Patents by Inventor Siu-Tat Chui

Siu-Tat Chui 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: 10018507
    Abstract: Electromagnetic detectors and methods for manufacturing electromagnetic detectors are described. The electromagnetic detectors include at least one electromagnetic sensor, where each electromagnetic sensor includes a conductive part having a perimeter, a first connection point on the perimeter of the conductive part, a second connection point on the perimeter of the conductive part, a connection point axis extending between the first and the second connection points, a secondary axis perpendicular to the connection point axis extending through a midpoint between the first and second connection points, the secondary axis dividing the conductive part into two portions that are asymmetrical to one another. The electromagnetic detector also includes a voltage detector coupled to the first and the second connection points to detect voltages produced by the conductive part when exposed to electromagnetic waves.
    Type: Grant
    Filed: June 8, 2017
    Date of Patent: July 10, 2018
    Assignee: UNIVERSITY OF DELAWARE
    Inventor: Siu-Tat Chui
  • Publication number: 20180017439
    Abstract: Electromagnetic detectors and methods for manufacturing electromagnetic detectors are described. The electromagnetic detectors include at least one electromagnetic sensor, where each electromagnetic sensor includes a conductive part having a perimeter, a first connection point on the perimeter of the conductive part, a second connection point on the perimeter of the conductive part, a connection point axis extending between the first and the second connection points, a secondary axis perpendicular to the connection point axis extending through a midpoint between the first and second connection points, the secondary axis dividing the conductive part into two portions that are asymmetrical to one another. The electromagnetic detector also includes a voltage detector coupled to the first and the second connection points to detect voltages produced by the conductive part when exposed to electromagnetic waves.
    Type: Application
    Filed: June 8, 2017
    Publication date: January 18, 2018
    Applicant: UNIVERSITY OF DELAWARE
    Inventor: SIU-TAT CHUI
  • Publication number: 20090207651
    Abstract: A method for storing data in a magnetic memory element of an array of elements which avoids inadvertent switching of other elements is disclosed. First and second magnetic fields are applied to a selected magnetic element for a first time interval to switch the element into an intermediate state where minor domains are created. A second value of magnetic fields are then applied large enough to switch the magnetization of the minor domains, but not large enough to switch the magnetization of an adjacent memory cell. Once the minor domain is switched, the magnetization of the magnetic element assumes the state where the major domain has a magnetization direction representing the value of the stored data bit. Reducing the grain size of crystallites contained in a bit reduces the intrinsic anisotropy of the magnetic memory element thus improving bit selectivity.
    Type: Application
    Filed: December 23, 2008
    Publication date: August 20, 2009
    Applicant: University of Delaware
    Inventor: Siu-Tat Chui
  • Publication number: 20080273381
    Abstract: A method for storing data in a magnetic memory element of an array of elements which avoids inadvertent switching of other elements. First and second magnetic fields are applied to a selected magnetic element for a first time interval to switch the element into an intermediate state where minor domains are created. A second value of magnetic fields are then applied large enough to switch the magnetization of the minor domains, but not large enough to switch the magnetization of an adjacent memory cell. Once the minor domain is switched, the magnetization of the magnetic element assumes the state where the major domain has a magnetization direction representing the value of the stored data bit.
    Type: Application
    Filed: March 1, 2006
    Publication date: November 6, 2008
    Inventor: Siu-Tat Chui
  • Patent number: 7362195
    Abstract: A directional R.F. circulator directs radio frequency signals without an external biasing magnetic field. Layers of ferromagnetic materials and insulating materials form a laminated nano-structure. The layers are selected to have a thickness smaller than the wavelength of the radio frequency signals, and smaller than the skin depth of the signals in the material. The ferromagnetic materials and insulators form a resonant cavity having a resonant frequency near the operating frequency for the signal. A plurality of connectors are located around the periphery of the laminated ferromagnetic material to provide input and output ports for the device. This circulator is compatible with semiconductor thin-film processing, and may be integrated onto a monolithic integrated circuit. A method of forming a directional R.F. circulator is also disclosed.
    Type: Grant
    Filed: April 10, 2006
    Date of Patent: April 22, 2008
    Assignee: University of Delaware
    Inventor: Siu-Tat Chui
  • Publication number: 20070263430
    Abstract: A method for storing data in a magnetic memory element of an array of elements which avoids inadvertent switching of other elements is disclosed. First and second magnetic fields are applied to a selected magnetic element for a first time interval to switch the element into an intermediate state where minor domains are created. A second value of magnetic fields are then applied large enough to switch the magnetization of the minor domains, but not large enough to switch the magnetization of an adjacent memory cell. Once the minor domain is switched, the magnetization of the magnetic element assumes the state where the major domain has a magnetization direction representing the value of the stored data bit. Reducing the grain size of crystallites contained in a bit reduces the intrinsic anisotropy of the magnetic memory element thus improving bit selectivity.
    Type: Application
    Filed: May 15, 2007
    Publication date: November 15, 2007
    Inventor: Siu-Tat Chui
  • Publication number: 20060226926
    Abstract: A directional R.F. circulator directs radio frequency signals without an external biasing magnetic field. Layers of ferromagnetic materials and insulating materials form a laminated nano-structure. The layers are selected to have a thickness smaller than the wavelength of the radio frequency signals, and smaller than the skin depth of the signals in the material. The ferromagnetic materials and insulators form a resonant cavity having a resonant frequency near the operating frequency for the signal. A plurality of connectors are located around the periphery of the laminated ferromagnetic material to provide input and output ports for the device. This circulator is compatible with semiconductor thin-film processing, and may be integrated onto a monolithic integrated circuit. A method of forming a directional R.F. circulator is also disclosed.
    Type: Application
    Filed: April 10, 2006
    Publication date: October 12, 2006
    Applicant: UNIVERSITY OF DELAWARE
    Inventor: Siu-Tat Chui
  • Publication number: 20050161630
    Abstract: A left-handed composite material which includes a mixture of a ferromagnetic material and a dielectric material. The direction of magnetization of the ferromagnetic material, and its volume fraction are controlled such that the composite material exhibits negative permeability in a frequency region near the ferromagnetic resonance frequency, and low eddy current losses. Furthermore, the handedness of the material may be locally tuned to be alternately converted into a right-handed material or a left-handed material by application of an external magnetic field, electric field, or mechanical stress. Such materials are easy to make and can be easily scaled up for industrial use.
    Type: Application
    Filed: February 27, 2003
    Publication date: July 28, 2005
    Inventors: Siu-Tat Chui, John Xiao
  • Patent number: 5757056
    Abstract: A double tunnel junction is disclosed that can be used as a magnetic sensor or as random access memories. The preferred embodiment comprises three magnetic metal materials separated by two insulating layers. A current is passed through the first tunnel junction thereby developing a voltage in the second junction. The resistance of this device can be changed over a 100% when an external magnetic field of just a few gauss is applied.
    Type: Grant
    Filed: November 12, 1996
    Date of Patent: May 26, 1998
    Assignee: University of Delaware
    Inventor: Siu-Tat Chui