Abstract: Microwave hairpin-comb filters utilize a plurality of hairpin (i.e., folded) half-wavelength microstrip or stripline resonators arranged side-by-side and all with the same orientation. The coupling regions between resonators extend parallel to the sides of the resonators for substantially 1/8 to 1/4 wavelength at the frequency of resonance of the resonators. This length of coupling region between resonators, along with all resonators being oriented in the same direction, result in resonance effects in the coupling regions between the resonators. These effects greatly reduce the couplings between the resonators so that the resonators can be very closely spaced so as to produce a compact filter structure yet still have a narrow passband. The structure can also be made to produce poles of attenuation adjacent to the passband in order to enhance the filter cutoff characteristic.

Abstract: Herein disclosed is a band-pass filter for a radio wave having a wavelength range of a high frequency, such as a microwave and a milliwave. The band-pass filter comprises: a dielectric substrate; input and output terminals; and a plurality of conductive strip line resonators being capable of resonating with a predetermined wavelength. Each of the strip line resonators has two ends and bent line extending from one end to the other end with a predetermined length corresponding to the wavelength. The one end and the other end are placed face to face with each other to provide a gap therebetween. In the band-pass filter, the plurality as arranged on the dielectric substrate in series and spaced apart from each other at predetermined intervals along a predetermined position line and coupled with each other through the inductive and capacitive coupling to transfer the signal between the resonators one after another.

Abstract: A bulk superconductor including a plurality of units each composed of a substrate and a superconductive layer of R--Ba--Cu--O, where R is selected from La, Nd, Sm, Eu, Gd, Y, Dy, Ho, Er, Tm, Yb and mixtures thereof, formed on the substrate. The units are arranged in a row or in a matrix such that the superconductive layers of respective units are superconductively joined with each other.

Abstract: A planar filter for performing signal filtering at radio frequencies is provided. The planar filter can include asymmetrical resonators, wherein each resonator is asymmetrical about a longitudinal center axis through the resonator. In addition, the resonators can be grouped in coupled pairs such that the resonators in each coupled pair are asymmetrical about a longitudinal center axis between the paired resonators. In addition, a coupling structure is provided that includes both distributed coupling and tapped coupling to a resonator. Further, a bandstop filter device is provided that includes coupling between resonators in the filter.

Abstract: A lanthanum aluminate (LaAlO.sub.3) substrate on which thin films of layered perovskite copper oxide superconductors are formed. Lanthanum aluminate, with a pseudo-cubic perovskite crystal structure, has a crystal structure and lattice constant that closely match the crystal structures and lattice constants of the layered perovskite superconductors. Therefore, it promotes epitaxial film growth of the superconductors, with the crystals being oriented in the proper direction for good superconductive electrical properties, such as a high critical current density. In addition, LaAlO.sub.3 has good high frequency properties, such as a low loss tangent and low dielectric constant at superconductive temperatures. Finally, lanthanum aluminate does not significantly interact with the superconductors. Lanthanum aluminate can also used to form thin insulating films between the superconductor layers, which allows for the fabrication of a wide variety of superconductor circuit elements.

Abstract: Superconducting multiplexing/demultiplexing arrangements include a number of signal input devices and a number of signal output devices. A number of resonators provides a number of filters. Each filter represents a channel. The resonator(s) operate(s) devices at lest in dual mode, and tuning devices are provided so that at least some of the resonators is/are tuneable. A method is provided of multiplexing signals incoming to a multiplexing arrangement with a number of resonators, each of the resonators having a number of input ports which are so arranged that a number of mulitpole filters are created. Input signals having different frequencies are supplied to the different input ports of the resonators, each of which is operated in three modes. Coupling devices are arranged which at least comprise the angle between the input ports and a symmetry plane. The angles are non-perpendicularly azimuth.

Abstract: A superconducting notch or band reject filter arrangement includes a superconducting dielectric resonator and a waveguide arrangement including a microstrip line to which the resonator is connected. The resonator is a parallel-plate resonator with a chip of a non-linear dielectric material device on which superconductors are arranged and the waveguide arrangement includes a contact device or a coupling device, the resonator being connected to the contact device of the waveguide arrangement in such a way that electric contact is provided, and the filter arrangement is frequency tuneable. Through the arrangement, the insertion losses are low.

