Murata Manufacturing Co., Ltd.

Shohei Imai

Satoshi Tanaka

Takeshi Kogure

Yoshiaki Sukemori

A first transistor having a base or a gate supplied with a high-frequency signal through a capacitor, and supplied with a bias current through a resistive element, a second transistor having a base or a gate connected to an emitter or a source of the first transistor, and a collector or a drain connected to an output terminal, and a third transistor having a collector or a drain connected to the base or the gate of the first transistor, and an emitter or a source connected to reference potential are provided, and the third transistor is provided such that a current flowing through the collector or the drain of the third transistor increases when a current flowing through the collector or the drain of the second transistor increases.

Power amplifier circuit and differential power amplifier circuit

A power amplifier circuit includes a first amplifier transistor, a first nonlinear element, and a current control circuit. The first amplifier transistor has a base or a gate into which a first signal is input, a collector or a drain from which a signal resulting from amplification of the first signal is output, and an emitter or a source that is grounded. The first nonlinear element is connected between the collector or the drain of the first amplifier transistor and the base or the gate of the first amplifier transistor. The current control circuit is connected between the ground and the base or the gate of the first amplifier transistor and controls current flowing through the first nonlinear element.

Power amplifier circuit, doherty amplifier circuit, multistage amplifier circuit, and power amplifier apparatus

A power amplifier circuit includes a first amplifier that, in a region where an input signal level is a first level or higher, amplifies a signal split from an input signal and outputs an amplified signal; a first converter connected to an output side of the first amplifier and converts an impedance on the output side of the first amplifier; and at least one or more second amplifiers that, in a region where the input signal level is a second level or higher, amplify a signal split from the input signal and output an amplified signal. Output sides of the second amplifiers are connected in series with an output side of the first converter.

Power amplifier circuit

A power amplifier module includes a first amplifier, a power splitter, a second amplifier, a third amplifier, a phase shifter, a combining unit, and a controller. The first amplifier amplifies a first signal and outputs a second signal. The power splitter splits the second signal into a third signal and a fourth signal. The second amplifier amplifies the third signal and outputs a fifth signal. The third amplifier amplifies the fourth signal and outputs a sixth signal. The phase shifter receives the fifth signal and shifts a phase of the fifth signal. The combining unit combines the fifth signal having the phase shifted by the phase shifter and the sixth signal and outputs an amplified signal of the second signal. The controller outputs a first control signal for controlling a power level of the sixth signal output from the third amplifier.

Power amplifier module

A power amplifier circuit includes a first amplifier that, in a region where an input signal level is a first level or higher, amplifies a signal split from an input signal and outputs an amplified signal; a first converter connected to an output side of the first amplifier and converts an impedance on the output side of the first amplifier; and at least one or more second amplifiers that, in a region where the input signal level is a second level or higher, amplify a signal split from the input signal and output an amplified signal. Output sides of the second amplifiers are connected in series with an output side of the first converter. The first converter makes an absolute value of the impedance on the output side of the first amplifier larger than absolute values of impedances on the output sides of the second amplifiers.

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Kyoto, Japan

Shohei Imai