Patents by Inventor Yoichi Okubo

Yoichi Okubo 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: 6904267
    Abstract: To provide an amplifying device with reduced size, weight and cost. The amplifying device delays input signals using digital delay sections in a main signal system, performs offset rotation processing of digital input signals in carrier offset sections and power detection in a power detecting section in a control system, matches phases of a multi-carrier signal of the main signal system and a power value signal of the control system in a phase control section, and gives distortion compensation in a predistorter for canceling a nonlinear characteristic generated in an amplifier.
    Type: Grant
    Filed: August 28, 2002
    Date of Patent: June 7, 2005
    Assignee: Hitachi Kokusai Electric Inc.
    Inventors: Naoki Hongo, Yoichi Okubo, Masaki Suto, Tetsuhiko Miyatani
  • Patent number: 6856196
    Abstract: A distortion compensator that compensates for distortion arising in a main amplifier 10 that amplifies a signal effectively compensates for third order distortion which is unbalanced between the higher frequency band and lower frequency band. An amplitude detector 3 detects the level of a signal subject to amplification and a signal level change direction detection means 7 detects the direction of change in the level of the signal. A signal level change control means 4-8 stores the correspondence between the signal level and the mode of changing the signal in order to compensate for distortion for when the direction of change in the signal level is positive and when it is negative, and controls a signal change means 9 so that the amplitude and phase of the signal is changed in a mode of changing the signal corresponding to the detected direction of change in the signal level and the detected signal level.
    Type: Grant
    Filed: June 23, 2003
    Date of Patent: February 15, 2005
    Assignee: Hitachi Kokusai Electric Inc.
    Inventors: Yoichi Okubo, Kiyoshi Funada, Yasuo Sera, Masaki Suto, Masato Horaguchi, Kazuyoshi Sato, Toshio Takada, Tetsuhiko Miyatani, Naoki Hongo
  • Patent number: 6809588
    Abstract: A distortion compensation circuit reduces an unbalance between higher and lower 3rd order distortions, the distortions being generated by an amplifier which amplifies an input signal having at least two frequency components. Amplitude modulation means, which includes an amplitude detector, an amplitude circuit, a phase circuit and another amplitude circuit, generates sideband signals corresponding to an instantaneous phase difference between the higher and lower 3rd order distortions, such that distortions generated by the amplifier can be cancelled. Further, sideband signal generating means, which includes an amplitude circuit, a delay circuit, an AM modulator, another amplitude circuit, another delay circuit and a PM modulator, performs AM and PM on the input signal to thereby generate sideband signals, such that distortions generated by the amplifier can be cancelled.
    Type: Grant
    Filed: September 25, 2002
    Date of Patent: October 26, 2004
    Assignee: Hitachi Kokusai Electric Inc.
    Inventors: Toshio Takada, Yoichi Okubo, Masaki Suto, Masato Horaguchi, Naoki Hongo
  • Patent number: 6773634
    Abstract: A conductive polymer composition comprising 100 parts by weight of a crystalline polymer (A) and 5 to 150 parts by weight of a conductive powder (B) dispersed in the crystalline polymer (A) is disclosed. The crystalline polymer (A) shows crystal transition, thereby the conductive polymer composition exhibits PTC characteristics.
    Type: Grant
    Filed: June 28, 2002
    Date of Patent: August 10, 2004
    Assignee: UBE Industries, Ltd.
    Inventors: Yasumasa Iwamoto, Tadatoshi Aridomi, Yoichi Okubo
  • Patent number: 6753728
    Abstract: A distortion reducing circuit compensates an upper side third-order distortion and a lower side third-order distortion produced by an amplifier for amplifying a fundamental signal including multiple frequency components. The distortion reducing circuit includes a second harmonic reflection coefficient regulation circuit, installed at an output side of the amplifier, for regulating reflection coefficients for multiple frequency components included in a second harmonic signal to have a constant value.
    Type: Grant
    Filed: May 24, 2002
    Date of Patent: June 22, 2004
    Assignee: Hitachi Kokusai Electric Inc.