Abstract: High temperature superconductor mini-filters and mini-multiplexers utilize self-resonant spiral resonators and have very small size and very low cross-talk between adjacent channels.

Abstract: The present invention provides an electronically tunable resonating apparatus which uses a tunable dielectric material which is biased by an electric field to alter the resonant frequency in a resonating cavity. The electrodes which apply the electric field are connected to a variable voltage source. The electrodes can therefore apply a plurality of electric field strengths and provide a range of resonant frequencies in the resonating apparatus. The resonating apparatus is particularly useful for microwave and millimeterwave electromagnetic energy.

Abstract: A narrow bandwidth (1 to >100 MHz) HTS microwave filter (30 or 50) is described which is tunable over a moderate frequency range (100 to >1000 MHz at X-band). The low loss (<1 dB) and GHz/microsecond tuning rates enable the filter to operate as a radar preselector filter. The filter consists of a multi-pole microstrip or stripline HTS coupled one-half resonator pattern deposited onto a ferrite substrate (32 or 52, 54). The ferrite substrate is operated in a latching mode like that in the operation of digital phase shifters. The filter tunability arises from the variation of the effective permeability with the remanent magnetization.

Abstract: An a-axis high temperature superconducting film having preferential in-plane orientation is formed. In the preferred embodiment, an a-axis film has substantial amounts of superconductor oriented with its c-axis in a unified direction. YBCO on neodymium gallate (110) plane has resulted in a high temperature superconductor with over 80% by volume being a-axis with c-axis in-plane alignment in one preferential direction. These films are epitaxial. The preferred method of film growth is for in situ growth by laser ablation. Preferably, the a-axis film is nucleated by laser ablation on onto a substrate which is at a temperature of 50 to 100.degree. C. less than the optimal substrate temperature for c-axis growth. Optionally, once a-axis nucleation has begun, the substrate temperature may be increased to optimize superconductor properties.

Abstract: A ferroelectric phase shifter in the form of a coplanar waveguide and a method of fabrication thereof in which a ferroelectric film and a high temperature superconductor film are deposited onto a substrate in of a number of configurations. The high temperature superconductor material is biased in order to vary the dielectric constant of the ferroelectric material. Changing the dielectric constant enables varying the amount of phase shift of a wave applied to the phase shifter.

Abstract: A symmetrical coplanar waveguide is formed by a spiral with three arms. One arm is 1, the second arm is 2 and the 3rd arm is 41. The arms 1 and 2, and spiral arms 1 and 41 are separated by equal distance. The spiral arms 1, 2 and 41 are formed by the deposition of films of a conductor, layer 3, on a film 14 of a single crystal ferroelectric material, layer 2, which is deposited on a single crystal dielectric material, layer 1. Input is 10 and the output is 11. The CPW spiral arms 1, 2 and 41 form a time delay device. When a bias voltage V is applied between the spiral arms 1 and 2, and between 1 and 41 through a bias filter made of L and C, the permittivity of the ferroelectric film between the spiral arms 1 and 2, and between 1 and 41 or across the CPW, changes producing a change in the time delay.

Abstract: A superconducting garnet thin film system (10) is provided for high frequency microwave applications where a single crystal high temperature superconducting (HTSC) layer (18) is integrated with a garnet substrate (12). A first perovskite compound buffer layer (14) is epitaxially grown on an upper surface of the garnet substrate layer (12) and defines a lattice constant less than the lattice constant of the garnet substrate layer (12) with the first perovskite layer being aligned in a cube on cube parallel orientation with respect to the garnet substrate layer (12). A second perovskite layer (16) is epitaxially grown on an upper surface of the first perovskite layer (14) at an orientation of 45.degree. to first layer (14) and defines a lattice constant less than the lattice constant of the first perovskite layer.

