Abstract: A piston assembly for use in a motor comprises a cylinder having a bore, an electrically conductive piston reciprocally disposed within the cylinder bore, a gas cavity formed within the piston, and one or more gas bearings associated with the piston, each of the one or more gas bearings including an aperture formed within the piston and an electrically conductive tubular member extending through the aperture, the tubular member having a lumen in communication between the gas cavity and the cylinder bore. The piston assembly may be used in connection with a motor used in a cryocooler that is driven by oscillating magnetic energy fields.

Abstract: RF switches and methods of use are provided. In one embodiment, a RF switch includes first and second switch assemblies, each comprising an elongate member and a magnetic housing on an end of the member. The magnet is disposed between contact pads for first and second circuits, and an electromagnetic source is coupled to the assemblies. Each switch has a first and second state. Another RF switch of the present invention includes a rotor, an elongate member disposed centrally through the rotor, an actuator coupled to the member and configured to rotate the member and the rotor, and a contact on the rotor that may touch a substrate. The contact is used to complete a first path or a second path.

Abstract: A method of fabricating an electrostatic actuator with an intrinsic stress gradient is provided. An electrode is formed on a substrate and a support layer is formed over the electrode. A metal layer is deposited onto the support layer via a deposition process. Deposition process conditions are varied in order to induce a stress gradient into the metal layer. The intrinsic stress in the metal layer increases in the direction from the bottom to the top of the metal layer. The support layer under the electrode is removed to release the electrostatic actuator.

Abstract: The present invention provides an anchor system for securing a MEMS device to a substrate comprising multiple anchors. A MEMS structure, built in accordance with the one embodiment of the invention, comprises a flexible beam suspended over a substrate and a base attached to each end of the beam. Each base is supported above the substrate by multiple anchors attached to the surface of the substrate. Each anchor further comprises anchor legs along its sides that support the base off of the substrate. In one embodiment, the anchors of each base are located away from the interface between the beam and the base. In another embodiment, the lengths of the anchor legs of the anchors are made longer along a direction of good side-wall step coverage than along a direction of poor side-wall step coverage.

Abstract: An improved dewar design that accelerates the manufacturing process of a dewar. In a preferred embodiment, the dewar includes an evacuation port that may be larger in size by a factor of ten over the size of evacuation ports of conventional dewars. The oversized evacuation port, however, does not result in an increase in the overall size or profile of the dewar. The dewar is evacuated and hermetically sealed using an re-usable evacuation tool.

Abstract: A HTS-based RF receiver includes a cryocooler and a cryogenic enclosure in thermal communication with the cryocooler. The cryogenic enclosure contains a HTS filter and a LNA therein. A first MEMS bypass switch is positioned between a RF input and the HTS filter, the first MEMS bypass switch operatively coupling the RF input to the HTS filter. A second MEMS bypass switch is positioned between the LNA and RF output, the second MEMS bypass switch operatively coupling the LNA to the RF output. A bypass pathway located within the cryogenic enclosure is connected between the first and second MEMS switches to bypass the HTS filter and LNA when an operating parameter of the RF receiver falls outside a pre-determined range.

Abstract: A HTS-based RF receiver includes a cryocooler and a cryogenic enclosure in thermal communication with the cryocooler. The cryogenic enclosure contains a HTS filter and a LNA therein. A first MEMS bypass switch is positioned between a RF input and the HTS filter, the first MEMS bypass switch operatively coupling the RF input to the HTS filter. A second MEMS bypass switch is positioned between the LNA and RF output, the second MEMS bypass switch operatively coupling the LNA to the RF output. A bypass pathway located within the cryogenic enclosure is connected between the first and second MEMS switches to bypass the HTS filter and LNA when an operating parameter of the RF receiver falls outside a pre-determined range.

Abstract: A method of tuning a high temperature superconductor (HTS) resonator includes the steps of providing a HTS inductor and a HTS capacitor, the HTS capacitor being electrically connected to the HTS inductor. A tuning body is provided adjacent to the HTS inductor and the HTS capacitor. The relative position of the tuning body with respect to the HTS inductor and the HTS capacitor is altered so as to tune the resonator. A tunable resonant circuit is provided that includes a substrate having a planar surface. At least one resonator formed from HTS material is disposed on the substrate, the resonator having one or more turns that when combined, turn through greater than 360°.

Abstract: A dual-mode resonator comprises a dielectric substrate having a region divided into four quadrants, and a ring resonator forming quadrangularly symmetrical configurations within the four quadrants of the region. The symmetrical configurations may be formed from folded sections of the resonator, so that parallel lines with opposite currents that cancel to minimize the far-field radiation of the filter structures. The symmetrical configuration can also be meandered, so that opposite currents in parallel line segments within each meander and the line segments that interconnect the meanders cancel to minimize the far-field radiation of the filter structures. One resonator can be used in a two-pole dual-mode filter structures, or multiple resonators can be used in more complex dual-mode filter structures.

Abstract: A magnet ring assembly for use with a piston assembly includes a cylindrical magnet holder having an inner surface, an annular ledge formed around the inner surface of the cylindrical magnet holder, and a swaged axial edge opposite the annular ledge, and a plurality of arcuate magnet sectors having a radially uniform magnetic polarity, the plurality of magnets being bonded around the inner surface of the cylindrical magnet holder, each of the plurality of magnets having opposing axial edges, one of the axial edges being disposed on the annular ledge, and the other of the axial edges being captured by the swaged axial edge of the cylindrical magnet holder. The magnet ring assembly can be used in connection with a crycooler.

