Patents by Inventor Tadao Nagatsuma
Tadao Nagatsuma 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: 12165977Abstract: A terahertz module includes: a terahertz chip which includes an active device which emits a terahertz wave; and a dielectric substrate coupled to the terahertz chip. The terahertz chip includes a semiconductor substrate. The active device is disposed on an upper surface of the semiconductor substrate. A cutout is formed in a portion of a first side surface, among a plurality of side surfaces of the dielectric substrate, the cutout extending from an upper side of the first side surface to a lower side of the first side surface. The terahertz chip is fit into the cutout in such a direction that the upper surface of the semiconductor substrate is parallel to the first side surface and the semiconductor substrate is arranged in a bottom side of the cutout.Type: GrantFiled: July 8, 2021Date of Patent: December 10, 2024Assignees: ROHM CO., LTD., OSAKA UNIVERSITYInventors: Masayuki Fujita, Daniel Jonathan Headland, Tadao Nagatsuma, Yosuke Nishida
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Publication number: 20240260244Abstract: According to the present invention, a laminate has: a fiber aggregate including a plurality of nanofibers aggregated into a sheet; and a reflective substrate on which the fiber aggregate is placed and which has a reflectance of 0.1% or more. In this laminate, the fiber aggregate includes: a first orientation part formed in a part of a thickness direction of the fiber aggregate; and a second orientation part formed nearer to the reflective substrate than the first orientation part and having a lower degree of orientation than the first orientation part.Type: ApplicationFiled: July 28, 2021Publication date: August 1, 2024Applicants: Nitto Denko Corporation, OSAKA UNIVERSITYInventors: Yusuke Kamano, Shotaro Masuda, Masaya Nagai, Tadao Nagatsuma, Masayuki Fujita
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Publication number: 20230260913Abstract: A terahertz module includes: a terahertz chip which includes an active device which emits a terahertz wave; and a dielectric substrate coupled to the terahertz chip. The terahertz chip includes a semiconductor substrate. The active device is disposed on an upper surface of the semiconductor substrate. A cutout is formed in a portion of a first side surface, among a plurality of side surfaces of the dielectric substrate, the cutout extending from an upper side of the first side surface to a lower side of the first side surface. The terahertz chip is fit into the cutout in such a direction that the upper surface of the semiconductor substrate is parallel to the first side surface and the semiconductor substrate is arranged in a bottom side of the cutout.Type: ApplicationFiled: July 8, 2021Publication date: August 17, 2023Inventors: Masayuki FUJITA, Daniel Jonathan HEADLAND, Tadao NAGATSUMA, Yosuke NISHIDA
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Publication number: 20230178898Abstract: An UC dielectric waveguide of the embodiments includes: a dielectric substance wiring propagating a terahertz wave; and a medium disposed around the dielectric substance wiring and having a large refractive index difference with respect to the dielectric substance wiring. A THz circuit of the embodiments includes a dielectric substance THz circuit connected between a first and second UC dielectric waveguides. The dielectric substance THz circuit includes a circuit including a linear-shaped UC dielectric waveguide, a bent-shaped UC dielectric waveguide, and a Y-coupled branch circuit. There are included a first holding unit holding the first UC dielectric waveguide and a second holding unit holding the second UC dielectric waveguide. The THz circuit of the embodiments may include a 2×2 evanescent coupler. Provided is a THz circuit having mechanical strength obtained by applying the UC dielectric waveguide having high confinement and transmission efficiencies of THz waves with a simple structure.Type: ApplicationFiled: January 26, 2023Publication date: June 8, 2023Inventors: Masayuki FUJITA, Daniel Jonathan HEADLAND, Withawat WITHAYACHUMNANKUL, Tadao NAGATSUMA
