Patents by Inventor Atsushi Ajioka
Atsushi Ajioka 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: 9530437Abstract: A magnetic head has a magnetic head slider that includes a recording element that generates a recording signal magnetic field, a microwave magnetic field generating element that generates a microwave magnetic field, a terminal electrode, and a first transmission line that interconnects the terminal electrode and the microwave magnetic field generating element. A second transmission line is connected to the terminal electrode, the second transmission line being used to transmit a microwave signal from the outside of the magnetic head slider to the magnetic head slider. A capacitor connected to the first transmission line is provided between the terminal electrode and the microwave magnetic field generating element. Accordingly, in the magnetic head, a microwave signal is efficiently propagated.Type: GrantFiled: September 8, 2015Date of Patent: December 27, 2016Assignee: TDK CorporationInventors: Tomohiko Shibuya, Atsushi Ajioka, Sadaharu Yoneda, Atsushi Tsumita
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Patent number: 9503035Abstract: There is provided a high-frequency amplifier including a divider, a plurality of amplifiers for amplifying a high-frequency signal distributed by the divider and outputting the amplified high-frequency signal, a combiner for combining amplified high-frequency signals, a base substrate, a conductor pattern that is connected to a ground end of each of the amplifiers, and a ground electrode. Each of the conductor patterns has a first conductive portion. A slot is disposed between the two conductor patterns connected to the corresponding adjacent amplifiers. Between the adjacent amplifiers, two vias are formed so that the slot is sandwiched between the vias. One of the two conductor patterns is connected to the ground electrode via one of the two vias, and the other one of the conductor patterns is connected to the ground electrode via the other one of the two vias.Type: GrantFiled: December 16, 2014Date of Patent: November 22, 2016Assignee: TDK CORPORATIONInventors: Tomohiko Shibuya, Atsushi Ajioka, Atsushi Tsumita, Sadaharu Yoneda
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Publication number: 20160093318Abstract: A magnetic head has a magnetic head slider that includes a recording element that generates a recording signal magnetic field, a microwave magnetic field generating element that generates a microwave magnetic field, a terminal electrode, and a first transmission line that interconnects the terminal electrode and the microwave magnetic field generating element. A second transmission line is connected to the terminal electrode, the second transmission line being used to transmit a microwave signal from the outside of the magnetic head slider to the magnetic head slider. A capacitor connected to the first transmission line is provided between the terminal electrode and the microwave magnetic field generating element. Accordingly, in the magnetic head, a microwave signal is efficiently propagated.Type: ApplicationFiled: September 8, 2015Publication date: March 31, 2016Inventors: Tomohiko SHIBUYA, Atsushi AJIOKA, Sadaharu YONEDA, Atsushi TSUMITA
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Patent number: 9252716Abstract: A high-frequency amplifier circuit includes a balanced-unbalanced converter converting a single-ended signal into differential signals. The output of a first amplifier amplifying the single-ended signal is connected to the signal terminal on the unbalanced side of the balanced-unbalanced converter. The input of a second amplifier amplifying one of the differential signals is connected to one signal terminal on the balanced side of the balanced-unbalanced converter. The input of a third amplifier amplifying another of the differential signals is connected to another signal terminal on the balanced side of the balanced-unbalanced converter. An impedance element is inserted between an element on the balanced side of the balanced-unbalanced converter and a ground.Type: GrantFiled: April 10, 2014Date of Patent: February 2, 2016Assignee: TDK CORPORATIONInventors: Sadaharu Yoneda, Atsushi Ajioka, Tomohiko Shibuya, Atsushi Tsumita
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Patent number: 9184706Abstract: Since a high-frequency signal that is output from a high-frequency oscillator circuit section is detected in a detector circuit and a bias of a negative voltage is supplied from a bias circuit section to the high-frequency amplifier circuit section with a detection voltage that is detected, a negative power supply circuit such as a DC/DC converter or a peripheral circuit is not required, and since a negative bias voltage can be supplied to a high-frequency amplifier circuit, downsizing can be achieved with a low cost.Type: GrantFiled: January 8, 2014Date of Patent: November 10, 2015Assignee: TDK CORPORATIONInventors: Tomohiko Shibuya, Atsushi Ajioka, Sadaharu Yoneda, Atsushi Tsumita
