General Electric Company

Lockheed Martin Corporation

Other

Seth D Silverstein

William E Engeler

Jeffrey Michael Ashe

Robert Leland Nevin

Himanshu B Vakil

Joseph M Pimbley

Jerome S Prener

Gregory Michael Kautz

Alan D Devoe

Lambert T Devoe

Thomas Bert Gorczyca

Richard Louis Zinser

Frederick Wilson Wheeler

Richard Yung Chiao

Pierino Gianni Bonanni

Mario Ghezzo

Lewis Jones Thomas, Iii

Kai Erik Thomenius

Steven Robert Koch

Guanghan Xu

Anthony Wykeham Jacomb-Hood

Rolf S Bergman

Peter D Johnson

Timothy Dietrich Page

Charles Samuel Huey

Robert Hershenfeld

A method for calibrating a remote system having a plurality of N elements, N being a positive integer number. An input signal to each of the N elements is processed according to beamforming bits to determine the output of a corresponding element. The output of the plurality of N elements is a composite signal. The method includes the steps of: (a) transmitting a calibration signal to input the plurality of N elements of the remote system; (b) selecting a first set of beamforming bits for each of the plurality of N elements based upon entries of a predetermined invertible matrix; (c) processing the calibration signal at the remote system according to the beamforming bits for each of the N plurality of elements; (d) detecting a reference signal from the remote system and the composite signal transmitted from the N plurality of elements based on the first set of beamforming bits; (e) repeating steps (b)-(d) for successive sets of beamforming bits to generate a set of signals; and (f) processing the set of signals for generating calibration data for each of the N plurality of elements of the remote system. Preferably, the remote system comprises a phased array system and wherein each of the N plurality of elements comprises an individual antenna in the phased array system.

Method and apparatus for calibrating a remote system which employs coherent signals

A thermal processor for at least one semiconductor wafer includes a reactor chamber having a material substantially transparent to light including a wavelength within the range of about 200 nanometers to about 800 nanometers for holding the at least one semiconductor wafer. A coating including a material substantially reflective of infrared radiation can be present on at least a portion of the reactor chamber. A light source provides radiant energy to the at least one semiconductor wafer through the coating and the reactor chamber. The light source can include an ultraviolet discharge lamp, a halogen infrared incandescent lamp, or a metal halide visible discharge lamp. The coating can be situated on an inner or outer surface of the reactor chamber. If the reactor chamber has inner and outer walls, the coating can be situated on either the inner wall or the outer wall.

Thermal processor for semiconductor wafers

Data for high-frame-rate high-resolution (i.e., low f-number) ultrasonic imaging are acquired by a technique that involves transmitting multiple physically separated beams simultaneously and acquiring imaging data for more than one scan line during receive. Spatial apodization is used to influence the transmit beamformation and to form two controlled and focused spatially separate beams with a single firing of the transducer array elements and without use of additional timing electronics.

Method and apparatus for high-frame-rate high-resolution ultrasonic

The frame rate in medical ultrasound imaging is increased significantly by reducing the number of transmit events per image frame using spatially encoded transmit events in accordance with an invertible encoding matrix. First, M sets of encoded signals are transmitted, one set after the next, from M transmitting elements of a transducer array. For each transmission, all M transmitting elements are activated simultaneously in accordance with the encoding of a particular set of signals. The resulting scattering data are stored for each of the M transmit events, and are subsequently decoded with the inverse of the encoding matrix to obtain individual elemental information. The complete set of scattering data captures the time history of the ultrasound pulses that are transmitted from a single transducer element of the phased array, such as the m-th transmitter element, scattered by the medium under investigation, and subsequently received at the n-th receiver element, for all M transmitters and N receivers. The invertible code is preferably an orthogonal phase code such as a Hadamard code.