Abstract: A microwave filter has a plurality of resonators and at least one transmission line mounted on a substrate having a ground plane. The filter can have input and output couplings that are transmission lines formed on the substrate or it can have input and output probes. The resonators have one or more gaps extending entirely therethrough, the gaps splitting the resonators into two or more slices. The transmission lines extend into the gap to couple energy into or out of a resonator or between two adjacent resonators. The transmission lines can have tapered ends or can be located off center so that they are closer to one side of a gap than to another side.

Abstract: A high power high temperature superconductive circuit for use in various microwave devices including filters, dielectric resonator filters, multiplexers, transmission lines, delay lines, hybrids and beam-forming networks has thin gold films deposited either on a substrate or on top of the high temperature superconductive film. Alternatively, other metal films can be used or a plurality of dielectric films can be used or a dielectric constant gradient substrate can be used. The use of these materials in a part or parts of a microwave circuit reduces the current density in those parts compared to the level of current density if only high temperature superconductive film is used. This increases the power handling capability of the circuit.

Abstract: The invention provides methods to manufacture dense, complex c-axis oriented ceramic oxide layers with thickness greater than 2.5 microns (.mu.m) on a metallic substrate (composites) without the use of an interfacial barrier, buffer, or surface layer using a metalorganic deposition process and thermomechanical reaction treatments is disclosed. A porous amorphous metal oxide ceramic deposit is formed directly on the substrate by spray pyrolyzing a mixed metalorganic precursor solution onto the metallic substrate. The metallic substrate has been previously heated to temperatures greater than the boiling point of the organic solvent and are high enough to initiate in situ decomposition of the metalorganic precursor salts. The process does not apply the precursor solution to the substrate as a liquid coating that is pyrolyzed in subsequent processing steps.

Abstract: A coplanar waveguide is formed by a spiral with two arms. One arm is labelled 1, and the second arm is labelled 2. The arms labelled 1 and 2 are separated by equal distance. The spiral arms labelled 1 and 2 are formed by the deposition of a film of a conductor, a third layer, on a film 14 of a single crystal ferroelectric material, a second layer, which is deposited on a single crystal dielectric material, a first layer 1. Input is 10 and the output is 11. The CPW spiral arms labelled 1 and 2 forms a time delay device. When a bias voltage V is applied between the two spiral arms labelled 1 and 2 through a bias filter made of an inductor L and a capacitor C, the permittivity of the ferroelectric film between the two spiral arms labelled 1 and 2, or across the CPW, producing a change in the time delay.

Abstract: Novel structures and methods for forming useful high temperature superconducting devices, most particularly resonators, are provided. Structures resulting in reduced peak current densities relative to known structures achieve numerous desirable benefits, especially including the reduced intermodulation effects of earlier resonators. In one aspect of this invention, a spiral in, spiral out resonator is provided, characterized in that it has an odd number of long runs, at least equal to five long runs, where the long runs are connected by turns, and wherein there are at least two sequential turns of the same handedness, followed by at least two turns of the opposite handedness. In yet another aspect of this invention, it has been discovered that reducing the size of the input and output pads of HTS resonators increases the relative inductance compared to the capacitance. Yet another resonator structure is a spiral snake resonator having a terminal end disposed within the resonator.

Abstract: In a small transmission line type high-frequency circuit element that has small loss due to conductor resistance and has a high Q value, an error in the dimension of a pattern, etc. can be corrected to adjust element characteristics. An elliptical shape resonator (12) that is formed of an electric conductor is formed on a substrate (11a), while a pair of input-output terminals (13) are formed on a substrate (11b). Substrate (11a) on which resonator (12) is formed and substrate (11b) on which input-output terminal (13) is formed are located parallel to each other, with a surface on which resonator (12) is formed and a surface on which input-output terminal (13) is formed being opposed. Substrates (11a) and (11b) that are located parallel to each other are relatively moved by a mechanical mechanism that uses a screw and moves slightly. Also, substrate (11a) is rotated by the mechanical mechanism that uses a screw and moves slightly around the center axis of resonator (12) as a rotation axis (18).

