Abstract: In a high frequency transmission line having a dielectric substrate and a conductor line which is provided on the dielectric substrate for allowing electric current to flow therethrough, the conductor line has a non-grain-boundary oxide superconductor layer with twin walls but without grain boundaries. The high frequency transmission line is in the form of a plane circuit. It is preferable that an oriented oxide superconductor layer is provided between the dielectric substrate and the non-grain-boundary oxide superconductor layer.

Abstract: An electrical interconnect provides a path between cryogenic or cryocooled circuitry and ambient temperatures. As a system, a cryocable 10 is combined with a trough-line contact or transition 20. In the preferred embodiment, the cryocable 10 comprises a conductor 11 disposed adjacent an insulator 12 which is in turn disposed adjacent another conductor 13. The components are sized so as to balance heat load through the cryocable 10 with the insertion loss. In the most preferred embodiment, a coaxial cryocable 10 has a center conductor 11 surrounded by a dielectric 12 (e.g. Teflon.TM.) surrounded by an outer conductor 13 which has a thickness between about 6 and 20 microns. The heat load is preferably less than one Watt, and most preferably less than one tenth of a Watt, with an insertion loss less than one decibel. In another aspect of the invention, a trough-line contact or transition 20 is provided in which the center conductor 11 is partially enveloped by dielectric 12 to form a relatively flat portion 28.

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 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: 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 resonant structure has a center conductor, a dielectric element, and an outer conductor. The center conductor is a substrate with a coating of a superconductor on its outer surface, and the outer conductor is a substrate with a coating of a superconductor on its inner surface. The dielectric element has a passageway which is sized for receiving the inner conductor so that there is substantially complete contact between the layers of superconductor coating and the dielectric. Similarly, the outer surface of the dielectric element is sized to match the inner superconductor coated surface of the outer conductor.

Abstract: A superconductor layer is formed on one side of a dielectric substrate, and with this superconductor layer as a conductor layer of the bottommost layer, superconductor layers and dielectric layers are alternately laminated with each other. Thus, a superconducting multilayer electrode is provided which is laminated with at least one TEM mode transmission line which is constituted of a pair of superconductor layers with a dielectric layer sandwiched in between, and the superconductor layer and the dielectric layer have film thicknesses which are set so that the maximum value of the current density flowing through each superconductor layer becomes the same. The resistance to electric power of the superconducting multilayer electrode is proportional to the number of laminated layers.

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: The pass band filter has planar ring resonators arranged in pairs partly side-by-side and partly one above the other and a housing cover for each resonator. Each resonator includes a respective substrate provided with upper and lower conductive layers of high temperature superconductor material on respective opposite sides of the corresponding substrate, so that each planar ring resonator is operable in an edge-current-free TM010-oscillator mode. A respective coupling hole of radius r.sub.i is provided in the lower conductive layer (3) of each resonator and the lower conductive layers of both resonators in each pair face each other so that both resonators are coupled. Each housing cover has a respective truncated cone-shaped step ring (20) having a corresponding inner housing cover radius (r.sub.G). The radius ratio r.sub.i /r.sub.a (r.sub.

Abstract: An electrically tunable planar filter has a filter element including a substrate having an upper side and a wave-guide arranged on the upper side of the substrate, at least one tuning element composed of at least one material selected from the group consisting of a ferroelectric material and an antiferroelectric material with adjustable voltage applied to the tuning element and thereby with an adjustable dielectric constant, the tuning element being arranged at the upper side of the substrate.

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: A planar dual mode filter has one or more resonators with L-shaped sections that are oriented back to back to one another. The filter can be constructed by adjusting the size of a gap between the back to back sections and adjusting the offset distance between adjacent sections. Further, coupling between adjacent resonators can be controlled by adjusting a distance between the adjacent resonators. The filters can be co-planar, stripline, suspended microstripline or microstripline. The filters have a film on a substrate with a ground plane. The film can be gold, silver or copper or it can be a ceramic material that becomes superconductive at cryogenic temperatures.