Method and apparatus for ultrasonic beamforming with spatially encoded

The precise three-axis attitude of a space-borne phases-array antenna is estimated based on the assumption that the array geometry, consisting of the number of radiating elements and their relative spacing in three dimensions, is known and that the array position and coarse knowledge of the array attitude are available a priori. An estimate is first made of the set of complex-valued gains that define each element's straight-through contribution to the signals received at each of two or more remote calibration sites, where a 'straight-through' antenna configuration is defined as the condition in which all elements are made to radiate with the same amplitude and phase. An optimization strategy is then used to determine which array attitude lying in the neighborhood of the coarsely known attitude is most consistent with the full set of straight-through gain values. Another technique for estimating the precise angular location of a receiver with respect to the coordinates of the space-borne phased-array antenna is based on the assumptions that the array geometry is known, and that the receiver bearing is coarsely known or available. After an estimate is made of the set of complex-valued gains that define each element's straight-through contribution to a composite signal measured at the receiver site, an optimization strategy is used to determine which receiver direction lying in the neighborhood of the coarsely known direction is most consistent with the latter set of straight-through gain values.

Method for estimating the precise orientation of a satellite-borne

An architecture that provides for coherent detection of the relative amplitude and phase of a calibration signal used in the remote calibration of an active transmitting or receiving phased array system employs two coherent signals, one being a reference signal and the other being the calibration signal that contains the relative amplitude and phase information desired in the calibration process. Direct sequence spread spectrum techniques are used to transmit the two coherent signals. Continuous time binary antipodal waveform signals are generated and used to transmit the reference and calibration signals. Relevant amplitude and phase information needed for the calibration can be extracted while compensating for non-synchronized oscillators and the effects of Doppler shifts due to relative motion of the transmitting and receiving platforms. The detection architecture is effective for satellite-based phased array systems, including geostationary, medium and low earth orbit communication satellites, and space-based synthetic aperture radar reconnaissance satellites.

Coherent detection architecture for remote calibration of coherent

An architecture for remote calibration of coherent systems uses coherent reference and calibration signals that contain the relative amplitude and phase information desired in the calibration process. Circuitry extracts the relevant amplitude and phase information needed for the calibration while compensating for non-synchronized clocks and the effects of Doppler shifts due to relative motion of the transmitting and receiver platforms. The coherent detection architectures can be used effectively with any scheme designed to determine the relative amplitudes and phases of the signals emitted from the different elements of the phased array. These architectures are particularly applicable to coherent encoding calibration procedures that enhance the effective SNR by using coherent transmission of orthogonal transform encoded signals from N elements of the phased array. In an example calibration architecture, coherent elemental signals are encoded using controlled switching of the delay phase control circuits themselves to effectively generate a perfect orthogonal transform encoding of the signal vectors, even though the control circuits may be imperfect; no additional encoding hardware is required. The switching is dictated by matrix elements of an N xN invertible binary matrix, with the most preferred embodiment being an orthogonal binary matrix, i.e., a Hadamard matrix. The coherent signals are decoded with the inverse of the same binary matrix used in the control circuit encoding.

A Tripulse method determines the orientation or attitude of a phased-array antenna located at a remote site, such as an aircraft or spacecraft. Three pulses are transmitted from the phased-array antenna in an estimated direction toward a coherent receiver, with a sum beam, and with first and second difference beams formed by reversal of the phase of certain elements above a first axis of symmetry, and to one side of a second axis of symmetry. The received signals are processed in a manner which determines the error between the assumed direction and the actual direction of the receiver. To determine the rotational position of the array antenna, the same steps are performed for a second remote receiver, and additional processing determines the complete attitude, including yaw, of the phased-array antenna. The coherent receiver may use the first transmitted pulse as a reference, or it may use a separate reference signal.

