Patents by Inventor Keith Barnes

Keith Barnes 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: 20080051390
    Abstract: The present invention provides a compound of formula I and the use thereof for the therapeutic treatment, prevention or amelioration of a disease or disorder characterized by elevated ?-amyloid deposits or ?-amyloid levels in a patient.
    Type: Application
    Filed: August 16, 2007
    Publication date: February 28, 2008
    Applicant: Wyeth
    Inventors: Michael Malamas, Keith Barnes, Matthew Johnson
  • Patent number: 7280002
    Abstract: A method and apparatus is presented for generating a reference voltage that biases a metal-oxide-semiconductor (MOS) transistor used as a varactor in capacitive tuning applications. In one embodiment, a biasing circuit is implemented. The biasing circuit comprises a diode-clamped FET and an element coupled to the diode-clamped FET at a connection point. The element produces a constant current through the diode-clamped FET. A voltage is produced at the connection point. The voltage is one gate overdrive plus a threshold voltage above ground or one gate overdrive plus a threshold voltage below VDD. Establishing a threshold voltage in this way enables the biasing circuit to track an ideal voltage of a varactor that is coupled to the biasing circuit through the threshold voltage.
    Type: Grant
    Filed: March 3, 2005
    Date of Patent: October 9, 2007
    Assignee: Avago Technologies General IP Pte Ltd
    Inventors: Alvin Leng Sun Loke, Tin Tin Wee, Robert Keith Barnes, Kari Lee Arave, Thomas Edward Cynkar, James Ruhl Pfiester
  • Patent number: 7277518
    Abstract: A phase-locked loop includes a voltage-controlled oscillator and a charge-pump loop filter. The voltage-controlled oscillator includes a varactor having a first set of capacitor cells configured to adjust a capacitance based on a first control voltage, and a second set of capacitor cells configured to adjust a capacitance based on a second control voltage. The charge-pump loop filter receives a first and a second update signal, each having at least one state based on a phase difference between a first clock and a second clock, and comprises a first component and a second component. The first component is configured to adjust, during an update period, a voltage across an impedance from a reference level based on the states of the first and second update signals and to return the voltage across the impedance to the reference level prior to an end of the update period, wherein the voltage across the impedance comprises the first control voltage.
    Type: Grant
    Filed: November 20, 2003
    Date of Patent: October 2, 2007
    Assignee: Avago Technologies General IP (Singapore) Pte. Ltd.
    Inventors: Alvin Leng Sun Loke, James Oliver Barnes, Robert Keith Barnes, Michael M. Oshima, Ronald Ray Kennedy, Charles E. Moore
  • Patent number: 7274764
    Abstract: In one embodiment, the present invention provides a phase-locked loop comprising a charge-pump loop filter and a phase detector system. The charge-pump loop filter is configured to provide a control voltage having a voltage level based on a state of a first control signal and on a state of a second control signal. The phase detector system is configured to receive a first clock, a second clock, and a control signal defining a plurality of states including a first state and a second state. The phase detector system is further configured to provide the first control signal and the second control signal each having a state based on a phase difference between the first and second clocks when the control signal has the first state, and to provide the first control signal and second control signal each having a state asynchronously controlled by the control signal when the control signal has the second state.
    Type: Grant
    Filed: November 20, 2003
    Date of Patent: September 25, 2007
    Assignee: Avago Technologies General IP (Singapore) Pte. Ltd
    Inventors: Alvin Leng Sun Loke, Robert Keith Barnes, James Oliver Barnes
  • Publication number: 20050282826
    Abstract: The present invention provides a compound of formula I and the use thereof for the therapeutic treatment, prevention or amelioration of a disease or disorder characterized by elevated ?-amyloid deposits or ?-amyloid levels in a patient.
    Type: Application
    Filed: June 15, 2005
    Publication date: December 22, 2005
    Applicant: Wyeth
    Inventors: Michael Malamas, James Erdei, Iwan Gunawan, Keith Barnes, Matthew Johnson, Yu Hui
  • Patent number: 6975176
    Abstract: In one embodiment, the present invention provides a system including a varactor and a voltage generator. The varactor includes a set of substantially equal voltage-tunable capacitor cells, each having a capacitive range that varies with a first plurality of operating parameters and each providing a capacitance within the range based on a voltage level of a reference voltage. The voltage generator is configured to provide the reference voltage, wherein the voltage level of the reference voltage corresponds to a desired capacitance within the capacitive range and varies based on a second plurality of operating parameters which are substantially the same as the first plurality of operating parameters, and wherein the voltage level of the reference voltage causes each capacitor cell to provide the desired capacitance.