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Patent number: 9099968Abstract: The problem to be solved is to alleviate the distortion characteristic of an amplifier and to prevent the drop in gain with respect to a low-level high-frequency signal. A bias control circuit (10) for controlling the bias of an amplifier (20) which amplifies a high-frequency signal is provided herein with a detector (11) for detecting the envelope of the high-frequency signal, a first bias circuit (12) for supplying a constant bias current to the amplifier (20) and a second bias circuit (14) for supplying a bias current that varies with the variation of the level of the envelope of the high-frequency signal to the amplifier.Type: GrantFiled: January 17, 2012Date of Patent: August 4, 2015Assignee: TDK CORPORATIONInventors: Tomohiko Shibuya, Atsushi Ajioka, Atsushi Tsumita
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Publication number: 20150180419Abstract: There is provided a high-frequency amplifier including a divider, a plurality of amplifiers for amplifying a high-frequency signal distributed by the divider and outputting the amplified high-frequency signal, a combiner for combining amplified high-frequency signals, a base substrate, a conductor pattern that is connected to a ground end of each of the amplifiers, and a ground electrode. Each of the conductor patterns has a first conductive portion. A slot is disposed between the two conductor patterns connected to the corresponding adjacent amplifiers. Between the adjacent amplifiers, two vias are formed so that the slot is sandwiched between the vias. One of the two conductor patterns is connected to the ground electrode via one of the two vias, and the other one of the conductor patterns is connected to the ground electrode via the other one of the two vias.Type: ApplicationFiled: December 16, 2014Publication date: June 25, 2015Inventors: Tomohiko SHIBUYA, Atsushi AJIOKA, Atsushi TSUMITA, Sadaharu YONEDA
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Patent number: 8896380Abstract: A high frequency amplifier is characterized wherein a power amplification element and at least one of temperature compensation elements are adjacently provided on a first semiconductor layer, a first wiring pattern connected to the power amplification element, a second wiring pattern connected to the temperature compensation element, and a ground electrode are provided on at least one of second semiconductor layers existing in layers different from the first semiconductor layer, and the ground electrode is formed on the second semiconductor layer corresponding to a region that substantially projects a crevice part on which the temperature compensation element and the power amplification element are provided, on the same plane as the first semiconductor element.Type: GrantFiled: March 28, 2013Date of Patent: November 25, 2014Assignee: TDK CorporationInventors: Tomihiko Shibuya, Atsushi Ajioka, Atsushi Tsumita
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Publication number: 20140312972Abstract: A high-frequency amplifier circuit includes a balanced-unbalanced converter converting a single-ended signal into differential signals. The output of a first amplifier amplifying the single-ended signal is connected to the signal terminal on the unbalanced side of the balanced-unbalanced converter. The input of a second amplifier amplifying one of the differential signals is connected to one signal terminal on the balanced side of the balanced-unbalanced converter. The input of a third amplifier amplifying another of the differential signals is connected to another signal terminal on the balanced side of the balanced-unbalanced converter. An impedance element is inserted between an element on the balanced side of the balanced-unbalanced converter and a ground.Type: ApplicationFiled: April 10, 2014Publication date: October 23, 2014Applicant: TDK CorporationInventors: Sadaharu YONEDA, Atsushi AJIOKA, Tomohiko SHIBUYA, Atsushi TSUMITA
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Publication number: 20140210556Abstract: Since a high-frequency signal that is output from a high-frequency oscillator circuit section is detected in a detector circuit and a bias of a negative voltage is supplied from a bias circuit section to the high-frequency amplifier circuit section with a detection voltage that is detected, a negative power supply circuit such as a DC/DC converter or a peripheral circuit is not required, and since a negative bias voltage can be supplied to a high-frequency amplifier circuit, downsizing can be achieved with a low cost.Type: ApplicationFiled: January 8, 2014Publication date: July 31, 2014Applicant: TDK CORPORATIONInventors: Tomohiko SHIBUYA, Atsushi AJIOKA, Sadaharu Yoneda, Atsushi TSUMITA
