Patents by Inventor Takayuki Matsuzuka
Takayuki Matsuzuka 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: 9543902Abstract: A power amplifier includes: an amplifier; an input matching circuit connected to an input of the amplifier; an output matching circuit connected to an output of the amplifier; and a low-frequency processing circuit connected to the input matching circuit or the output matching circuit, wherein the low-frequency processing circuit includes a first line having a first end connected to the input matching circuit or the output matching circuit, a first shot stub connected to a second end of the first line and including a second line and a first capacitor connected in series each other, and a second short stub connected to the second end of the first line in parallel with the first short stub and including a third line and a second capacitor which are connected in series each other, the first line has a length of ?/8, the second line has a length of ?/4, and the third line has a length of ?/8 with respect to a wavelength ? of a fundamental frequency.Type: GrantFiled: October 29, 2015Date of Patent: January 10, 2017Assignee: Mitsubishi Electric CorporationInventors: Takayuki Matsuzuka, Junichi Udomoto, Tetsuo Kunii, Hiromitsu Utsumi
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Publication number: 20160285421Abstract: A power amplifier includes: an amplifier; an input matching circuit connected to an input of the amplifier; an output matching circuit connected to an output of the amplifier; and a low-frequency processing circuit connected to the input matching circuit or the output matching circuit, wherein the low-frequency processing circuit includes a first line having a first end connected to the input matching circuit or the output matching circuit, a first shot stub connected to a second end of the first line and including a second line and a first capacitor connected in series each other, and a second short stub connected to the second end of the first line in parallel with the first short stub and including a third line and a second capacitor which are connected in series each other, the first line has a length of ?/8, the second line has a length of ?/4, and the third line has a length of ?/8 with respect to a wavelength ? of a fundamental frequency.Type: ApplicationFiled: October 29, 2015Publication date: September 29, 2016Applicant: MITSUBISHI ELECTRIC CORPORATIONInventors: Takayuki MATSUZUKA, Junichi UDOMOTO, Tetsuo KUNII, Hiromitsu UTSUMI
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Patent number: 8917144Abstract: A power amplifier includes: an amplification element amplifying an input signal; and a bias circuit supplying a bias current to an input of the amplification element. The bias circuit includes a reference voltage terminal to which a battery voltage is applied from a battery, a first resistor having a first end connected to the reference voltage terminal, a second resistor connected between a second end of the first resistor and ground, and a first transistor. The first transistor has a control terminal connected to a connection point between the first resistor and the second resistor, a first terminal connected to a power supply, and a second terminal connected to the input of the amplification element. The first and second resistors are the same material.Type: GrantFiled: March 15, 2013Date of Patent: December 23, 2014Assignee: Mitsubishi Electric CorporationInventors: Kazuhiro Iyomasa, Takayuki Matsuzuka
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Patent number: 8686795Abstract: A power amplifier includes: an amplifier having a base into which input signals are input, a collector to which a collector voltage is supplied, and an emitter; and a bias circuit for supplying a bias current to the base of the amplifier. The bias circuit includes a first transistor having a first control terminal into which a reference voltage is input, a first terminal to which a power voltage is applied, and a second terminal connected to the base of the amplifier. A capacitance adjusting circuit elevates capacitance between a grounding point and at least one of the first control terminal and the first terminal when the collector voltage of the amplifier is lowered.Type: GrantFiled: September 12, 2012Date of Patent: April 1, 2014Assignee: Mitsubishi Electric CorporationInventors: Atsushi Okamura, Takayuki Matsuzuka