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Publication number: 20210271099Abstract: The transmission device of the present embodiment includes a waveguide unit which transmits a terahertz-wave signal, and a plurality of ports provided around the waveguide unit and each composed of a waveguide and a planar lens, the waveguide unit and the ports being integrated on a planar substrate with dielectric properties. The planar lens diffuses, in an arcuate shape, a terahertz-wave signal by a reflective index set by a staggering arrangement of first through-holes, transmits the diffused terahertz-wave signal to the waveguide unit in parallel, or focuses a terahertz-wave signal which is transmitted in parallel through the waveguide unit. A beam splitter transmits a terahertz-wave signal, which is transmitted in parallel from a first planar lens, to a second planar lens, by reflection or transmission by a refractive index set by a grid arrangement of second through-holes.Type: ApplicationFiled: February 25, 2021Publication date: September 2, 2021Applicant: Osaka UniversityInventors: Naoya Kukutsu, Masato Kikuchi, Tadao Nagatsuma, Masayuki Fujita, Daniel Jonathan Headland, Tomoki Sagisaka, Li Yi
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Patent number: 10761126Abstract: Provided is an electro-optic probe for detecting an electromagnetic wave, including: an electro-optic crystal; and an optical fiber optically coupled to the electro-optic crystal, wherein a direction of a unique axis of the electro-optic crystal and a polarization direction of light from the optical fiber that enters the electro-optic crystal are set to be in line with each other, or wherein a direction of a unique axis of the electro-optic crystal and a unique polarization direction of the optical fiber are set to be in line with each other.Type: GrantFiled: June 28, 2016Date of Patent: September 1, 2020Assignee: Osaka UniversityInventors: Shintarou Hisatake, Tadao Nagatsuma, Hirohisa Uchida
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Patent number: 10451663Abstract: An electromagnetic field measurement device includes a first probe and a second probe arranged in a space to measure an electric field, a reference signal generator that generates a reference signal, a first multiplier that multiplies the reference signal by a signal obtained via the first probe, a second multiplier that multiplies a signal obtained via the second probe by the signal output from the first multiplier, and a synchronous detector that extracts a signal component that is synchronous with the reference signal from the signal output from the second multiplier.Type: GrantFiled: August 9, 2016Date of Patent: October 22, 2019Assignee: OSAKA UNIVERSITYInventors: Shintarou Hisatake, Tadao Nagatsuma
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Patent number: 10276919Abstract: A THz device includes: an antenna electrode capable of transmitting and receiving a THz wave to free space; first transmission lines capable of transmitting the THz wave, the first transmission lines respectively connected to the antenna electrodes; an active element of which a main electrode is connected to each of the first transmission lines; second transmission lines capable of transmitting the THz wave, the second transmission lines connected to the first active device; pad electrodes respectively connected to the second transmission lines; and a low-pass filter with respect to the THz wave, the low-pass filter connected to the pad electrodes, wherein impedance matching of between the antenna electrode and the active element is performed by an impedance conversion of the first transmission lines. The THz device is capable of the high-efficiency matching between the active element and the antenna due to the impedance conversion effect of the transmission line.Type: GrantFiled: February 27, 2017Date of Patent: April 30, 2019Assignees: ROHM CO., LTD., OSAKA UNIVERSITYInventors: Sebastian Diebold, Masayuki Fujita, Tadao Nagatsuma, Jaeyoung Kim, Toshikazu Mukai, Kazuisao Tsuruda
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Publication number: 20180238948Abstract: An electromagnetic field measurement device includes a first probe and a second probe arranged in a space to measure an electric field, a reference signal generator that generates a reference signal, a first multiplier that multiplies the reference signal by a signal obtained via the first probe, a second multiplier that multiplies a signal obtained via the second probe by the signal output from the first multiplier, and a synchronous detector that extracts a signal component that is synchronous with the reference signal from the signal output from the second multiplier.Type: ApplicationFiled: August 9, 2016Publication date: August 23, 2018Inventors: Shintarou HISATAKE, Tadao NAGATSUMA
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Publication number: 20180188305Abstract: Provided is an electro-optic probe for detecting an electromagnetic wave, including: an electro-optic crystal; and an optical fiber optically coupled to the electro-optic crystal, wherein a direction of a unique axis of the electro-optic crystal and a polarization direction of light from the optical fiber that enters the electro-optic crystal are set to be in line with each other, or wherein a direction of a unique axis of the electro-optic crystal and a unique polarization direction of the optical fiber are set to be in line with each other.Type: ApplicationFiled: June 28, 2016Publication date: July 5, 2018Applicant: OSAKA UNIVERSITYInventors: Shintarou Hisatake, Tadao Nagatsuma, Hirohisa Uchida