Method for determining orientation and attitude of a satellite- or

A method and apparatus for remotely calibrating a system having a plurality of N elements, such as a phased array system, is provided. The method includes generating coherent signals, such as a calibration signal and a reference signal having a predetermined spectral relationship between one another. The calibration signal which is applied to each respective one of the plurality of N elements can be orthogonally encoded using a unitary transform encoder that uses a predetermined transform matrix, such as a Hadamard transform matrix or a two-dimensional discrete Fourier transform matrix, to generate a set of orthogonally encoded signals. The set of orthogonally encoded signals and the reference signal are transmitted to a remote location. The transmitted set of orthogonally encoded signals is coherently detected at the remote location. The coherently detected set of orthogonally encoded signals is then decoded using the inverse of the predetermined encoding matrix to generate a set of decoded signals. The set of decoded signals is then processed for generating calibration data for each element of the phased array system.

Method and apparatus for remotely calibrating a phased array system used

An ear canal device holder for devices other than speaker/microphone amplification systems that am to be inserted into the canal of the human ear. The device holder is made of a flexible silicone material comprising a body and structural support element(s) such that the device is held within the body of the holder and the body and device are secured in the ear by the structural element(s). In addition the device holder minimizes the attenuation of sound waves that pass through the ear canal to the tempanic membrane, while maximizing comfort and secure fit.

Ear canal device holder

A method and apparatus for remotely calibrating a system having a plurality of N elements, such as a phased array system, is provided. The method includes generating coherent signals, such as a calibration signal and a reference signal having a predetermined spectral relationship between one another. The calibration signal which is applied to each respective one of the plurality of N elements can be orthogonally encoded based on the entries of a predetermined invertible encoding matrix, such as a binary Hadamard matrix, to generate first and second sets of orthogonally encoded signals. The first and second sets of orthogonally encoded signals and the reference signal are transmitted to a remote location. The transmitted first and second sets of orthogonally encoded signals are coherently detected at the remote location. The coherently detected first and second sets of orthogonally encoded signals are then decoded using the inverse of the predetermined invertible encoding matrix to generate a set of decoded signals. The set of decoded signals is then processed for generating calibration data for each element of the system.

A small target phased array Doppler detection system receives signals from remote moving targets and determines Doppler frequency shift and the respective powers of coherent electromagnetic signals for the purpose of detection and identification of relatively small, slow moving targets in the presence of scattering echoes due to clutter. The system employs covariance analysis of the received signals followed by eigenanalysis to produce eigenvectors and eigenvalues. A superresolution algorithm creates dwell manifold vectors which indicate velocities of targets from the eigenvectors. The relative power of radar echoes contribute information relevant to the identification of real moving targets as opposed to false alarms.

Small target doppler detection system

A phased array source identification receives signals from remote sources and determines direction of arrival angles and the respective powers of coherent electromagnetic signals for the purpose of spatial localization and identification of relatively low power coherent sources in the presence of other coherent sources of relatively large signal power. The system employs covariant analysis of the received signals followed by eigenanalysis to produce eigenvectors and eigenvalues. A superresolution algorithm creates array manifold vectors corresponding to source direction of arrival, that lie in the signal subspace of the eigenvectors. In radar applications low power sources correspond to targets, while the high power sources would correspond to jammers. The relative power of radar echoes contribute information relevant to the identification of real sources as opposed to false alarms. Other applications may include cellular telephone systems and sonar systems.

Source identification system for closely separated spatial sources

Parallel architectures preprocesses large matrices from sampled coherent time apertures receiving signals from distant sources to produce lower order matrices, derived from pseudo coherent time apertures, which are computationally less burdensome. The large matrices are processed by frequency shifting, low pass filtering with an FIR filter, and executing front-end decimation to create the pseudo coherent time apertures, each corresponding to different subbands of the temporal frequency spectrum. The signals representing the pseudo coherent time apertures are processed using matrix based superresolution spectral estimation algorithms such as the Tufts-Kumaresan (T-K) reduced rank modified covariance algorithm and the Linear Minimum Free Energy algorithms to produce an image of the sources.

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Schenectady, NY, United States of America

Seth D Silverstein