Abstract: An analog-to-digital converter for converting an analog input signal to a digital output signal is described. The ADC includes a comparator circuit having first to nth stages of comparators responsive to the analog input signal. Each comparator includes a plurality of magnetoelectronic devices for performing comparison function. Each magnetoelectronic device has one or more ferromagnetic elements capable of being switched into a first or second magnetization states. The amplitude of analog input signal upon exceeding a predetermined threshold level (IS or VS) of a respective magnetoelectronic device sets a magnetization state of the respective magnetoelectronic device to the first state and the resulting output of the respective magnetoelectronic device to a HIGH state, and vice-versa. In one embodiment, the magnetoelectronic device is a Hybrid Hall Effect device. In another embodiment, the magnetoelectronic device is an isolator.

Abstract: A method and apparatus for interfacing locomotive 3D movements of a user to a reference in a virtual or remote environment are provided. Initially, a 3D motion of a body portion of a user is sensed as the user takes a gestural pace. This sensing includes the determining of a beginning and an end of the gestural pace taken by the user, the determining of a 3D direction characteristic of the body portion motion during the gestural pace, and the determining of a 3D extent characteristic of the body portion motion during the gestural pace. Next, a 3D direction and extent of motion in the environment corresponding to the determined direction and extent characteristics of the gestural pace is computed. Finally, the computed 3D motion is used to move the reference in the environment.

Abstract: An optical image reject down-converter for mapping a received radio frequency (RF) into an arbitrary intermediate frequency range and for precluding interference between the received signals. A received radio frequency signal is down-converted into an intermediate frequency band for use by an electronic circuit in other devices. Optical light is divided into a first path and a second path. Light in the first path is transferred into an optical sideband by a first optical modulator or phase modulator. Light in a second path is converted into sidebands by a second, non-cascaded optical modulator and then passed through a tunable narrow-band optical filter which selects the desired sideband. The optical spectrum of the second path then primarily includes light at the frequency equal to the original laser frequency plus the additional sidebands. The filtered sideband is heterodyned with the light from the first path, resulting in a down-conversion to the desired intermediate frequency.

Abstract: A method and apparatus to enable the use of low cost high RIN optical sources for microwave photonic links by combining the wide-gain bandwidth and low cost of an EDFA, with the narrow gain bandwidth of a Brillouin amplifier. The hybrid Brillouin/EDFA (“hybrid amplifier”) apparatus of the present invention includes at least two couplers, a phase modulator, an Erbium-doped fiber, a laser source to pump the Erbium fiber, an optical circulator, and a length of fiber used for Brillouin amplification. Optical signals from the laser source are split into two optical paths by a polarization maintaining coupler. Optical signals passing through a first path are amplified by the Erbium doped fiber, and the amplified signals are passed through the optical circulator before sending the optical signals into one end of a spool of fiber in order to pump the Brillouin acoustic wave.

Abstract: A device for determining the photon energy E1 and direction cone angle of incident gamma ray includes a radiation detector for receiving an incident gamma ray having an unknown photon energy E1 and an unknown direction and for scattering the gamma ray with two Compton scattering interactions and a subsequent scattering or absorption interaction. The detector provides three outputs, each output corresponding to one of the Compton scattering and the subsequent scattering or absorption interactions, to a processor, which is programmed to calculate the photon energy E1 and direction cone angle of the incident gamma ray based on these outputs.

Abstract: A nuclear quadrupole resonance (NQR) method and probe for generating RF magnetic fields in different directions to distinguish NQR from acoustic ringing induced in a sample. Generally, an RF magnetic field is generated along an axis towards a sample to induce a resonance signal in the sample. The resonance signal includes NQR and acoustic ringing. The resonance signal is detected along the RF magnetic field axis. The acoustic ringing is detected along a direction orthogonal to the RF magnetic field axis. As a result, the NQR in the resonance signal can be distinguished from the acoustic ringing in the resonance signal.

Abstract: A method for Doppler compensation in a phase coherent underwater communications system includes the steps of receiving a communications signal from a plurality of underwater communications channels, where the signal consists of a sequence of raw data; then applying a Doppler estimation to the data; demodulating the raw data; low pass filtering the demodulated raw data; applying resampling and downsampling to the data at a fractional sampling rate, for n samples per symbol, and generating a synchronized, Doppler-phase-corrected output signal; then applying the synchronized, Doppler-phase-corrected fractionally sampled signal to a phase locked loop and equalizer; then comparing an estimated symbol with a decision symbol and updating a plurality of tap coefficients; and h) outputting decision symbols.

Abstract: Various embodiments of low-mass sound generators each having a wide frequency band are disclosed. In some embodiments, the acoustic transducer acting as the sound generator is constructed of four layers of PVDF film. The top and bottom bi-laminate members are separately formed in a pre-curved manner to form a rippled geometry.

Abstract: The present invention is an electronic structure having a buffer layer with a short average carrier lifetime, at least about 1000 Å thick with an upper face, and an integrated circuit disposed over the upper face of the buffer layer, where this integrated circuit would otherwise be susceptible to soft errors, due to its configuration, its clock speed, its use environment, or a combination of these factors. In a preferred embodiment, the preferably high recombination rate buffer layer is an LT GaAs or GaAs:Er buffer layer.

Abstract: The location of a submerged tow vehicle (LOST) system provides a device for accurately determining a position of an underwater vehicle towed by a surface craft or aircraft, such as a helicopter. The LOST system utilizes five sources of input data to compute a best estimate of the towed vehicle's position. These are (1) high resolution bathymetry data in an area of the towed vehicle's transit, (2) ocean depth at a position of the towed vehicle, (3) the towed vehicle's velocity over sea bottom, (4) a slant range from the towed vehicle to a known reference point, and (5) a position and course of the towing vehicle. The LOST system is comprised of a slant range updater, a maximum likelihood estimator, a constrained adaptive tracker and a slant range corrector.

Abstract: A method and apparatus for correcting changes in the mean wavelength of a broadband optical source due to changes in temperature. An optical filter is placed so as to filter the output of source, the filter being selected so that, as a function of temperature, its center wavelength changes as fast or faster than the wavelength centroid of the source.