    Inventors: Yoichi Okubo, Kiyoshi Funada, Masaki Suto, Masato Horaguchi, Toshio Takada, Naoki Hongo
  • Patent number: 6741128
    Abstract: There is provided a distortion canceling circuit for reducing an unbalance between a higher and a lower 3rd order distortion at frequencies of (2·f2−f1) and (2·f1−f2), respectively, the distortions being generated by an amplifier which amplifies an input signal having at least two frequency components, i.e., f1 and f2. Phase modulation control means supply a control signal, which has a difference frequency of (f2−f1), to phase modulation means, the control signal being generated based on the amplified input signal outputted from the amplifier. The phase modulation means performs phase modulation on the amplified input signal based on the supplied control signal to thereby generate a higher and a lower side-band signal having frequencies of (2·f2−f1) and (2·f1−f2), respectively, each of which has an identical amplitude and a phase difference of 180° with respect to each other.
    Type: Grant
    Filed: April 25, 2002
    Date of Patent: May 25, 2004
    Assignee: Hitachi Kokusai Electric Inc.
    Inventors: Yoichi Okubo, Kiyoshi Funada, Masaki Suto, Masato Horaguchi, Toshio Takada, Naoki Hongo
  • Patent number: 6714073
    Abstract: A distortion compensation amplification apparatus for compensating distortion generated while amplifying a signal, includes a distributor for distributing an input signal to provide a first and a second outputs, a first delay means for delaying the first output through the use of a surface acoustic wave element, a compensation value generation circuit, responsive to the second output, for determining amplitude and phase compensation values to be used in compensating the distortion, a second delay means for delaying the compensation values according to a delay time of the first delay means, and a predistortion circuit for compensating the output of the first delay means in response to the delayed compensation values. And the second delay means includes at least one type of circuit among the type of an analog delay circuit and a digital delay circuit.
    Type: Grant
    Filed: November 26, 2002
    Date of Patent: March 30, 2004
    Assignee: Hitachi Kokusai Electric Inc.
    Inventors: Masaki Suto, Yoichi Okubo, Toshio Takada, Naoki Hongo
  • Publication number: 20040041628
    Abstract: A distortion compensator that compensates for distortion arising in a main amplifier 10 that amplifies a signal effectively compensates for third order distortion which is unbalanced between the higher frequency band and lower frequency band. An amplitude detector 3 detects the level of a signal subject to amplification and a signal level change direction detection means 7 detects the direction of change in the level of the signal. A signal level change control means 4-8 stores the correspondence between the signal level and the mode of changing the signal in order to compensate for distortion for when the direction of change in the signal level is positive and when it is negative, and controls a signal change means 9 so that the amplitude and phase of the signal is changed in a mode of changing the signal corresponding to the detected direction of change in the signal level and the detected signal level.
    Type: Application
    Filed: June 23, 2003
    Publication date: March 4, 2004
    Inventors: Yoichi Okubo, Kiyoshi Funada, Yasuo Sera, Masaki Suto, Masato Horaguchi, Kazuyoshi Sato, Toshio Takada, Tetsuhiko Miyatani, Naoki Hongo
  • Patent number: 6698224
    Abstract: An electronic apparatus includes a thermally insulated vessel having a cooling part therein. Disposed inside the thermally insulated vessel are a first electronic part and a second electronic part. The second electronic part is spaced apart from the cooling part while the first electronic part is in direct contact with the cooling part, such that the two electronic parts can operate at different cooling temperatures.
    Type: Grant
    Filed: October 4, 2002
    Date of Patent: March 2, 2004
    Assignee: Hitachi Kokusai Electric Inc.
    Inventors: Noriyuki Kagaya, Yoichi Okubo, Masaki Suto, Hideaki Takahashi, Takashi Uchida
  • Publication number: 20030174019
    Abstract: A distortion compensation amplification apparatus for compensating distortion generated while amplifying a signal, includes a distributor for distributing an input signal to provide a first and a second outputs, a first delay means for delaying the first output through the use of a surface acoustic wave element, a compensation value generation circuit, responsive to the second output, for determining amplitude and phase compensation values to be used in compensating the distortion, a second delay means for delaying the compensation values according to a delay time of the first delay means, and a predistortion circuit for compensating the output of the first delay means in response to the delayed compensation values. And the second delay means includes at least one type of circuit among the type of an analog delay circuit and a digital delay circuit.