Abstract: An electromagnetic device, such as a resonator for a filter, incorporates a high-purity polycrystalline alumina. The device may include a superconducting component, which must be cooled significantly below room temperature. The high-purity polycrystalline alumina may be a dielectric slab in a stripline resonator, or may be used as a stand for holding other components. The high-purity polycrystalline alumina exhibits a very low loss tangent at cryogenic temperatures, and therefore will result in an electromagnetic device with superior performance characteristics.

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: A filter for processing electromagnetic signals has a housing with resonators located inside the cavity of that housing. The resonators, which may be made in part from superconducting material, have rounded exterior surfaces without corners to provide a more desirable coating surface and uniform electric field around the resonators. The filter housing may be composed of a plurality of housing cells, each containing a resonator. These cells can be removably attached to other cells so that resonators may be added to or removed from the filter as may be required for a particular application.

Abstract: A high frequency signal generator using a superconducting quantum interference device is disclosed including: a magnetic signal generator for supplying a low frequency magnetic signal to a superconducting quantum interference device; a first filter for selectively supplying only the magnetic signal to the superconducting quantum interference device, and preventing a high frequency signal generated from the superconducting quantum interference device from flowing to the magnetic signal generator; the superconducting quantum interference device for frequency-multiplying the magnetic signal generated from the first filter to the high frequency signal of a sinusoidal wave according to the frequency, waveform and amplitude of the magnetic signal; a second filter for preventing the magnetic signal generated from the magnetic signal generator from flowing to a high frequency guide and antenna, and selectively supplying only the high frequency signal generated from the superconducting quantum interference device to t

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: An electrical interconnect provides a path between cryogenic or cryocooled circuitry and ambient temperatures. As a system, a cryocable 10 is combined with a trough-line contact or transition 20. In the preferred embodiment, the cryocable 10 comprises a conductor 11 disposed adjacent an insulator 12 which is in turn disposed adjacent another conductor 13. The components are sized so as to balance heat load through the cryocable 10 with the insertion loss. In the most preferred embodiment, a coaxial cryocable 10 has a center conductor 11 surrounded by a dielectric 12 (e.g. Teflon.TM.) surrounded by an outer conductor 13 which has a thickness between about 6 and 20 microns. The heat load is preferably less than one Watt, and most preferably less than one tenth of a Watt, with an insertion loss less than one decibel. In another aspect of the invention, a trough-line contact or transition 20 is provided in which the center conductor 11 is partially enveloped by dielectric 12 to form a relatively flat portion 28.

Abstract: An electromagnetic filter has a unitary filter body defining a number of cavities. A cover for the filter body has several resonators attached to it which are located in the cavities when the cover is attached to the filter body. The cover has a recess into which a transmission line is placed. Passageways through the cover connect the transmission line with coupling mechanisms mounted on the cover adjacent the resonators. The resonators have a generally toroidal shape and the coupling mechanisms are shaped to provide the desired coupling between the transmission line and the resonators. An adjustable capacitor attached to the coupling loop has a passageway through its housing to eliminate moisture from the capacitor. The resonator and cavities may be tuned by use of a tuning mechanism which is also designed to minimize moisture which might prevent movement of the tuner during tuning.

Abstract: A microwave bandpass filter has a planar configuration formed in microstrip or stripline where a circuit is printed onto a substrate. The filter has at least two patch resonators with a T-shaped coupling path extending between the two resonators. In a further embodiment of the invention, one or more resonators is isolated from other resonators in the filter by being located in a compartmentalized housing or separate housings to eliminate undesirable coupling between a resonator in one compartment and a resonator in another compartment. The filter of the present invention has improved performance characteristics over previous patch resonator filters.

Abstract: The superconductor bandpass filter for electromagnetic signals includes a substrate (5); striplines (1) made of a type II superconductive material arranged on the substrate and a tuning device (2) for tuning the superconductor bandpass filter consisting of a device for changing a magnetic penetration depth .lambda.(T) of the striplines (1), so as to change the effective length, effective width and effective spacing of the striplines and thus to change the center frequency and/or the bandwidth. The device for changing the magnetic penetration depth .lambda.(T) of the striplines (1) advantageously includes a device for exerting a mechanical force or stress on the striplines and/or a device for varying a magnetic field applied to the striplines.

