Patents by Inventor David Ki Wai Cheng

David Ki Wai Cheng 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).

  • Chipless microwave identification tag
    Patent number: 8274368
    Abstract: A chipless microwave identification tag (200) comprising: a dielectric substrate (210); and a plurality of antenna elements (220) made from a conductive material and disposed on at least one surface (205, 255) of the dielectric substrate (210); wherein when the tag (200) is excited by an incident microwave signal (131), a reflected wave (141) to identify the tag (200) is generated with a number of specific frequencies altered by microwave resonation of the antenna elements (220).
    Type: Grant
    Filed: March 2, 2009
    Date of Patent: September 25, 2012
    Assignee: The Hong Kong Polytechnic University
    Inventors: Kai Leung Yung, Ching Yuen Chan, David Ki Wai Cheng
  • CHIPLESS MICROWAVE IDENTIFICATION TAG
    Publication number: 20090267739
    Abstract: A chipless microwave identification tag (200) comprising: a dielectric substrate (210); and a plurality of antenna elements (220) made from a conductive material and disposed on at least one surface (205, 255) of the dielectric substrate (210); wherein when the tag (200) is excited by an incident microwave signal (131), a reflected wave (141) to identify the tag (200) is generated with a number of specific frequencies altered by microwave resonation of the antenna elements (220).
    Type: Application
    Filed: March 2, 2009
    Publication date: October 29, 2009
    Applicant: The Hong Kong Polytechnic University
    Inventors: Kai Leung Yung, Ching Yuen Chan, David Ki Wai Cheng
  • Core having magnetic properties
    Patent number: 7381483
    Abstract: A magnetic core is made of a composite magnetic material having a relative permeability of between 1 and 29 at a frequency range from 20 kHz to 2.5 MHz. The composite magnetic material consists of cobalt and nickel particles having an average diameter in the range of 1 to 100 micrometers, and a polymer base binding the particles to form a core.
    Type: Grant
    Filed: October 27, 2004
    Date of Patent: June 3, 2008
    Assignee: The Hong Kong Polytechnic University
    Inventors: Ka Wai Eric Cheng, Chak Yin Tang, David Ki Wai Cheng, Hang Wu
  • Composite magnetic material
    Publication number: 20030235705
    Abstract: A compound for a composite magnetic material having low permeability and low loss magnetic properties includes a polymer resin bonding agent and a filler comprising one or more ferromagnetic materials. The ferromagnetic materials are Cobalt and Nickel particles having an average diameter of less than 100 micrometers. The particles are coated with a titanic coupling agent to facilitate disbursement through the resin and increase the bond strengthen between the particles and the resin.
    Type: Application
    Filed: June 24, 2002
    Publication date: December 25, 2003
    Applicant: The Hong Kong Polytechnic University
    Inventors: Ka Wai Eric Cheng, Chak Yin Tang, David Ki-Wai Cheng, Hang Wu