Patents by Inventor Takahide Kurahashi
Takahide Kurahashi 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: 9154004Abstract: In the rare earth sintered magnet, the ratio of R2 to the sum of R1 and R2 that are contained in crystal grain boundaries surrounding the crystal grains in the rare earth sintered magnet body is higher than the ratio of R2 to the sum of R1 and R2 in the crystal grains, and the concentration of R2 increases from the central portion of the rare earth sintered magnet body toward the surface of the rare earth sintered magnet body. In addition, the degree of unevenness in residual magnetic flux density on the surface of the rare earth sintered magnet body is smaller than 3.0%.Type: GrantFiled: March 4, 2011Date of Patent: October 6, 2015Assignee: TDK CORPORATIONInventors: Makoto Iwasaki, Fumitaka Baba, Satoshi Tanaka, Hideki Sasaki, Takahide Kurahashi, Hitoshi Maro, Keiichi Morimoto, Seiichi Endo
-
Publication number: 20120139388Abstract: In the rare earth sintered magnet, the ratio of R2 to the sum of R1 and R2 that are contained in crystal grain boundaries surrounding the crystal grains in the rare earth sintered magnet body is higher than the ratio of R2 to the sum of R1 and R2 in the crystal grains, and the concentration of R2 increases from the central portion of the rare earth sintered magnet body toward the surface of the rare earth sintered magnet body. In addition, the degree of unevenness in residual magnetic flux density on the surface of the rare earth sintered magnet body is smaller than 3.0%.Type: ApplicationFiled: March 4, 2011Publication date: June 7, 2012Applicant: TDK CORPORATIONInventors: Makoto Iwasaki, Fumitaka Baba, Satoshi Tanaka, Hideki Sasaki, Takahide Kurahashi, Hitoshi Maro, Keiichi Morimoto, Seiichi Endo
-
Patent number: 7286025Abstract: A technique for improving a circulator element for its temperature characteristic is provided. A circulator element including a garnet type ferrite material, and a permanent magnet for applying a direct-current magnetic field to the garnet type ferrite material, wherein S11 represents the saturation magnetization of said garnet type ferrite material at a temperature T1, S12 represents one at a temperature T2, and S13 represents one at a temperature T3; and S21 represents the saturation magnetization of said permanent magnet at a temperature T1, S22 represents one at a temperature T2, and S23 represents one at a temperature T3, where T1<T2<T3, and the saturation magnetizations S11, S12, S13, S21, S22 and S23 are relative values providing that the saturation magnetizations at the temperature T2 is 1, and wherein the relations |(S12?S11)/(T2?T1)|<|(S22?S21)/(T2?T1)| and |(S13?S12)/(T3?T2)|>|(S23?S22)/(T3?T2)| are satisfied.Type: GrantFiled: July 6, 2005Date of Patent: October 23, 2007Assignee: TDK CorporationInventors: Kenji Endou, Takahide Kurahashi, Sakae Henmi, Hidenori Ohata
-
Publication number: 20060006956Abstract: A technique for improving a circulator element for its temperature characteristic is provided. A circulator element including a garnet type ferrite material, and a permanent magnet for applying a direct-current magnetic field to the garnet type ferrite material, wherein S11 represents the saturation magnetization of said garnet type ferrite material at a temperature T1, S12 represents one at a temperature T2, and S13 represents one at a temperature T3; and S21 represents the saturation magnetization of said permanent magnet at a temperature T1, S22 represents one at a temperature T2, and S23 represents one at a temperature T3, where T1?T2?T3, and the saturation magnetizations S11, S12, S13, S21, S22 and S23 are relative values providing that the saturation magnetizations at the temperature T2 is 1, and wherein the relations |(S12?S11)/(T2?T1)|<|(S22?S21)/(T2?T1)| and |(S13?S12)/(T3?T2)|>|(S23?S22)/(T3?T2)| are satisfied.Type: ApplicationFiled: July 6, 2005Publication date: January 12, 2006Inventors: Kenji Endou, Takahide Kurahashi, Sakae Henmi, Hidenori Ohata
-
Patent number: 6462628Abstract: An isolator device with a built-in power amplifier includes a single dielectric multi-layered substrate, a high frequency power amplifier circuit, an isolator element, and circuit elements provided to the dielectric multi-layered substrate. The high frequency power amplifier circuit and the isolator element are connected with each other through the circuit elements and united with the single dielectric multi-layered substrate.Type: GrantFiled: March 26, 2001Date of Patent: October 8, 2002Assignee: TDK CorporationInventors: Ryoichi Kondo, Takahide Kurahashi, Shinya Nakai, Hajime Kato
-
Patent number: 6433649Abstract: A non-reciprocal circuit element includes a microstrip TMn10 resonator (n is a positive integer) with a metal disk and branches projecting from the metal disk in a trigonally symmetric structure, and a ferrite magnetic body spontaneously magnetized and coaxially disposed on the microstrip TMn10 resonator. The metal disk and the branches are formed on a non-magnetic dielectric board having a ground conductor on its bottom face. The ferrite magnetic body is arranged so that a position of an electric field node matches to one of the branches.Type: GrantFiled: May 14, 2001Date of Patent: August 13, 2002Assignee: TDK CorporationInventors: Taro Miura, Makoto Hasegawa, Takahide Kurahashi, Hidenori Ohata, Sakae Henmi, Kazuaki Suzuki
-