Abstract: The present invention provides a superconducting transmission delay line phase shifter which has an essential structure as follows. The superconducting transmission delay line phase shifter has a layer made of a material showing a low dielectric loss the layer comprising first, second and third sections, wherein the second section being positioned between the first and third sections. The superconducting transmission delay line phase shifter also has a ferroelectric selectively provided in the second section. The ferroelectric extends between boundaries of the second section to the first and third sections. The superconducting transmission delay line phase shifter also has a thin film made of a conductor having a high conductivity. The conductive thin film extends across the bottoms of the first, second and third sections. The superconducting transmission delay line phase shifter also has a superconducting signal transmission line, on which signals are transmitted.

Abstract: A composite material is disclosed which includes a substrate, an oriented film provided on a surface of the substrate and formed of a crystal of a Y123 metal oxide of the formula LnBa.sub.2 Cu.sub.3 O.sub.y wherein Ln stands for Y or an element belonging to the lanthanoid and y is a number of 6-7, and a layer of a Y123 metal oxide of the formula LnBa.sub.2 Cu.sub.3 O.sub.y wherein Ln stands for Y or an element belonging to the lanthanoid and y is a number of 6-7 formed on the oriented film.

Abstract: Excellent films of a high Tc superconductor are easily produced on metal coated substrates at a temperature below 700.degree. C. These metal buffer films are made of Pt, Au, Ag, Pd, Ni or Ti. The film superconductivity is significantly improved by the metal buffer layer. Since it is easy to form this metal coating on a substrate, the invention can increase the potential number of usable substrates such as fibers, amorphous solids or semiconductors.

Abstract: A superconducting ceramic includes a laminate and a superconducting ceramic tape joined to the laminate. The laminate and superconductor tape are joined such that the tape is under a compressive stress. The compressive stress is of a greater amount than the compressive stress which results from differences in thermal expansion of the tape and the laminate. The greater compressive stress can be achieved by putting the laminate under a greater tension than the superconducting ceramic tape during joining of the superconducting ceramic tape to the laminate.

Abstract: A high-temperature superconductive microwave delay line that operates in an essentially pure TEM field configuration in a compact assembly. The delay line is a planar signal delay line which includes first and second substrates made of first and second dielectric materials; each substrate can be LAO material. First and second patterned delay line segments having a configuration, are formed of first and second conductive materials on the obverse sides of the first and second substrates, respectively. On the reverse side of each of the first and second substrates, respective first and second ground planes are formed using respective first and second conductive materials, which are preferred to be high-temperature superconductive films, such as YBCO films. The delay line also includes coupling means for coupling the first patterned delay line segment to the second patterned delay line segment, thus bringing the two patterned delay line segments into substantial contact.

Abstract: A tuning mechanism for tuning a resonant circuit is provided. The tuning mechanism comprises a spring pin having a superconductive, dielectric or magnetic tuning tip attached thereto. The spring pin is slidably inserted into a filter package wall through a mating hole. A mechanism is provided for adjusting the position of the tip within the electromagnetic field above the filter element. The tip may be shaped, thus allowing adjustment of both the height of the tip above the filter element and the position of the tip in a plane parallel to the plane of the filter. Optionally, the spring pin may include an offset to allow close spacing of the tips along with wider spacing of the actuator end of the pin.

Abstract: A first electrically conductive layer whose thickness is equal to or smaller than the skin depth of the radio wave used for communication, a dielectric layer whose permittivity is changed by application of electric field, and a second electrically conductive layer whose thickness is equal to or smaller than the skin depth of the radio wave used for communication are sequentially stacked near a resonance element which is formed on the front surface of a dielectric substrate having a ground layer formed on the rear surface thereof. The effective permittivity of the dielectric layer is changed in a wide range by changing a voltage applied between the first and second electrically conductive layers to change the electric field applied to the dielectric layer. As a result, the impedance of the resonance element is changed, and when a plurality of resonance elements are arranged closely to each other to construct a filter, the coupling degree between the resonance elements is changed.

