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).
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Patent number: 8780010Abstract: 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: GrantFiled: August 30, 2011Date of Patent: July 15, 2014Assignee: Semiconductor Technology Academic Research CenterInventor: Atsushi Sanada
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Publication number: 20130017348Abstract: 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: ApplicationFiled: March 24, 2011Publication date: January 17, 2013Applicant: YAMAGUCHI UNIVERSITYInventor: Atsushi Sanada
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Publication number: 20120212395Abstract: 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: ApplicationFiled: August 30, 2011Publication date: August 23, 2012Inventor: Atsushi SANADA
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Patent number: 8198953Abstract: 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: GrantFiled: September 18, 2007Date of Patent: June 12, 2012Assignee: Yamaguchi UniversityInventor: Atsushi Sanada
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Patent number: 8125717Abstract: 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: GrantFiled: March 14, 2008Date of Patent: February 28, 2012Assignee: Yamaguchi UniversityInventor: Atsushi Sanada
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Patent number: 8026854Abstract: 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: GrantFiled: June 27, 2007Date of Patent: September 27, 2011Assignee: Yamaguchi UniversityInventor: Atsushi Sanada
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Patent number: 7864114Abstract: 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: GrantFiled: February 27, 2006Date of Patent: January 4, 2011Assignee: National University Corporation Yamaguchi UniversityInventor: Atsushi Sanada
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Publication number: 20100118412Abstract: 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: ApplicationFiled: March 14, 2008Publication date: May 13, 2010Applicant: YAMAGUCHI UNIVERSITYInventor: Atsushi Sanada
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Patent number: 7696951Abstract: 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: GrantFiled: February 27, 2006Date of Patent: April 13, 2010Assignee: National University Corporation Yamaguchi UniversityInventor: Atsushi Sanada
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Publication number: 20100007436Abstract: 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: ApplicationFiled: September 18, 2007Publication date: January 14, 2010Applicant: YAMAGUCHI UNIVERSITYInventor: Atsushi Sanada
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Publication number: 20090179823Abstract: 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: ApplicationFiled: February 27, 2006Publication date: July 16, 2009Inventor: Atsushi Sanada
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Publication number: 20090174609Abstract: 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: ApplicationFiled: June 27, 2007Publication date: July 9, 2009Applicant: YAMAGUCHI UNIVERSITYInventor: Atsushi Sanada
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Publication number: 20090033586Abstract: 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: ApplicationFiled: February 27, 2006Publication date: February 5, 2009Inventor: Atsushi Sanada
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Patent number: 7391288Abstract: 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: GrantFiled: April 18, 2007Date of Patent: June 24, 2008Assignee: The Regents of the University of CaliforniaInventors: Tatsuo Itoh, Atsushi Sanada, Christophe Caloz
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Patent number: 7330090Abstract: 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: GrantFiled: March 28, 2005Date of Patent: February 12, 2008Assignee: The Regents of the University of CaliforniaInventors: Tatsuo Itoh, Atsushi Sanada, Christophe Caloz
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Publication number: 20060066422Abstract: 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: ApplicationFiled: March 28, 2005Publication date: March 30, 2006Inventors: Tatsuo Itoh, Atsushi Sanada, Christophe Caloz