Abstract: A MEMS device of the invention comprises a substrate and a pair of MEMS elements supported by the substrate, each of the MEMS elements having a bottom surface facing the substrate, a top surface and a side wall. The side walls are in spaced-apart, confronting relationship and the bottom surfaces are substantially coplanar. The bottom surface of each of the MEMS elements carries an electrically conductive layer, at least one of the pair of MEMS elements being movable relative to the other MEMS element to vary the spacing between the side walls.

Abstract: An apparatus for optically coupling a light source with a light-receiving end face of an optical waveguide comprises a lens for focusing a light beam emitted from the light source at a focal point on the light-receiving end face of the optical waveguide. An adaptive coupler, positioned in the optical path, is responsive to a beam steering control signal for steering and aligning the focal point relative to the light-receiving end face of the optical waveguide. In one form, the adaptive coupler comprises a pair of transparent substrates having confronting, parallel inner faces, the inner face of one of the pair of substrates carrying a beam intercepting, optically transparent, constant potential electrode and the inner face of the other of the pair of substrates carrying an electrically resistive, beam intercepting, optically transparent film. A pair of spaced apart electrodes in electrical contact with the film apply a linear voltage gradient along the film.

Abstract: A heterojunction bipolar transistor (HBT) is disclosed that includes successive emitter, base and collector and sub-collector epitaxial layers and emitter, base and collector contact metals contacting the emitter, base and sub-collector layers respectively. A passivation material is included that covers the uncovered portions of the layers and covers substantially all of the contact metals. The passivation material has a planar surface and a portion of each of the contact metals protrudes from the surface. Planar metals are included on the planar surface, each being isolated from the others and in electrical contact with a respective contact metal. A method for fabricating an HBT is also disclosed, wherein successive emitter, base, collector and sub-collector epitaxial layers are deposited on a substrate, with the substrate being adjacent to the sub-collector layer.

Abstract: A MEMS fabrication process eliminates through-wafer etching, minimizes the thickness of silicon device layers and the required etch times, provides exceptionally precise layer to layer alignment, does not require a wet etch to release the moveable device structure, employs a supporting substrate having no device features on one side, and utilizes low-temperature metal-metal bonding which is relatively insensitive to environmental particulates. This process provided almost 100% yield of scanning micromirror devices exhibiting scanning over a 12° optical range and a mechanical angle of ±3° at a high resonant frequency of 2.5 kHz with an operating voltage of only 20 VDC.

Abstract: Reversible electrochemical mirror (REM) devices typically comprise a conductive oxide mirror electrode that is substantially transparent to radiation of some wavelengths, a counter electrode that may also be substantially transparent, and an electrolyte that contains ions of an electrodepositable metal. A voltage applied between the two electrodes causes electrodeposition of a mirror deposit on the mirror electrode and dissolution of the mirror deposit on the counter electrode, and these processes are reversed when the polarity of the applied voltage is changed. Such REM devices provide precise control over the reflection and transmission of radiation and can be used for a variety of applications, including smart windows and automatically adjusting automotive mirrors.

Abstract: Micro-electromechanical (MEM) devices having their fixed and movable members immersed in a liquid medium. Movement is effected by applying a stimulus which creates a force that causes the movable member to move with respect to the fixed member. The movable and fixed members are immersed in a liquid medium having desired characteristics. The liquid is preferably selected to have a viscosity which critically damps the motion of the movable member. The liquid may also be chosen to provide a dielectric constant greater than one, which, where applicable, increases the electrostatic force created for a given drive voltage, and the device's capacitance sensing range, over what they would be in air. The liquid medium might also be used to improve the device's thermal dissipation characteristics, or to provide improved isolation between structures.

Abstract: A locally distributed electrode is made by placing a conducting metallic oxide layer and a counter electrode in contact with a noble metal electroplating solution and applying a negative potential to the metallic oxide layer relative to the counter electrode, such that the noble metal is electrodeposited from the solution preferentially at defect sites on a surface of the metallic oxide layer. The noble metal nuclei are selectively electrodeposited at the defect sites to form a locally distributed electrode made up of a dot matrix of metallic islands. For reversible electrochemical mirror (REM) devices, the presence of the noble metal renders mirror metal electrodeposition at the defect sites reversible so that the defects become part of the dot matrix electrode and extraneous deposition of the mirror metal on the conducting metallic oxide is avoided.

Abstract: A MEMS device with a electrostatic comb actuator is comprised of a supporting substrate, with device features on only one side, and two silicon device layers locally bonded together by thermal compression bonding of metal pads. Use of a supporting substrate enables the silicon device layers to be relatively thin and eliminates the through-wafer etch procedure, which greatly reduces silicon etch times and improves the accuracy and yield of the etch processes. Use of metal-metal interlayer bonds avoids the need for a wet chemical etch for release of the moveable structure so that the device can be fabricated with high yield. Scanning micromirror devices according to the present invention were fabricated with almost 100% yield and exhibited scanning over a 12° optical range and a mechanical angle of ±3° at a high resonant frequency of 2.5 kHz with an operating voltage of only 20 VDC.

Abstract: A focal plane array has a plurality of detectors for each pixel of the array. The detector having the best operability for each pixel is determined and a custom microlens array is fabricated, with each lens having a focal point directed to the best detector on each pixel. A Multiplexer (MUX) similarly transmits signals from the selected detectors while blocking transmission from the non-selected detectors.

Abstract: There is disclosed a core structure with a very low profile, high power density and lower losses. Higher core surface area and improved core utilization in terms of flux density are other desirable feature in the disclosed design. The disclosed design also allowed for a larger core area where the DC fluxes are added, thereby reducing the air-gap requirements in the cores derived from low saturation density materials such as ferrites. The cellular nature of the design can also be effectively employed in vertically packaged power converters and modules.

