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Patent Agency Ranking
公开(公告)号：US20210234523A1
公开(公告)日：2021-07-29
申请号：US17230101
申请日：2021-04-14
Applicant: Murata Manufacturing Co., Ltd.
Inventor： Fuminori MORISAWA , Kazuhiko ISHIMOTO , Fumio HARIMA
Abstract: There is provided a power amplifier circuit with improved operation speed of the protection function against overcurrent or overvoltage. The power amplifier circuit includes an amplifier configured to amplify a radio frequency signal and output the radio frequency signal, a bias current supply circuit configured to supply a bias current to the amplifier, a detection circuit configured to detect whether the current or voltage of the amplifier is equal to or greater than a predetermined threshold; and a draw circuit configured to, when the detection circuit detects that the current or voltage is equal to or greater than the predetermined threshold, draw at least a part of the bias current supplied to the amplifier.
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公开(公告)号：US20230216454A1
公开(公告)日：2023-07-06
申请号：US18182661
申请日：2023-03-13
Applicant: Murata Manufacturing Co., Ltd.
Inventor： Kazuhiko ISHIMOTO
CPC classification number: H03F3/1935 , H03F3/21 , H03F1/0216 , H03F2200/451
Abstract: A current control circuit controls a bias current that is supplied to an amplifier transistor that amplifies a radio-frequency signal and includes a node, a constant current source circuit that supplies a first current to the node, and a variable current source circuit that supplies a second current to the node, based on a result of comparison between a potential of the node and a reference potential. The node outputs a control current including the first current and the second current for controlling the bias current.
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公开(公告)号：US20200252029A1
公开(公告)日：2020-08-06
申请号：US16781058
申请日：2020-02-04
Applicant: Murata Manufacturing Co., Ltd.
Inventor： Mikiko FUKASAWA , Kazuhiko ISHIMOTO
Abstract: A current control circuit controls a base current of a first transistor included in a bias circuit outputting a bias current to a power amplifier based on a base-collector voltage of the first transistor. The current control circuit includes a first circuit that outputs a signal associated with the base-collector voltage of the first transistor, and a second circuit that, based on the signal, provides electrical continuity between a base of the first transistor and a reference potential.
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公开(公告)号：US20250030389A1
公开(公告)日：2025-01-23
申请号：US18775366
申请日：2024-07-17
Applicant: Murata Manufacturing Co., Ltd.
Inventor： Kazuhiko ISHIMOTO
Abstract: A bias power supply circuit operates in one of a plurality of current generation modes generating bias power source currents of different levels. The bias power source current is reduced where a first detection signal indicates that a power source voltage is less than a first threshold value. Under control of a bias control circuit, a bias circuit operates in one of an on mode and an off mode wherein the on mode is a mode in which the bias power source current generated by the bias power supply circuit is supplied to a power amplifying transistor as a bias current, and the off mode is a mode in which the bias current whose level is reduced compared with a case where the bias circuit operates in the on mode is supplied or supply of the bias current is stopped.
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公开(公告)号：US20210278871A1
公开(公告)日：2021-09-09
申请号：US17329714
申请日：2021-05-25
Applicant: Murata Manufacturing Co., Ltd.
Inventor： Kazuhiko ISHIMOTO
IPC: G05F3/26 , G01R19/165 , H03F3/193 , G05F1/46
Abstract: A current output circuit includes an input circuit that outputs a second current in response to a first current when the first current is inputted, an output circuit that outputs a third current in response to the second current, and a control circuit that causes the output circuit to output a current when a control signal is inputted before the first current is inputted to the input circuit. The output circuit includes transistors of a first group and the input circuit includes transistors of a second group.
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