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Publication number: 20170250458Abstract: A THz device includes: an antenna electrode capable of transmitting and receiving a THz wave to free space; first transmission lines capable of transmitting the THz wave, the first transmission lines respectively connected to the antenna electrodes; an active element of which a main electrode is connected to each of the first transmission lines; second transmission lines capable of transmitting the THz wave, the second transmission lines connected to the first active device; pad electrodes respectively connected to the second transmission lines; and a low-pass filter with respect to the THz wave, the low-pass filter connected to the pad electrodes, wherein impedance matching of between the antenna electrode and the active element is performed by an impedance conversion of the first transmission lines. The THz device is capable of the high-efficiency matching between the active element and the antenna due to the impedance conversion effect of the transmission line.Type: ApplicationFiled: February 27, 2017Publication date: August 31, 2017Applicants: ROHM CO., LTD., OSAKA UNIVERSITYInventors: Sebastian DIEBOLD, Masayuki FUJITA, Tadao NAGATSUMA, Jaeyoung KIM, Toshikazu MUKAI, Kazuisao TSURUDA
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Patent number: 9632247Abstract: The THz-wave device comprises: a 2D-PC slab; lattice points periodically arranged in the 2D-PC slab, the lattice points for diffracting the THz waves in PBG frequencies of photonic band structure of the 2D-PC slab in order to prohibit existence in a plane of the 2D-PC; a 2D-PC waveguide disposed in the 2D-PC slab and formed with a line defect of the lattice points; and an RTD device disposed on the 2D-PC waveguide.Type: GrantFiled: March 10, 2015Date of Patent: April 25, 2017Assignees: ROHM CO., LTD., OSAKA UNIVERSITYInventors: Masayuki Fujita, Tadao Nagatsuma, Kazuisao Tsuruda, Dai Onishi
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Patent number: 9496622Abstract: The photonic-crystal (PC) slab absorber includes: a two-dimensional (2D)-PC slab composed of semiconducting materials; and a lattice point periodically arranged in the 2D-PC slab, the lattice point for forming resonant-state which can capture an electromagnetic waves incident from an outside by resonating an electromagnetic wave in a band edge of a photonic band structure of the 2D-PC slab in the plane of the 2D-PC slab. The 2D-PC slab is doped with impurities and can absorb the captured electromagnetic wave in the band edge resonant frequency of the 2D-PC slab.Type: GrantFiled: March 7, 2014Date of Patent: November 15, 2016Assignees: ROHM CO., LTD., OSAKA UNIVERSITYInventors: Masayuki Fujita, Tadao Nagatsuma, Ryoma Kakimi, Dai Onishi, Eiji Miyai
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Publication number: 20160178843Abstract: The THz-wave device comprises: a 2D-PC slab; lattice points periodically arranged in the 2D-PC slab, the lattice points for diffracting the THz waves in PBG frequencies of photonic band structure of the 2D-PC slab in order to prohibit existence in a plane of the 2D-PC; a 2D-PC waveguide disposed in the 2D-PC slab and formed with a line defect of the lattice points; and an RTD device disposed on the 2D-PC waveguide.Type: ApplicationFiled: March 10, 2015Publication date: June 23, 2016Applicants: ROHM CO., LTD., OSAKA UNIVERSITYInventors: Masayuki FUJITA, Tadao NAGATSUMA, Kazuisao TSURUDA, Dai ONISHI
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Patent number: 9188742Abstract: The terahertz-wave connector includes: a 2D-PC slab; lattice points periodically arranged in the 2D-PC slab, the lattice points for diffracting the THz waves in PBG frequencies of photonic band structure of the 2D-PC slab in order to prohibit existence in a plane of the 2D-PC slab; a 2D-PC waveguide disposed in the 2D-PC slab and formed with a line defect of the lattice points; and an adiabatic mode converter disposed at the edge face of the 2D-PC slab to which the 2D-PC waveguide extended, the 2D-PC waveguide extended to the adiabatic mode converter. There is provided also the THz-wave IC to which such a terahertz-wave connector is applied.Type: GrantFiled: March 4, 2014Date of Patent: November 17, 2015Assignees: ROHM CO., LTD., OSAKA UNIVERSITYInventors: Masayuki Fujita, Tadao Nagatsuma, Tsukasa Ishigaki, Dai Onishi, Eiji Miyai
