Patents by Inventor Atsushi Sanada

Atsushi Sanada 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: 8780010
    Abstract: A metamaterial including at least one spiral conductor. Only a magnetic permeability selected from among an effective dielectric constant and the magnetic permeability of the metamaterial becomes negative, so that the metamaterial have a negative refractive index characteristic. The material includes a plurality of unit cells arrayed in one of one-dimensional direction, two-dimensional directions, and three-dimensional directions. Each of the unit cells includes a dielectric substrate having first and second surfaces disposed in a substantially parallel relationship, and first and second spiral conductors. The first spiral conductor is formed on the first surface of the dielectric substrate, and the second spiral conductor is formed in one of a same direction as and an opposite direction to the first spiral conductor, on the second surface of the dielectric substrate, to oppose the first spiral conductor and to be electromagnetically coupled with the first spiral conductor.
    Type: Grant
    Filed: August 30, 2011
    Date of Patent: July 15, 2014
    Assignee: Semiconductor Technology Academic Research Center
    Inventor: Atsushi Sanada
  • Publication number: 20130017348
    Abstract: An invisible enclosure includes a cylindrical central enclosure having a cavity formed therein and an outer shell formed of homogenous materials, with an object in the cavity and the central enclosure itself being substantially invisible with an electromagnetic wave. The central enclosure is formed by laminating a large number of cylindrical layered films formed by radially laminating a plurality of materials having different permittivities. Effective values of respective permittivities of respective parts of the central enclosure are adjusted by adjusting permittivities and radial thicknesses of respective layers of the layered films along a radius value of the central enclosure. The radial element of a permittivity tensor is set to be a value sequentially increasing along a radius from the innermost circumference of the central enclosure to the outermost circumference thereof and is set to be a predetermined value smaller than the permittivity of the outer shell at the outermost circumference.
    Type: Application
    Filed: March 24, 2011
    Publication date: January 17, 2013
    Applicant: YAMAGUCHI UNIVERSITY
    Inventor: Atsushi Sanada
  • Publication number: 20120212395
    Abstract: A metamaterial includes at least one spiral conductor. Only a magnetic permeability selected from among an effective dielectric constant and the magnetic permeability of the metamaterial becomes negative, so that the metamaterial have a negative refractive index characteristic. The material includes a plurality of unit cells arrayed in one of one-dimensional direction, two-dimensional directions, and three-dimensional directions. Each of the unit cells includes a dielectric substrate having first and second surfaces in substantial parallel, and first and second spiral conductors. The first spiral conductor formed on the first surface of the dielectric substrate, and the second spiral conductor formed in one of a same direction as and an opposite direction to the first spiral conductor, on the second surface of the dielectric substrate, to oppose the first spiral conductor and to be electromagnetically coupled with the first spiral conductor.
    Type: Application
    Filed: August 30, 2011
    Publication date: August 23, 2012
    Inventor: Atsushi SANADA
  • Patent number: 8198953
    Abstract: A two-dimensional left-handed metamaterial that functions as a two-dimensional electromagnetic wave propagation medium in which the equivalent permittivity and permeability of the medium are both negative, exhibits superior low-loss, broadband characteristics as a left-handed material, and has a simple constitution, enabling low-cost manufacture.
    Type: Grant
    Filed: September 18, 2007
    Date of Patent: June 12, 2012
    Assignee: Yamaguchi University
    Inventor: Atsushi Sanada
  • Patent number: 8125717
    Abstract: A three-dimensional left-handed metamaterial having a completely new constitution, which functions as a three-dimensional electromagnetic wave propagation medium and in which an equivalent permittivity and a permeability of the medium simultaneously take negative values. The three-dimensional left-handed metamaterial is structured such that cubic unit cells 5 are disposed repeatedly in three orthogonal directions of a three-dimensional space, and includes: a first particle 1 constituted by a conductor and disposed in positions centering on respective vertices of the unit cell; a second particle 2 constituted by a conductor and disposed in positions centering on face center points, which are centers of respective faces of the unit cell; a first connecting portion constituted by a conductor, which connects the first particles to a center point of the unit cell; and a second connecting portion constituted by a conductor, which connects the second particles to the center point.
    Type: Grant
    Filed: March 14, 2008
    Date of Patent: February 28, 2012
    Assignee: Yamaguchi University
    Inventor: Atsushi Sanada
  • Patent number: 8026854
    Abstract: The present invention provides a sripline-type transmission line which can easily change and control transmission characteristics by changing the permittivity of a substrate, and also provides an antenna that can extensively change and control the direction of radiation with the frequency of an electromagnetic wave constant, by using this transmission line.