Publication number: 20010045872Abstract: A non-reciprocal circuit element includes a microstrip TMn10 resonator (n is a positive integer) with a metal disk and branches projecting from the metal disk in a trigonally symmetric structure, and a ferrite magnetic body spontaneously magnetized and coaxially disposed on the microstrip TMn10 resonator. The metal disk and the branches are formed on a non-magnetic dielectric board having a ground conductor on its bottom face. The ferrite magnetic body is arranged so that a position of an electric field node matches to one of the branches.Type: ApplicationFiled: May 14, 2001Publication date: November 29, 2001Applicant: TDK CORPORATIONInventors: Taro Miura, Makoto Hasegawa, Takahide Kurahashi, Hidenori Ohata, Sakae Henmi, Kazuaki Suzuki
-
Publication number: 20010017576Abstract: An isolator device with a built-in power amplifier includes a single dielectric multi-layered substrate, a high frequency power amplifier circuit, an isolator element, and circuit elements provided to the dielectric multi-layered substrate. The high frequency power amplifier circuit and the isolator element are connected with each other through the circuit elements and united with the single dielectric multi-layered substrate.Type: ApplicationFiled: March 26, 2001Publication date: August 30, 2001Applicant: TDK CORPORATIONInventors: Ryoichi Kondo, Takahide Kurahashi, Shinya Nakai, Hajime Kato
-
Patent number: 6235221Abstract: A multilayer ceramic part of the invention comprises an internal conductor layer and a ceramic layer which are formed by co-firing. The internal conductor layer is formed of an electrical conducting material containing silver as a main component, and the ceramic layer is formed of an yttrium-iron-garnet based oxide magnetic material with silver added thereto. Thus, the multilayer ceramic part can be fabricated in high yields, even when its size is much more smaller than that of a multilayer ceramic part fabricated until now.Type: GrantFiled: May 20, 1999Date of Patent: May 22, 2001Assignee: TDK CorporationInventors: Kazuaki Suzuki, Takahide Kurahashi, Hidenori Ohata
-
Patent number: 6215371Abstract: A non-reciprocal circuit element includes a plurality of inner conductors intersecting with keeping insulation with each other, a shield conductor connected in common to one end of the inner conductors, and a capacitor connected between the shield conductor and a ground of the non-reciprocal circuit element, for adjusting only eigen values of in-phase excitation. Thus, smaller size, lighter weight and lower height can be attained and also temperature characteristics can be optionally adjusted without changing material used and without inviting increased insertion loss.Type: GrantFiled: July 16, 1999Date of Patent: April 10, 2001Assignee: TDK CorporationInventors: Takahide Kurahashi, Hidenori Ohata, Akihito Watanabe, Yoshinori Matsumaru
-
Patent number: 6120884Abstract: An object is to provide a conductor paste of quality which uses a silver base internal conductor, suppresses the generation of voids and the concomitant occurrence of cracks even when co-fired with ceramic material by the conductor melting method, and has improved productivity, reduced cost, and improved electrical properties. The conductor paste is prepared by dispersing a silver base conductive material and a metal oxide in a vehicle. At least one of Ga oxide, La oxide, Pr oxide, Sm oxide, Eu oxide, Gd oxide, Dy oxide, Er oxide, Tm oxide, and Yb oxide is used as the metal oxide. The conductor paste is fired at a temperature between the melting point and lower than the boiling point of the conductive material.Type: GrantFiled: May 12, 1998Date of Patent: September 19, 2000Assignee: TDK CorporationInventors: Katsuhiko Igarashi, Hidenori Ohata, Takahide Kurahashi, Kazuaki Suzuki
-
Patent number: 5847628Abstract: A ground conductor and a signal conductor are provided in an insulating magnetic body respectively. The insulating magnetic body is a compound member that combines ferromagnetic metal particles and an insulating resin. A signal transmission element, a connector or a circuit board with high frequency stopping and low pass characteristics which will ensure reliable absorption of high frequency components in the high frequency range, can be provided. The ground conductor and the signal conductor are provided on opposite sides of the insulating magnetic body.Type: GrantFiled: September 25, 1997Date of Patent: December 8, 1998Assignee: TDK CorporationInventors: Fumio Uchikoba, Shigeyuki Nakajima, Takashi Ito, Taro Miura, Makoto Kobayashi, Takahide Kurahashi, Yasushi Iijima
-
Patent number: 5796323Abstract: A ground conductor and a signal conductor are provided in an insulating magnetic body respectively. The insulating magnetic body is a compound member that combines ferromagnetic metal particles and an insulating resin. A signal transmission element, a connector or a circuit board with high frequency stopping and low pass characteristics which will ensure reliable absorption of high frequency components in the high frequency range, can be provided.Type: GrantFiled: June 12, 1997Date of Patent: August 18, 1998Assignee: TDK CorporationInventors: Fumio Uchikoba, Shigeyuki Nakajima, Takashi Ito, Taro Miura, Makoto Kobayashi, Takahide Kurahashi, Yasushi Iijima
-
Patent number: 5594397Abstract: A ground conductor and a signal conductor are provided in an insulating magnetic body respectively. The insulating magnetic body is a compound member that combines ferromagnetic metal particles and an insulating resin. A signal transmission element, a connector or a circuit board with high frequency stopping and low pass characteristics which will ensure reliable absorption of high frequency components in the high frequency range, can be provided.Type: GrantFiled: March 23, 1995Date of Patent: January 14, 1997Assignee: TDK CorporationInventors: Fumio Uchikoba, Shigeyuki Nakajima, Takashi Ito, Taro Miura, Makoto Kobayashi, Takahide Kurahashi, Yasushi Iijima