Patents by Inventor Tadashi Takagi
Tadashi Takagi 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: 8311146Abstract: A transmission device (10) includes: a series/parallel converter (11); an MSK modulator (31) for modulating a signal on a channel basis; a D/A converter (13); a frequency converter (14a) for conversion into different carrier frequencies; a synchronization circuit (32); an amplifier (15); a multiplexer (16) for multiplexing amplification signals; and an antenna (19).Type: GrantFiled: March 4, 2008Date of Patent: November 13, 2012Assignees: Mitsubishi Electric Corporation, Tohoku UniversityInventors: Akinori Fujimura, Yasushi Sogabe, Fumio Ishizu, Tadashi Takagi, Hiroyuki Nakase, Kazuo Tsubouchi, Suguru Kameda, Shoichi Oshima
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Patent number: 7675383Abstract: A switch circuit includes: a first input and output terminal; a first inductor connected with the first input and output terminal; a capacitor connected with the first inductor; a second input and output terminal connected with the capacitor; a first MEMS switch connected with one end of the capacitor; a second MEMS switch connected with the other end of the capacitor; and a second inductor connected between the first MEMS switch and the second MEMS switch, and satisfies a relationship of f=1/(2??CL1)=1/(2??CL2), where L1 is an inductance of the first inductor, L2 is an inductance of the second inductor, C is a capacitance of the capacitor, and f is a use frequency.Type: GrantFiled: January 27, 2005Date of Patent: March 9, 2010Assignee: Mitsubishi Electric CorporationInventors: Masatake Hangai, Tamotsu Nishino, Shinnosuke Soda, Kenichi Miyaguchi, Kenji Kawakami, Masaomi Tsuru, Satoshi Hamano, Moriyasu Miyazaki, Tadashi Takagi
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Publication number: 20100054357Abstract: A transmission device (10) includes: a series/parallel converter (11); an MSK modulator (31) for modulating a signal on a channel basis; a D/A converter (13); a frequency converter (14a) for conversion into different carrier frequencies; a synchronization circuit (32); an amplifier (15); a multiplexer (16) for multiplexing amplification signals; and an antenna (19).Type: ApplicationFiled: March 4, 2008Publication date: March 4, 2010Applicants: MITSUBISHI ELECTRIC CORPORATION, TOHOKU UNIVERSITYInventors: Akinori Fujimura, Yasushi Sogabe, Fumio Ishizu, Tadashi Takagi, Hiroyuki Nakase, Kazuo Tsubouchi, Suguru Kameda, Shoichi Oshima
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Patent number: 7541894Abstract: A phase-shifting circuit includes: a first parallel circuit which is connected across input and output terminals of a high frequency signal, composed of a first inductor and a first switching element that exhibits a through state in an ON state and a capacitive property in an OFF state, and produces parallel resonance at a prescribed frequency when the first switching element is in the OFF state; a series circuit composed of a second inductor and a third inductor and connected in parallel with the first parallel circuit; a capacitor having its first terminal connected to a point of connection of the second and third inductors; and a second parallel circuit which is connected across a second terminal of the capacitor and a ground, composed of a fourth inductor and a second switching element that exhibits a through state in an ON state and a capacitive property in an OFF state, and produces parallel resonance at a prescribed frequency when the second switching element is in the OFF state.Type: GrantFiled: July 27, 2004Date of Patent: June 2, 2009Assignee: Mitsubishi Electric CorporationInventors: Kenichi Miyaguchi, Morishige Hieda, Tamotsu Nishino, Masatake Hangai, Moriyasu Miyazaki, Yukihisa Yoshida, Tadashi Takagi, Mikio Hatamoto
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Patent number: 7495529Abstract: Provided is a small-size phase shift circuit having a broad band characteristic. The phase shift circuit includes: a first switching element for switching between a through path and a capacitance capacity; a second switching element for switching the capacitance capacity for the through path and the ground; and a first and a second inductor having inductance. One end of the first switching element is connected to one end of the second switching element by the first inductor while the other ends of the first and the second switching element are connected to each other by the second inductor. One end of the first switching element is connected to a high-frequency signal input terminal while the other end of the first switching element is connected to a high-frequency signal output terminal. Thus, it is possible to constitute a phase device satisfying a predetermined condition.Type: GrantFiled: March 26, 2004Date of Patent: February 24, 2009Assignee: Mitsubishi Denki Kabushiki KaishaInventors: Kenichi Miyaguchi, Morishige Hieda, Tamotsu Nishino, Masatake Hangai, Moriyasu Miyazaki, Norihiro Yunoue, Hideki Hatakeyama, Yukihisa Yoshida, Tadashi Takagi