Abstract: An improved high temperature superconducting planar filter wherein the coupling circuit or connecting network is located, in whole or in part, on the side of the substrate opposite the resonators and enables higher power handling capability.

Abstract: An adjustable coupler for coupling electromagnetic energy into or out of a resonant cavity has an input/output line connected to a loop or conductor. A base of the coupler has a passageway into which a bolt is inserted. Threads on a bolt engage threads on a nut attached to the conductor. A head of the bolt is held in place on the outside of the base so that rotation of the head moves the nut and conductor.

Abstract: The present invention relates to a tuneable fringe effect capacitor for conducting radio frequency energy. The capacitor includes a thin film of ferroelectric material, a pair of films of a conductive material deposited on the ferroelectric film with a gap between the films, and a substrate for the ferroelectric material and the conductive films. The capacitance value across the gap is varied by applying a voltage to the ferroelectric material and thereby altering the dielectric constant of the ferroelectric material.

Abstract: The planar superconducting resonator includes a substrate (1), a symmetrically shaped stripline (2) applied to the substrate (1) in which two orthogonal electromagnetic modes are excitable and including a symmetry perturbation for coupling the two orthogonal electromagnetic modes, an additional stripline (5) arranged on the substrate in the vicinity of the symmetry perturbation, a Josephson junction (3) arranged between the symmetry perturbation and the additional stripline (5) and a device for generating and controlling a magnetic field at the Josephson junction (3) so that the degree of coupling between the two orthogonal electromagnetic modes is varied. The Josephson junction (3) is formed by a non-superconducting layer (4) arranged between the symmetry perturbation and the additional stripline (5).

Abstract: High power high temperature superconductor filters having TM.sub.0i0 mode (i=1, 2, 3, . . . ) circular shaped high temperature superconductor planar resonators or symmetrical polygon shaped resonators which eliminates wrap-around H-field and very sharp current peaks at the edge of the resonator are provided.

Abstract: A number of MMIC ferroelectric variable time delay devices are presented. Each embodiment has a microstrip configuration deposited on a ferroelectric film which is deposited on a high Tc superconductor substrate connected to the ground. A bias electric field changes the permittivity of the ferroelectric material. As a result, a variable time delay is obtained.

Abstract: Lumped element electrical components, such as inductors and capacitors, are formed to include high temperature superconducting materials. In the preferred embodiment, thin film epitaxial high temperature superconductors are patterned to form capacitors and inductors on low loss substrates. Preferably, a ground plane is formed on the back side of the substrate, most preferably being formed of high temperature superconducting material, or other highly conductive materials such as gold or copper. Various advantageous structures include a planar spiral structure, a zig-zag serpentine structure, a single coil structure and a double coil structure. Single layer and multilayer structures are included. Improved narrow bandpass filters and high Q resonator structures are formed.

Abstract: Lumped element electrical components, such as inductors and capacitors, are formed to include high temperature superconducting materials. In the preferred embodiment, thin film epitaxial high temperature superconductors are patterned to form capacitors and inductors on low loss substrates. Preferably, a ground plane is formed on the back side of the substrate, most preferably being formed of high temperature superconducting material, or other highly conductive materials such as gold or copper. Various advantageous structures include a planar spiral structure, a zig-zag serpentine structure, a single coil structure and a double coil structure. Single layer and multilayer structures are included. Improved narrow bandpass filters, bandreject filters and high Q resonator structures are formed. Chebyshev bandpass filters are formed from multiple series connected zig-zag filter structures.

Abstract: Three embodiments of a tunable ferroelectric transmitting system are included. Each embodiment includes a tunable oscillator and a tunable antenna. Two embodiments include a negative resistance diode, the frequency of oscillation being controlled by a single crystal tunable ferroelectric resonator. The third embodiment uses a transistor. The tunable antenna is made of a single crystal tunable ferroeletric resonator. All conducting depositions are made of films of a high Tc superconducting material.

