Patents Assigned to GTE Laboratories
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Patent number: 5253250Abstract: A method and apparatus is disclosed for signaling a switch of the target destination of a data packet having a header specifying the destination address and an information frame. The data packet along with a separate instance of the header is subcarrier multiplexed and simultaneously transmitted. The separate header is transmitted at a lower speed than the data packet permitting detection and processing by less expensive receivers.Type: GrantFiled: December 31, 1991Date of Patent: October 12, 1993Assignee: GTE Laboratories IncorporatedInventors: John Schlafer, Elliot Eichen, Robert Olshansky
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Patent number: 5243671Abstract: An apparatus for coupling light from a laser chip into an unetched and uncoated optical fiber includes a substrate carrier having a V-groove extending axially through the substrate carrier. The fiber has a beveled end with an inner and outer face and is positionable in the plane of the laser chip within the V-groove such that light emitted by the laser chip strikes the inner face of the beveled end and is totally internally reflected into the fiber core.Type: GrantFiled: December 31, 1991Date of Patent: September 7, 1993Assignee: GTE Laboratories IncorporatedInventors: Emil S. Koteles, Paul Melman, Barbara Foley
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Patent number: 5243652Abstract: A communication system includes a remote mobile node which acquires time-correlated data of its actual position from a global positional system (GPS), and securely transmits the information as a position history to a central facility. The mobile node includes encrypted programming material such as copyrighted video. At the central facility, a comparison is made between the received position history and predetermined signature data representing acceptable time-position histories. If a positive match is detected, a decryption key associated with the matched history is forwarded to the mobile node for decoding of the encrypted programming material.Type: GrantFiled: September 30, 1992Date of Patent: September 7, 1993Assignee: GTE Laboratories IncorporatedInventors: Melvin J. Teare, Stephen S. Walker
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Patent number: 5241246Abstract: A high frequency applicator for energizing electrodeless lamps is described. The applicators are end cups electrically attached to the ends of phased feed points of a planar transmission line, and facing each other so as to form a gap between the end cups. The end cups each have a concave surface facing the gap which forces an electric field concentration in the vicinity of the end cups and in the gap between the opposing end cups. Such a field configuration is useful for energizing a lamp capsule placed within the gaps formed by the end cups. The end cups can be made of metal or metallized ceramic.Type: GrantFiled: September 10, 1991Date of Patent: August 31, 1993Assignee: GTE Laboratories IncorporatedInventors: Walter P. Lapatovich, Scott J. Butler, Jason R. Bochinski
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Patent number: 5239401Abstract: Optical communication methods and apparatus are disclosed for transmitting two or more optical signals with different optical carrier frequencies on a single optical fiber with high spectral efficiency. Each optical carrier is typically modulated with multiple modulated subcarriers. In one embodiment, an optical phase modulator provides cancellation of second order intermodulation products in each optical signal, thereby permitting the optical carrier frequencies to be spaced by 2f.sub.max, where f.sub.max is the maximum modulation frequency. In another embodiment, a single sideband optical phase modulator provides cancellation of second order intermodulation products and one signal sideband, thereby permitting the optical carrier frequencies to be spaced by f.sub.max.Type: GrantFiled: December 31, 1990Date of Patent: August 24, 1993Assignee: GTE Laboratories IncorporatedInventor: Robert Olshansky
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Patent number: 5237825Abstract: An apparatus for cryogenically cooling a sample comprises a sample chamber within which the sample is suspended, and a vacuum chamber enclosing the sample chamber. A cryogenic element forms at least part of the sample chamber and is in spaced-apart relation to the sample. The element is maintained at cryogenic temperatures by a gas cryopump. A sufficient amount of heat-conductive gas is introduced into the sample chamber for placing the sample in thermal communication with the cryogenic element, thereby cooling the sample to cryogenic temperatures.Type: GrantFiled: November 8, 1991Date of Patent: August 24, 1993Assignee: GTE Laboratories IncorporatedInventors: Werner Menzi, Emil S. Koteles
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Patent number: 5238868Abstract: A method of selectively tuning the bandedge of a semi-conductor heterostructure includes forming a disordered region which is spatially separated from a quantum well active region, and subsequently annealing the heterostructure so that vacancies/defects in the disordered region diffuse into the quantum well region and enhance interdiffusion at the well-barrier heterojunctions. The tuning is spatially selective when the heterostructure is masked so that exposed portions correspond to regions where bandgap tuning is desirable. The heterostructures of interest are III-V material systems, such as AlGaAs/GaAs, where the active region includes structures such as a single quantum well, a multiple quantum well, or a superlattice.Type: GrantFiled: July 1, 1991Date of Patent: August 24, 1993Assignee: GTE Laboratories IncorporatedInventors: Boris S. Elman, Emil S. Koteles, Paul Melman, Craig A. Armiento