    Type: Grant
    Filed: June 27, 2007
    Date of Patent: September 27, 2011
    Assignee: Yamaguchi University
    Inventor: Atsushi Sanada
  • Patent number: 7864114
    Abstract: Each of unit cells constituting a negative permeability medium includes a metal patch formed on a surface of a dielectric substrate. The dielectric substrate has a rear surface having a ground conductor formed on its entire surface. A positive permeability medium is an existing micro strip line and each of unit cells has a two-dimensional structure having a metal strip connected in four directions. The dielectric substrate has a rear surface having a ground conductor formed on its entire surface. The negative permeability medium is arranged at the left side adjacent to the positive permeability medium formed by unit cells arranged at the right side so that the media oppose to each other. A waveguide formed by the positive/negative permittivity medium or the positive/negative permeability medium of the meta material for propagation of a surface wave is formed at the boundary of the two media.
    Type: Grant
    Filed: February 27, 2006
    Date of Patent: January 4, 2011
    Assignee: National University Corporation Yamaguchi University
    Inventor: Atsushi Sanada
  • Publication number: 20100118412
    Abstract: A three-dimensional left-handed metamaterial having a completely new constitution, which functions as a three-dimensional electromagnetic wave propagation medium and in which an equivalent permittivity and a permeability of the medium simultaneously take negative values. The three-dimensional left-handed metamaterial is structured such that cubic unit cells 5 are disposed repeatedly in three orthogonal directions of a three-dimensional space, and includes: a first particle 1 constituted by a conductor and disposed in positions centering on respective vertices of the unit cell; a second particle 2 constituted by a conductor and disposed in positions centering on face center points, which are centers of respective faces of the unit cell; a first connecting portion constituted by a conductor, which connects the first particles to a center point of the unit cell; and a second connecting portion constituted by a conductor, which connects the second particles to the center point.
    Type: Application
    Filed: March 14, 2008
    Publication date: May 13, 2010
    Applicant: YAMAGUCHI UNIVERSITY
    Inventor: Atsushi Sanada
  • Patent number: 7696951
    Abstract: A two-dimensional structure medium comprising a conductor pattern as unit cells formed on the upper surface of a substrate and a conductor pattern formed on the lower surface of the substrate and exhibiting a left-handed characteristic achieved without using a via by utilizing the interaction between an inductance component formed by connecting a part of a floating island pattern out of the conductor pattern on the lower surface of the substrate with a pattern as the ground portion and a capacitance component of parallel-plate mode formed by the conductor pattern on the upper surface of the substrate and the conductor pattern on the lower surface of the substrate.
    Type: Grant
    Filed: February 27, 2006
    Date of Patent: April 13, 2010
    Assignee: National University Corporation Yamaguchi University
    Inventor: Atsushi Sanada
  • Publication number: 20100007436
    Abstract: The present invention provides a two-dimensional left-handed metamaterial that functions as a two-dimensional electromagnetic wave propagation medium in which the equivalent permittivity and permeability of the medium are both negative, exhibits superior low-loss, broadband characteristics as a left-handed material, and has a simple constitution, enabling low-cost manufacture. The two-dimensional left-handed metamaterial is formed by disposing unit structures 10 constituted by a conductor regularly on a plane, the unit structure including: a columnar first prism, a central axis of which is oriented perpendicularly to the plane; a columnar second prism that has a central axis in an identical direction to the first prism and is disposed at a remove from the first prism in a central axis direction; and a connecting body for electrically connecting the first prism and the second prism to each other.
    Type: Application
    Filed: September 18, 2007
    Publication date: January 14, 2010
    Applicant: YAMAGUCHI UNIVERSITY
    Inventor: Atsushi Sanada
  • Publication number: 20090179823
    Abstract: A two-dimensional structure medium comprising a conductor pattern as unit cells formed on the upper surface of a substrate and a conductor pattern formed on the lower surface of the substrate and exhibiting a left-handed characteristic achieved without using a via by utilizing the interaction between an inductance component formed by connecting a part of a floating island pattern out of the conductor pattern on the lower surface of the substrate with a pattern as the ground portion and a capacitance component of parallel-plate mode formed by the conductor pattern on the upper surface of the substrate and the conductor pattern on the lower surface of the substrate.
