Patents by Inventor Tomoaki Kawata

Tomoaki Kawata 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: 11276909
    Abstract: Disclosed herein is a nonreciprocal circuit element that includes a magnetic rotator disposed between first and second ground conductors, and a permanent magnet that applies a DC magnetic field to the magnetic rotator. The magnetic rotator includes a first ferrite core having a first surface covered with the first ground conductor, a second ferrite core having a second surface covered with the second ground conductor, a first center conductor directly fixed to a third surface of the first ferrite core positioned opposite to the first surface, and a second center conductor directly fixed to a fourth surface of the second ferrite core positioned opposite to the second surface.
    Type: Grant
    Filed: March 13, 2020
    Date of Patent: March 15, 2022
    Assignee: TDK CORPORATION
    Inventors: Hidenori Ohata, Yoshinori Matsumaru, Tomoaki Kawata
  • Publication number: 20200295425
    Abstract: Disclosed herein is a nonreciprocal circuit element that includes a magnetic rotator disposed between first and second ground conductors, and a permanent magnet that applies a DC magnetic field to the magnetic rotator. The magnetic rotator includes a first ferrite core having a first surface covered with the first ground conductor, a second ferrite core having a second surface covered with the second ground conductor, a first center conductor directly fixed to a third surface of the first ferrite core positioned opposite to the first surface, and a second center conductor directly fixed to a fourth surface of the second ferrite core positioned opposite to the second surface.
    Type: Application
    Filed: March 13, 2020
    Publication date: September 17, 2020
    Inventors: Hidenori OHATA, Yoshinori MATSUMARU, Tomoaki KAWATA
  • Patent number: 9601816
    Abstract: A dielectric line includes a line portion and a surrounding dielectric portion. The line portion is formed of a first dielectric having a first relative permittivity. The surrounding dielectric portion is formed of a second dielectric having a second relative permittivity. The line portion propagates one or more electromagnetic waves of one or more frequencies within the range of 1 to 10 GHz. In a cross section orthogonal to the direction of propagation of the one or more electromagnetic waves through the line portion, the surrounding dielectric portion is present around the line portion. The first relative permittivity is 1,000 or higher. The second relative permittivity is lower than the first relative permittivity.
    Type: Grant
    Filed: July 25, 2014
    Date of Patent: March 21, 2017
    Assignee: TDK CORPORATION
    Inventors: Shigemitsu Tomaki, Tomoaki Kawata, Kiyoshi Hatanaka, Toshio Sakurai, Yasunori Sakisaka
  • Patent number: 9585250
    Abstract: [Problem to be solved] The present invention provides a conductive paste for constrained firing and a ceramic substrate manufactured with the conductive paste, the conductive paste having an excellent plating resistance and a good adherence against a ceramic substrate and a plated film even after plating treatment, wherein a constraining layer after firing can be easily removed without remaining on a surface conductor in a case where co-firing is performed. [Solution] Provided is a conductive paste comprising 60 to 95 mass % of an Ag powder as the content in a paste composition, 0.5 to 5 mass % of a borosilicate based glass powder relative to the Ag powder, the remainder being a platinum group metal additive and an organic vehicle, wherein the platinum group metal additive contains at least two metals of Ru and Rh, and the content of Ru and the content of Rh in the platinum group metal additive are 0.05 to 5 mass % of Ru and 0.001 to 0.
    Type: Grant
    Filed: October 2, 2013
    Date of Patent: February 28, 2017
    Assignees: TDK Corporation, Tanaka Kikinzoku Kogyo K.K.
    Inventors: Minoru Sato, Tomoaki Kawata, Masahiro Hirano, Shigekazu Onozumi
  • Patent number: 9464005
    Abstract: A dielectric ceramic composition is represented by a general formula “xBi2O3.yZnO.(z-a)Nb2O5.aV2O5”. The variables, “x”, “y”, “z” and “a” in the general formula respectively satisfy the following conditions: 2.90?x?3.10, 1.90?y?2.10, 1.90?z?2.10, and 0.0005?a?0.020.
    Type: Grant
    Filed: April 1, 2014
    Date of Patent: October 11, 2016
    Assignee: TDK CORPORATION
    Inventors: Tomohiro Arashi, Osamu Taguchi, Tomoaki Kawata
  • Publication number: 20150282309
    Abstract: [Problem to be solved] The present invention provides a conductive paste for constrained firing and a ceramic substrate manufactured with the conductive paste, the conductive paste having an excellent plating resistance and a good adherence against a ceramic substrate and a plated film even after plating treatment, wherein a constraining layer after firing can be easily removed without remaining on a surface conductor in a case where co-firing is performed. [Solution] Provided is a conductive paste comprising 60 to 95 mass % of an Ag powder as the content in a paste composition, 0.5 to 5 mass % of a borosilicate based glass powder relative to the Ag powder, the remainder being a platinum group metal additive and an organic vehicle, wherein the platinum group metal additive contains at least two metals of Ru and Rh, and the content of Ru and the content of Rh in the platinum group metal additive are 0.05 to 5 mass % of Ru and 0.001 to 0.
