Limiter circuit and power amplifier circuit
AssigneeMurata Manufacturing Co., Ltd.
InventorYoshifumi TAKAHASHI
Life of this patent
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Abstract
There is provided a limiter circuit and a power amplifier circuit that are capable of effectively limiting output power of an amplifying transistor based on the amplitude of an input signal. A limiter circuit is connectable to an amplifying transistor that amplifies and outputs a radio frequency signal and controls a voltage to be applied to the amplifying transistor, based on the radio frequency signal. The limiter circuit includes an input signal detection transistor that detects power of the radio frequency signal and a voltage limiting transistor that limits the voltage to be applied to the amplifying transistor, based on current flowing to the input signal detection transistor.
Claims18
A limiter circuit connected to an amplifying transistor that amplifies and outputs a radio frequency signal, the limiter circuit being configured to control a voltage applied to the amplifying transistor based on the radio frequency signal, the limiter circuit comprising:
- an input signal detection transistor configured to detect a power of the radio frequency signal;
- and
- a voltage limiting transistor configured to limit the voltage applied to the amplifying transistor based on a current flowing to the input signal detection transistor.
A limiter circuit comprising:
- an input terminal;
- an output terminal;
- an input signal detection transistor that is electrically connected to the input terminal and that is configured to detect a power of a radio frequency signal;
- and
- a voltage limiting transistor having a first terminal that is electrically connected to the output terminal, and a third terminal electrically connected to a first supply voltage terminal,
- wherein an amplifying transistor configured to amplify and output a radio frequency signal is connected between the input terminal and the output terminal.
Dependencies are inferred from the claim text.