Abstract: A multiple elastic feature network having N independent sets of M feature specific neurons that respond to the temporal properties of a number of targets. The targets are represented by sets of M feature specific coordinates. Each of the neurons and its coordinates are labeled with a different one of the feature types, and have an associated receptive field and distortion, locking and expectation parameters. A sequence of candidate coordinates, which include the targets' coordinates as well as false or ghost coordinates, is input to the MEFN. Each successive candidate coordinate selects the closest neuron that has the same feature type and whose receptive field includes the candidate coordinates. The coordinates of the selected neuron and the other neurons in its set are adjusted towards the candidate coordinates.
Abstract: A high-Q pump cavity is formed from undoped crystal pieces that are diffusion bonded to a doped core of the same crystal host material. The resulting monolithic pump cavity has 2 opposing convex-curved sides which have a highly-reflective coating on their outer surfaces, except in narrow slit-shaped areas on each curved side through which laser-diode-supplied pump light enters the cavity. The curvature of the two curved sides is such that nearly all the pump light rays that pass through the slit-shaped areas are focussed by the curvature onto the doped core, and rays that enter the cavity are redirected through the doped core many times, resulting in efficient, uniform absorption. The cavity has two opposing flat sides that interface with metal heat sink blocks to facilitate the removal of internally-generated heat. Thermally induced astigmatic lensing caused by this heat is countered by cavity design in which the core shape and the dimensions of the cavity minimize this astigmatism.
Abstract: A method and system are disclosed for inverting a satellite spinning about a first desired spin axis to spin about a second desired spin axis substantially antiparallel to the first desired spin axis. A tumbling motion is induced in the satellite so that a spin axis of the satellite oscillates between the first desired spin axis and the second desired spin axis. The tumbling motion is induced by sensing at least one component of the angular rate vector and controlling a single degree of freedom momentum storage device based upon the at least one component of the angular rate vector. The single degree of freedom momentum storage device has an orientation of variation substantially perpendicular to the desired spin axis. The single degree of freedom momentum storage device is controlled so that the first desired spin axis is made an intermediate inertia axis of an effective inertia matrix.
Abstract: A phased array radar system employs programmable microelectromechanical (MEM) switches and transmission lines to provide true time delays or phase shifts in order to steer the array beam. The array includes an excitation signal source, a power division network for dividing the excitation signal into a plurality of excitation signal components, a plurality of programmable time delay/phase shift circuits including the transmission lines and MEM switches, and a plurality of radiating elements. An adaptive controller provides the control signals to set the MEM switches and select the time delay/phase shift through each time delay/phase shift circuit, thereby steering the array beam to a desired direction.
Type:
Grant
Filed:
October 29, 1996
Date of Patent:
May 26, 1998
Assignee:
Hughes Electronics Corporation
Inventors:
Robert Y. Loo, Juan F. Lam, Vince L. Jones, Jar J. Lee, Darren E. Atkinson
Abstract: A method of transporting speech information over a wireless cellular communications system is provided. By determining the existence and compatibility of the destination port with the origination port in a given telephone call, the present invention is capable of using only one compression step and one decompression step. Accordingly, voice signal degradation and delay associated with multiple compression/decompression steps may be reduced.
Type:
Grant
Filed:
June 7, 1995
Date of Patent:
May 26, 1998
Assignee:
Hughes Electronics Corporation
Inventors:
Kirk H. Berry, Debabrata Chowdhury, Shrirang Jangi, Kumar Swaminathan
Abstract: A microwave/millimeter wave circuit structure supports discrete circuit elements by flip-chip mounting to an interconnection network on a low cost non-ceramic and non-semiconductor dielectric substrate, preferably Duroid. The necessary precise alignment of the circuit elements with contact pads on the substrate network required for the high operating frequencies is facilitated by oxidizing the interconnection network, but providing the contact pads from a non-oxidizable material to establish a preferential solder bump wetting for the pads. Alternately, the contact bumps on the flip-chips can be precisely positioned through corresponding openings in a passivation layer over the interconnection network. For thin circuit substrates that are too soft for successful flip-chip mounting, stiffening substrates are laminated to the circuit substrates.
