Abstract: Provided is a detector circuit that includes: a first transistor that has an alternating current signal input to a base thereof, and that outputs a first detection signal that depends on the alternating current signal from a collector thereof; a second transistor that has the first detection signal input to a base thereof, and that outputs a second detection signal that depends on the first detection signal from a collector thereof; and an alternating current signal path along which the alternating current signal is supplied to the base of the second transistor.

Abstract: Provided is a detector circuit that includes: a first transistor that has an alternating current signal input to a base thereof, and that outputs a first detection signal that depends on the alternating current signal from a collector thereof; a second transistor that has the first detection signal input to a base thereof, and that outputs a second detection signal that depends on the first detection signal from a collector thereof; and an alternating current signal path along which the alternating current signal is supplied to the base of the second transistor.

Abstract: Provided is a detector circuit that includes: a first transistor that has an alternating current signal input to a base thereof, and that outputs a first detection signal that depends on the alternating current signal from a collector thereof; a second transistor that has the first detection signal input to a base thereof, and that outputs a second detection signal that depends on the first detection signal from a collector thereof; and an alternating current signal path along which the alternating current signal is supplied to the base of the second transistor.

Abstract: Provided is a detector circuit that includes: a first transistor that has an alternating current signal input to a base thereof, and that outputs a first detection signal that depends on the alternating current signal from a collector thereof; a second transistor that has the first detection signal input to a base thereof, and that outputs a second detection signal that depends on the first detection signal from a collector thereof; and an alternating current signal path along which the alternating current signal is supplied to the base of the second transistor.

Abstract: A high-frequency amplifier circuit (10) includes a high-frequency amplifier (101) and a bias circuit (20). The bias circuit (20) includes bias control elements (102, 103). An emitter of the bias control element (102) is connected to a base of the amplifier (101) via a resistor (201). An emitter of the bias control element (103) is connected to a collector of a switch element (104) via a resistor (203). The switch element (104) is a common emitter. A resistor (204) is connected between the emitter of the bias control element (102) and the emitter of the bias control element (103). A control voltage (VCTL) is applied to bases of the bias control elements (102, 103). A bias current adjustment voltage (VLIN) corresponding to an operation mode is applied to a base of the switch element (104).

Abstract: A high-frequency amplifier circuit (10) includes a high-frequency amplifier (101) and a bias circuit (20). The bias circuit (20) includes bias control elements (102, 103). An emitter of the bias control element (102) is connected to a base of the amplifier (101) via a resistor (201). An emitter of the bias control element (103) is connected to a collector of a switch element (104) via a resistor (203). The switch element (104) is a common emitter. A resistor (204) is connected between the emitter of the bias control element (102) and the emitter of the bias control element (103). A control voltage (VCTL) is applied to bases of the bias control elements (102, 103). A bias current adjustment voltage (VLIN) corresponding to an operation mode is applied to a base of the switch element (104).

Abstract: A high-frequency module including a power amplifying circuit includes a high-frequency power amplifying element, a matching circuit, and a driving power-supply circuit. The high-frequency power amplifying element includes a high-frequency amplifying circuit and a directional coupler. A first end of a main line of the directional coupler is connected to an output terminal of a latter-stage amplifying circuit of the high-frequency amplifying circuit. A second end of the main line of the directional coupler is connected through an output matching circuit to a high-frequency signal output terminal of the high-frequency power amplifying element. The output terminal of the latter-stage amplifying circuit is also connected to a second driving power-supply voltage application terminal of the high-frequency power amplifying element. The second driving power-supply voltage application terminal is connected to the high-frequency signal output terminal by a connecting conductor.