Patents Represented by Attorney Walter G. Sutcliff
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Patent number: 5812104Abstract: Pixel luminance of an electroluminescent display panel is controlled by a row driver applying a voltage equal to the panel's threshold voltage, and column drivers applying the voltage value above the threshold voltage to bring the pixel to the desired luminance. Each column driver independently samples a stepped ramp voltage signal at its own predetermined time selected as a function of the desired luminance. Each column driver then holds the sampled voltage value, and applies to its corresponding column electrode at the appropriate time a voltage equal to the sampled voltage value. The voltage rate of change of each individual step of the stepped ramped voltage signal can be controlled to vary the luminance levels, and to uniformly separate each of the luminance levels.Type: GrantFiled: January 30, 1997Date of Patent: September 22, 1998Assignee: Northrop Grumman CorporationInventors: Mohan L. Kapoor, Thomas John Rebeschi
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Patent number: 5812221Abstract: A UHF transmitter for digital TV signals includes, for example, twelve silicon carbide transistor RF output power amplifier panels driven in parallel by two silicon carbide amplifier driver panels and where each panel is comprised of two modules each further including a 180.degree. signal splitter, a pair of quadraphase signal splitters and combiners, a 180.degree. signal combiner, and five RF amplifier pallets which themselves are comprised of two silicon carbide transistors located on a common flange and operated in push-pull relationship so as to suppress even order distortion products and reduce sensitivity to ground currents. A monitoring system, including a touch screen control display and control panel senses the status of all assemblies so as to allow an operator to control the transmitter and inquire about the status of the various components and power supplies, and to replace one or more units as required without the need for turning the transmitter off.Type: GrantFiled: February 14, 1997Date of Patent: September 22, 1998Assignee: Northrop Grumman CorporationInventors: Carlton Daniel Davis, Robert Kent Long, Jack Jerome Hawkins
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Patent number: 5812078Abstract: A low noise accurate signal generator for a calibration system or a radar system includes a generator of a digital data stream having a predetermined frequency spectrum incorporated therein. A series connected array of Josephson junctions is coupled to and excited by the digital data stream to provide a stream of pulses with quantum mechanically accurate time integral. A low pass analog signal filter is coupled to the pulses of accurate time integral for extracting analog signals of the predetermined frequency spectrum. For radar applications, a low phase-noise local oscillator of a fixed RF frequency and the output of the filter are coupled to a signal mixer which outputs low phase-noise chirped RF signals for use in generating transmit pulses for the radar system whereby enhanced detection of targets in "clutter" can be obtained.Type: GrantFiled: May 22, 1997Date of Patent: September 22, 1998Assignee: Northrop Grumman CorporationInventors: John Xavier Przybysz, Anthony Hodge Worsham, Samuel Paul Benz, Clark Allen Hamilton
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Patent number: 5812101Abstract: A relatively low cost, portable, low complexity, low power helmet mounted display using an electroluminescent display and associated drive circuitry configured and interconnected to take advantage of our ability to provide a -180 V and +240 V output to a row driver from a single -180 V and an already existing +60 V Supply, thus eliminating size, weight and expense of supplying a separate 240 V power supply. The +60 V power supply is already supplying the +60 V to the column driver circuitry. Also included is a column driver with a direct analog interface with an input buffer, the buffer including a polarity inverter and an adder for selectively inverting the external analog signal and adding a DC voltage.Type: GrantFiled: April 4, 1996Date of Patent: September 22, 1998Assignee: Northrop Grumman CorporationInventors: Dominick L. Monarchie, Thomas J. Rebeschi, Russell A. Budzilek
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Patent number: 5808579Abstract: A cell averaging (CA) constant false alarm rate (CFAR) device for use in a radar system which filters noise and clutter from a signal containing a plurality of range cells. A moving window average calculator (MWAC) calculates a moving window average (MWA) for each range cell in a signal. A central processing unit (CPU) estimates a skew factor of a probability density function (PDF) and calculates an offset factor based on information contained in the signal. A multiplying device multiplies the offset factor by the MWA calculated for each range cell and creates a second signal containing a plurality of range cells. A comparator compares each range cell of the second signal to each corresponding range cell of the original signal, selects a the larger value of the two signals, and creates a third signal which is essentially free of noise and clutter.Type: GrantFiled: December 20, 1996Date of Patent: September 15, 1998Assignee: Northrop Grumman CorporationInventor: Paul E. Rademacher
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Patent number: 5807773Abstract: A method of aligning a gate and a source of a silicon carbide static induction transistor comprising the steps of depositing an oxide layer over the transistor, forming oxide spacers from the oxide layer where the oxide spacers are adjacent the source, depositing a metal layer over the transistor and removing the oxide spacers so that the resulting gates are accurately aligned with the source.Type: GrantFiled: July 30, 1996Date of Patent: September 15, 1998Assignee: Northrop Grumman CorporationInventors: Li-Shu Chen, Rowland C. Clarke, Richard R. Siergiej
