Abstract: A variable superconducting delay line system and method having a high temperature superconducting trace and ground plane characterized by a variable inductance L per unit length and capacitance C per unit length, wherein the system and method permit users to select a delay time for an incoming signal propagating through a the transmission line. The system is adapted to keep the ratio of L/C constant, while independently changing L and C to achieve the desired delay time, which corresponds to the product of L times C.

Abstract: A waveguide cavity filter having a conductive housing, a plurality of high dielectric constant ceramic resonators disposed within the conductive housing and at least a portion of a sheet of superconductive material which is constrained to be at an ambient temperature below the critical temperature of the superconductor and disposed in contact with at least one of the side walls of the conductive housing and with an opposing surface of each of the resonators, such that the resonators are in close superconductive contact with the side walls of the conductive housing. In particularly, the superconductive sheet is a layer of high temperature superconductor. In a first embodiment of the invention, the resonators in the shape of cylindrical plugs are disposed with a flat surface juxtaposed to the side wall.

Abstract: Planar dual mode filters (30) are formed by a conductive resonator (20) having circular symmetry and two pairs of symmetrically oriented planar conductive leads (22, 26 and 24, 28). The conductive leads (22, 26 and 24, 28) are aligned colinearly with two orthogonal diameters (32, 34, respectively) of the circular conductive resonator (20) and are electrically isolated from said resonator (20). A perturbation (38) located on an axis (36) oriented symmetrically with respect to the two pairs of conductive lead (22, 26 and 24, 28) couples electromagnetic modes which are injected into the resonator (20) by the planar conductive leads (22, 26 and 24, 28). Higher order filter circuits can be realized by combining multiple filters (30) of the present invention. The filters (30) are amenable to printed circuit (microstrip to stripline) fabrication using superconductors for the conductive elements.

Abstract: A superconducting variable phase shifter providing improved performance in the microwave and millimeter wave frequency ranges. The superconducting variable phase shifter includes a transmission line and an array of superconducting quantum interference devices (SQUID's) connected in parallel with and distributed along the length of the transmission line. A DC control current I.sub.DC varies the inductance of the individual SQUID's and thereby the distributed inductance of the transmission line, thus controlling the propagation speed, or phase shift, of signals carried by the transmission line. The superconducting variable phase shifter provides a continuously variable time delay or phase shift over a wide signal bandwidth and over a wide range of frequencies, with an insertion loss of less than 1 dB. The phase shifter requires less than a milliwatt of power and, if one or more of the Josephson junctions fails, the whole device remains operational, since the SQUID's are connected in parallel.

Abstract: A dual mode microstrip resonator (1) usable in the design of microwave communication filters. The substantially square resonator (1) provides paths for a pair of orthogonal signals which are coupled together using a perturbation located in at least one corner of the resonator (1). The perturbation can be introduced by notching (3) the resonator (1) or by adding a metallic or dielectric stub (5) to the resonator (1).

Abstract: An improved transmission system for electrical energy comprising a plurality of ball members interspersed by mating members enclosed within at least one protective outer wrapping, with the ball members and the mating members being in contact with adjacent members and being formed of material which is electrically conductive at superconductor temperatures and each having an axial opening extending therethrough to permits passage of a suitable coolant fluid, such as liquid helium.

Abstract: A transmission line using superconductors instead of conventional conductors substantially reduces ohmic losses compared to conventional conductors. The superconductors are cooled by refrigerant flowing through a hollow superconducting inner conductor. The refrigerant is transported to the inner conductor using a novel connector.

Abstract: A phase shifter having a reference path and a delay path, light sources, and superconductive switches. Each of the superconductive switches is terminated in a virtual short circuit, which may be a radial stub. Switching between the reference path and delayed path is accomplished by illuminating the superconductive switches connected to the desired path, while not illuminating the superconductive switches connected to the other path.

Abstract: A Frequency Domain Infrared Superconducting Transmission Line (FIRST) detector is comprised of a folded superconducting transmission line (36) interposed between a bottom electrode (32) and a top, radiation absorbing electrode (40). Dielectric layers (34, 38) separate the transmission line from the top and bottom electrodes. An optically induced change in the kinetic inductance of the transmission line shifts the transmission line phase velocity and resonant frequency. The shift in resonant frequency attenuates the propagating wave amplitude proportionally to the product of the transmission line Q and the frequency shift. A stacked pair of such detectors (50), sharing a common ground electrode (60), is disclosed to provide an inherent rejection of noise events due to ionizing radiation such as gamma radiation and package-generated Compton electrons.

