Patents by Inventor David H. Evans

David H. Evans has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Publication number: 20030002604
    Abstract: A frequency offset diversity receiver comprises a first RF receiver branch (10) and a second RF receiver branch (12), an RF signal combiner (14) having first and second inputs (11,13) and an output, the first and second receiver branches being coupled to the first and second inputs (11,13), respectively, frequency shifting means (26) in the second receiver branch (12) for shifting a received signal frequency by at least one channel bandwidth, an intermediate frequency (IF) stage (28,30) coupled to the output of the signal combining means (14) for converting the combined RF signal to baseband, frequency demultiplexing means (36) for recovering the baseband signals corresponding to the RF signals received by the first and second receiver branches (10,12) and a baseband signal combiner (42) for combining the demultiplexed signals to provide an output signal (44).
    Type: Application
    Filed: June 26, 2002
    Publication date: January 2, 2003
    Applicant: KONINKLIJKE PHILIPS ELECTRONICS N.V.
    Inventors: Robert Fifield, David H. Evans
  • Publication number: 20020129337
    Abstract: An improved source-level debugger for object-oriented application programs which may include linked native language dynamic load libraries. The debugger is compatible with the Java Platform Debugger Architecture (JDPA), and provides new capabilities such as patching of Java variables and reading and writing strings from and to the application under test and being run by a local or remote Java Virtual Machine.
    Type: Application
    Filed: March 8, 2001
    Publication date: September 12, 2002
    Applicant: International Business Machines Corporation
    Inventors: David H. Evans, Christopher James Gay, Anthony Paul Scherk
  • Publication number: 20020122393
    Abstract: A method whereby a mobile terminal (MT) operating in a wireless local area network (WLAN), for example HiperLAN2, can effect antenna diversity. The mobile terminal which has at least two antennas (24, 26) monitors downlink fields in successive time frames in a time division radio transmission for indications of when downlink message signals are to be sent to mobile terminals other than the one effecting the monitoring and determines from the indications when there will be in the time frame a time period of sufficient duration for the mobile terminal to effect antenna diversity measurements. The mobile terminal measures in the selected time period the quality of signal reception by each of the at least two antennas and selects the one of the said at least two antennas providing the better (or best) quality of signal reception.
    Type: Application
    Filed: February 4, 2002
    Publication date: September 5, 2002
    Applicant: KONINKLIJKE PHILIPS ELECTRONICS N.V.
    Inventors: Richard J. Caldwell, David H. Evans, Robert Fifield
  • Patent number: 6430707
    Abstract: A client station on computer network uses an operating system such as JavaOS which is permanently stored at the server rather than on storage media at the client location. JavaOS is loaded and installed at the client upon bootup of the client. Java is an interpreted language; the source is available at the server and is downloaded as such. Upon the occurrence of a malfunction that causes the client to go off-line, i.e., disappear from the network, a dump image is sent to the server before the client reboots, so that the cause of failure can be determined. The dump image includes the contents of memory, including the JavaOS operating system, and the stack, threads, registers, and local/global variables, which can be analyzed at a source level. This image is sent to the server in formatted packets, by a path separate from that of the TCP/IP network protocol, since the client would not be functioning properly on the network.
    Type: Grant
    Filed: March 31, 1999
    Date of Patent: August 6, 2002
    Assignee: International Business Machines Corporation
    Inventors: Gareth Christopher Matthews, Edwin James Hilpert, Jr., David H. Evans, Brian L. Naylor
  • Publication number: 20020039884
    Abstract: A radio communication system comprises a communication channel between a transmitter having parts operating according to a plurality of radio standards and having a plurality of antennas and a receiver having parts operating according to a corresponding plurality of radio standards having at least one antenna. In such a system the communication channel comprises a plurality of paths having a range of characteristics. Data for transmission is generated by one or more applications and is transmitted using an appropriate radio standard.
    Type: Application
    Filed: November 28, 2001
    Publication date: April 4, 2002
    Applicant: KONINKLIJKE PHILIPS ELECTRONICS N.V..
