Patents by Inventor Takao Kawahara
Takao Kawahara 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: 8988089Abstract: A first switch is arranged such that a first terminal thereof is connected to an AC test unit and a second terminal thereof is connected to an I/O terminal and a DC test unit. A first switch is configured so as to be capable of switching states between a connection state in which the first terminal and the second terminal are connected to each other, and a disconnection state in which they are disconnected from each other. A bypass capacitor is arranged between the first terminal and the second terminal, and is configured to bypass the frequency component which is cut off by the first switch.Type: GrantFiled: April 22, 2010Date of Patent: March 24, 2015Assignee: Advantest CorporationInventors: Takao Kawahara, Takayuki Nakamura
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Patent number: 8547124Abstract: A DUT is connected to an I/O terminal. An AC test unit performs an AC test operation for the DUT. A DC test unit performs a DC test operation for the DUT. An optical semiconductor switch is arranged such that a first terminal thereof is connected to the AC test unit and a second terminal thereof is connected to the I/O terminal. The optical semiconductor switch 10 is configured to be capable of switching states, according to control signals input to control terminals, between a connection state in which the first terminal and the second terminal are connected to each other, and a disconnection state in which they are disconnected from each other. A first impedance circuit is arranged on a signal line for the control signal to be input to the positive-electrode control terminal. Furthermore, a second impedance circuit is arranged on a signal line for the control signal to be input to the negative-electrode control terminal.Type: GrantFiled: April 22, 2010Date of Patent: October 1, 2013Assignee: Advantest CorporationInventors: Takao Kawahara, Takayuki Nakamura
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Patent number: 8203347Abstract: A reflection element determination device derives error factors in a first signal source and a second signal source based on measurement results of a signal in respective states in which reflection elements are respectively connected to the first signal source and the second signal source, and measurement results of a signal in a state in which the first signal source and the second signal source are connected with each other via a transmission element, derives transmission characteristics of the transmission element based on the measurement results of a signal in the state in which the first signal source and the second signal source are connected with each other via the transmission element and the derived error factors, and determines whether the reflection elements realize predetermined reflection states based on the derived transmission characteristics of the transmission element and transmission characteristics of the transmission element which have been known before the derivation, where the transmissiType: GrantFiled: August 24, 2007Date of Patent: June 19, 2012Assignee: Advantest CorporationInventors: Yoshikazu Nakayama, Takao Kawahara, Masato Haruta
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Publication number: 20120019272Abstract: A DUT is connected to an I/O terminal. An AC test unit performs an AC test operation for the DUT. A DC test unit performs a DC test operation for the DUT. An optical semiconductor switch is arranged such that a first terminal thereof is connected to the AC test unit and a second terminal thereof is connected to the I/O terminal. The optical semiconductor switch 10 is configured to be capable of switching states, according to control signals input to control terminals, between a connection state in which the first terminal and the second terminal are connected to each other, and a disconnection state in which they are disconnected from each other. A first impedance circuit is arranged on a signal line for the control signal to be input to the positive-electrode control terminal. Furthermore, a second impedance circuit is arranged on a signal line for the control signal to be input to the negative-electrode control terminal.Type: ApplicationFiled: April 22, 2010Publication date: January 26, 2012Applicant: ADVANTEST CORPORATIONInventors: Takao Kawahara, Takayuki Nakamura
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Publication number: 20110291682Abstract: A first switch is arranged such that a first terminal thereof is connected to an AC test unit and a second terminal thereof is connected to an I/O terminal and a DC test unit. A first switch is configured so as to be capable of switching states between a connection state in which the first terminal and the second terminal are connected to each other, and a disconnection state in which they are disconnected from each other. A bypass capacitor is arranged between the first terminal and the second terminal, and is configured to bypass the frequency component which is cut off by the first switch.Type: ApplicationFiled: April 22, 2010Publication date: December 1, 2011Applicant: ADVANTEST CORPORATIONInventors: Takao Kawahara, Takayuki Nakamura