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Patent number: 5805124Abstract: A method and apparatus for providing a driver circuit for an electroluminescent display panel comprising a row driver including positive row drive elements and negative row drive elements, a first power lead with a first predetermined voltage V.sub.neg connected in series through a first switch connection to a first node, the first node connected to a first current limiter to the negative row drive elements, a second current limiter operably connected between a first fixed potential to a second node, the second node connected to the positive row drive elements, a third current limiter connected between the negative row drive element and the second fixed potential, a second power lead with a second predetermined voltage V.sub.Type: GrantFiled: April 4, 1996Date of Patent: September 8, 1998Assignee: Norhtrop Grumman CorporationInventors: Mohan L. Kapoor, Thomas J. Rebeschi, Peter O. Shanaghan, Daniel J. Toffolo
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Patent number: 5801442Abstract: Cooling of densely packaged semiconductor devices is achieved by microchannels which extract heat by forced convection and the use of fluid coolant located as close as possible to the heat source. The microchannels maximize heat sink surface area and provides improved heat transfer coefficients, thereby allowing a higher power density of semiconductor devices without increasing junction temperature or decreasing reliability. In its preferred embodiment, a plurality of microchannels are formed directly in the substrate portion of a silicon or silicon carbide chip or die mounted on a ground plane element of a circuit board and where a liquid coolant is fed to and from the microchannels through the ground plane. The microchannels comprise a plurality of closed-ended slots or grooves of generally rectangular cross section. Fabrication methods include deposition and etching, lift-off processing, micromachining and laser cutting techniques.Type: GrantFiled: July 22, 1996Date of Patent: September 1, 1998Assignee: Northrop Grumman CorporationInventors: Robin E. Hamilton, Paul G. Kennedy, John Ostop, Martin L. Baker, Gregory A. Arlow, John C. Golombeck, Thomas J Fagan, Jr.
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Patent number: 5798733Abstract: A position guidance apparatus is a microprocessor based tool used to aid a parachute jumper in reaching a predetermined target position in an interactive manner. The device is particularly valuable in aiding those who have to do parachute jumps under hazardous conditions such as at night, into terrain with no visible orientation features, or into terrain wherein a precisely located landing is desired. The position guidance apparatus provides locational/directional guidance in a visual and potentially audible manner to guide the user in steering himself into an appropriate targeted landing zone. The apparatus is one that is preferably strapped onto the forearm of a user and provides a small graphical display of current position, target position, and predicted destination position. Alternatively, the display can be implemented as a heads-up display for the user.Type: GrantFiled: January 21, 1997Date of Patent: August 25, 1998Assignee: Northrop Grumman CorporationInventor: Jeffrey Noel Ethridge
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Patent number: 5793056Abstract: A technique for defining the active area of a high-T.sub.c superconductor Josephson junction uses an epitaxial slotted insulator patterned over the edge of the superconductor thin film-insulator bilayer. The superconductor/normal-metal/superconductor edge junction formed between the slotted insulator has a small active area. The counter electrode provided as an interconnect of the junction can therefore be wider than the active area of the edge junction since it can overlap onto the patterned slotted insulator. The use of the slotted insulator enables fabrication of junctions having resistances and critical currents in the desired range for high-T.sub.c superconductor circuits while enabling the use of wide, low inductance interconnects.Type: GrantFiled: February 21, 1997Date of Patent: August 11, 1998Assignee: Northrop Grumman CorporationInventors: Martin G. Forrester, Brian D. Hunt
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Patent number: 5788768Abstract: A silicon carbide feedstock charge for growing silicon carbide boules in a physical vapor transport system. The feedstock charge includes silicon carbide particles, as well as any dopant material, if required, in a structure which is rigid and self supportable. An elongated feedstock charge may be moved toward the seed crystal as the feedstock is depleted during boule growth. The feedstock charge may be tailored to provide a non-uniform flux for growing more planar boule faces.Type: GrantFiled: May 8, 1997Date of Patent: August 4, 1998Assignee: Northrop Grumman CorporationInventors: Donovan L. Barrett, Richard H. Hopkins
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Patent number: 5788777Abstract: A susceptor assembly for use in an epitaxial growth reactor for growing silicon carbide epitaxial layers. The susceptor assembly is rotatable about a central axis and includes a plurality of cavities each for receiving a wafer holder. A plurality of gas passageways leading to respective cavities, carries gas for levitating and rotating the wafer holders in their respective cavities. All of the gas passageways in the susceptor assembly are non-radially oriented.Type: GrantFiled: March 6, 1997Date of Patent: August 4, 1998Inventor: Albert A. Burk, Jr.
