Power amplifier circuit
AssigneeMurata Manufacturing Co., Ltd.
InventorsTakayuki TSUTSUI, Masao KONDO, Satoshi TANAKA
Life of this patent
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Abstract
A power amplifier circuit includes a first transistor that amplifies a first signal and outputs a second signal; a second transistor that amplifies the second signal and outputs a third signal; a bias circuit that supplies a bias current to a base of the second transistor; and a bias adjustment circuit that adjusts the bias current by subjecting the first signal to detection. The bias adjustment circuit controls the bias current such that a first current extracted from the bias circuit depends on a magnitude of the first signal.
Claims20
A power amplifier circuit comprising:
- a first transistor configured to amplify a first signal and output a second signal;
- a second transistor configured to amplify the second signal and output a third signal;
- a bias circuit configured to supply a bias current to a base of the second transistor;
- and
- a bias adjustment circuit configured to adjust the bias current by subjecting the first signal to detection,
- wherein the bias adjustment circuit controls the bias current such that a first current extracted from the bias circuit depends on a magnitude of the first signal,
- wherein the bias circuit includes:
- a first resistance element having one end to which a bias control voltage is supplied, and
- a third transistor having a base connected to another end of the first resistance element and an emitter from which the bias current is outputted, and
- wherein the first current is extracted from the base of the third transistor.
A power amplifier circuit comprising:
- a first transistor configured to amplify a first signal and output a second signal;
- a second transistor configured to amplify the second signal and output a third signal;
- a bias circuit configured to supply a bias current to a base of the second transistor;
- and
- a bias adjustment circuit configured to adjust the bias current by subjecting the first signal to detection,
- wherein the bias adjustment circuit controls the bias current such that a first current extracted from the bias circuit depends on a magnitude of the first signal,
- wherein the bias circuit includes:
- a resistance element connected in series with an inductor and a second capacitor, the inductor and the second capacitor being connected in parallel to each other.
Dependencies are inferred from the claim text.