Abstract: A power amplifier circuit includes an amplifier that receives an input signal with an alternating current and outputs an output signal obtained by amplifying power of the input signal to a first node; an inductive element that is connected between the first node and a second node; and a variable capacitor that is connected between the second node and a reference potential, and whose electrostatic capacitance increases as power of the output signal increases.

Abstract: A power amplifier circuit includes a power amplifier that amplifies an input signal and outputs the amplified signal from an output terminal thereof, a first filter circuit that has a frequency characteristic that attenuates an Nth-order harmonic of the amplified signal, N that is an integer greater than or equal to 2, and a second filter circuit that has a frequency characteristic that attenuates the Nth-order harmonic of the amplified signal. The first filter circuit includes a first capacitor and a first inductor. The first capacitor and the first inductor are connected in series between the output terminal and ground. The second filter circuit includes a second capacitor and a second inductor. The second capacitor and the second inductor are connected in series between the output terminal and ground.

Abstract: A power amplifier circuit includes an amplifier that receives an input signal with an alternating current and outputs an output signal obtained by amplifying power of the input signal to a first node; an inductive element that is connected between the first node and a second node; and a variable capacitor that is connected between the second node and a reference potential, and whose electrostatic capacitance increases as power of the output signal increases.

Abstract: A power amplifier circuit includes a power amplifier that amplifies an input signal and outputs the amplified signal from an output terminal thereof, a first filter circuit that has a frequency characteristic that attenuates an Nth-order harmonic of the amplified signal, N that is an integer greater than or equal to 2, and a second filter circuit that has a frequency characteristic that attenuates the Nth-order harmonic of the amplified signal. The first filter circuit includes a first capacitor and a first inductor. The first capacitor and the first inductor are connected in series between the output terminal and ground. The second filter circuit includes a second capacitor and a second inductor. The second capacitor and the second inductor are connected in series between the output terminal and ground.

Abstract: A power amplifier circuit includes an amplifier that receives an input signal with an alternating current and outputs an output signal obtained by amplifying power of the input signal to a first node; an inductive element that is connected between the first node and a second node; and a variable capacitor that is connected between the second node and a reference potential, and whose electrostatic capacitance increases as power of the output signal increases.

Abstract: A power amplifier circuit includes a power amplifier that amplifies an input signal and outputs the amplified signal from an output terminal thereof, a first filter circuit that has a frequency characteristic that attenuates an Nth-order harmonic of the amplified signal, N that is an integer greater than or equal to 2, and a second filter circuit that has a frequency characteristic that attenuates the Nth-order harmonic of the amplified signal. The first filter circuit includes a first capacitor and a first inductor. The first capacitor and the first inductor are connected in series between the output terminal and ground. The second filter circuit includes a second capacitor and a second inductor. The second capacitor and the second inductor are connected in series between the output terminal and ground.

Abstract: A power amplifier circuit includes an amplifier that receives an input signal with an alternating current and outputs an output signal obtained by amplifying power of the input signal to a first node; an inductive element that is connected between the first node and a second node; and a variable capacitor that is connected between the second node and a reference potential, and whose electrostatic capacitance increases as power of the output signal increases.

Abstract: A power amplifier circuit includes a power amplifier that amplifies an input signal and outputs the amplified signal from an output terminal thereof, a first filter circuit that has a frequency characteristic that attenuates an Nth-order harmonic of the amplified signal, N that is an integer greater than or equal to 2, and a second filter circuit that has a frequency characteristic that attenuates the Nth-order harmonic of the amplified signal. The first filter circuit includes a first capacitor and a first inductor. The first capacitor and the first inductor are connected in series between the output terminal and ground. The second filter circuit includes a second capacitor and a second inductor. The second capacitor and the second inductor are connected in series between the output terminal and ground.

Abstract: A power divider includes first and second amplifiers (AMP1, AMP2), and an isolation circuit. AMP1 includes a first capacitor (C1) with one end connected to input, a first FET (FET1) having a gate connected to the other end of C1, a first feedback circuit connecting the FET1 drain and the one end of C1, a first source circuit connecting the FET1 source and ground, and a second capacitor connecting the FET1 drain and a first output. AMP2 includes a third capacitor with one end connected to input, a second FET (FET2) having a gate connected to the other end of the third capacitor, a second feedback circuit connecting the FET2 drain and the one end of the third capacitor, a second source circuit connecting the FET2 source and ground, and a fourth capacitor connecting the FET2 drain and a second output. The isolation circuit connects the FET1 and FET2 sources.

Abstract: Disclosed is a power divider including a first amplifier, a second amplifier, and an isolation circuit. The first amplifier includes a first capacitor with one end thereof connected to an input terminal, a first FET having a gate terminal connected to the other end of the first capacitor, a first feedback circuit connected between a drain terminal of the first FET and the one end of the first capacitor, a first source circuit connected between a source terminal of the first FET and the ground, and a second capacitor connected between the drain terminal of the first FET and a first output terminal.