Abstract: The high power band-pass filters are made of sections of circular waveguide resonators with sections of waveguide in between them. In the center of the waveguide resonator a ferroelectric disc, with a hole in the center, is placed. A bias is applied to the inner side of the ferroelectric disc. On the application of a bias voltage, the permittivity of the ferroelectric disc changes. As a result, the resonant frequency of the circular cavity changes. Application of different levels of bias voltages produces different resonant frequencies of the filter. The interior conducting surfaces of the waveguide(s) and the waveguide resonator(s) have high Tc superconducting material and the waveguide flanges have high Tc superconducting material on the conducting surfaces.The band-stop filters are made of a section of a main waveguide with branch waveguide resonator(s) connected on the broad-wall of the main waveguide with waveguide sections in between the resonators.

Abstract: Microstrip/stripline transmission lines have a plurality of strips on a substrate where strips are separated by a gap. This arrangement results in a reduced maximum current density compared to previous transmission lines with the same power handling capability. The strips can have the same width or different widths. The gaps can have the same width or different widths. The transmission lines can be used in filters and resonators and can be made of high temperature superconductive materials.

Abstract: TM.sub.0i0 mode (i=1, 2, 3, . . . ) planar high temperature superconductor resonators useful in high temperature superconducting filters, filter banks and multiplexers comprise a shaped high temperature superconductor film and a high temperature superconductor ground plate deposited on opposite sides of a dielectric substrate, wherein the shaped high temperature superconductor film has an aperture in the center thereof and has a shape selected from the group consisting of circles and polygons.

Abstract: An oxide superconductor composite having improved texture and durability. The oxide superconductor composite includes an oxide superconductor phase substantially surrounded with/by a noble metal matrix, the noble metal matrix comprising a metal oxide in an amount effective to form metal oxide domains that increase hardness of the composite. The composite is characterized by a degree of texture at least 10% greater than a comparable oxide superconductor composite lacking metal oxide domains. An oxide superconducting composite may be prepared by oxidizing the precursor composite under conditions effective to form solute metal oxide domains within the silver matrix and to form a precursor oxide in the precursor alloy phase; subjecting the oxidized composite to a softening anneal under conditions effective to relieve stress within the noble metal phase; and converting the oxide precursor into an oxide superconductor.

Abstract: A superconducting ceramic film is deposited on a substrate sputtering. In virtue of the low thermal conductivity of ceramic, a laser beam is radiated to the ceramic film in order to remove the irradiated portion by sublimation and produce a pattern on the ceramic film.

Abstract: This invention pertains to monolithic filters of the band-pass or band-reject type which a single crystal ferroelectric material having an electric field dependent permittivity. The filters are comprised of: a first layer of a single crystal dielectric material; a second layer of a single crystal high T.sub.c superconductor material; a third layer of a single crystal ferroelectric material; and a fourth layer of high T.sub.c superconductive microstrip lines configured into the various filter circuits, including resonator circuits and transformer circuits. The filters are capable of operating at power levels up to 0.5 MW at a temperature slightly above the Curie temperature to avoid hysteresis.

Abstract: A high temperature superconductor (HTS) tri-layer structure and a method for providing the same are described. Preferable two dimensional growth for all layers is provided resulting in smooth surfaces and highly crystalline layers. Full oxygenation of HTS under-layer(s) is provided despite having thick intervening dielectric mid-layer. HTS over- and under-layers are preferably structurally and electrically similar and have high crystallinity, the HTS layers have high T.sub.c (e.g. >90K) comparable to T.sub.c of single layer superconductor layers and a high J.sub.c (e.g. >10.sup.6 A/cm.sup.2), the tri-layer properties do not significantly degrade as the thickness of the layers is increased, and the dielectric mid-layer has high resistivity and is substantially pin-hole free.

Abstract: A coaxial cavity is loaded with a single crystal ferroelectric rod whose permittivity is dependent on the electric field in which it is immersed. Application of a bias voltage changes the permittivity of the ferroelectric rod of the cavity and thus changing the frequency of the coaxial cavity. A tunable coaxial filter is obtained. By placing the cavity in the main transmission line, a bandpass tunable filter is obtained. By placing the cavity in a branch line, a band reject tunable filter is obtained.

Abstract: A biaxially textured article includes a rolled and annealed, biaxially textured substrate of a metal having a face-centered cubic, body-centered cubic, or hexagonal close-packed crystalline structure; and an epitaxial superconductor or other device epitaxially deposited thereon.

