pulse signal from the trigger recognizer is produced concurrently with a gating event, and electrical variable delay which may comprise superconducting devices and produces a delayed pulse signal in response to an output signal by the hold-off gate and a strobe pulse generator which produces a signal to the sampling gate in response to the pulse signal from the electrical variable delay output.

Abstract: There is provided a quantum flux parametron-type superconducting circuit in which a path with a Josephson device is connected in parallel with exciting inductors of the quantum flux parametron or inductors of exciting line magnetically coupled with the exciting inductors, thereby constructing a phase regulator.