Patents Represented by Attorney Walter G. Sutcliff
  • Patent number: 5812104
    Abstract: 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: Grant
    Filed: January 30, 1997
    Date of Patent: September 22, 1998
    Assignee: Northrop Grumman Corporation
    Inventors: Mohan L. Kapoor, Thomas John Rebeschi
  • Patent number: 5812221
    Abstract: 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: Grant
    Filed: February 14, 1997
    Date of Patent: September 22, 1998
    Assignee: Northrop Grumman Corporation
    Inventors: Carlton Daniel Davis, Robert Kent Long, Jack Jerome Hawkins
  • Patent number: 5812078
    Abstract: 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: Grant
    Filed: May 22, 1997
    Date of Patent: September 22, 1998
    Assignee: Northrop Grumman Corporation
    Inventors: John Xavier Przybysz, Anthony Hodge Worsham, Samuel Paul Benz, Clark Allen Hamilton
  • Patent number: 5812101
    Abstract: 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: Grant
    Filed: April 4, 1996
    Date of Patent: September 22, 1998
    Assignee: Northrop Grumman Corporation
    Inventors: Dominick L. Monarchie, Thomas J. Rebeschi, Russell A. Budzilek
  • Patent number: 5808579
    Abstract: 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: Grant
    Filed: December 20, 1996
    Date of Patent: September 15, 1998
    Assignee: Northrop Grumman Corporation
    Inventor: Paul E. Rademacher
  • Patent number: 5807773
    Abstract: 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: Grant
    Filed: July 30, 1996
    Date of Patent: September 15, 1998
    Assignee: Northrop Grumman Corporation
    Inventors: Li-Shu Chen, Rowland C. Clarke, Richard R. Siergiej
  • Patent number: 5805124
    Abstract: 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: Grant
    Filed: April 4, 1996
    Date of Patent: September 8, 1998
    Assignee: Norhtrop Grumman Corporation
    Inventors: Mohan L. Kapoor, Thomas J. Rebeschi, Peter O. Shanaghan, Daniel J. Toffolo
  • Patent number: 5801442
    Abstract: 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: Grant
    Filed: July 22, 1996
    Date of Patent: September 1, 1998
    Assignee: Northrop Grumman Corporation
    Inventors: Robin E. Hamilton, Paul G. Kennedy, John Ostop, Martin L. Baker, Gregory A. Arlow, John C. Golombeck, Thomas J Fagan, Jr.
  • Patent number: 5798733
    Abstract: 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: Grant
    Filed: January 21, 1997
    Date of Patent: August 25, 1998
    Assignee: Northrop Grumman Corporation
    Inventor: Jeffrey Noel Ethridge
  • Patent number: 5793056
    Abstract: 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: Grant
    Filed: February 21, 1997
    Date of Patent: August 11, 1998
    Assignee: Northrop Grumman Corporation
    Inventors: Martin G. Forrester, Brian D. Hunt
  • Patent number: 5788768
    Abstract: 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: Grant
    Filed: May 8, 1997
    Date of Patent: August 4, 1998
    Assignee: Northrop Grumman Corporation
    Inventors: Donovan L. Barrett, Richard H. Hopkins
  • Patent number: 5788777
    Abstract: 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: Grant
    Filed: March 6, 1997
    Date of Patent: August 4, 1998
    Inventor: Albert A. Burk, Jr.
  • Patent number: 5788765
    Abstract: 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: Grant
    Filed: August 30, 1996
    Date of Patent: August 4, 1998
    Assignee: Northrop Grumman Corporation
    Inventors: Narsingh B. Singh, William D. Partlow, Steven Strauch, Albert M. Stewart, John F. Jackovitz, David W. Coffey
  • Patent number: 5786797
    Abstract: 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: Grant
    Filed: August 30, 1996
    Date of Patent: July 28, 1998
    Assignee: Northrop Grumman Corporation
    Inventors: Mohan Lal Kapoor, Dominic Louis Monarchie, Thomas John Rebeschi, Russell Anthony Budzilek
  • Patent number: 5786792
    Abstract: 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: Grant
    Filed: December 15, 1995
    Date of Patent: July 28, 1998
    Assignee: Northrop Grumman Corporation
    Inventors: Peter A. Bellus, Robert J. Miklosko, Thomas P. Fontana
  • Patent number: 5782194
    Abstract: 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: Grant
    Filed: November 8, 1996
    Date of Patent: July 21, 1998
    Assignee: Northrop Grumman Corporation
    Inventor: David G. Tipton
  • Patent number: 5783872
    Abstract: 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: Grant
    Filed: July 25, 1996
    Date of Patent: July 21, 1998
    Assignee: Northrop Grumman Corporation
    Inventor: James W. Blair
  • Patent number: 5781167
    Abstract: 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: Grant
    Filed: April 4, 1996
    Date of Patent: July 14, 1998
    Assignee: Northrop Grumman Corporation
    Inventors: Thomas J. Rebeschi, Russell A. Budzilek
  • Patent number: 5779190
    Abstract: 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: Grant
    Filed: November 22, 1995
    Date of Patent: July 14, 1998
    Assignee: Northrop Grumman Corporation
    Inventors: James E. Rambo, Jerry H. Bowling, Robert S. Kincade
  • Patent number: 5781305
    Abstract: 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: Grant
    Filed: April 18, 1997
    Date of Patent: July 14, 1998
    Inventor: Philip Downes