    Type: Application
    Filed: October 2, 2013
    Publication date: October 1, 2015
    Applicants: TANAKA KIKINZOKU KOGYO K.K., TDK CORPORATION
    Inventors: Minoru Sato, Tomoaki Kawata, Masahiro Hirano, Shigekazu Onozumi
  • Publication number: 20150035626
    Abstract: A dielectric line includes a line portion and a surrounding dielectric portion. The line portion is formed of a first dielectric having a first relative permittivity. The surrounding dielectric portion is formed of a second dielectric having a second relative permittivity. The line portion propagates one or more electromagnetic waves of one or more frequencies within the range of 1 to 10 GHz. In a cross section orthogonal to the direction of propagation of the one or more electromagnetic waves through the line portion, the surrounding dielectric portion is present around the line portion. The first relative permittivity is 1,000 or higher. The second relative permittivity is lower than the first relative permittivity.
    Type: Application
    Filed: July 25, 2014
    Publication date: February 5, 2015
    Inventors: Shigemitsu TOMAKI, Tomoaki KAWATA, Kiyoshi HATANAKA, Toshio SAKURAI, Yasunori SAKISAKA
  • Publication number: 20140302320
    Abstract: A dielectric ceramic composition is represented by a general formula “xBi2O3-yZnO-(z-a)Nb2O5-aV2O5”. In the general formula, values “x”, “y”, “z” and “a” respectively satisfy the following conditions: 2.90?x?3.10, 1.90?y?2.10, 1.90?z?2.10, and 0.0005?a?0.020.
    Type: Application
    Filed: April 1, 2014
    Publication date: October 9, 2014
    Applicant: TDK CORPORATION
    Inventors: Tomohiro ARASHI, Osamu TAGUCHI, Tomoaki KAWATA
  • Patent number: 6340649
    Abstract: The composition of dielectric ceramics is formed in that a main component is expressed with a general formula of xBaO·yNd2O3·zTiO2 (provided that the general formula has the relation of 6≦x≦23, 13≦y≦30, 64≦z≦68 and x+y+z=100), and in relation with the main components, sub-components are contained of Cu oxides 0.1 to 3.0 wt % in terms of CuO, Zn oxide 0.1 to 4.0 wt % in terms of ZnO, and B oxide 0.1 to 3.0 wt % in term of B2O3. It is preferable that Ag 0.3 to 1.5 wt % is contained as the sub-component.
    Type: Grant
    Filed: March 15, 2000
    Date of Patent: January 22, 2002
    Assignee: TDK Corporation
    Inventors: Tomoaki Kawata, Akira Nakamura, Toshio Sakurai, Aya Fukuhara
  • Patent number: 6184165
    Abstract: A dielectric porcelain composition according to the present invention is composed of a main component expressed in a general formula of xBaO·y((1−t)Nd2O3·tSm2O3)·zTiO2, where 6≦x≦23, 13≦y≦30, 64≦z≦68, 0≦t<1 and x+y+z=100. The main component contains a sub component containing Cu oxide in the range of 0.1 to 3.0 wt % in terms of CuO and glass composition in the range of 2.0 to 10 wt %. Further, 90 wt % or more of the glass composition is at least one selected from SiO2, B2O3, MgO, BaO, SrO, ZnO and CaO, in the ranges of: 5 wt %≦SiO2≦15 wt %; 15 wt %≦B2O3≦25 wt %; 50 wt %≦(MgO+BaO+SrO+ZnO+CaO)≦80 wt %; 90 wt %≦(SiO2+B2O3+MgO+BaO+SrO+ZnO+CaO)≦100 wt %.
    Type: Grant
    Filed: July 15, 1999
    Date of Patent: February 6, 2001
    Assignee: TDK Corporation
    Inventor: Tomoaki Kawata
  • Patent number: 5723395
    Abstract: In a dielectric ceramic composition comprising TiO.sub.2 and ZnO as a main component, B.sub.2 O.sub.3 and/or a B.sub.2 O.sub.3 -containing vitreous component is contained as an auxiliary component. This establishes a low-temperature firing capability which permits Ag, Cu, Ag base alloy or Cu base alloy to be used as an internal conductor. A choice of a compositional ratio of the main component enables a choice of a temperature coefficient while a choice of the content of the auxiliary component enables a choice of a sintering temperature. It is further possible to control the crystalline structure, dielectric constant, Q value, temperature coefficient, insulation resistance (IR) and grain size of the composition by adding a Cu oxide, Ni oxide, Mn oxide, and Si oxide and adjusting their contents.
    Type: Grant
    Filed: June 28, 1996
    Date of Patent: March 3, 1998
    Assignee: TDK Corporation
    Inventors: Takashi Suzuki, Tomoaki Kawata, Kunihiko Kawasaki, Masako Nitta