    Inventors: Deborah L. Raynes, David H. Evans, Matthew P.J. Baker
  • Publication number: 20010012275
    Abstract: In a radio communication system comprising a plurality of stations (100a,100b,100c) operating in a peer-to-peer mode, each station stores information relating to the transmission parameters of other stations. Such information may include the frequency offset and received signal strength of signals from the other stations. One station acts as central controller and allocates time slots for transmission from a first station (100a) to a second station (100b). Before the first station (100a) receives a signal from the second station (100b) it makes initial adjustments to its receiver circuitry depending on the stored information about previous signals received from that station (100b). This simplifies the task of adjusting the receiver circuitry during the preamble of the signal transmitted by the second station (100b).
    Type: Application
    Filed: February 1, 2001
    Publication date: August 9, 2001
    Applicant: Philips Corporation
    Inventors: Richard J. Caldwell, Robert Fifield, David H. Evans
  • Patent number: 5920813
    Abstract: In a cell of a microwave cellular video distribution system, e.g a multichannel video distribution system operating at frequencies of around 29 GHz or 40 GHz, the transmitting antenna is composed of individual antenna sectors (62a,62b,62c . . . ) for transmitting the microwave signal towards different sectors (216a,216b,216c . . . ) of the cell. In accordance with the present invention, a respective monitor (D,R) is present in each of the different sectors (216a,216b,216c . . . ) of each/the cell to monitor the microwave signal transmitted in that sector. The antenna sectors (62a,62b,62c . . . ) are individually fed through controllable feed means (59,60,61) which permit individual control of the power level of the microwave signals transmitted by the individual antenna sectors (62a,62b,62c . . . ), including the switching off of that sector. A feedback coupling (40,44,49) is present between each monitor (R,D) and the controllable feed means (59,60,61) of the respective antenna sector (62a,62b,62c . . .
    Type: Grant
    Filed: August 28, 1995
    Date of Patent: July 6, 1999
    Assignee: U.S. Philips Corporation
    Inventors: David H. Evans, Ian M. Clarke
  • Patent number: 5901315
    Abstract: A method for debugging a target application comprising Java code having native method dll's associated therewith. The method is carried out in a computer having an operating system, a system debug application programming interface (API), and a Java virtual machine having a Java debug API. According to the method, the Java virtual machine is first launched under the system debug API. The application is then run under the Java virtual machine. Because the Java virtual machine that runs the target application itself runs under the system debug API, simultaneous control of the target application via the system debug API and the Java debug API is enabled. Thus, the method effects the debug of the target application by simultaneously debugging the Java code and the native method dynamic load libraries.
    Type: Grant
    Filed: June 13, 1997
    Date of Patent: May 4, 1999
    Assignee: International Business Machines Corporation
    Inventors: Jonathan W. Edwards, David H. Evans, Michael G. Vassil
  • Patent number: 5754145
    Abstract: A printed antenna comprises an end fed elongate first dipole element (12) provided on one side of a dielectric substate (10). A second dipole element (16, 17) is provided on the opposite side of the dielectric substrate. The second dipole comprises first and second elongate elements (16, 17) disposed one on each side of the longitudinal axis of the first dipole element as viewed through the substrate. A ground plane (14) on the second side of the substrate is connected to the first and second elements (16, 17) at a distance from a free end of the first dipole element corresponding substantially to a quarter wavelength of the frequency (or centre frequency) above interest. The first and second elements (16, 17) are a quarter of a wavelength long and may be inclined relative to the first dipole element (12) or extend parallel thereto (4 (not shown)). Pairs of the printed antennas may be connected with switching elements to form antenna diversity arrangements.
    Type: Grant
    Filed: July 29, 1996
    Date of Patent: May 19, 1998
    Assignee: U.S. Philips Corporation
    Inventor: David H. Evans
  • Patent number: 5386522
    Abstract: The physical memory of a computer may not be directly accessable to the operator during the operation of a program due to the operational requirements of the operating system. Direct access to the physical memory of the computer during such operation may be possible through the aliasing of the physical memory locations and the creation of virtual alias addresses which will then give operator the necessary control to directly access any memory location thereby permitting the debugging of the program.
    Type: Grant
    Filed: December 30, 1991
    Date of Patent: January 31, 1995
    Assignee: International Business Machines, Corp.