Abstract: A bandpass filter comprises multiple side-coupled strip line resonators wherein the resonators are staggered or offset with respect to their nearest neighbors by substantially 1/4 wavelength or less. In the preferred embodiment, the strip line bandpass filter structure has substantially parallel resonators arrayed with substantially constant spacing between the resonators with 1/4 wavelength overlap or less. Generally, the amount of stagger between nearest neighbors is reduced for resonators toward the center of the filter. Coupling between resonators is controlled by varying the relative amount of stagger between resonators. The resonators may be formed from normal metal or superconducting materials, such as YBCO or thallium containing superconductors. A strip line structure may be formed by utilizing two mirror structures each comprising a substrate having a ground plane and a patterned staggered resonator array formed on the substrate on a side opposite the ground plane.

Abstract: A filter for processing electromagnetic signals has a housing with resonators located inside the cavity of that housing. The resonators, which may be made in part from superconducting material, have rounded exterior surfaces without corners to provide a more desirable coating surface and uniform electric field around the resonators. The filter housing may be composed of a plurality of housing cells, each containing a resonator. These cells can be removably attached to other cells so that resonators may be added to or removed from the filter as may be required for a particular application.

Abstract: The present invention is a superconducting radiofrequency window assembly for use in an electron beam accelerator. The srf window assembly (20) has a superconducting metal-ceramic design. The srf window assembly (20) comprises a superconducting frame (30), a ceramic plate (40) having a superconducting metallized area, and a superconducting eyelet (50) for sealing plate (40) into frame (30). The plate (40) is brazed to eyelet (50) which is then electron beam welded to frame (30). A method for providing a ceramic object mounted in a metal member to withstand cryogenic temperatures is also provided. The method involves a new metallization process for coating a selected area of a ceramic object with a thin film of a superconducting material. Finally, a method for assembling an electron beam accelerator cavity utilizing the srf window assembly is provided.

Abstract: High Tc superconducting limiters are designed to operate at two or more levels of input signals. In one waveguide embodiment, multiple half wavelength branch waveguide lines are connected to a main waveguide line. The half wavelength lines are terminated with tuned circuits of a capacitance, made of a ferroelectric material, and an inductance provided by a waveguide line. In another waveguide embodiment, the branch lines are terminated in tuned cavities each having a ferroelectric material. In a microstrip embodiment, multiple half wavelength branch ferroelectric lines of different impedances are connected to a main line. In a second microstrip line embodiment, tuned circuits, with differing L and C values, are connected to a main transmission line through a half a wavelength branch transmission line. The capacitance is made of a ferroelectric material. The conductor, deposited on the microstrip lines, and the waveguides are made of a single crystal high Tc superconductor.

Abstract: Microwave bandpass filters contain dielectric resonators mounted in dielectric blocks, which are in turn mounted in cavities. There can be more than one dielectric resonator per cavity. Significant size reduction has been achieved over prior art filters. The filters can be operated at cryogenic temperatures and since the results attainable at cryogenic temperatures are repeatable, the filters can be tuned at cryogenic temperatures and returned to room temperature before being returned to cryogenic temperatures for operating purposes. When operated at cryogenic temperatures, the filters contain shorting plates having high temperature superconducting material thereon. The filters can be constructed with various configurations and can be operated in either a single mode or a dual-mode. Previous single mode or dual-mode dielectric resonator filters are larger in size and mass than the filters of the present application.

Abstract: A sensitive detector and detector system with multi-state element or elements employing the phenomenon of stochastic resonance to enhance signal-to-noise ratio (SNR) and detector sensitivity. Signal output is enhanced by the addition of external noise at the input. A single detector element has these improved outputs. Several stochastic resonance elements may be connected in arrays to further increase SNR of the output, increase detector sensitivity, and linearize the relation between input and output.

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 be used to form thin insulating films between the superconductor layers, which allows for the fabrication of a wide variety of superconductor circuit elements.