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Publication number: 20140070890Abstract: A power amplifier includes: an amplification element amplifying an input signal; and a bias circuit supplying a bias current to an input of the amplification element. The bias circuit includes a reference voltage terminal to which a battery voltage is applied from a battery, a first resistor having a first end connected to the reference voltage terminal, a second resistor connected between a second end of the first resistor and ground, and a first transistor. The first transistor has a control terminal connected to a connection point between the first resistor and the second resistor, a first terminal connected to a power supply, and a second terminal connected to the input of the amplification element. The first and second resistors are the same material.Type: ApplicationFiled: March 15, 2013Publication date: March 13, 2014Applicant: Mitsubishi Electric CorporationInventors: Kazuhiro Iyomasa, Takayuki Matsuzuka
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Patent number: 8659352Abstract: A power amplifier includes: a first amplifying element amplifying an input signal; a second amplifying element amplifying an output signal of the first amplifying element; a third amplifying element amplifying the input signal; a first switch connected between an output of the first amplifying element and an input of second amplifying element; a second switch connected between an output of the first amplifying element and an output of the third amplifying element; a third switch connected between an output of the first amplifying element and an output of the second amplifying element; a reference voltage generating a circuit generating reference voltage; a bias circuit supplying a bias current, based on the reference voltage, to inputs of the first, second, and third amplifying elements; and a control circuit controlling the first, second and third switches and the reference voltage generating circuit.Type: GrantFiled: August 31, 2012Date of Patent: February 25, 2014Assignee: Mitsubishi Electric CorporationInventors: Takayuki Matsuzuka, Kazuhiro Iyomasa
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Publication number: 20130241659Abstract: A power amplifier includes: a first amplifying element amplifying an input signal; a second amplifying element amplifying an output signal of the first amplifying element; a third amplifying element amplifying the input signal; a first switch connected between an output of the first amplifying element and an input of second amplifying element; a second switch connected between an output of the first amplifying element and an output of the third amplifying element; a third switch connected between an output of the first amplifying element and an output of the second amplifying element; a reference voltage generating a circuit generating reference voltage; a bias circuit supplying a bias current, based on the reference voltage, to inputs of the first, second, and third amplifying elements; and a control circuit controlling the first, second and third switches and the reference voltage generating circuit.Type: ApplicationFiled: August 31, 2012Publication date: September 19, 2013Applicant: MITSUBISHI ELECTRIC CORPORATIONInventors: Takayuki Matsuzuka, Kazuhiro Iyomasa
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Publication number: 20130207729Abstract: A power amplifier includes: an amplifier having a base into which input signals are input, a collector to which a collector voltage is supplied, and an emitter; and a bias circuit for supplying a bias current to the base of the amplifier. The bias circuit includes a first transistor having a first control terminal into which a reference voltage is input, a first terminal to which a power voltage is applied, and a second terminal connected to the base of the amplifier. A capacitance adjusting circuit elevates capacitance between a grounding point and at least one of the first control terminal and the first terminal when the collector voltage of the amplifier is lowered.Type: ApplicationFiled: September 12, 2012Publication date: August 15, 2013Applicant: MITSUBISHI ELECTRIC CORPORATIONInventors: Atsushi Okamura, Takayuki Matsuzuka
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Patent number: 8461929Abstract: A power amplifier includes a first amplifier unit, a second amplifier unit, and an attenuator. The second amplifier receives a signal from the first amplifier unit and amplifies the signal. The attenuator is provided between the first and second amplifier units. The attenuator has arms, including at least one parallel arm and at least one series arm, and has switches connected to the arms to switch the electrical connection states of the arms with respect to the first and second amplifier units. The at least one parallel arm and the at least one series arm are alternately arranged, in the order named, as viewed in the direction from the first amplifier unit to the second amplifier unit.Type: GrantFiled: August 1, 2011Date of Patent: June 11, 2013Assignee: Mitsubishi Electric CorporationInventors: Kazuya Yamamoto, Miyo Miyashita, Takayuki Matsuzuka, Kenji Mukai