    Type: Application
    Filed: November 26, 2002
    Publication date: September 18, 2003
    Applicant: Hitachi Kokusai Electric Inc.
    Inventors: Masaki Suto, Yoichi Okubo, Toshio Takada, Naoki Hongo
  • Publication number: 20030085762
    Abstract: A distortion compensation circuit reduces an unbalance between higher and lower 3rd order distortions, the distortions being generated by an amplifier which amplifies an input signal having at least two frequency components. Amplitude modulation means, which includes an amplitude detector, an amplitude circuit, a phase circuit and another amplitude circuit, generates sideband signals corresponding to an instantaneous phase difference between the higher and lower 3rd order distortions, such that distortions generated by the amplifier can be cancelled. Further, sideband signal generating means, which includes an amplitude circuit, a delay circuit, an AM modulator, another amplitude circuit, another delay circuit and a PM modulator, performs AM and PM on the input signal to thereby generate sideband signals, such that distortions generated by the amplifier can be cancelled.
    Type: Application
    Filed: September 25, 2002
    Publication date: May 8, 2003
    Applicant: Hitachi Kokusai Electric Inc.
    Inventors: Toshio Takada, Yoichi Okubo, Masaki Suto, Masato Horaguchi, Naoki Hongo
  • Publication number: 20030084677
    Abstract: An electronic apparatus includes a thermally insulated vessel having a cooling part therein. Disposed inside the thermally insulated vessel are a first electronic part and a second electronic part. The second electronic part is spaced apart from the cooling part while the first electronic part is in direct contact with the cooling part, such that the two electronic parts can operate at different cooling temperatures.
    Type: Application
    Filed: October 4, 2002
    Publication date: May 8, 2003
    Applicant: Hitachi Kokusai Electric Inc.
    Inventors: Noriyuki Kagaya, Yoichi Okubo, Masaki Suto, Hideaki Takahashi, Takashi Uchida
  • Publication number: 20030085761
    Abstract: A distortion reducing circuit compensates an upper side third-order distortion and a lower side third-order distortion produced by an amplifier for amplifying a fundamental signal including multiple frequency components. The distortion reducing circuit includes a second harmonic reflection coefficient regulation circuit, installed at an output side of the amplifier, for regulating reflection coefficients for multiple frequency components included in a second harmonic signal to have a constant value.
    Type: Application
    Filed: May 24, 2002
    Publication date: May 8, 2003
    Applicant: Hitachi Kokusai Electric Inc.
    Inventors: Yoichi Okubo, Kiyoshi Funada, Masaki Suto, Masato Horaguchi, Toshio Takada, Naoki Hongo
  • Publication number: 20030060184
    Abstract: The radio signal receiving device that has an input terminal for inputting an input signal and an output terminal for amplifying the signal inputted to the input terminal and then outputting the signal, comprises an insulating container comprising the input terminal and the output terminal, and an amplifier that is contained in the insulating container and amplifies the signal and then outputs the signal as the output signal. Bias voltage from one of the amplifier input terminal of the amplifier and the amplifier output terminal of the amplifier is applied to the output signal outputted to the amplifier output terminal of the amplifier.
    Type: Application
    Filed: September 17, 2002
    Publication date: March 27, 2003
    Inventors: Noriyuki Kagaya, Yoichi Okubo, Masaki Suto, Takashi Uchida, Hideaki Takahashi
  • Publication number: 20030053552
    Abstract: A distortion compensator for compensating for distortion produced in an amplifier that amplifies a signal includes a signal level detection means for detecting a level of a signal to be amplified and distortion compensation means for conducting distortion compensation based on the detection result separately for each frequency band signal of multiple frequency band signals contained in the signal to be amplified. The distortion compensator improves distortion compensation performance by reducing the effect of frequency characteristics that restrict the distortion compensation performance limit.