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Publication number: 20080136557Abstract: A switch circuit includes: a first input and output terminal; a first inductor connected with the first input and output terminal; a capacitor connected with the first inductor; a second input and output terminal connected with the capacitor; a first MEMS switch connected with one end of the capacitor; a second MEMS switch connected with the other end of the capacitor; and a second inductor connected between the first MEMS switch and the second MEMS switch, and satisfies a relationship of f=1/(2??CL1)=1/(2??CL2), where L1 is an inductance of the first inductor, L2 is an inductance of the second inductor, C is a capacitance of the capacitor, and f is a use frequency.Type: ApplicationFiled: January 27, 2005Publication date: June 12, 2008Inventors: Masatake Hangai, Tamotsu Nishino, Shinnosuke Soda, Kenichi Miyaguchi, Kenji Kawakami, Masaomi Tsuru, Satoshi Hamano, Moriyasu Miyazaki, Tadashi Takagi
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Publication number: 20070273456Abstract: A phase-shifting circuit includes: a first parallel circuit which is connected across input and output terminals of a high frequency signal, composed of a first inductor and a first switching element that exhibits a through state in an ON state and a capacitive property in an OFF state, and produces parallel resonance at a prescribed frequency when the first switching element is in the OFF state; a series circuit composed of a second inductor and a third inductor and connected in parallel with the first parallel circuit; a capacitor having its first terminal connected to a point of connection of the second and third inductors; and a second parallel circuit which is connected across a second terminal of the capacitor and a ground, composed of a fourth inductor and a second switching element that exhibits a through state in an ON state and a capacitive property in an OFF state, and produces parallel resonance at a prescribed frequency when the second switching element is in the OFF state.Type: ApplicationFiled: July 27, 2004Publication date: November 29, 2007Inventors: Kenichi Miyaguchi, Morishige Hieda, Tamotsu Nishino, Masatake Hangai, Moriyasu Miyazaki, Yukihisa Yoshida, Tadashi Takagi, Mikio Hatamoto
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Publication number: 20070188264Abstract: Provided is a small-size phase shift circuit having a broad band characteristic. The phase shift circuit includes: a first switching element for switching between a through path and a capacitance capacity; a second switching element for switching the capacitance capacity for the through path and the ground; and a first and a second inductor having inductance. One end of the first switching element is connected to one end of the second switching element by the first inductor while the other ends of the first and the second switching element are connected to each other by the second inductor. One end of the first switching element is connected to a high-frequency signal input terminal while the other end of the first switching element is connected to a high-frequency signal output terminal. Thus, it is possible to constitute a phase device satisfying a predetermined condition.Type: ApplicationFiled: March 26, 2004Publication date: August 16, 2007Inventors: Kenichi Miyaguchi, Morishige Hieda, Tamotsu Nishino, Masatake Hangai, Moriyasu Miyazaki, Norihiro Yunoue, Hideki Hatakeyama, Yukihisa Yoshida, Tadashi Takagi
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Publication number: 20070164818Abstract: A high efficiency amplifier has an analog predistortion circuit (5) connected between an input side dividing circuit (2) and a quarter-wave line (6). This offers an advantage of being able to improve the linearity of the entire amplifier because the nonlinear distortion of a peak amplifier (7) is compensated.Type: ApplicationFiled: June 18, 2004Publication date: July 19, 2007Inventors: Kenichi Horiguchi, Masatoshi Nakayama, Tadashi Takagi
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Patent number: 7167064Abstract: A phase shift circuit and a phase shifter are achieved which are small in size and wide in bandwidth. The phase shift circuit includes a capacitor, and a series circuit composed of a switching element which exhibits capacitivity when it is in an off-state and an inductor connected in series with this switching element, the series circuit being connected in parallel with the capacitor. The capacitor and one terminal of the series circuit are connected with a high frequency signal input/output terminal, and the other terminal thereof is connected with ground.Type: GrantFiled: January 7, 2003Date of Patent: January 23, 2007Assignee: Mitsubishi Denki Kabushiki KaishaInventors: Kenichi Miyaguchi, Morishige Hieda, Michiaki Kasahara, Tadashi Takagi, Mikio Hatamoto