Abstract: There is disclosed a core structure with a very low profile, high power density and lower losses. The disclosed design allows for a larger core area where the DC fluxes are added, thereby reducing the air-gap requirements in the cores derived from low saturation density materials such as ferrites. The cellular nature of the design can be effectively employed in vertically packaged power converters and modules. Also disclosed is a DC-DC converter topology which preferably employs the disclosed core. N AC drive voltages drive N current doubler rectifiers (CDRs) in accordance with the symmetric modulation scheme; each CDR provides two rectified output currents to an output node. Each AC drive voltage has a switching period Ts. The drive voltages are phase-shifted by Ts/(2*N), such that the rectified output currents of the CDRs are interleaved, thereby reducing output voltage ripple.

Abstract: An electrical generator has a plurality of mutually spaced magnets that move together relative to at least one coil to generate an electrical signal in the coils. Equal numbers of magnets and coils, with equal lengths and spacings between them, are preferably employed. Significant enhancements in power output are achieved by orienting successive magnets in magnetic opposition to each other, so that the magnetic fields from successive magnets along the axis of movement substantially cancel each other at locations between the magnets.

Abstract: A thin InGaAs contact layer is provided for the collector of a heterojunction bipolar transistor (HBT) above an InP sub-collector. The contact layer provides a low resistance contact mechanism and a high thermal conductivity path for removing device heat though the sub-collector, and also serves as an etch stop to protect the sub-collector during device fabrication. A portion of the sub-collector lateral to the remainder of the HBT is rendered electrically insulative, preferably by an ion implant, to provide electrical isolation for the device and improve its planarity by avoiding etching through the sub-collector.

Abstract: A multi layered high impedance structure presents a high impedance to multiple frequency signals, with a different frequency for each layer. Each layer comprises a dielectric substrate, and an array of radiating elements such as parallel conductive strips or conductive patches on the substrate's top surface with a conductive layer on the bottom surface of the bottommost layer. The radiating elements of succeeding layers are vertically aligned with conductive vias extending through the substrates to connect the radiating elements to the ground plane. Each layer presents as a series of parallel resonant L-C circuits to an E field at a particular signal frequency, resulting in a high impedance surface at that frequency. The new structure can be used as the substrate for a microstrip patch antenna to provide an optimal electrical distance between the resonator and backplane at multiple frequencies.

Abstract: A dynamic magnet system, particularly useful for electrical generation, employs multiple magnets in polar opposition to each other for individual movement relative to a support structure. The magnets have a critical angle of displacement from a horizontal static position of less than 1 degree, with at least some of the magnets having mutually different properties. With different magnetic strengths, a greater movement is produced for both magnets in response to movements of the support structure, for particular ranges of magnetic strength ratios, than would be the case with equal magnets. The magnet movement can be translated into an electrical signal to power an operating system. Ultra low friction ferrofluid bearings can be used to establish static coefficients of friction between the magnets and support structure less than 0.02, enabling useful power generation from only slight movements of the support structure.

Abstract: A mechanical translator includes at least one magnet that is disposed on a substrate to carry a load and has a magnetic axis generally transverse to the substrate, establishing a magnetic field with maximum external density adjacent the substrate. An ultra low friction interface is obtained with ferrofluid bearings, such as a light mineral oil medium mixed with isoparaffinic acid, which establish a critical angle of displacement from a horizontal static position of less than 1 degree, and preferably less than 10 minutes. A controller of magnetic material can be placed on the opposite side of the substrate to control the movement of the magnets.

Abstract: A dynamic magnet system, particularly useful for electrical generation, employs multiple magnets in polar opposition to each other and having a critical angle of displacement from a horizontal static position of less than 1 degree, to induce an electrical signal in one or more surrounding coils. The magnets interact with each other to yield multiple modes of oscillation and a greater range of response to applied inputs than is achievable with a single magnet system. A lubricant for the magnets is preferably a ferrofluid that establishes a static coefficient of friction between the magnets and their support structure less than about 0.02, with a viscosity less than 10 centipoise. The magnets can be oriented for movement in a primarily horizontal direction and are adaptable to numerous different kinds of support structures, including ring-shaped.

Abstract: An electrical generator includes a magnet constrained to move relative to a conductor by a support structure, with a ferrofluid bearing providing an ultra low friction interface between the magnet and support structure. The assembly has a critical angle of displacement from a horizontal static position of less than 1 degree, and preferably less than 10 minutes. An electrical signal is generated in the conductor by the moving magnetic field.

Abstract: Test probe pads are located lateral to, and spaced from, the emitter, base or collector region of a bipolar transistor, preferably on separate pedestals, and connected to their respective transistor regions by air bridges. The probe pads, transistor contacts and air bridges are preferably formed as common metallizations. In the case of an HBT, a gap in the subcollector below the air bridges insulates the test transistor from capacitor loading by the probe pads. The test transistors can be used to characterize both themselves and functional circuit transistors fabricated with the same process on the same wafer by testing at an intermediate stage of manufacture, thus allowing wafers to be discarded without completing the manufacture if their transistors do not meet specifications.

Abstract: Test probe pads are located lateral to, and spaced from, the emitter, base or collector region of a bipolar transistor, preferably on separate pedestals, and connected to their respective transistor regions by air bridges. The probe pads, transistor contacts and air bridges are preferably formed as common metallizations. In the case of an HBT, a gap in the subcollector below the air bridges insulates the test transistor from capacitor loading by the probe pads. The test transistors can be used to characterize both themselves and functional circuit transistors fabricated with the same process on the same wafer by testing at an intermediate stage of manufacture, thus allowing wafers to be discarded without completing the manufacture if their transistors do not meet specifications.