Abstract: A microwave grating 10 for a dispersive delay line, the grating comprising: (a) a terminal 12 for receiving a wideband RF signal including multiple RF signals of different frequencies; (b) a primary transmission line 14 capable of carrying the wideband RF signal, the primary transmission line 14 being electrically connected to said terminal 12; and (c) a plurality of non-resonant open-stub transmission lines 16 each having a length 18, the open-stub transmission lines 16 being capacitively loaded on the primary transmission line 14 at spaced locations 20 along the primary transmission line 14. Each open-stub transmission line 16 effects perturbations in the signal carrying capability of the primary transmission line 14 where the open-stub transmission line is located.

Abstract: Microwave hairpin-comb filters utilize a plurality of hairpin (i.e., folded) half-wavelength microstrip or stripline resonators arranged side-by-side and all with the same orientation. The coupling regions between resonators extend parallel to the sides of the resonators for substantially 1/8 to 1/4 wavelength at the frequency of resonance of the resonators. This length of coupling region between resonators, along with all resonators being oriented in the same direction, result in resonance effects in the coupling regions between the resonators. These effects greatly reduce the couplings between the resonators so that the resonators can be very closely spaced so as to produce a compact filter structure yet still have a narrow passband. For example, a compact narrow band filter structure is possible using high-Q nominally half wavelength hairpin resonators. The structure can also be made to produce poles of attenuation adjacent to the passband in order to enhance the filter cutoff characteristic.

Abstract: A superconducting oxide ceramic pattern is described. The pattern is comprised of a high Tc superconducting region and a low Tc superconducting region which exhibits a resistivity at the liquid nitrogen temperature while the high Tc region is superconducitive at that temperature. The low Tc region is doped with impurity such as Si and then subjected to thermal treatment to oxidizing the impurity.

Abstract: A main CPW structure is formed by depositing two parallel films of a conductor on a film of a single crystal ferroelectric material. Cavities are formed by placing irises in a main CPW structure. These cavities are tuned to a dominant resonant frequency. By the application of a bias voltage to the main CPW structure with cavities, the permittivity of the film of the ferroelectric material, underneath the CPW structure, is changed. Thus the dominant resonant frequency of the filter is changed. By changing the level of the bias voltages, different dominant resonant frequencies of the filter are obtained. Thus a tunable band pass filter is obtained. With branch cavities on a CPW structure deposited on a ferroelectric film, a tunable band reject filter is obtained.

Abstract: A superconducting article including a flexible polycrystalline metal substrate, a layer of an adhesion layer material upon the surface of the flexible polycrystalline metal substrate, a layer of a cubic oxide material upon the adhesion layer material, the first layer of cubic oxide material deposited by ion beam assisted deposition, a layer of a buffer material upon the ion beam assisted deposited cubic oxide material layer, and, a layer of YBCO upon the buffer material layer is provided and has demonstrated J.sub.c 's of 1.3.times.10.sup.6 A/cm.sup.2, and I.sub.c 's of 120 Amperes across a sample 1 cm wide.

Abstract: A main symmetrical CPW structure is formed by depositing three parallel films of a conductor on a film of a single crystal ferroelectric material. Cavities are formed by placing irises in a main CPW structure. These cavities are tuned to a dominant resonant frequency. By the application of a bias voltage to the main CPW structure with cavities, the permittivity of the film of the ferroelectric material, underneath the CPW structure, is changed. Thus the dominant resonant frequency of the filter is changed. By changing the level of the bias voltages, different dominant resonant frequencies of the filter are obtained. Thus a tunable band pass filter is obtained. With branch cavities on a CPW structure deposited on a ferroelectric film, a tunable band reject filter is obtained.

Abstract: This invention permits superconducting ceramics, as well as other ceramic materials, to be spray deposited onto indefinitely large sheets of metallic substrate from a carboxylic acid salt solution. Elemental metal precursors of the superconductor are introduced into the solution as carboxylic acid salts. The deposit formed on the malleable metallic substrate is then thermomechanically calcined to form c-axis textured metal-superconductor composite sheet structures. These composite sheet structures can be formed by pressing together two ceramic-substrate structures, ceramic face-to-face, to form a metal-ceramic-metal sheet structure, or by overlaying a metal sheet over the deposited structure. Once the structure has been thermomechanically calcined, the c-axis of the superconductor is oriented parallel to the vector defining the plane of the metal sheet, i.e., perpendicular to the surface of the plane.