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Patent number: 7123116Abstract: A phase shifter includes an FET 2a having its drain electrode connected to an input/output terminal 1a; and FET 2b having its drain electrode connected to the source electrode of the FET 2a and its source electrode connected to an input/output terminal 1b; and FET 2c having its drain electrode connected to the source electrode of the FET 2a; and an inductor 3a having its first terminal connected to the source electrode of the FET 2c and its second terminal connected to a ground. It can reduce the insertion loss by narrowing the gate width of the FET 2a, and carries out the phase shift of a high-frequency signal with suppressing the reflection.Type: GrantFiled: March 26, 2002Date of Patent: October 17, 2006Assignee: Mitsubishi Denki Kabushiki KaishaInventors: Morishige Hieda, Kenichi Miyaguchi, Michiaki Kasahara, Tadashi Takagi, Hiroshi Ikematsu, Norio Takeuchi, Hiromasa Nakaguro, Kazuyoshi Inami
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Publication number: 20050179136Abstract: In a multi-layer substrate module receiving from an external earth node (20) supply of a reference potential (Vss) for grounding, a plurality of ground lines (170-1, 170-2, 170-3) are provided respectively corresponding to a plurality of internal circuits (210, 220, 230). Moreover, a common node (Ncmn) for coupling the ground lines (170-1, 170-2, 170-3) is provided in an insulating layer (105C) of the multi-layer substrate module. The common node (Ncmn) is electrically coupled to the earth node 20 through a ground pin terminal 204 shared by the plurality of internal circuits (210, 220, 230). Preferably, the common node (Ncmn) is provided in the lowest insulating layer of the multi-layer substrate module. Thus, parasitic inductance of the portion through which an earth current flows, that is, the portion common to the plurality of internal circuits (210, 220, 230), can be suppressed with a small number of ground pin terminals.Type: ApplicationFiled: April 19, 2005Publication date: August 18, 2005Applicant: MITSUBISHI DENKI KABUSHIKI KAISHAInventors: Takatoshi Katsura, Kenji Itoh, Hiroaki Nagano, Youji Isota, Mitsuhiro Shimozawa, Tadashi Takagi, Noriharu Suematsu, Masayoshi Ono, Kenichi Maeda
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Patent number: 6906411Abstract: In a multi-layer substrate module receiving from an external earth node supply of a reference potential for grounding, a plurality of ground lines are provided respectively corresponding to a plurality of internal circuits. Moreover, a common node for coupling the ground lines is provided in an insulating layer of the multi-layer substrate module. The common node is electrically coupled to the earth node through a ground pin terminal shared by the plurality of internal circuits. Preferably, the common node is provided in the lowest insulating layer of the multi-layer substrate module. Thus, parasitic inductance of the portion through which an earth current flows, that is, the portion common to the plurality of internal circuits, can be suppressed with a small number of ground pin terminals. Accordingly, the inflow phenomenon of the earth current between the plurality of internal circuits is prevented, enabling stable operation.Type: GrantFiled: June 29, 2000Date of Patent: June 14, 2005Assignee: Mitsubishi Denki Kabushiki KaishaInventors: Takatoshi Katsura, Kenji Itoh, Hiroaki Nagano, Youji Isota, Mitsuhiro Shimozawa, Tadashi Takagi, Noriharu Suematsu, Masayoshi Ono, Kenichi Maeda
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Patent number: 6861906Abstract: A high-frequency semiconductor device according to the present invention achieves improvements in degradation of noise characteristics and a reduction in gain, and an improvement in reduction in power efficiency while suppressing a concentration of a current to multifinger HBTs. In the multifinger HBTs constituting a first stage and an output stage of an amplifier 10, basic HBTs 14 that constitute the multifinger HBT 12 corresponding to the first stage, are each made up of an HBT 14a and an emitter resistor 14b connected to the corresponding emitter of the HBT 14a, whereas basic HBTs 18 that constitute the multifinger HBT 16 corresponding to the output stage, are each comprised of an HBT 18a and a base resistor 18c connected to the corresponding base of the HBT 18a. The high-frequency semiconductor device according to the present invention is useful as a high output power amplifier used in satellite communications, ground microwave communications, mobile communications, etc.Type: GrantFiled: May 11, 2001Date of Patent: March 1, 2005Assignee: Mitsubishi Denki Kabushiki KaishaInventors: Kazutomi Mori, Shintaro Shinjo, Kousei Maemura, Teruyuki Shimura, Kazuhiko Nakahara, Tadashi Takagi
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Patent number: 6784743Abstract: A high frequency amplifier in which a common emitter bipolar transistor is used, and in that a constant current source and a constant voltage source are switched to apply a DC bias to a base terminal of the bipolar transistor in accordance with a power level of a high frequency signal input to the bipolar transistor or a power level of a high frequency signal output therefrom, and a frequency mixer in that a DC bias is applied to a base of at least one of a bipolar transistor for the input of a high frequency signal and a bipolar transistor for the input of a local oscillation wave by using a configuration for applying the DC bias to a base of an amplifying bipolar transistor employed in the high frequency amplifier.Type: GrantFiled: July 30, 2002Date of Patent: August 31, 2004Assignee: Mitsubishi Denki Kabushiki KaishaInventors: Eiji Taniguchi, Noriharu Suematsu, Chiemi Sawaumi, Kenichi Maeda, Takayuki Ikushima, Hiroyuki Joba, Tadashi Takagi