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Publication number: 20140070891Abstract: To prevent a wrap-around signal from an output detection circuit unit that occurs when commonality is achieved between the power supply of the output detection circuit unit and the bias power supply of a power amplification unit. When commonality is achieved between the power supply of a diode of an output detection circuit unit and the power supply of a bias circuit, a resonance circuit is connected between the bias circuit and the output detection circuit unit, thereby preventing a wrap-around signal from the output side of a power amplification transistor from being input to the input side of the power amplification transistor.Type: ApplicationFiled: September 20, 2012Publication date: March 13, 2014Applicant: TDK CORPORATIONInventors: Tomohiko Shibuya, Atsushi Ajioka, Atsushi Tsumita
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Publication number: 20130328626Abstract: The problem to be solved is to alleviate the distortion characteristic of an amplifier and to prevent the drop in gain with respect to a low-level high-frequency signal. A bias control circuit (10) for controlling the bias of an amplifier (20) which amplifies a high-frequency signal is provided herein with a detector (11) for detecting the envelope of the high-frequency signal, a first bias circuit (12) for supplying a constant bias current to the amplifier (20) and a second bias circuit (14) for supplying a bias current that varies with the variation of the level of the envelope of the high-frequency signal to the amplifier.Type: ApplicationFiled: January 17, 2012Publication date: December 12, 2013Applicant: TDK CORPORATIONInventors: Tomohiko Shibuya, Atsushi Ajioka, Atsushi Tsumita
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Publication number: 20130257540Abstract: A high frequency amplifier is characterized wherein a power amplification element and at least one of temperature compensation elements are adjacently provided on a first semiconductor layer, a first wiring pattern connected to the power amplification element, a second wiring pattern connected to the temperature compensation element, and a ground electrode are provided on at least one of second semiconductor layers existing in layers different from the first semiconductor layer, and the ground electrode is formed on the second semiconductor layer corresponding to a region that substantially projects a crevice part on which the temperature compensation element and the power amplification element are provided, on the same plane as the first semiconductor element.Type: ApplicationFiled: March 28, 2013Publication date: October 3, 2013Applicant: TDK CorporationInventors: Tomihiko SHIBUYA, Atsushi AJIOKA, Atsushi TSUMITA
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Patent number: 7120394Abstract: A small-sized, front-end module is offered which is for use in a wireless communication device such as a mobile phone and which can suppress harmonics to a sufficiently low level. The front-end module has at least a switching circuit for switching one antenna between a transmiting system and a receiving system, a power amplifier for power-amplifying a transmission signal, and a low-pass filter inserted between the switching circuit and power amplifier. These components are integrated. A first kind of harmonics is produced from the switching circuit toward the power amplifier and reflected by the low-pass filter. A second kind of harmonics is produced from the power amplifier toward the antenna. A third kind of harmonics is produced from the switching circuit toward the antenna. The third kind of harmonics is canceled by the reflected first kind of harmonics and the second kind of harmonics.Type: GrantFiled: November 7, 2003Date of Patent: October 10, 2006Assignee: TDK CorporationInventors: Yoshihiro Suzuki, Atsushi Ajioka, Masashi Katsumata
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Publication number: 20040152426Abstract: A small-sized, front-end module is offered which is for use in a wireless communication device such as a mobile phone and which can suppress harmonics to a sufficiently low level. The front-end module has at least a switching circuit for switching one antenna between a transmiting system and a receiving system, a power amplifier for power-amplifying a transmission signal, and a low-pass filter inserted between the switching circuit and power amplifier. These components are integrated. A first kind of harmonics is produced from the switching circuit toward the power amplifier and reflected by the low-pass filter. A second kind of harmonics is produced from the power amplifier toward the antenna. A third kind of harmonics is produced from the switching circuit toward the antenna. The third kind of harmonics is canceled by the reflected first kind of harmonics and the second kind of harmonics.Type: ApplicationFiled: November 7, 2003Publication date: August 5, 2004Applicant: TDK CORPORATIONInventors: Yoshihiro Suzuki, Atsushi Ajioka, Masashi Katsumata