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Patent number: 5236690Abstract: A chemical vapor purification process for preparing metal fluorides. The process involves melting a metal selected from the metals forming fluorides suitable for use in fluoride glass and thermodynamically partitionable from cation contaminants, for example aluminum, gallium, or indium. Chlorine, bromine, or iodine is bubbled through a stoichiometric excess of the melt, under reaction conditions selected to result in generation of a gaseous halide of the metal. The gaseous halide is then isolated from the melt and reacted with a gaseous fluorinating agent to form a solid fluoride of the metal.Type: GrantFiled: January 31, 1991Date of Patent: August 17, 1993Assignee: GTE Laboratories IncorporatedInventors: Robert C. Folweiler, Barry C. Farnsworth
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Patent number: 5235671Abstract: In an adaptive subband excited transform speech encoding system, a range of quantizers are available and are dynamically selected for each window of speech. The quantizers designated for individual subbands are determined to minimize mean squared error distortion in the recreated signal while using no more than a predetermined number of quantization bits per window of speech.Type: GrantFiled: October 15, 1990Date of Patent: August 10, 1993Assignee: GTE Laboratories IncorporatedInventor: Baruch Mazor
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Patent number: 5235219Abstract: Electrical circuitry for changing the operating voltage conditions of CMOS inverter circuitry so as to shift its threshold voltage in a direction to cause the duty cycle of the output signals to equal the duty cycle of the input signals. An average filtered DC output voltage from the inverter circuitry is used as a control signal to a variable voltage supply which changes the operating voltages, thus shifting the threshold level of the inverter circuitry.Type: GrantFiled: April 1, 1992Date of Patent: August 10, 1993Assignee: GTE Laboratories IncorporatedInventors: Michael Cooperman, Phillip Andrade
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Patent number: 5231414Abstract: An antenna has a dielectric slab with an inner surface and an outer surface. The inner surface is mounted on a metal backplate. A radiating spiral is located on the outer surface of the dielectric slab and has a pitch of one wavelength at the design frequency. A circular waveguide, for providing RF energy in the TM.sub.01 mode, passes through the metal backplate to terminate at the inner surface of the dielectric slab. A metal cap is located on outer surface of the dielectric slab coaxial with the circular waveguide and at the center of the spiral. The metal cap has a surface is sloped away from the outer dielectric surface and has one or more concentric choke grooves formed on the sloped surface. The grooves are one quarter wavelength deep at the design frequency.Type: GrantFiled: December 23, 1991Date of Patent: July 27, 1993Assignee: GTE Laboratories IncorporatedInventor: John P. Ladds
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Patent number: 5228050Abstract: A monolithically integrated multiple-wavelength laser structure includes an array of lasing structures each having a cavity length chosen to correspond to a desired lasing wavelength. The array is suitable for use as a transmitter in a wavelength division multiplexing communication system. The lasing structures preferably include quantum well active regions.Type: GrantFiled: February 3, 1992Date of Patent: July 13, 1993Assignee: GTE Laboratories IncorporatedInventors: Joanne LaCourse, Robert B. Lauer
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Patent number: 5224184Abstract: An opto-electronic interconnect is disclosed that provides for optical communication between chip devices. Optical signals, transmitted from one of the edges of a first chip device, are directed by a lens focusing apparatus to the edge of a second chip device, whereupon the signal is detected. The optical ports for transmission or reception of the optical signals are grouped into an optical segment, which may have either a semi-circular or planar geometry.Type: GrantFiled: May 21, 1991Date of Patent: June 29, 1993Assignee: GTE Laboratories IncorporatedInventor: Robert A. Boudreau
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Patent number: 5221445Abstract: Apparatus and method for determining the identity and concentration of a component in a test atmosphere having a known concentration of oxygen. At least one solid electrolyte oxygen sensor is used, with each sensor having a solid electrolyte wall in contact with, and interposed between, a first electrode and a second electrode. The first electrode is in communication with the test atmosphere. A first negative voltage is applied across the first and second electrodes of a sensor, causing electrochemical oxygen pumping and a first electric current to flow through the corresponding solid electrolyte wall. The first negative voltage is selected to cause the first electric current magnitude to be on a first current plateau. The magnitude of the first electric current is measured.A second negative voltage is applied across the first and second electrodes of a sensor, causing electrochemical oxygen pumping and a second electrical current to flow through the corresponding solid electrolyte wall.Type: GrantFiled: April 17, 1989Date of Patent: June 22, 1993Assignee: GTE Laboratories IncorporatedInventors: Da Y. Wang, Daniel T. Kennedy, Burton W. MacAllister, Jr.
