Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.