Abstract: Digitally-controlled, variable-gain mixers and amplifiers are provided which couple transconductance cells to receive respective tap signals from a fixed attenuator that receives a first input signal. A gain interpolator provides first and second control currents with amplitudes that correspond to a segment of a control word and a multiplexer responds to another control-word segment by routing the control currents to a selected pair of adjacent transconductance cells. In response, the transconductance cells provide amplifier current signals which can also be routed to a transistor switch that mixes them with a second input signal to generate a mixer output signal whose amplitude corresponds to the control word.

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: 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: 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: Image sensors are provided that reduce conflicts between different sensor functions because sensor structures do not demand access to the same internal spaces. Accordingly, sensor structures can be independently arranged to enhance their respective functions. In particular, sensor embodiments include a substrate, semiconductor devices and an interconnect structure carried over the substrate, reference and sense electrodes and a photoconductive medium that are carried over the interconnect structure, and vias that couple the reference and sense electrodes to the interconnect structure and semiconductor devices. Different sensor elements do not demand access through the same internal VLSI spaces and may thus be arranged to enhance their respective sensor functions. In addition, sensors of the invention will respond to radiation rays that are orthogonal to the sensor's upper face and also to radiation rays that are tilted from this relationship.

Abstract: The invention monitors a communication channel and estimates its characteristics from time to time, thus providing a dynamic estimate of channel characteristics. Based on the channel characteristics, a control processor calculates a preferred configuration of digital (and optionally, analog) signal processing to best manage the available energy for the present channel characteristics. The selected configuration is then down-loaded into communication modules stored in extra memory during runtime.

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 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: An electrical generator has a plurality of 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: Method and system for a diode shunting configuration wherein the configuration prevents a transimpedance amplifier from saturation while maintaining high transimpedance gain and bandwidth. In one embodiment of the present invention, a diode is coupled to the input of a transimpedance amplifier in order to prevent the transimpedance amplifier from saturation. Moreover, the diode serves to divert current such that in cases where the input current is low the diode never turns on and only represents a minimal, mostly capacitive load on the input; in cases where the input current is high, the diode conducts and diverts any excess input current from the transimpedance amplifier.

Abstract: A system for arc detection testing using synthesized arcs is disclosed, which uses voltage and current waveform generators to generate an arc's analog form voltage and current waveform from a digital form of the arc's captured waveforms. A voltage waveform amplifier and a current waveform amplifier are included, with the outputs of the voltage and current waveform generators coupled to the inputs of the voltage and current waveform amplifiers, respectively. The outputs of the voltage and current waveform amplifiers are connected in circuit to a device under test to test the device's response to the waveforms. A method for testing a device's response to a simulated arcing condition is also disclosed. An electric arc's voltage and current waveforms are captured in digital form. Analog form voltage and current waveform are generated from the captured digital voltage and current waveforms.

Abstract: Analog-to-digital converter (ADC) structures and methods are provided that reduce an initial converter nonlinearity by introducing an inverse nonlinearity into the converter's response that is substantially the inverse of the initial converter nonlinearity. In a pipelined ADC embodiment, for example, upstream converter stages are selected that generate an upstream digital code which defines sufficient upstream code words to designate respective segments of the inverse nonlinearity. In response to each of the upstream code words, the conversion gain of the remaining downstream converter stages is then sufficiently adjusted to insert the inverse nonlinearity into the converter response.

Abstract: Buffer amplifiers are provided with a replica current generator that supplements a buffer transistor and is configured to provide a replica current which substantially equals required load currents in the amplifier's output load. Because the current of the buffer transistor remains constant, its base-emitter voltage Vbe remains constant and the amplifier linearly reproduces the input signal Sin across the output load.

Abstract: High-speed differential amplifiers are provided for use with switched-capacitor structures. These amplifiers reduce current demand during small-signal operation and generate high slew currents during large-signal operation. These processes are realized with slew-current generation structures that directly generate slew currents during large-signal operation and thus avoid the degradation of intermediate current-genration structures.

Abstract: An elongated perimeter light is disclosed, which comprises a linear array of light sources (LEDs) that are electrically illuminated. The array of light sources is disposed within an elongated transparent tube, with the tube transmitting and dispersing the light from the array giving the appearance that said array of light sources is a continuous light source. The array of light sources is capable of being cut at intervals down its length to shorten it. The light sources that remain in the array continue to emit light and the tube can be cut to match the length of said array. The present invention also discloses systems for lighting structural features, with one system according to the present invention comprising a plurality of elongated perimeter lights. The perimeter lights are electrically coupled in a daisy chain with the electrical power at each of the perimeter lights being transmitted to the successive light.

Abstract: A timing vernier applies a pair of stable bias voltages to intermediate points of an impedance string to establish reliable and calibratable delay cell biases for a fine multiplexer. A coarse input multiplexer is switched to a new timing signal substantially immediately after passing a prior valid timing signal to maximize the time prior to each valid output that the waveform is independent of the prior delay pattern. Logic circuitry is provided for three different phase differential regimes between successive timing signals to ensure that invalid output signals separated by less than a clock period are not produced. Mask commands are inserted into a series of timing control commands to equalize the average rates of writing and reading out the timing control commands with the mask commands skipped at readout.

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: Parallel analog-to-digital converter systems are provided in which converters are temporally interleaved. In particular, converters are partitioned into at least two converter groups which are assigned different respective group converter periods that are multiples of the system periods. With converters in each of the converter groups, respective samples are processed over that group's respective group converter period and the group converter periods of all converters are temporally shifted to process each of the samples with at least one of the converters.

Abstract: Electric arc monitoring is effected by exploiting the discovery that electric arcs are fractal phenomena in that all essential information that signifies “arc” is contained in each fractal subset. These fractal subsets are logarithmically distributed over the arc spectrum. Monitoring of arcs is most advantageously effected on a fractal subset (16) of low logarithmic order where the amplitude is higher pursuant to the 1/f characteristic of electric arcs, where cross-induction among neighboring circuit is lower, and where travel between the arc (12) and the arc signature pickup (23) is longer than at the high frequencies customary for electric arc detection. Fractal subset transformation (17) reduces the danger of false alarms. Arc signature portions may be processed in out of phase paths (242, 342) or treated as modulated carriers (42) for monitoring.

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.