    Inventor: David H. Evans
  • Patent number: 5294895
    Abstract: In addition to a first opening (11) forming a primary output from a waveguide cavity (10) of a microwave oscillator, a coupling aperture (12) in a reflective wall (32) provides a secondary output which does not degrade the performance or tuning characteristics of the source. Less than -20 dB of the source power may be coupled out via the aperture (12) and is used in a feed-back loop (12,21,23,24,36) with an harmonic mixer (21) and frequency discriminator (24) to stabilize the source. The mixer comprises a further waveguide section (15) separated from the source cavity (10) by the reflective wall (32). An advantageous mixer assembly comprises a circuit substrate which is mounted across the further waveguide cavity (15) and which carries an inductive probe by which the signal from the coupling aperture (12) is fed to an antiparallel pair of mixer diodes on the substrate. The whole assembly may be bolted together through holes (34).
    Type: Grant
    Filed: September 30, 1992
    Date of Patent: March 15, 1994
    Assignee: U.S. Philips Corporation
    Inventors: Stuart M. Feeney, David H. Evans, Kenneth Holford
  • Patent number: 5280290
    Abstract: A simple self-oscillating mixer circuit is provided, suitable for forming with an antenna (21) the complete front end of an inexpensive short-range FMCW radar. A modulating signal (40), e.g. from a sweep generator (44), is applied to a control terminal (14) to sweep the RF output (R) of the self-oscillating mixer SOM (10). A cancellation circuit (6 to 9) is connected between the control terminal (14) and an IF output line (13) to remove a corresponding modulation (41) which occurs on the IF line (13) and so to generate a substantially demodulated IF output signal (I). Advantageously a grounded-source MESFET in a feed-back network forms the SOM (10) and has the IF output line (13) taken from its gate. In this case the IF modulation (41) is inverted with respect to the modulating signal (40), and so the cancellation is achieved by adding the modulating signal (40) to the modulated IF output signal (41), e.g. via a resistor network 6 to 8.
    Type: Grant
    Filed: October 14, 1992
    Date of Patent: January 18, 1994
    Assignee: U.S. Philips Corporation
    Inventor: David H. Evans
  • Patent number: 5218980
    Abstract: An improved dishwasher system utilizes ultrasonic signals to clean a wide range of kitchen and/or dining ware items. The system includes one or more ultrasonic signal generators submerged within a water bath and regulated by a controller to generate an ultrasonic signal, resulting in the production of a large quantity of cavitation bubbles which implode with a vigorous cleaning action against submerged kitchen ware items. The controller rapidly varies the specific frequency of the generated ultrasonic signal, preferably in conjunction with a rapid on-off pulse cycling of the signal, to prevent damage to or breakage of fragile ware items.
    Type: Grant
    Filed: October 10, 1991
    Date of Patent: June 15, 1993
    Inventor: David H. Evans
  • Patent number: 5211703
    Abstract: A stationary blade of a steam turbine having a rotor and an inner cylinder for mounting the stationary blade in a row with plural identical stationary blades, comprising an airfoil having a leading edge, a trailing edge, a pressure-side concave surface and suction-side convex surface extending between the leading and trailing edges. A stagger angle being defined by as an angle of a chord between the leading and trailing edges to a longitudinal axis of the rotor; an outer ring for connecting a proximal end of the airfoil to the inner cylinder; an inner ring connected to a distal end of the airfoil; and a seal assembly carried by the inner ring and sealingly engaging the rotor; wherein the stagger angle ranges from about 42.degree. at the distal end of the airfoil to about 52.degree. at the proximal end.
    Type: Grant
    Filed: October 24, 1990
    Date of Patent: May 18, 1993
    Assignee: Westinghouse Electric Corp.
    Inventors: Jurek Ferleger, David H. Evans
  • Patent number: 5203673
    Abstract: An apparatus is provided for controlling rotating blade tip clearance in a turbo-machine utilizing conical tipped blades. The apparatus comprises an approximately conical blade ring mounted for axially sliding displacement in the turbo-machine cylinder. The conical blade ring encircles the tips of the rotating blades and forms a blade tip clearance therebetween. The tip clearance is controlled during operation of the turbo-machine by axially displacing the conical blade ring. Piston cylinders, actuated by pressurized fluid extracted from the turbo-machine, are used to displace the blade ring. Springs, adapted to bias the blade ring into a position of increased tip clearance, oppose the piston cylinder so that failure of the piston cylinder will not result in a loss of tip clearance.
