Patents by Inventor David A. Chavez

David A. Chavez 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: 20040030107
    Abstract: The present invention generally relates to novel processes for protein purification in high salt solutions such as cell culture broth by increasing the dynamic binding capacity of a resin with the addition of polyethylene glycol.
    Type: Application
    Filed: November 12, 2002
    Publication date: February 12, 2004
    Inventors: Min Wan, Mark David Chavez, Jeffrey Lee Schrimsher
  • Patent number: 6549772
    Abstract: A multiple antenna cellular network communicates with a mobile station over a plurality of antennas. The antennas are arranged in a plurality of positions to customize a cell or cells. A transceiver is coupled to the antennas and configured to receive inbound information from the mobile station and transmit outbound information to the mobile station. A processor is coupled to the transceiver and configured to decode the inbound information and to encode the outbound information to communicate with the mobile station. In another embodiment, the transmit signal power is continuously modified to move interference nulls to improve quality so that a fixed location user can receive a high quality signal. Exemplary embodiments are provided for use with the Global Systems for Mobile Communication (GSM) protocol and can be applied to other digital technologies.
    Type: Grant
    Filed: May 30, 2000
    Date of Patent: April 15, 2003
    Assignee: Interwave Communications International Ltd.
    Inventors: David A. Chavez, Ian L. Sayers, Gerald F. Sage
  • Patent number: 6078823
    Abstract: A multiple antenna cellular network communicates with a mobile station over a plurality of antennas. The antennas are arranged in a plurality of positions to customize a cell or cells. A transceiver is coupled to the antennas and configured to receive inbound information from the mobile station and transmit outbound information to the mobile station. A processor is coupled to the transceiver and configured to decode the inbound information and to encode the outbound information to communicate with the mobile station. In another embodiment, the antennas are similarly deployed to create a cell or cells. The transmit signal power is continuously modified to improve quality and to move the nulls so that a fixed location user can receive a high quality signal. Exemplary embodiments are provided for use with the Global Systems for Mobile Communication (GSM) protocol and can be applied to other digital technologies.
    Type: Grant
    Filed: January 3, 1996
    Date of Patent: June 20, 2000
    Assignee: Interwave Communications International Ltd.
    Inventors: David A. Chavez, Ian L. Sayers, Gerald F. Sage
  • Patent number: 6070071
    Abstract: A multiple antenna cellular network communicates with a mobile station over a plurality of antennas. The antennas are arranged in a plurality of positions to customize a cell or cells. A transceiver is coupled to the antennas and configured to receive inbound information from the mobile station and transmit outbound information to the mobile station. A processor is coupled to the transceiver and configured to decode the inbound information and to encode the outbound information to communicate with the mobile station. In another embodiment, the transmit signal power is continuously modified to move interference nulls to improve quality so that a fixed location user can receive a high quality signal. Exemplary embodiments are provided for use with the Global Systems for Mobile Communication (GSM) protocol and can be applied to other digital technologies.
    Type: Grant
    Filed: November 12, 1996
    Date of Patent: May 30, 2000
    Assignee: InterWAVE Communications International Ltd.
    Inventors: David A. Chavez, Ian L. Sayers, Gerald F. Sage
  • Patent number: 5374919
    Abstract: A method and apparatus are provided for carrying and accessing multiple safety devices, wherein the removal of one safety device simultaneously activates a second safety device. The method includes removing a chemical spray canister secured to a pack body, wherein an activation cord pulls an alarm pin thereby activating an audible alarm. The apparatus includes a spray canister and an audible alarm attached to a pack body, the canister and alarm being concealed by a cover. The cover is attached to the pack body with multiple slide fasteners. The cover has attached thereto a rip cord, so that when the rip cord is pulled by the user, the cover is partially or completely removed to expose the spray canister and the alarm; the spray canister and the alarm are interconnected by a cord so that removal of the spray canister simultaneously activates the audible alarm.
    Type: Grant
    Filed: December 27, 1993
    Date of Patent: December 20, 1994
    Inventors: Sean R. Zelka, David A. Chavez