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Publication number: 20040145429Abstract: A phase shifter includes an FET 2a having its drain electrode connected to an input/output terminal 1a; an FET 2b having its drain electrode connected to the source electrode of the FET 2a and its source electrode connected to an input/output terminal 1b; an FET 2c having its drain electrode connected to the source electrode of the FET 2a; and an inductor 3a having its first terminal connected to the source electrode of the FET 2c and its second terminal connected to a ground. It can reduce the insertion loss by narrowing the gate width of the FET 2a, and carries out the phase shift of a high-frequency signal with suppressing the reflection.Type: ApplicationFiled: October 30, 2003Publication date: July 29, 2004Inventors: Morishige Hieda, Kenichi Miyaguchi, Michiaki Kasahara, Tadashi Takagi, Hiroshi Ikematsu, Norio Takeuchi, Hiromasa Nakaguro, Kazuyoshi Inami
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Patent number: 6750720Abstract: Between resistors 13, 14 and an NPN bipolar transistor 12 are interposed PNP bipolar transistors 21, 22 forming a current mirror 20 that uses a collector current of the NPN bipolar transistor 12 as a reference current, and determines a collector current of an NPN bipolar transistor 11. This makes possible to design a size ratio A of the PNP bipolar transistors 21, 22 so as to approximate a voltage drop &Dgr;Vb to a value close to zero, and to suppress the voltage drop &Dgr;Vb of the base voltage Vb accordingly to achieve a high power output and high efficiency when a high frequency input signal Pin increases and generates a base rectified current.Type: GrantFiled: June 12, 2002Date of Patent: June 15, 2004Assignee: Mitsubishi Denki Kabushiki KaishaInventors: Kazutomi Mori, Shintarou Shinjo, Hiroyuki Joba, Yoshinori Takahashi, Yukio Ikeda, Tadashi Takagi
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Publication number: 20040085112Abstract: A phase shift circuit and a phase shifter are achieved which are small in size and wide in bandwidth. The phase shift circuit includes a capacitor, and a series circuit composed of a switching element which exhibits capacitivity when it is in an off-state and an inductor connected in series with this switching element, the series circuit being connected in parallel with the capacitor. The capacitor and one terminal of the series circuit are connected with a high frequency signal input/output terminal, and the other terminal thereof is connected with ground.Type: ApplicationFiled: September 9, 2003Publication date: May 6, 2004Inventors: Kenichi Miyaguchi, Morishige Hieda, Michiaki Kasahara, Tadashi Takagi, Mikio Hatamoto
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Patent number: 6674341Abstract: A miniaturized phase shifter and a multi-bit phase shifter are provided, in which filters are constructed using capacitors at FET pinch-off and pass phase can be shifted by turning the FET on and off, the phase shifter including: a first FET having a drain electrode connected to an input terminal and a source electrode connected to an output terminal; a second FET, in which one of a drain electrode and a source electrode thereof is connected to the source electrode of the first FET and the other is connected to ground via a first inductor; and a third FET, in which one of a drain electrode and a source electrode thereof is connected to the drain electrode of the first FET and the other is connected to ground via a second inductor.Type: GrantFiled: August 27, 2002Date of Patent: January 6, 2004Assignee: Mitsubishi Denki Kabushiki KaishaInventors: Morishige Hieda, Kenichi Miyaguchi, Kazutomi Mori, Michiaki Kasahara, Tadashi Takagi, Hiroshi Ikematsu, Norio Takeuchi, Hiromasa Nakaguro, Kazuyoshi Inami
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Publication number: 20030020563Abstract: A miniaturized phase shifter and a multi-bit phase shifter are provided, in which filters are constructed using capacitors at FET pinch-off and pass phase can be shifted by turning the FET on and off, the phase shifter including: a first FET having a drain electrode connected to an input terminal and a source electrode connected to an output terminal; a second FET, in which one of a drain electrode and a source electrode thereof is connected to the source electrode of the first FET and the other is connected to ground via a first inductor; and a third FET, in which one of a drain electrode and a source electrode thereof is connected to the drain electrode of the first FET and the other is connected to ground via a second inductor.Type: ApplicationFiled: August 27, 2002Publication date: January 30, 2003Inventors: Morishige Hieda, Kenichi Miyaguchi, Kazutomi Mori, Michiaki Kasahara, Tadashi Takagi, Hiroshi Ikematsu, Norio Takeuchi, Hiromasa Nakaguro, Kazuyoshi Inami