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Patent number: 8432227Abstract: A power amplifier includes: an amplifying element having a base into which input signals are inputted, a collector to which a collector voltage is applied, and an emitter; and a bias circuit supplying a bias current to the base of the amplifying element. The bias circuit includes a bias current lowering circuit which lowers the bias current when the collector voltage is lower than a prescribed threshold value.Type: GrantFiled: November 22, 2011Date of Patent: April 30, 2013Assignee: Mitsubishi Electric CorporationInventors: Atsushi Okamura, Kazuya Yamamoto, Takayuki Matsuzuka
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Patent number: 8354888Abstract: A power amplifier includes an input matching circuit, an amplifier transistor for amplifying an input signal received through the input matching circuit, an element for varying the collector voltage of the amplifier transistor, a bias circuit for varying the idle current in the amplifier transistor, and a compensation circuit for varying capacitance of the input matching circuit to maintain the phase shift and the input reflection in the power amplifier constant when the collector voltage and the idle current are varied, to prevent a decrease in the efficiency of the power amplifier due to changes in the output power of the amplifier transistor.Type: GrantFiled: August 1, 2011Date of Patent: January 15, 2013Assignee: Mitsubishi Electric CorporationInventors: Takayuki Matsuzuka, Kazuya Yamamoto, Takao Moriwaki
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Publication number: 20120306579Abstract: A power amplifier includes: an amplifying element having a base into which input signals are inputted, a collector to which a collector voltage is applied, and an emitter; and a bias circuit supplying a bias current to the base of the amplifying element. The bias circuit includes a bias current lowering circuit which lowers the bias current when the collector voltage is lower than a prescribed threshold value.Type: ApplicationFiled: November 22, 2011Publication date: December 6, 2012Applicant: Mitsubishi Electric CorporationInventors: Atsushi OKAMURA, Kazuya Yamamoto, Takayuki Matsuzuka
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Patent number: 8217722Abstract: A power amplifier comprises: an amplifying transistor for amplifying an input signal; a reference voltage generating circuit which generates a reference voltage; a bias circuit generating a bias voltage based on the reference voltage and supplying the bias voltage to the amplifying transistor; and a booster elevating an enable voltage input from outside and outputting the enable voltage. The reference voltage generating circuit is turned ON/OFF in correspondence with an output voltage of the booster. The booster includes: an enable terminal to which the enable voltage is applied; a power source terminal connected to a power source; a transistor having a control electrode connected to the enable terminal, a first electrode connected to the power source terminal, and a second electrode that is grounded; and a FET resistor connected between the first electrode of the transistor and the power source terminal. A gate electrode of the FET resistor is open.Type: GrantFiled: April 4, 2011Date of Patent: July 10, 2012Assignee: Mitsubishi Electric CorporationInventors: Kazuya Yamamoto, Miyo Miyashita, Satoshi Suzuki, Takayuki Matsuzuka
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Publication number: 20120154055Abstract: A power amplifier includes a first amplifier unit, a second amplifier unit, and an attenuator. The second amplifier receives a signal from the first amplifier unit and amplifies the signal. The attenuator is provided between the first and second amplifier units. The attenuator has arms, including at least one parallel arm and at least one series arm, and has switches connected to the arms to switch the electrical connection states of the arms with respect to the first and second amplifier units. The at least one parallel arm and the at least one series arm are alternately arranged, in the order named, as viewed in the direction from the first amplifier unit to the second amplifier unit.Type: ApplicationFiled: August 1, 2011Publication date: June 21, 2012Applicant: MITSUBISHI ELECTRIC CORPORATIONInventors: Kazuya Yamamoto, Miyo Miyashita, Takayuki Matsuzuka, Kenji Mukai
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Publication number: 20120146733Abstract: A power amplifier includes an input matching circuit, an amplifier transistor for amplifying an input signal received through the input matching circuit, an element for varying the collector voltage of the amplifier transistor, a bias circuit for varying the idle current in the amplifier transistor, and a compensation circuit for varying capacitance of the input matching circuit to maintain the phase shift and the input reflection in the power amplifier constant when the collector voltage and the idle current are varied, to prevent a decrease in the efficiency of the power amplifier due to changes in the output power of the amplifier transistor.Type: ApplicationFiled: August 1, 2011Publication date: June 14, 2012Applicant: MITSUBISHI ELECTRIC CORPORATIONInventors: Takayuki Matsuzuka, Kazuya Yamamoto, Takao Moriwaki