Abstract: A joint device structure for capacitive microwave coupling of a superconducting device arranged on a substrate with room temperature circuitry; including a superconducting wave guide of an oxide superconductor on said substrate from one side to the superconducting device launching microwave to the superconducting device, a pair of superconducting groundplanes of an oxide superconductor arranged at an end of the superconducting wave guide sandwiching the end of the superconducting wave guide with a little gap and a microwave probe-head connected to the room temperature circuitry arranged above the superconducting wave guide with a coupling gap having three probing pins corresponding to the superconducting wave guide and the superconducting groundplanes.

Abstract: A superconductor/insulator metal oxide hetero structure for electric field tunable microwave device, including a dielectric substrate, a first superconducting electrode of an oxide superconductor provided on said dielectric substrate, an insulating layer formed on the first superconducting electrode and a second electrode arranged on the insulating layer in which the conductivity of the first superconducting electrode and/or the dielectric property of the insulating layer can be changed by a dc bias voltage applied between the first and the second electrodes so that surface resistance and/or surface reactance can be changed.

Abstract: Periodic and pseudo-periodic slow wave structures comprising a plurality of adjacent sections, each section comprising a dielectric ring in contact with a disk coated with high temperature superconducting thin film, having coupling between the sections and tunable phase velocity for use in particle accelerators and traveling wave tubes are disclosed.

Abstract: A feed network parallel superconductive tunnel junction circuit that acts as a doubly balanced mixer and can be utilized as a millimeter wave satellite communications link. A quadrature-fed mixer circuit relies on a network of 90 degree couplers to feed signal and local oscillator power to four identical SIS detectors where SIS is a superconductor-insulator-superconductor layer construction. Power applied to either port is split equally to each detector, and the relative phase relationship of the signal and the LO is preserved. By selecting the appropriate polarity of the dc junction bias, the detected IF output of the SIS detectors adds coherently.

Abstract: A microwave component includes a superconducting signal conductor formed on a first dielectric substrate, and a superconducting ground conductor formed on a second dielectric substrate. The first dielectric substrate is stacked on the superconducting ground conductor of the second dielectric substrate. Each of the superconducting signal conductor and the superconducting ground conductor is formed of an oxide superconductor thin film of which crystals are orientated in such a manner that the c-planes of the crystals are parallel to the direction in which an electro-magnetic field generated by microwave launched to the microwave component changes.

Abstract: There is disclosed a superconducting microwave component including a first substrate of a dielectric material with a conductor line of an oxide superconductor formed in a required pattern on the surface, a second substrate of a dielectric with a grounding conductor of an oxide superconductor formed on the surface, and a third substrate of a dielectric which is laid on the first and the second substrates, with the third substrate sandwiched between the first and the second substrates.

Abstract: Microwave bandpass filters contain dielectric resonators mounted in dielectric blocks, which are in turn mounted in cavities. There can be more than one dielectric resonator per cavity. Significant size reduction has been achieved over prior art filters. The filters can be operated at cryogenic temperatures and since the results attainable at cryogenic temperatures are repeatable, the filters can be tuned at cryogenic temperatures and returned to room temperature before being returned to cryogenic temperatures for operating purposes. When operated at cryogenic temperatures, the filters contain shorting plates having high temperature superconducting material thereon. The filters can be constructed with various configurations and can be operated in either a single mode or a dual-mode. Previous single mode or dual-mode dielectric resonator filters are larger in size and mass than the filters of the present application.

Abstract: The design of a high Tc superconducting band reject tunable ferroelectric filter (TFF) is presented. The band reject TFF consists of a main microstrip line on a dielectric substrate. One or more half wavelength microstrip resonators, on a ferroelectric substrate, is coupled to the main microstrip line. At a resonant frequency of a resonator, a short circuit is presented on the main microstrip line resulting in a rejection of signal of that frequency. By applying a bias voltage to a resonator, the frequency of the resonator and, as such, the reject band of the filter is changed. Different resonators can be tuned to different frequencies.