    Type: Grant
    Filed: January 21, 1992
    Date of Patent: April 20, 1993
    Assignee: Westinghouse Electric Corp.
    Inventor: David H. Evans
  • Patent number: 5192190
    Abstract: A stationary blade for a steam turbine includes an airfoil portion having an inner diameter end and an outer diameter end; an inner ring portion integrally formed at the inner diameter end of the airfoil portion; and an outer ring portion integrally formed at the outer diameter end of the airfoil portion, the airfoil, inner ring and outer ring portions being envelope forged from a single bar stock, and each blade being welded together with an adjacent, substantially identical blade with welds provided at the inner and outer ring portions, the inner ring portion welds comprising a first, upstream weld and a second, downstream weld which is lower than the upstream weld.
    Type: Grant
    Filed: May 8, 1992
    Date of Patent: March 9, 1993
    Assignee: Westinghouse Electric Corp.
    Inventors: Jurek Ferleger, David H. Evans
  • Patent number: 5161942
    Abstract: A honeycomb seal cooperatively associated with a rotatable blade of a steam turbine having a cylinder, seal include a backing plate fixedly connected to a mounting portion of the cylinder, the mounting portion having an associated moisture removal channel. A plurality of rows of honeycomb cells extend radially inwardly from the backing plate so that each cell is open adjacent said blades. The said backing plate is perforated with at least one perforation for each honeycomb cell for communicating moisture collected in the honeycomb cells to the moisture removal channel of the mounting portion of the cylinder.
    Type: Grant
    Filed: October 24, 1990
    Date of Patent: November 10, 1992
    Assignee: Westinghouse Electric Corp.
    Inventors: Shun Chen, David H. Evans, Manuel I. Llaneras, Ashok T. Patel, George J. Silvestri, Jr.
  • Patent number: 4999587
    Abstract: In a waveguide oscillator, a Gunn diode or other negative-resistance oscillator device (2) has a resonant cap (3) for coupling to the waveguide (1), and a tuning varactor diode (11) is coupled by a probe (13) to the electromagnetic filed in the vicinity of the cap (3). In accordance with the invention, a mechanically simple, compact and cheap oscillator arrangement is obtained by integrating both the varactor diode (11) and the probe (13) in a circuit body (10) mounted in the waveguide (1), preferably in an area below the plane of the cap (3) so as to reduce perturbation of the filed. The probe is formed as a conductive track (13) on the circuit body (10), for example as a transmission line coupling to the electric field and preferably located at the front surface (18) of the body (10) or as a current loop extending on a side wall of the body (10) and coupling to the magnetic field.
    Type: Grant
    Filed: January 3, 1990
    Date of Patent: March 12, 1991
    Assignee: U.S. Philips Corp.
    Inventor: David H. Evans
  • Patent number: 4893126
    Abstract: An integrated millimeter-wave transceiver comprising a substrate on which is provided an annular slot antenna (D) and a balanced mixer (F). Transmitter power is applied to one point of the antenna and the balanced mixer (F) is coupled to a second point of the antenna, the second point being orthogonal to the one point in the plane of the antenna. The coupling of the balanced mixer to the second point is by way of a coplanar waveguide (C). A short circuit (H) in the coplanar waveguide (G) at a quarter wavelength from the mixer prevents an even (asymmetric) mode on the coplanar waveguide from being propagated to the antenna. An IF signal is derived using an RF band stop filter (I).
    Type: Grant
    Filed: September 21, 1988
    Date of Patent: January 9, 1990
    Assignee: U.S. Philips Corporation
    Inventor: David H. Evans
  • Patent number: 4878810
    Abstract: Within a rotor blade row of a steam turbine, rotor blades having one resonant frequency alternate with rotor blades having a second, different resonant frequency. The two different resonant frequencies are achieved by profiling the tips of every other rotor blade.
    Type: Grant
    Filed: May 20, 1988
    Date of Patent: November 7, 1989
    Assignee: Westinghouse Electric Corp.
    Inventor: David H. Evans