    Type: Application
    Filed: August 19, 2002
    Publication date: March 20, 2003
    Inventors: Naoki Hongo, Yoichi Okubo, Masaki Suto, Masato Horaguchi, Toshio Takada
  • Publication number: 20030045247
    Abstract: To provide an amplifying device with reduced size, weight and cost. The amplifying device delays input signals using digital delay sections in a main signal system, performs offset rotation processing of digital input signals in carrier offset sections and power detection in a power detecting section in a control system, matches phases of a multi-carrier signal of the main signal system and a power value signal of the control system in a phase control section, and gives distortion compensation in a predistorter for canceling a nonlinear characteristic generated in an amplifier.
    Type: Application
    Filed: August 28, 2002
    Publication date: March 6, 2003
    Inventors: Naoki Hongo, Yoichi Okubo, Masaki Suto, Tetsuhiko Miyatani
  • Publication number: 20030045253
    Abstract: To provide an amplifying device which is reduced in size, weight and cost and which can improve the distortion compensation performance. In the amplifying device, input signals are each subjected to digital orthogonal modulation using an IF and further to offset rotation processing in digital orthogonal modulators, then bifurcated into a main signal system and a control system, and detection of a power value is performed at an IF band in a power detecting section of the control system. Therefore, offset rotation processing of the input signals in the power detection is not required, so that a structure for matching phases of a multi-carrier signal and a power value signal is not required, resulting in improving the distortion compensation performance without using an analog delay line.
    Type: Application
    Filed: August 28, 2002
    Publication date: March 6, 2003
    Inventors: Naoki Hongo, Yoichi Okubo, Masaki Suto, Tetsuhiko Miyatani
  • Publication number: 20030027596
    Abstract: The present invention relates to an economical and highly reliable receiving apparatus for receiving radio signal transmitted from a mobile communication terminal within radio zone. The receiving apparatus has antenna sections that receive radio signal transmitted from the mobile communication terminal and are provided in each of a plurality of sectors divided from the radio zone, and receiving units that are provided in each of the antenna sections and that perform a predetermined process to the radio signal received by the antenna section. Further, receiving apparatus has four cooling sections for receipt filter and LNA within two receiving units. Each of the cooling sections cools the same number of receipt filter and LNA.
    Type: Application
    Filed: June 20, 2002
    Publication date: February 6, 2003
    Inventors: Yoichi Okubo, Masaki Suto, Noriyuki Kagaya, Takashi Uchida, Kiyoshi Funada, Kotaro Takenaga
  • Publication number: 20030022639
    Abstract: A peak limiter for use in a system for amplifying a multi-carrier signal receives a baseband signal of each carrier of the multi-carrier signal. The multi-carrier signal is computationally estimated to have carriers combined in an RF band, and obtains power information of the multi-carrier signal to limit an amplitude of the baseband signal based on the power information of the estimated multi-carrier signal to thereby provide peak-limited baseband signals. Thus, the distortion generated by performing the unnecessary peak limitation can be effectively prevented to thereby improve the reliability of the entire system.
    Type: Application
    Filed: July 26, 2002
    Publication date: January 30, 2003
    Applicant: Hitachi Kokusai Electric Inc.
    Inventors: Naoki Hongo, Yoichi Okubo, Masaki Suto, Masato Horaguchi, Toshio Takada, Tetsuhiko Miyatani
  • Publication number: 20030015285
    Abstract: A conductive polymer composition comprising 100 parts by weight of a crystalline polymer (A) and 5 to 150 parts by weight of a conductive powder (B) dispersed in the crystalline polymer (A) is disclosed. The crystalline polymer (A) shows crystal transition, thereby the conductive polymer composition exhibits PTC characteristics.
    Type: Application
    Filed: June 28, 2002
    Publication date: January 23, 2003
    Inventors: Yasumasa Iwamoto, Tadatoshi Aridomi, Yoichi Okubo