Abstract: A method of constructing ultra-low-loss miniaturized microstrip type microwave transmission lines, circuits, and resonators and their resulting structures are disclosed. The method includes etching a groove of the appropriate width and depth into the surface of a first substrate as determined by a preselected characteristic impedance. Appropriate thin film superconductors are then deposited on the surfaces of the first substrate and a second substrate. The thin film superconductors are then patterned after which the two substrates are sealed together by field-assisted thermal bonding such that a novel two-conductor electromagnetic transmission line results.

Abstract: A multilayered radiation detector device (50) including a resonant cavity structure wherein one cavity wall electrode includes a portion of a photovoltaic radiation detector (52). Specifically, a RFM detector has a superconducting transmission line electrode (54) electrically coupled to a high mobility semiconductor layer (58) of the photovoltaic detector. The superconductor transmission line electrode inductance forms, in combinations with a photodetector depletion region capacitance, a series resonant or a parallel resonant circuit. A radiation-induced change in the capacitance results in a change in the circuit resonant frequency and a corresponding variation in the amplitude of an on-resonance RF signal applied to the circuit. In another embodiment the resonant cavity structure includes a gap having a width that is modulated by an amount of absorbed radiation, the radiation-induced change in the distributed cavity capacitance resulting in a change in the cavity resonant frequency.

Abstract: A cryogenic microwave test chamber consists of a dry-sample receiving char which is partly immersed in liquid nitrogen. Waveguides from either end of the interior of the dry chamber are connected to and sealed to outgoing waveguides in regions immersed in the liquid nitrogen. Dry nitrogen is introduced through the waveguide and is circulated through the dry chamber to prevent condensation therein during cooling. A heat conductive metal tube surrounds the dry chamber and is spaced therefrom and acts as a heat barrier. Waveguide flanges on the opposite ends of the dry chamber slidably seal the chamber.

Abstract: A microwave cavity filter using resonators of superconducting coatings, one-half wavelength long on quartz tubes mounted within the cavity that carry refrigerant to cool the superconductor substantially reduces ohmic losses and permits shrinking the size of conventional cavity filters.

Abstract: Electrical conductor comprising a glass fibre (12) with a hollow center within which is a liquid solution (14) containing D.sup.+ or other boson ions. Coherent light from a laser (15) is directed into the solution to render the boson ions coherent, inducing a superconducting state. In another embodiment, the laser is replaced by a microwave source.

Abstract: An electromagnetic resonator has two or more non-intersecting, substantially overlapping surfaces of approximately similar size and shape separated from one another by a distance which is small in comparison to the physical extent of the surfaces. One or more substantially non-intersecting, electrically conductive paths cover substantial portions of each surface. The widths of the paths are substantially smaller than the physical extent of the surfaces. No path on any one of the surfaces is electrically connected to a path on any of the other surfaces. The conductive paths are oriented such that, for each of the surfaces, macroscopic current flows, with respect to the surfaces, in a direction other than the direction in which microscopic current flows in the paths.

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: A Frequency Domain Infrared Superconducting Transmission Line (FIRST) detector is comprised of a folded superconducting transmission line 18 coupled at an input port 18a to a narrow band microwave source and coupled at an output port 18b to a microwave power monitor 22. An optically induced change in the kinetic inductance of the transmission line shifts the transmission line phase velocity and resonant frequency. The shift in resonant frequency attenuates the propagating wave amplitude proportionally to the product of the transmission line Q and the frequency shift. When fabricated with a densely folded superconducting line and operated at a nominal resonant frequency of several GHz the use of either linear or logarithmic Schottky barrier detectors enables a realization of a dynamic range of eight orders of magnitude.

Abstract: A ferrite device has a closed superconductor which encircles a ferrite element. The closed superconductor continuously circulates a current to produce a magnetic field for biasing the ferrite element.