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Publication number: 20100042347Abstract: A reflection element determination device derives error factors in a first signal source and a second signal source based on measurement results of a signal in respective states in which reflection elements are respectively connected to the first signal source and the second signal source, and measurement results of a signal in a state in which the first signal source and the second signal source are connected with each other via a transmission element, derives transmission characteristics of the transmission element based on the measurement results of a signal in the state in which the first signal source and the second signal source are connected with each other via the transmission element and the derived error factors, and determines whether the reflection elements realize predetermined reflection states based on the derived transmission characteristics of the transmission element and transmission characteristics of the transmission element which have been known before the derivation, where the transmissiType: ApplicationFiled: August 24, 2007Publication date: February 18, 2010Applicant: ADVANTEST CORPORATIONInventors: Yoshikazu Nakayama, Takao Kawahara, Masato Haruta
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Patent number: 7075488Abstract: An insulative member is formed with a hole. An antenna element is provided as a conductive foil adhered onto the insulative member and having a contact section opposing to the hole. A conductive member is fitted into the hole through the contact section of the antenna element, such that a part of the contact section is clamped between an outer face of the conductive member and an inner face of the hole.Type: GrantFiled: September 28, 2004Date of Patent: July 11, 2006Assignee: Yokowo Co., Ltd.Inventors: Takao Kawahara, Seiji Go, Yasuhiro Minoura
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Publication number: 20050068235Abstract: An insulative member is formed with a hole. An antenna element is provided as a conductive foil adhered onto the insulative member and having a contact section opposing to the hole. A conductive member is fitted into the hole through the contact section of the antenna element, such that a part of the contact section is clamped between an outer face of the conductive member and an inner face of the hole.Type: ApplicationFiled: September 28, 2004Publication date: March 31, 2005Inventors: Takao Kawahara, Seiji Go, Yasuhiro Minoura
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Patent number: 6522300Abstract: A whip antenna is movable between a first position corresponding to a state in which the whip antenna is extended from a casing of the mobile communication terminal, and a second position corresponding to a state the whip antenna is accommodated within the casing. A built-in antenna is disposed within the casing. A power feeding circuit is disposed within the casing. A first matching circuit has a first impedance, through which the power feeding circuit and the whip antenna are electrically connected when the whip antenna is placed at the first position. A second matching circuit has a second impedance which is higher than the first impedance, through which the whip antenna is grounded when the whip antenna is placed at the second position. A switch mechanism is opened so that the built-in antenna is electrically disconnected from the power feeding circuit when the whip antenna is placed at the first position, and closed so that the built-in antenna is electrically connected to the power feeding circuit.Type: GrantFiled: December 28, 2001Date of Patent: February 18, 2003Assignee: Yokowo Co., Ltd.Inventors: Tadashi Oshiyama, Atsushi Sato, Katsutoshi Okubo, Takao Kawahara, Seiji Gou
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Publication number: 20020126050Abstract: A whip antenna is movable between a first position corresponding to a state in which the whip antenna is extended from a casing of the mobile communication terminal, and a second position corresponding to a state the whip antenna is accommodated within the casing. A built-in antenna is disposed within the casing. A power feeding circuit is disposed within the casing. A first matching circuit has a first impedance, through which the power feeding circuit and the whip antenna are electrically connected when the whip antenna is placed at the first position. A second matching circuit has a second impedance which is higher than the first impedance, through which the whip antenna is grounded when the whip antenna is placed at the second position. A switch mechanism is opened so that the built-in antenna is electrically disconnected from the power feeding circuit when the whip antenna is placed at the first position, and closed so that the built-in antenna is electrically connected to the power feeding circuit.Type: ApplicationFiled: December 28, 2001Publication date: September 12, 2002Applicant: Yokowo Co., Ltd.Inventors: Tadashi Oshiyama, Atsushi Sato, Katsutoshi Okubo, Takao Kawahara, Seiji Gou
