Patents by Inventor Leo Li

Leo Li 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).

  • Patent number: 7479404
    Abstract: The invention provides sensor compositions and method of making sensors.
    Type: Grant
    Filed: July 8, 2005
    Date of Patent: January 20, 2009
    Assignee: The Board of Trustees of the University of Illinois
    Inventors: Brian T. Cunningham, Ian Block, Leo Li-Ying Chan
  • Publication number: 20060235805
    Abstract: A universal system with a unique process is presented to validate the authenticity of a merchandise item using the manufacturer's digital signature embedded in a RFID/smart card tag that is mounted with a merchandise item. This system consists of only the tag reader and the tag and doesn't require complicated mounting methods. New process and methods are devised to allow manufacturers to make and deploy the tags with its own digital signature, and enable buyers not only to validate the authenticity of a merchandise item easily and reliably, but also to check the authenticity of the tag reader itself before the first use.
    Type: Application
    Filed: April 13, 2005
    Publication date: October 19, 2006
    Inventors: Feng Peng, Leo Li, XUJUN LIANG
  • Patent number: 6766178
    Abstract: A multi-band RF architecture including a GSM quadrature modulator for modulating an intermediate frequency (IF) wherein the frequency of the modulated IF signal is changed such that each of the GSM, DCS 1800, and PCS 1900 bands have a respective IF. An intermediate frequency (IF) filter with a pass band that covers the GSM IF, the DCS 1800 IF, and the PCS 1900 IF is connected to the output of the modulator and outputs to a transmit phase lock loop, which translates the IF signal from the IF filter to either a GSM band radio frequency signal, a DCS 1800 band radio frequency signal, or a PCS 1900 band radio frequency signal, depending on the frequency of a local oscillator (LO). The receiver employs a down converter which provides a down converted output signal selected by high side injection for the GSM band an by low side injection for the DCS 1800 and PCS 1900 bands.
    Type: Grant
    Filed: August 31, 1999
    Date of Patent: July 20, 2004
    Assignee: Skyworks Solutions, Inc.
    Inventors: Morten Damgaard, Leo Li
  • Patent number: 6208875
    Abstract: A dual band RF architecture including a GSM quadrature modulator for modulating an intermediate frequency (IF) wherein the frequency of the modulated IF signal is changed such that one IF is used for the GSM band and another IF is used for the DCS 1800 band. An intermediate frequency (IF) filter with a pass band that covers both the GSM IF and the DCS 1800 IF is connected to the output of the modulator and outputs to a transmit phase lock loop, which translates the IF signal from the IF filter to either a DCS 1800 band radio frequency signal or a GSM band radio frequency signal, depending on the frequency of a local oscillator (LO). The receiver employs a down converter which provides a down converted output signal selected by high side injection for the GSM band an by low side injection for the DCS 1800 band.
    Type: Grant
    Filed: April 8, 1998
    Date of Patent: March 27, 2001
    Assignee: Conexant Systems, Inc.
    Inventors: Morten Damgaard, Leo Li
  • Patent number: 6005443
    Abstract: A frequency synthesizer for generating two or more output frequency ranges using a Phase Locked Loop (PLL) circuit having a single voltage-controlled oscillator (VCO). In a first embodiment, a frequency multiplier is connected to the output of the VCO. The output of the VCO and the output of the frequency multiplier are selectably fed back, depending upon which output frequency is desired. The output frequency may be taken directly from the VCO or the frequency multiplier. When the output frequency is taken from the output of the frequency multiplier, a control signal adjusts the gain of the phase detector and/or loop filter in order to compensate for the loop gain caused by the frequency multiplier. In a second embodiment, instead of adjusting the phase detector and/or loop filter gain, the values of the N and M dividers are adjusted. In a third embodiment, a frequency multiplier is connected to the output of the VCO and multiplies the output by a predetermined multiplier value.
    Type: Grant
    Filed: March 19, 1998
    Date of Patent: December 21, 1999
    Assignee: Conexant Systems, Inc.
    Inventors: Morten Damgaard, Leo Li
  • Patent number: 5915212
    Abstract: The present invention provides increased geographical coverage and system capacity for mobile/portable radio transceivers using adjacent and typically separate radio communication frequency bands. A radio that transceives in just one frequency band is adapted to provide a configurable duplexing arrangement to permit communications in extended frequency bands. Duplexing circuitry is connected between the radio antenna and the radio transmitter and receiver. Depending upon the mode of operation of the radio transceiver, switches are selectively operated for variously configuring the antenna, duplexer circuitry, receiver, and transmitter to permit communications in a first or a second set of transmit/receive frequency bands. In one preferred example embodiment, only a single duplexer is employed connected to the antenna and transceiving circuitry through plural switches.
    Type: Grant
    Filed: August 29, 1996
    Date of Patent: June 22, 1999
    Assignee: Ericsson Inc.
    Inventors: Thomas A. Przelomiec, Leo Li, John R. Lane, Brian D. Justin, Seyed Tabaian, John R. Rowland, Robert Blaser