Abstract: An arrangement for a superconducting resonator suitable for use in electronic filters is disclosed, in which a resonator exhibits an increased amount of internal inductance without a lengthening of the resonator. By utilizing a relatively thin dielectric material, a significant amount of magnetic field is made to exist in a layer of the superconductors nearest to the dielectric. This magnetic field induces a non-negligible internal inductance within the layer. The net result of having this extra inductance is that the wave velocity is no longer a constant, independent of dielectric thickness. Thus the resonator can be constructed to be significantly shorter than the conventional wave velocity equation would imply. Hence, the present invention provides a reduction in the length as well as in the cross-sectional area of a resonator, which means that one or more of such resonators may then be advantageously utilized to achieve significantly reduced filter size.

Abstract: A microwave switch comprises a transmission line section which separates into two arms, at least one of which can go from a normal state to a superconductive state at a critical temperature, a junction rejoining the two arms in a second microwave transmission line section, and means to control the normal or superconductive state of one arm or of the two arms. The difference in length between the two arms is chosen to be substantially equal to an odd of half wavelengths of operation of the switch in such a way that the switch is off or on when the two arms are respectively in the same state, namely normal or superconductive, or in a different state. The state of the arms can be controlled by a magnetic field which causes the critical temperature to vary.

Abstract: A microvertex particle detector for use in a high energy physic collider including a plurality of parallel superconducting thin film strips separated from a superconducting ground plane by an insulating layer to form a plurality of superconducting waveguides. The microvertex particle detector indicates passage of a charged subatomic particle by measuring a voltage pulse measured across a superconducting waveguide caused by the transition of the superconducting thin film strip from a superconducting to a non-superconducting state in response to the passage of a charged particle. A plurality of superconducting thin film strips in two orthogonal planes plus the slow electromagnetic wave propogating in a superconducting transmission line are used to resolve N.sup.2 ambiguity of charged particle events.

Abstract: The quality of superconducting cavity resonators depends to a very great extent on the surface quality of the cavities. The invention relates to a process for the manufacture of superconducting cavity resonators with improved surface quality, whereby even complex shaped cavity resonators can be made with cavities coated with NbN.

Abstract: A ceramic type superconductive layer (2) is formed on the outer peripheral surface of an optical fiber (1), and a stabilizing layer (3) is formed so that it contacts the outer peripheral surface of the superconductive layer (3). The diameter of the optical fiber is, for example, not more tha 100 .mu.m. The superconductive layer may be formed with a spirally extending groove (7) which divides the superconductive layer.

Abstract: For reduction in occupation area, there is disclosed a microwave device fabricated on a semi-insulating substrate and comprising a passive component area where a plurality of passive component elements are formed and an active component area where at least one active element is formed, the passive component area having a film overlain by a dielectric film and a strip conductor extending on the dielectric film, wherein the film and the strip conductor are formed by a superconductive material, so that the dielectric material is decreased in thickness by virtue of the strip conductor of the superconductive material.

Abstract: Microwave oscillators and amplifiers which utilize a superconducting slow-wave circuit. The slow circuit is made from materials which exhibit superconductivity at relatively high critical temperatures. The slow wave circuit is integral with the device's vacuum housing. Coolant exterior to the vacuum housing maintains the circuit in the superconducting state. The slow-wave circuit, which protrudes into the vacuum housing provides modulation of an electron beam which traverses the interior of the vacuum housing. Output power is ultimately extracted from the slow wave circuit.

Abstract: A superconducting, superdirective antenna array wherein a superconductive terial is employed for the elements of the array which are arranged in a uniform half-wave dipole has low ohmic resistance and a very high radiation efficiency. The superdirective antenna array which is a linear array has element spacing less than .lambda.o/2 where .lambda.o is the center frequency of the dipoles. The material of the array elements has a very high critical current (i.e., and a critical magnetic field), a requirement for maximum efficiency. The superconducting, superdirective antenna array is housed in a vacuum insulated container and is provided outlet connecting to means for obtaining and sustaining a vacuum as required for element material of fabrication. The material of fabrication for the antenna array elements is selected from a type II superconductor material selected from the group consisting of iridiumm, lead, mercury, tantalum, vanadium, a composite of niobium-tin-bronze, and alloys of the same.