Abstract: Superconducting transition metal oxide films are provided which exhibit very high onsets of superconductivity and superconductivity at temperatures in excess of 40.degree. K. These films are produced by vapor deposition processes using pure metal sources for the metals in the superconducting compositions, where the metals include multi-valent nonmagnetic transition metals, rare earth elements and/or rare earth-like elements and alkaline earth elements. The substrate is exposed to oxygen during vapor deposition, and, after formation of the film, there is at least one annealing step in an oxygen ambient and slow cooling over several hours to room temperature. The substrates chosen are not critical as long as they are not adversely reactive with the superconducting oxide film. Transition metals include Cu, Ni, Ti and V, while the rare earth-like elements include Y, Sc and La. The alkaline earth elements include Ca, Ba and Sr.

Abstract: A FET type superconducting device comprises a thin superconducting channel, a superconducting source region and a superconducting drain region formed of an oxide superconductor over a principal surface of the substrate, and a gate electrode on a gate insulator disposed on the superconducting channel for controlling the superconducting current flowing through the superconducting channel by a signal voltage applied to the gate electrode. The superconducting channel is formed of(Pr.sub.w Y.sub.1-w)Ba.sub.2 Cu.sub.3 O.sub.7-z (0<w<1, 0<z<1) oxide superconductororY.sub.1 Ba.sub.2 Cu.sub.3-v CO.sub.V O.sub.7-u (0<v<3, 0<u<1) oxide superconductor.These oxide superconductors have smaller carrier densities than the conventional oxide superconductor so that the superconducting channel has a larger thickness than the one funned of the conventional oxide superconductor.

Abstract: A novel ceramic substrate useful for the preparation of superconducting films, said substrate having the formula REBa.sub.2 MO.sub.6 where RE represents rare earth metals--Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu and M represents metals Nb, Sb, Sn, Hf, Zr; and a process for the preparation of superconducting YBa.sub.2 Cu.sub.3 O.sub.7-.delta. thick films on new ceramic substrate.

Abstract: Use of monolayer films for the direct modification of high-T.sub.c superconductor structures and devices. Methods for the formation of superconductor localized monolayer films have been discovered based on the spontaneous adsorption of molecules containing ligating functionalities, such as alkylamine, arylamine, and alkylthiol moieties. Molecules containing these types of functionalities are found to bind tenaciously to the metal ions which form the high-T.sub.c superconductor surface. The derivatized superconductor structures can be prepared simply by soaking the high-T.sub.c, superconductor structure or device in a dry organic solvent system which contains the derivatizing agent. Large changes in the superconductor interfacial properties can be achieved with such procedures allowing for the atomic level control of the surface properties of the superconductor.

Abstract: A superconducting multilayer ceramic substrate is disclosed, prepared by firing a laminate of at least two polymer bonded cast sheets of a ceramic dielectric oxide powder, at least one sheet of which has a metallization pattern provided thereon, to thereby form a superconducting oxide reaction layer at the interface between the sintered ceramic material and the embedded metallic conductor lines of the metallization pattern.

Abstract: Compounds of the general formula A.sub.2 MeSbO.sub.6 wherein A is either barium (Ba) or strontium (Sr) and Me is a non-magnetic ion selected from the group consisting of scandium (Sc), indium (In) and gallium (Ga) have been prepared and included in high critical temperature thin film superconductor structures.

Abstract: Excellent films of a high Tc superconductor are easily produced on metal coated substrates at a temperature below 700.degree. C. These metal buffer films are made of Pt, Au, Ag, Pd, Ni or Ti. The film superconductivity is significantly improved by the metal buffer layer. Since it is easy to form this metal coating on a substrate, the invention can increase the potential number of usable substrates such as fibers, amorphous solids or semiconductors.