    Type: Grant
    Filed: November 20, 2003
    Date of Patent: December 13, 2005
    Assignee: Agilent Technologies, Inc.
    Inventors: Alvin Leng Sun Loke, Robert Keith Barnes
  • Publication number: 20050195908
    Abstract: A wireless communication system is configured for adaptive modulation of a transmitted symbol. The specific modulation and/or coding is uniquely identified and data related thereto is embedded within the transmitted symbol. A receiver extracts pilot signals form the transmitted symbol and performs a correlation analysis to identify the particular modulation/coding used for that particular transmitted symbol. This permits adaptive modulation on a symbol-by-symbol basis. A base station communicating with a plurality of peripheral subscribers may utilize different modulation/coding for each subscriber depending on channel conditions.
    Type: Application
    Filed: March 4, 2005
    Publication date: September 8, 2005
    Applicant: NextNet Wireless, Inc.
    Inventors: J. Dunn, Mervin Grindahl, Keith Barnes
  • Publication number: 20050186956
    Abstract: A fixed wireless access system generally comprises a consumer premise equipment (CPE) unit, that is connected via an Ethernet interface to a personal computer or local area network, and a base station unit that is connected via an Ethernet interface to a network. As such, the CPE unit is preferably easily user-installed while the base station unit is preferably tower-mounted within a 1-5 mile range of the CPE unit. Both the CPE unit and base station unit preferably incorporate an integrated data transceiver/switch that enables a radio frequency air link operating in the 2.5-2.686 GHz range. Orthogonal frequency division multiplexing is used in the uplink and downlink transmissions between CPE units and base station units.
    Type: Application
    Filed: April 1, 2005
    Publication date: August 25, 2005
    Applicant: NextNet Wireless, Inc.
    Inventors: Mervin Grindahl, Vladimir Kelman, J. Dunn, Stuart Froelich, Keith Barnes
  • Publication number: 20050176378
    Abstract: A fixed wireless access system generally comprises a consumer premise equipment (CPE) unit, that is connected via an Ethernet interface to a personal computer or local area network, and a base station unit that is connected via an Ethernet interface to a network. As such, the CPE unit is preferably easily user-installed while the base station unit is preferably tower-mounted within a 1-5 mile range of the CPE unit. Both the CPE unit and base station unit preferably incorporate an integrated data transceiver/switch that enables a radio frequency air link operating in the 2.5-2.686 GHz range. Orthogonal frequency division multiplexing is used in the uplink and downlink transmissions between CPE units and base station units.
    Type: Application
    Filed: April 1, 2005
    Publication date: August 11, 2005
    Applicant: NextNet Wireless, Inc.
    Inventors: Mervin Grindahl, Vladimir Kelman, J. Dunn, Stuart Froelich, Keith Barnes
  • Publication number: 20050176379
    Abstract: A fixed wireless access system generally comprises a consumer premise equipment (CPE) unit, that is connected via an Ethernet interface to a personal computer or local area network, and a base station unit that is connected via an Ethernet interface to a network. As such, the CPE unit is preferably easily user-installed while the base station unit is preferably tower-mounted within a 1-5 mile range of the CPE unit. Both the CPE unit and base station unit preferably incorporate an integrated data transceiver/switch that enables a radio frequency air link operating in the 2.5-2.686 GHz range. Orthogonal frequency division multiplexing is used in the uplink and downlink transmissions between CPE units and base station units.
    Type: Application
    Filed: April 1, 2005
    Publication date: August 11, 2005
    Applicant: NextNet Wireless, Inc.