Abstract: A regenerator material for use inside a displacer of a Stirling cycle cryocooler includes a plurality of circular disks formed from a synthetic felt that is preferably polyester. The plurality of disks have an outer diameter that is greater than the inner diameter of the displacer. The plurality of circular disks form a stack within the displacer. The regenerator material minimizes operational variation between different cryocoolers. In addition, the regenerator material can be easily filled into the cryocooler displacer.

Abstract: A method of tuning a high temperature superconductor (HTS) resonator includes the steps of providing a HTS inductor and a HTS capacitor, the HTS capacitor being electrically connected to the HTS inductor. A tuning body is provided adjacent to the HTS inductor and the HTS capacitor. The relative position of the tuning body with respect to the HTS inductor and the HTS capacitor is altered so as to tune the resonator. A tunable resonant circuit is provided that includes a substrate having a planar surface. At least one resonator formed from HTS material is disposed on the substrate, the resonator having one or more turns that when combined, turn through greater than 360°.

Abstract: A filter network designed for providing high frequency selectivity with a high degree of reliability and availability. The filter network comprises a superconducting filter and a non-superconducting filter, or a combination thereof to form multiplexers. A receive side of the non-superconducting filter pre-filters received RF signals before inputting them to the superconducting filter. The non-superconducting filter is constructed and arranged to pass RF signals having a frequency within a first pass band to the superconducting filter. The superconducting device is constructed and arranged to exhibit a high-degree of frequency selectivity in further narrowing the received RF signals. Other aspects are directed to the arrangement, construction, and uses of the same structures to accomplish different but similar goals.

Abstract: RF switches and methods of use are provided. In one embodiment, a RF switch includes first and second switch assemblies, each comprising an elongate member and a magnetic housing on an end of the member. The magnet is disposed between contact pads for first and second circuits, and an electromagnetic source is coupled to the assemblies. Each switch has a first and second state. Another RF switch of the present invention includes a rotor, an elongate member disposed centrally through the rotor, an actuator coupled to the member and configured to rotate the member and the rotor, and a contact on the rotor that may touch a substrate. The contact is used to complete a first path or a second path.

Abstract: A circuit is provided wherein the electronic properties of the circuit are varied by a magnetic actuator. The circuit includes a fixed substrate and a movable substrate. The magnetic actuator comprises a magnetic driver on an upper surface of the fixed substrate that is substantially overlapped by an HTS reaction plate on the lower surface of the fixed substrate. A tuning current applied through a continuous strip of HTS material in the magnetic driver induces a repulsive magnetic force causing the movable substrate to move with respect to the fixed substrate.

Abstract: A tunable filter having a fixed substrate, a first and second plate comprising a high-temperature superconductor material on the fixed substrate, a movable substrate, a mechanical driver attached to the fixed substrate and the movable substrate, a floating plate comprising a high-temperature superconductor material on the fixed substrate wherein the floating plate, the first plate, and the second plate define a gap, and wherein the gap is varied by length changes in the mechanical driver is provided.

Abstract: A filter comprising a plurality of zig-zag hairpin-comb resonators that are separated by one or more coupling gaps is provided. The zig-zag hairpin-comb resonators may be fabricated using HTS or non-HTS planar structures, such as microstrip, stripline and suspended stripline. Each of the zig-zag hairpin-comb resonators comprises a pair of neighboring legs. The neighboring legs of adjacent resonators straddle a respective coupling gap. Each of the neighboring legs is formed with zig-zag sections. In this manner, the filters provide unusual compactness, as well as minimizing coupling between the resonators.

Abstract: A dual-mode resonator comprises a dielectric substrate having a region divided into four quadrants, and a ring resonator forming quadrangularly symmetrical configurations within the four quadrants of the region. The symmetrical configurations may be formed from folded sections of the resonator, so that parallel lines with opposite currents that cancel to minimize the far-field radiation of the filter structures. The symmetrical configuration can also be meandered, so that opposite currents in parallel line segments within each meander and the line segments that interconnect the meanders cancel to minimize the far-field radiation of the filter structures. One resonator can be used in a two-pole dual-mode filter structures, or multiple resonators can be used in more complex dual-mode filter structures.

Abstract: An improved dewar design that accelerates the manufacturing process of a dewar. In a preferred embodiment, the dewar includes an evacuation port that may be larger in size by a factor of ten over the size of evacuation ports of conventional dewars. The oversized evacuation port, however, does not result in an increase in the overall size or profile of the dewar. The dewar is evacuated and hermetically sealed using an re-usable evacuation tool.

Abstract: Multi-stage electric filters with improved intermodulation-distortion characteristics and a method for designing such electric filters is provided. In general, the invention may include a multi-resonator electric filter in which one or more of the resonators have been intentionally designed to have a different IP and/or Q than the other resonators in the electric filter. In one case, the electric filters include a 4-resonator Chebyshev narrow pass-band filter with at least the first resonator having a Q and/or IP different from at least one other resonator in the filter. The filter thereby has improved IMD power over conventional designed filters while maintaining high Q. In a preferred embodiment the filter may include a superconducting material. The relative Q and IP of the respective resonators in the improved filter may depend on the relative strength of in-band and out-of-band signals.