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Patent number: 8138836Abstract: An emitter-follower bias circuit supplying a bias voltage to the base of an amplification transistor includes: a depletion mode FET boosting a reference voltage; and an emitter-follower circuit generating the bias voltage in response to the reference voltage boosted by the depletion mode FET.Type: GrantFiled: September 3, 2010Date of Patent: March 20, 2012Assignee: Mitsubishi Electric CorporationInventors: Takayuki Matsuzuka, Kazuya Yamamoto, Tomoyuki Asada
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Publication number: 20120062321Abstract: A power amplifier comprises: an amplifying transistor for amplifying an input signal; a reference voltage generating circuit which generates a reference voltage; a bias circuit generating a bias voltage based on the reference voltage and supplying the bias voltage to the amplifying transistor; and a booster elevating an enable voltage input from outside and outputting the enable voltage. The reference voltage generating circuit is turned ON/OFF in correspondence with an output voltage of the booster. The booster includes: an enable terminal to which the enable voltage is applied; a power source terminal connected to a power source; a transistor having a control electrode connected to the enable terminal, a first electrode connected to the power source terminal, and a second electrode that is grounded; and a FET resistor connected between the first electrode of the transistor and the power source terminal. A gate electrode of the FET resistor is open.Type: ApplicationFiled: April 4, 2011Publication date: March 15, 2012Applicant: MITSUBISHI ELECTRIC CORPORATIONInventors: Kazuya Yamamoto, Miyo Miyashita, Satoshi Suzuki, Takayuki Matsuzuka
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Publication number: 20110187459Abstract: An emitter-follower bias circuit supplying a bias voltage to the base of an amplification transistor includes: a depletion mode FET boosting a reference voltage; and an emitter-follower circuit generating the bias voltage in response to the reference voltage boosted by the depletion mode FET.Type: ApplicationFiled: September 3, 2010Publication date: August 4, 2011Applicant: MITSUBISHI ELECTRIC CORPORATIONInventors: Takayuki Matsuzuka, Kazuya Yamamoto, Tomoyuki Asada
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Patent number: 7936219Abstract: A power amplifier and bias circuit includes a combination circuit in which a voltage drive bias circuit and a current drive bias circuit are connected in a parallel relationship with each other. The power amplifier bias circuit also includes an idle current control circuit which uses the collector voltage of amplifier transistors. When the collector voltage of the amplifier transistors is lower than the threshold voltage of a first transistor (approximately 1.3 V), the first transistor is turned off. At that time, since the reference voltage (2.4-2.5 V) is higher than the voltage for turning on both a second transistor and a diode (namely, approximately 1.3 V plus 0.7 V), a current flows and the first transistor turns on. As a result, a current is drawn from the bases of the amplifier transistors to GND through two resistances, so that the idle currents of the amplifier transistors decrease.Type: GrantFiled: February 25, 2010Date of Patent: May 3, 2011Assignee: Mitsubishi Electric CorporationInventors: Takayuki Matsuzuka, Kazuya Yamamoto, Atsushi Okamura
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Publication number: 20110018639Abstract: A power amplifier and bias circuit includes a combination circuit in which a voltage drive bias circuit and a current drive bias circuit are connected in a parallel relationship with each other. The power amplifier bias circuit also includes an idle current control circuit which uses the collector voltage of amplifier transistors. When the collector voltage of the amplifier transistors is lower than the threshold voltage of a first transistor (approximately 1.3 V), the first transistor is turned off. At that time, since the reference voltage (2.4-2.5 V) is higher than the voltage for turning on both a second transistor and a diode (namely, approximately 1.3 V plus 0.7 V), a current flows and the first transistor turns on. As a result, a current is drawn from the bases of the amplifier transistors to GND through two resistances, so that the idle currents of the amplifier transistors decrease.Type: ApplicationFiled: February 25, 2010Publication date: January 27, 2011Applicant: MITSUBISHI ELECTRIC CORPORATIONInventors: Takayuki Matsuzuka, Kazuya Yamamoto, Atsushi Okamura