Abstract: The electrical response phenomenon of electrostrictive polymers is used to harvest electrical power from the general movement of objects such as from human walking motion, for example. In a preferred embodiment of the invention, the polymer material is incorporated into the soles of footwear and is either full- or partial-wave rectified and then if desired converted to a direct current (DC) voltage level for suitable battery charging and the like.

Abstract: A series of sigma-delta modulators are connected in a cascaded architecture. Each sigma-delta modulator has a noise transfer function that defines a unique set of quantization noise transmission zeros. A circuit is coupled to the cascaded architecture and has a signal transfer function that is an approximation of the noise transfer function of a first sigma-delta modulator in the series of sigma-delta modulators.

Abstract: A digital mixing to baseband decimation filter includes a mixer section and a low-pass filter section. The mixer section generates in-phase and quadrature signal components at baseband from low-resolution, high-rate digital data lying within a signal passband offset from baseband. The low-pass filter section transforms an incoming data stream to high-resolution, low-rate digital data. The mixer section can precede or follow the filter section.

Abstract: A band-pass sigma-delta modulator includes a translator for tuning to a selected signal passband within the tuning range of the modulator. In a network implementation, the translator is integral with each integrator associated with the sigma-delta modulator(s). The translator can comprise a network having a transfer function defined in the Z-domain as (Z.alpha.-1)/(Z-.alpha.), where -1.ltoreq..alpha..ltoreq.1 defines the tuning. The value of .alpha. is defined as .alpha..tbd.cos(2.pi.f.sub.gm /f.sub.s), where f.sub.gm is the geometric mean frequency of the passband and f.sub.s is the input sample frequency of the sigma-delta modulator(s). The invention can benefit many signal processing applications such as, for example, A/D, D/A and D/D converters; and digital communication systems including digital radio and digital TV. In digital communications (e.g., radio, TV, etc.

Abstract: An illumination system for a semi-tractor and trailer includes a pair of illumination housings, one attached to either side of the trailer just above the rear wheels. A reflector within each housing reflects light from a light source downward and outward through a clear lens to encompass an arc extending from the vertical to a predetermined angle, e.g. approximately 45 degrees from vertical. Light is thus directed onto the pavement and any objects immediately adjacent the trailer rear wheels to aid the driver in close quarter maneuvering, turns, and when changing highway lanes. A control circuit is connected to each light source and to the turn signal lead on the respective trailer side to provide steady power to the light source only when the turn signal and/or emergency flasher circuit is enabled. An optional amber lens can be provided on the side of each illumination housing to resemble the ordinary running lights on a typical semi-trailer.

Abstract: A novel bridge type optoelectronic (OE) sample and hold circuit based upon current steering demonstrates a clear superiority in performance with respect to a direct OE sample and hold circuit. The bridge type OE sample and hold circuit permits a high-speed signal to be sampled with high accuracy to offer high charging capability, commanding signal isolation, reduced time jitter and reduced holding charge leakage which are distinct advantages over conventional electronic sample and hold circuits.

Abstract: Improved dynamic range resolution or accuracy analog to digital conversion ses linear prediction. An open loop or feed-forward architecture passes an analog signal to a coarse or orthodox analog-to-digital converter that provides digital signals representing a most significant part of the output signal and offers them as inputs to a digital linear predictor whose digital output signal is reconverted to analog form and fed to an analog adder. An analog delay device may be used to receive the next analog sample and, after the proper delay (if needed), feed it to the adder where the difference between the analog predicted value and the analog signal is determined and passed to a subsequent coarse or orthodox analog to digital converter. A closed loop or feedback configuration receives the analog input signal data as well as a feedback predicted value in analog form and passes the difference to a coarse or orthodox analog to digital converter.

Abstract: A number of high frequency signal sources such as a number of receiving annas have their information content extracted by an optoelectronic synchronous sampling system. A laser provides pulses of proper frequency and duration and feeds them to a fiberoptic bundle. In one embodiment the fibers are lengthened to be simultaneously actuated. Otherwise, each of the fibers in the bundle has a different length so that light emanating from their distal ends appears as a delayed series of actuating light pulses. Phase shifters, pressure or electric field effects, can effect delay and consequent beamforming. Optoelectronic switches are disposed adjacent the distal ends so that the delayed series of actuating pulses actuates the switches in a synchronous sequence to synchronously sample the high frequency signals received by each of the antennas. Interconnected analog-to-digtal and processing circuitry conditions the synchronously received samples for further use.

Abstract: A visual display has an increased readout capability due to its operation the transflective mode. A source of ambient light and light for radiation through the display from the backside together assure the increased readout capability. Heretofore, ambient light would degrade or washout a display making it nearly impossible for monitoring personnel to decipher alphanumeric or pictoral displays due to the decreased contrast. A pair of linear polarizers sandwich a twisted nematic liquid crystal and have their polarization axes either parallel or mutually orthogonally disposed so that the crystal will present bright or dark areas in response to applied potentials. Because a partially transmitting mirror is interposed between the sandwiched liquid crystal and the radiating light source, the ambient light augments the radiated light to enhance the visual display.