    Type: Application
    Filed: February 27, 2006
    Publication date: July 16, 2009
    Inventor: Atsushi Sanada
  • Publication number: 20090174609
    Abstract: A stripline-type transmission line can easily change and control transmission characteristics by changing the permittivity of a substrate, and also provides an antenna that can extensively change and control the direction of radiation with the frequency of an electromagnetic wave constant, by using the transmission line. The antenna has a substrate having a material With variable permittivity; a plurality of conductor patterns, which are periodically arranged in an intermediate plane of the substrate; an aperture-equipped ground conductor, which is disposed on a surface of the substrate, and in which a plurality of apertures are disposed; a ground conductor disposed on the rear surface of the substrate; and a permittivity controller for changing and controlling the permittivity of the variable permittivity material by applying a direct current voltage to the aperture-equipped ground conductor and the ground conductor.
    Type: Application
    Filed: June 27, 2007
    Publication date: July 9, 2009
    Applicant: YAMAGUCHI UNIVERSITY
    Inventor: Atsushi Sanada
  • Publication number: 20090033586
    Abstract: Each of unit cells constituting a negative permeability medium includes a metal patch formed on a surface of a dielectric substrate. The dielectric substrate has a rear surface having a ground conductor formed on its entire surface. A positive permeability medium is an existing micro strip line and each of unit cells has a two-dimensional structure having a metal strip connected in four directions. The dielectric substrate has a rear surface having a ground conductor formed on its entire surface. The negative permeability medium is arranged at the left side adjacent to the positive permeability medium formed by unit cells arranged at the right side so that the media oppose to each other. A waveguide formed by the positive/negative permittivity medium or the positive/negative permeability medium of the meta material for propagation of a surface wave is formed at the boundary of the two media.
    Type: Application
    Filed: February 27, 2006
    Publication date: February 5, 2009
    Inventor: Atsushi Sanada
  • Patent number: 7391288
    Abstract: A high frequency resonator circuit and method of fabrication is described which has a resonant frequency independent of physical resonator dimensions. The resonator operates in a zeroeth-order mode on a composite right/left-handed (CRLH) transmission line (TL). The LH wave properties of the CRLH-TL contributing anti-parallel phase and group velocities. In one variation, the unit cells are formed from microstrip techniques, preferably creating alternating interdigitated capacitors and stub inductors. The resonant wavelength of the resonator is dependent on the electrical characteristics of the unit cells and not the physical size of the resonator in relation to the desired resonant wavelength. The resonator is created with at least 1.5 unit cells and the Q of the resonator is substantially independent of the number of unit cells utilized. The resonator circuit is particularly well suited for reducing resonator size, and allows resonators of various wavelengths to be fabricated within a fixed board area.
    Type: Grant
    Filed: April 18, 2007
    Date of Patent: June 24, 2008
    Assignee: The Regents of the University of California
    Inventors: Tatsuo Itoh, Atsushi Sanada, Christophe Caloz
  • Patent number: 7330090
    Abstract: A high frequency resonator circuit and method of fabrication is described which has a resonant frequency independent of physical resonator dimensions. The resonator operates in a zeroeth-order mode on a composite right/left-handed (CRLH) transmission line (TL). The LH wave properties of the CRLH-TL contributing anti-parallel phase and group velocities. In one variation, the unit cells are formed from microstrip techniques, preferably creating alternating interdigitated capacitors and stub inductors. The resonant wavelength of the resonator is dependent on the electrical characteristics of the unit cells and not the physical size of the resonator in relation to the desired resonant wavelength. The resonator is created with at least 1.5 unit cells and the Q of the resonator is substantially independent of the number of unit cells utilized. The resonator circuit is particularly well suited for reducing resonator size, and allows resonators of various wavelengths to be fabricated within a fixed board area.
    Type: Grant
    Filed: March 28, 2005
    Date of Patent: February 12, 2008
    Assignee: The Regents of the University of California
    Inventors: Tatsuo Itoh, Atsushi Sanada, Christophe Caloz
  • Publication number: 20060066422
    Abstract: A high frequency resonator circuit and method of fabrication is described which has a resonant frequency independent of physical resonator dimensions. The resonator operates in a zeroeth-order mode on a composite right/left-handed (CRLH) transmission line (TL). The LH wave properties of the CRLH-TL contributing anti-parallel phase and group velocities. In one variation, the unit cells are formed from microstrip techniques, preferably creating alternating interdigitated capacitors and stub inductors. The resonant wavelength of the resonator is dependent on the electrical characteristics of the unit cells and not the physical size of the resonator in relation to the desired resonant wavelength. The resonator is created with at least 1.5 unit cells and the Q of the resonator is substantially independent of the number of unit cells utilized. The resonator circuit is particularly well suited for reducing resonator size, and allows resonators of various wavelengths to be fabricated within a fixed board area.
    Type: Application
    Filed: March 28, 2005
    Publication date: March 30, 2006
    Inventors: Tatsuo Itoh, Atsushi Sanada, Christophe Caloz