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Patent number: 6271804Abstract: An antenna for mounting on a vehicle which restrains damping of a signal voltage by reducing a stray capacitance of a signal path and has an improved antenna characteristic and a short physical length, and an antenna element which is suitable for an antenna for mounting on a vehicle and is flexible by using a helical coil of a large winding diameter are provided. In the antenna for mounting on a vehicle, with respect to a band signal having a short wavelength of a plurality of band signals to be transmitted/received, an antenna element is caused to resonate with a physical length shorter than ¼ of the wavelength of the band signal. A linear line portion is provided at the proximal end, and the antenna element is provided at a predetermined distance from vehicle body and a conductive member of the same electric potential as the vehicle body. The stray capacitance between the proximal end portion of the antenna element and the vehicle body is small, and a signal voltage is outputted without being damped.Type: GrantFiled: December 30, 1999Date of Patent: August 7, 2001Assignee: Yokowo Co., Ltd.Inventors: Wasuke Yanagisawa, Ryo Horie, Shozaburo Kameda, Takao Kawahara, Tomio Anbe, Katsuo Miki
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Patent number: 6259411Abstract: The invention being thus described, it will be obvious that the same may be varied in many ways. Such variations are not to be regarded as a departure from the spirit and scope of the invention, and all such modifications as would be obvious to one skilled in the art are intended to be included within the scope of the following claims.Type: GrantFiled: July 20, 1999Date of Patent: July 10, 2001Assignee: Yokowo Co., Ltd.Inventors: Wasuke Yanagisawa, Ryo Horie, Shozaburo Kameda, Takao Kawahara, Tomio Anbe, Katsuo Miki
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Patent number: 6256000Abstract: A motor-driven antenna device in which an antenna element (10) has a short protruding length so that the outer dimension of the entire device is reduced, and in which damping of an AM-band signal by a signal path is restrained with a small stray capacitance. A rack cord (12) to be meshed with a pinion gear (24) is connected to a proximal portion of the antenna element (10) made of a helical coil over its entire length, and the antenna element (10) is caused to protrude and move to be housed by rotational driving of a motor drive section. The rack cord (12), the motor drive section and the pinion gear (24) are housed in a case (14), and a guide (26) to which the rack cord (12) is abutted and moves while bending is provided in the case (14). Thus, the rack cord (12) is abutted and moves to the guide (26) by the movement of the antenna element (10).Type: GrantFiled: July 20, 1999Date of Patent: July 3, 2001Assignee: Yokowo Co., Ltd.Inventors: Wasuke Yanagisawa, Ryo Horie, Takumi Yano, Takao Kawahara, Yuichi Kagoshima, Tomio Anbe
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Patent number: 5995064Abstract: The antenna element (1) of a long conductor is formed with at least one returned portion (1a) arranged substantially in parallel to a longitudinal direction of the antenna element. In practice, a physical length of the antenna element in the longitudinal direction is determined to such a length as to be substantially resonated in a first frequency band, and the at least one returned portion (1a) is formed in such a way as to be resonated in a second frequency band twice higher than the first frequency band on the basis of an electric coupling with the adjacent antenna element.Type: GrantFiled: November 25, 1996Date of Patent: November 30, 1999Assignee: Kabushiki Kaisha Yokowa, also trading as Yokowo Co., Ltd.Inventors: Wasuke Yanagisawa, Ryo Horie, Takao Kawahara, Tadashi Oshiyama, Michio Arai, Takumi Yano, Atsushi Sato
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Patent number: 5453755Abstract: A plurality of insulators are disposed in holes, respectively, defined in a metal plate of a waveguide of a circularly-polarized-wave flat antenna. Each insulator has a through-hole and a protrusion. The through-hole extends from the outside of the metal plate to the inside of the waveguide. The protrusion protrudes outward beyond the metal plate. The protrusion has a groove which is open to the outside. Curl antenna elements each have a shaft portion, an arm portion, and a curl portion. The shaft portion is fitted in the through-hole of the insulator and partly protrudes outward from the metal plate. The arm portion extends from the protruded end of the shaft portion. The curl portion is in a substantially helical shape and connected to the top of the arm portion.Type: GrantFiled: January 21, 1993Date of Patent: September 26, 1995Assignee: Kabushiki Kaisha YokowoInventors: Hisamatsu Nakano, Motoshige Sekine, Kazuhiro Yokoyama, Yukio Nakagawa, Eiichi Tanaka, Shigeru Yoshida, Masaaki Kasama, Itsuo Nakayama, Takao Kawahara