    Inventors: Mervin Grindahl, Vladimir Kelman, J. Dunn, Stuart Froelich, Keith Barnes
  • Publication number: 20050171995
    Abstract: A fixed wireless access system generally comprises a consumer premise equipment (CPE) unit, that is connected via an Ethernet interface to a personal computer or local area network, and a base station unit that is connected via an Ethernet interface to a network. As such, the CPE unit is preferably easily user-installed while the base station unit is preferably tower-mounted within a 1-5 mile range of the CPE unit. Both the CPE unit and base station unit preferably incorporate an integrated data transceiver/switch that enables a radio frequency air link operating in the 2.5-2.686 GHz range. Orthogonal frequency division multiplexing is used in the uplink and downlink transmissions between CPE units and base station units.
    Type: Application
    Filed: April 1, 2005
    Publication date: August 4, 2005
    Applicant: NextNet Wireless, Inc.
    Inventors: Mervin Grindahl, Vladimir Kelman, J. Dunn, Stuart Froelich, Keith Barnes
  • Publication number: 20050049146
    Abstract: A composition comprising a) compounds of formula (I) wherein A-B denotes C—C or C?C; X is S, O, SO, SO2, NRa, or CRbRc; R1, R2 are H, halogen, OH, SH, NH2, CN, NO2, alkyl, alkoxy, alkylamino, dialkylamino, alkylthio, alkenyl, alkenyloxy, alkenylamino, alkenylthio, alkynyl, alkynyloxy, alkynylamino, alkynylthio, alkylsulfonyl, alkylsulfoxyl, alkenylsulfonyl, alkynylsulfoxyl, formyl, alkylcarbonyl, hydroxycarbonyl, alkoxycarbonyl, carbonyloxy, alkylcarbonyloxy, phenyloxy, C(O)NRdRe, (SO2)nNRdRe, or C(?NORf)-?p-Rf?, a mono- or bicyclic 5- to 10-membered aromatic ringsystem, a 5- to 10-membered heteroaromatic ring system, or cycloalkyl, each optionally substituted, which is unfused or fused to the aromatic group to which it is bonded and which, when unfused, is bonded directly or through an O, S, alkyl, or alkoxy linkage; R3, R4 are each independently H, alkyl, haloalkyl, alkylamine, alkoxy, cycloalkyl, wherein the carbon atoms in these aliphatic groups may be substituted, or R3 and R4 together with the n
    Type: Application
    Filed: November 2, 2002
    Publication date: March 3, 2005
    Inventors: John Chiarello, William Wood, Deborah Culbertson, Daniel Smith, Robin Sperry, Thomas Schmidt, Gerd Steiner, Markus Kordes, Wolfgang Deyn, Norbert Gotz, Michael Hofmann, Keith Barnes, James Takasugi, Michael Treacy, Hassan Oloumi-sadeghi, Robert Diehl
  • Patent number: 5705116
    Abstract: Polymer precursor formulations suitable for stereolithography may be prepared from compositions containing vinyl ether functionalized compounds and epoxy functionalized compounds plus an effective mount of a cationic photoinitiator and an ultraviolet light-absorbing compound to provide a predetermined depth of cure. Preferably, the ultraviolet light-absorbing compound is anthracene or its derivatives. Anthracenes having pendant alkoxy groups are preferred for use with light wavelengths greater than 360 nm, particularly 9,10-dimethoxy-2-ethyl anthracene.
    Type: Grant
    Filed: June 21, 1995
    Date of Patent: January 6, 1998
    Inventors: Eugene Valentine Sitzmann, Russell Frank Anderson, Darryl Keith Barnes, Ashwin B. Patel
  • Patent number: 4661921
    Abstract: Debugging and development of hardware and software for microprocessors make desirable use of commercially available logic analyzers and in circuit emulators. The probes of the former have heretofore comprised clips which have been clipped onto exposed contacts on the plug of an emulator probe, the pins of which have been fitted into sockets in a printed circuit board or the like to replace a removed microprocessor. The foregoing step has been difficult (in part because of space limitations when as many as 64 clips have been required), time consuming and subject to possible error. A combination plug socket is provided in accordance with this invention. The pins of the plug side of the latter fit into the socket in the board and are connected to wires leading to the logic analyzer with a buffer resistor network interposed. The pins of the plug of the emulator fit into the socket side of the plug/socket.
    Type: Grant
    Filed: April 23, 1984
    Date of Patent: April 28, 1987
    Assignee: Kontron Electronics, Inc.
    Inventor: Keith Barnes