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Patent number: 5788765Abstract: Crystals formed of a solid-solution of K.sub.2 Ni(SO.sub.4).sub.2 6H.sub.2 O provide very good materials for filtering ultraviolet light and will not deteriorate in temperatures as high as 110.degree. C. They are particularly useful in sensing devices which seek to identify the presence of ultraviolet light in the UV missile warning band.Type: GrantFiled: August 30, 1996Date of Patent: August 4, 1998Assignee: Northrop Grumman CorporationInventors: Narsingh B. Singh, William D. Partlow, Steven Strauch, Albert M. Stewart, John F. Jackovitz, David W. Coffey
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Patent number: 5786797Abstract: A thin film electroluminescent display panel is driven with either a symmetric or asymmetric drive scheme which includes at least one equalizing voltage pulse per write cycle to remove carriers trapped at the interfaces of dielectric layers and phosphor layer in order to stabilize the charge of each display panel pixel. The present invention reduces the smearing, latent image and pseudo persistence problems caused by carriers being retained and accumulated at the dielectric and phosphor layer interfaces.Type: GrantFiled: August 30, 1996Date of Patent: July 28, 1998Assignee: Northrop Grumman CorporationInventors: Mohan Lal Kapoor, Dominic Louis Monarchie, Thomas John Rebeschi, Russell Anthony Budzilek
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Patent number: 5786792Abstract: A tapered notch antenna structural panel array that can serve both as a structural member and an antenna is made from an injection molded monolithic three dimensional grid of thermoplastic material. The notch and feed line are in the form of microstrip or stripline circuitry formed to the sidewalls of adjacent cells. Dielectric sheets of material are bonded to the upper and lower edges of the grid. Interconnect circuitry on the antenna ground plane is supported by the sheet bonded to the lower edge and connected to the antenna circuitry of the sidewalls.Type: GrantFiled: December 15, 1995Date of Patent: July 28, 1998Assignee: Northrop Grumman CorporationInventors: Peter A. Bellus, Robert J. Miklosko, Thomas P. Fontana
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Patent number: 5782194Abstract: A bimetallic hull mount assembly (10) for reducing galvanic corrosion of a hull (12), including a foundation (14), made of a first material, welded to the hull (12), also made of the first material; and an insert (16), made of a second material, different from the first material, welded to the foundation (14); wherein a weld area (15) between the insert (16) and the foundation (14) is covered with paint (19), and where the insert (16) is welded to the foundation (14) in a controlled welding manufacturing environment, utilizing high performance dissimilar welding techniques to produce a dissimilar metal weld and the foundation (14) is welded to the hull (12) with a standard shipyard weld.Type: GrantFiled: November 8, 1996Date of Patent: July 21, 1998Assignee: Northrop Grumman CorporationInventor: David G. Tipton
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Patent number: 5783872Abstract: A battery temperature compensation circuit for a DC/DC converter which is used to charge an auxiliary battery for an electric vehicle and including, among other things, a voltage sensitive resistance, such as a thermistor, coupled to a clamped voltage divider network which generates a resistance vs. temperature characteristic so as to control the DC/DC converter and provide an output voltage for charging the auxiliary battery which matches the voltage vs. temperature profile of the battery.Type: GrantFiled: July 25, 1996Date of Patent: July 21, 1998Assignee: Northrop Grumman CorporationInventor: James W. Blair
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Patent number: 5781167Abstract: A method and apparatus for providing a column driver circuit for an electroluminescent display panel including a column driver with a column driver including a direct analog interface with an input buffer with an input for accepting an external analog signal and an output for outputting an analog signal for said electroluminescent display panel. The buffer includes a polarity inverter and an adder for selectively inverting the external analog signal and adding a DC voltage. The column driver further includes an output demultiplexer, a plurality of sample and hold circuits, and an output driver employing negative feedback techniques for comparing the feedback signal to a preselected external variable voltage and selecting the appropriate drive signal.Type: GrantFiled: April 4, 1996Date of Patent: July 14, 1998Assignee: Northrop Grumman CorporationInventors: Thomas J. Rebeschi, Russell A. Budzilek
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Patent number: 5779190Abstract: An unmanned aerial vehicle that includes symmetrical wings, tail section and internal compartments. The wings which include the only control surfaces can be attached to either side of the aircraft. An engine and a payload are non-symmetrically attached modules. Assembly and disassembly is performed with quick release pin and plate latches, quarter turn fasteners and guides that prevent improper assembly. The compartments include quick release hatch covers for the various internal craft compartments.Type: GrantFiled: November 22, 1995Date of Patent: July 14, 1998Assignee: Northrop Grumman CorporationInventors: James E. Rambo, Jerry H. Bowling, Robert S. Kincade
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Patent number: 5781305Abstract: A transmissometer for measuring a volume attenuation coefficient of a column of water, including a transmissometer housing; a light source, producing an optical light beam; a Y-splitter, splitting the optical light beam into two light beams within the transmissometer housing; a pressure proof connector and two optical fibers, routing the two light beams outside the transmissometer housing; two collimators for collimating outputs of the two optical fibers prior to transmission through the column of water; a reflecting prism, reflecting the outputs of the two collimators back into the transmissometer housing via a sensor view port where a distance between a first of the two collimators and the reflecting prism is R1 and a distance between a second of the two collimators and the reflecting prism is R2; two detectors for detecting intensities I1 and I2 of the two light beams reflected by the reflecting prism; and a processor for determining the volume attenuation coefficient of the column of water according to:.Type: GrantFiled: April 18, 1997Date of Patent: July 14, 1998Inventor: Philip Downes