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Publication number: 20150241630Abstract: The directional coupler includes: lattice points periodically arranged in the 2D-PC slab and configured to diffract optical waves, THz waves, or millimeter waves in PBG frequencies in PBG structure of the 2D-PC slab in order to prohibit existence in a plane of the 2D-PC slab; a first 2D-PC waveguide formed of a line defect; a second 2D-PC waveguide which can be mode-coupled to the first waveguide; a directional coupling unit disposed between the first waveguide and the second waveguide in two rows, and having lattice points between waveguides of which the radius is smaller than that of the lattice points, wherein in order to match the first waveguide with an operational band at a side of an input port from the directional coupling unit, the width of the second waveguide is narrowed so that the whole dispersion curve of the directional coupling unit is moved to a higher-frequency side.Type: ApplicationFiled: February 26, 2015Publication date: August 27, 2015Applicants: ROHM CO., LTD., OSAKA UNIVERSITYInventors: Masayuki FUJITA, Tadao NAGATSUMA, Dai ONISHI, Eiji MIYAI
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Publication number: 20140255040Abstract: The photonic-crystal (PC) slab absorber includes: a two-dimensional (2D)-PC slab composed of semiconducting materials; and a lattice point periodically arranged in the 2D-PC slab, the lattice point for forming resonant-state which can capture an electromagnetic waves incident from an outside by resonating an electromagnetic wave in a band edge of a photonic band structure of the 2D-PC slab in the plane of the 2D-PC slab. The 2D-PC slab is doped with impurities and can absorb the captured electromagnetic wave in the band edge resonant frequency of the 2D-PC slab.Type: ApplicationFiled: March 7, 2014Publication date: September 11, 2014Applicants: OSAKA UNIVERSITY, ROHM CO., LTD.Inventors: Masayuki FUJITA, Tadao NAGATSUMA, Ryoma KAKIMI, Dai ONISHI, Eiji MIYAI
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Publication number: 20140248020Abstract: The terahertz-wave connector includes: a 2D-PC slab; lattice points periodically arranged in the 2D-PC slab, the lattice points for diffracting the THz waves in PBG frequencies of photonic band structure of the 2D-PC slab in order to prohibit existence in a plane of the 2D-PC slab; a 2D-PC waveguide disposed in the 2D-PC slab and formed with a line defect of the lattice points; and an adiabatic mode converter disposed at the edge face of the 2D-PC slab to which the 2D-PC waveguide extended, the 2D-PC waveguide extended to the adiabatic mode converter. There is provided also the THz-wave IC to which such a terahertz-wave connector is applied.Type: ApplicationFiled: March 4, 2014Publication date: September 4, 2014Applicants: OSAKA UNIVERSITY, ROHM CO., LTD.Inventors: Masayuki FUJITA, Tadao NAGATSUMA, Tsukasa ISHIGAKI, Dai ONISHI, Eiji MIYAI
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Publication number: 20140132466Abstract: A dielectric film has a main surface and a back surface and is formed of resin. Electrodes that can receive or transmit an electromagnetic wave having a frequency of not less than 0.05 THz and not more than 10 THz in the terahertz band are formed on the main surface of the dielectric film. The electrodes constitute a tapered slot antenna. The dielectric film and the electrodes are formed of a flexible printed circuit board. A semiconductor device that is operable at a frequency in the terahertz band is mounted on the main surface of the dielectric film so as to be electrically connected to the electrodes.Type: ApplicationFiled: November 4, 2013Publication date: May 15, 2014Applicants: OSAKA UNIVERSITY, NITTO DENKO CORPORATIONInventors: Masami INOUE, Masayuki HODONO, Mitsuru HONJO, Tadao NAGATSUMA, Masayuki FUJITA
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Patent number: 7511511Abstract: A biological tissue equivalent phantom unit to be used by the specific absorption rate measuring system for evaluating absorption of electromagnetic wave energy includes a biological tissue equivalent phantom for absorbing an electromagnetic wave. In addition, two or more electro-optical crystals are arranged at two or more measurement points in the biological tissue equivalent phantom. The electro-optical crystals have a dielectric constant that is approximately equal to that of the biological tissue equivalent phantom. Two or more optical fibers are laid in the biological tissue equivalent phantom for optically connecting each of the electro-optical crystals to an external destination.Type: GrantFiled: May 29, 2007Date of Patent: March 31, 2009Assignees: NTT DoCoMo, Inc., Nippon Telegraph and Telephone CorporationInventors: Teruo Onishi, Ryo Yamaguchi, Shinji Uebayashi, Tadao Nagatsuma, Naofumi Shimizu, Hiroyoshi Togo