Transmission circuit
AssigneeMurata Manufacturing Co., Ltd.
InventorsMasatoshi Hase, Tsutomu Oonaro, Takashi Soga
Life of this patent
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Abstract
A transmission circuit appropriately controls output power in response to fluctuations in the impedance of a load. A transmission circuit includes: a transistor to which a bias current IB1 is supplied and that amplifies and outputs an input signal RFin; a transistor to which a bias current IB2 is supplied, that has a collector connected to the collector of the transistor, and that amplifies and outputs the input signal; a current generation circuit that generates a current I2 on the basis of a current I1 from the emitter of the transistor; and a bias control circuit that outputs a first bias control signal for controlling the bias current IB1 and a second bias control signal for controlling the bias current IB2 on the basis of the current I2.
Claims11
A transmission circuit comprising:
- a first amplifier transistor to which a first bias current or a first bias voltage is supplied, and that is configured to amplify a first input signal and to output a first amplified input signal;
- a second amplifier transistor to which a second bias current or a second bias voltage is supplied, that has a collector or a drain connected to a collector or a drain of the first amplifier transistor, and that is configured to amplify the first input signal and to output a second amplified input signal;
- a current generation circuit configured to generate a second current on the basis of a first current, the first current being from an emitter or a source of the second amplifier transistor;
- and
- a bias control circuit configured to output a first bias control signal that controls the first bias current or the first bias voltage, and a second bias control signal that controls the second bias current or the second bias voltage, on the basis of the second current.
Dependencies are inferred from the claim text.