Type:
Grant
Filed:
July 29, 1996
Date of Patent:
May 26, 1998
Assignee:
Hughes Electronics Corporation
Inventors:
Mehran Matloubian, Perry A. Macdonald, David B. Rensch, Lawrence E. Larson
Abstract: Continuous, elongated nickel plated graphite fibers are bound with an epoxy and are formed into a structural shape (11). An area (13) of the epoxy is removed by bead blasting to expose a layer of the plated graphite fibers (14), which are aligned in the desired direction of radio frequency current propagation. The bead blasted area (13) is then silver plated to obtain good contact to the plated graphite fibers (14) and resultant high conductivity from the structural shape (11).
Abstract: A switch matrix having internal redundancy by combining outputs of two internal channels to form one single internally redundant channel. 1 by N, M by 1 and M by N switch matrices may be constructed using the principles of the present invention. Each input signal line is coupled between a signal input and a terminating resistor and each output signal line is coupled between a signal output and a terminating resistor. Switching nodes are formed that comprise an input line, a plurality of output lines, and a plurality of pairs of couplers that are respectively interconnected by way of respective switches used to select the input line and couple it to a respective output line. Pairs of output signal lines are connected to a single signal output to form internally redundant channels. The nodes may include a second serially coupled switch connected between the input and output couplers to provide redundancy if either one of the switches fail in a closed state.
Abstract: Epitaxial growth of a chirped superlattice with constant dopings is achieved with minimal growth interruption time. This is done by doping only one of the two compositions during growth of its layer. For example, in the growth of a plurality of alternating layers of InP and GaInAs to form the superlattice, either the InP layers are doped with an n-type dopant, such as silicon, or the GaInAs layers are doped with a p-type dopant, such as beryllium. Alternatively, InP can equally be doped p-type (with beryllium) and GaInAs can be doped n-type (with silicon). In either case, the doping scheme described herein is easily done during molecular beam epitaxial growth by opening and closing the shutter of the dopant (silicon or beryllium) source cell at the appropriate times. To the electrical carriers, the doping superlattice scheme of the present invention presents a uniform doping without any need to change the doping cell temperature.
Abstract: In a satellite transponder architecture employing digital signal processing, a power monitor samples the data stream of carrier frequency samples on board the transponder and computes a power level for each of the carriers. This provides accurate and high frequency resolution power measurements within the communications link. These measurements are useful for computing critical transponder characteristics such as the effective isotropic radiated power (EIRP), receiver sensitivity, uplink sensitivity, operating points and, in a system using a phased array antenna, the total and component powers for each beam. The power monitor eliminates problems associated with external measurement methods, and improves the overall accuracy and reliability.
Abstract: A method of implementing an improved automatic link transfer for high mobility use in a wireless personal communication system is provided. The method includes retuning a subscriber unit to a new radio port frequency, reading an access message and initiating encrypted voice transmission from the subscriber unit, based on the access message, before receiving an acknowledgement from a radio port controller. A data structure for an access rights message is provided including a frame counter variable to allow for expedited processing of an automatic link transfer. A data structure for an automatic link transfer request message is provided that permits faster determination of the type of automatic link transfer necessary.
Abstract: An overcurrent protection circuit for protecting a boost-type non-isolated battery discharge controller from a fault current. The battery discharge controller includes multiple parallel-coupled power stages each having an input fuse and an output fuse having predetermined current ratings. The overcurrent protection circuit includes a resistor serially connected to an input of each of the output fuses of each of the power stages for limiting the fault current through each of the power stages to a predetermined level below the predetermined current ratings of the input and output fuses. The overcurrent protection circuit also includes a current bypass path for providing a current path around the power stages when the fault current exceeds the predetermined current ratings of the input and output fuses.