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Patent number: 5222091Abstract: A semiconductor laser having a high modulation bandwidth is made by utilizing an InGaAsP cap layer and an InGaAsP active layer of different crystal structure. Channels are anisotropically etched through the cap, cladding and active layers and partially through the buffer layer. The active and cap layers a laterally etched and a semi-insullating material is overlayed the sidewalls. A further etching leaves a thin wall of the semi-insulating material surrounding the active layer. 1.3 .mu.m InGaAsP lasers with 3 dB bandwidths of 24 GHz and intrinsic resonance frequencies in excess of 22 GHz have been successfully fabricated. This is the highest bandwidth ever reported for a semiconductor laser, and the highest resonance frequency for InGaAsP lasers. Excellent modulation efficiencies are observed to high frequencies.Type: GrantFiled: January 21, 1992Date of Patent: June 22, 1993Assignee: GTE Laboratories IncorporatedInventors: Roger P. Holmstrom, Edmund Meland, William Powazinik
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Patent number: 5222103Abstract: This invention features a differential QPSK digital communications apparatus and method, suitable for optical communications systems, where a pair of synchronous binary input data streams S.sub.0 (t) and S.sub.1 (t) are encoded into a pair of encoded binary data streams d.sub.0 (t) and d.sub.1 (t) which QPSK modulate the phase .phi.(t) of a carrier signal. An encoder features time delay circuits for delaying d.sub.0 (t) and d.sub.1 (t) by a period T to produce d.sub.0 (t-T) and d.sub.1 (t-T) respectively. A logic circuit produces d.sub.0 (t) and d.sub.1 (t) from S.sub.0 (t), S.sub.1 (t), d.sub.0 (t-T) and d.sub.1 (t-T) according to logical relationships. A microwave subcarrier is modulated by a microwave QPSK subcarrier modulator. The microwave QPSK subcarrier modulator includes an in-phase and quadrature subcarrier signal source, a mixer for mixing the in-phase subcarrier with d.sub.0 (t), a second mixer for mixing the quadrature subcarrier with d.sub.Type: GrantFiled: January 2, 1991Date of Patent: June 22, 1993Assignee: GTE Laboratories IncorporatedInventor: Richard W. Gross
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Patent number: 5217588Abstract: Apparatus and method for determining the concentration of NOx in a gas mixture. The gas mixture is supplied to two electrodes at which different NOx decomposition conditions are present. The electrodes may be of different materials or sizes or may be positioned in different gas enclosure environments. The NOx decomposes at different rates at the two electrodes and an emf is thus produced between the electrodes. The concentration of NOx in the gas mixture is determined from the measured emf.Type: GrantFiled: February 27, 1992Date of Patent: June 8, 1993Assignee: GTE Laboratories IncorporatedInventors: Da Y. Wang, Daniel T. Kennedy, Burton W. MacAllister, Jr.
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Patent number: 5214729Abstract: Apparatus for an an optical data buffer is disclosed which includes an optical splitter for splitting an incoming signal, and multiple fiber optic delay lines of varying length to delay the split signals. The delayed signals are combined and presented to an amplifier, which selectively amplifies or blocks further propogation of the individual signals. In another embodiment of the invention, the input signal is split and each signal is passed through a separate fiber delay line of differing length before being presented to an amplifier which selectively amplifies or blocks the individual signals. The output of the amplifier is combined into a single fiber optic cable.Type: GrantFiled: December 31, 1991Date of Patent: May 25, 1993Assignee: GTE Laboratories IncorporatedInventor: Kwang-Tsai Koai
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Patent number: 5211707Abstract: A field emission cathode having a parallel array of individual electrically conductive rods of metal silicide or germanide in a silicon-based or germanium-based single crystal matrix. Each rod has an emission end exposed at one major surface of the cathode and an ohmic contact end exposed at an opposite major surface. In a preferred cathode, the matrix and rod materials are the constituents of a eutectic composition. The cathode is fabricated by a process involving producing a composite boule from a eutectic composition of a silicon-based or germanium-based material and a metal. The composite cathode body is cut from the boule so that the rods are generally normal to the major surfaces. Etching may be used to expose a uniform length of the rods at the emitting surface.Type: GrantFiled: July 11, 1991Date of Patent: May 18, 1993Assignee: GTE Laboratories IncorporatedInventors: Brian M. Ditchek, Mark A. Neifeld, John C. Gustafson
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Patent number: 5204982Abstract: Apparatus for digital switching of FM signals includes multiple functional switching circuits, each having an input for receiving an FM signal at a first frequency and each generating first switching transients in response to the FM signal. The apparatus includes a dummy switching circuit corresponding to each functional switching circuit. The dummy switching circuits generate second switching transients in response to the FM signal. The second switching transients are shifted in phase relative to the first switching transients such that a crosstalk signal resulting from the first and second switching transients has a frequency of twice the first frequency. The apparatus further includes filters for attenuating the crosstalk signal. By shifting the frequency of the crosstalk signal to twice the frequency of the FM signal, the crosstalk signal is easily filtered.Type: GrantFiled: November 14, 1990Date of Patent: April 20, 1993Assignee: GTE Laboratories IncorporatedInventor: Michael Cooperman