Abstract: A power amplifier includes: a plurality of amplifiers; a tournament circuit including a plurality of transmission lines arranged in a tournament form and connected to the plurality of amplifiers; and a plurality of difference frequency short circuits each including an inductor and a capacitor connected in series to each other, wherein resonant frequencies of the plurality of difference frequency short circuits become smaller as the difference frequency short circuits are farther from the plurality of amplifiers, and difference frequency short circuits connected to a plurality of nodes in a stage closest to the amplifiers of the tournament circuit among the plurality of difference frequency short circuits include inductive reactance that resonates with impedance seen from the nodes toward the amplifiers at an operating frequency and have different resonant frequencies.

Abstract: A stub whose end is connected to an end of a transmission line, and a coupled line disposed in parallel with each of the transmission line and the stub, and electromagnetically coupled to each of the transmission line and the stub are included, and the stub and the coupled line operate as a first resonator for resonating with an odd order harmonic included in the amplified signal, and the transmission line, the stub, and the coupled line operate as a second resonator for resonating with an even order harmonic included in the amplified signal.

Abstract: Provided is an amplifier including: a first transistor connected to a signal input terminal; a second transistor connected to a signal output terminal; a wiring line configured to connect the first transistor and the second transistor to each other; and a variable inductor circuit which is electrically connected to the wiring line, and is grounded via a capacitor for DC current interruption, wherein the inductance value of the variable inductor circuit is set to an inductance value for canceling a parasitic capacitance between the first transistor and the second transistor.

Abstract: A stub whose end is connected to an end of a transmission line, and a coupled line disposed in parallel with each of the transmission line and the stub, and electromagnetically coupled to each of the transmission line and the stub are included, and the stub and the coupled line operate as a first resonator for resonating with an odd order harmonic included in the amplified signal, and the transmission line, the stub, and the coupled line operate as a second resonator for resonating with an even order harmonic included in the amplified signal.

Abstract: According to the present invention, an integrated circuit includes a first amplifier stage, a second amplifier stage, a first signal line connecting an output of the first amplifier stage and an input of the second amplifier stage to each other, a first plane for ground connected to the first amplifier stage, a second plane for ground connected to the second amplifier stage and at least one at least one line for ground connecting the first plane and the second plane to each other, wherein the at least one line has a center line having a length of 10 ?m to 1 mm, a width of the at least one line is ? or less of a width of the first plane, and a pattern ratio is 1 or more.

Abstract: A frequency includes an input terminal, an output terminal, a transistor having a gate terminal which receives input of a signal including a first frequency from the input terminal, a source terminal and a drain terminal connected to the output terminal by a main line, an output matching circuit provided in the main line, the output matching circuit shutting off the first frequency while allowing an output frequency multiplied from the first frequency to pass therethrough, a branch line including a power supply terminal for connection to a power supply, the branch line branching off from a branch point in the main line, and a first diode provided in the branch line, the first diode having an anode connected to the power supply terminal and a cathode connected on the branch point side.

Abstract: According to the present invention, an integrated circuit includes a first amplifier stage, a second amplifier stage, a first signal line connecting an output of the first amplifier stage and an input of the second amplifier stage to each other, a first plane for ground connected to the first amplifier stage, a second plane for ground connected to the second amplifier stage and at least one at least one line for ground connecting the first plane and the second plane to each other, wherein the at least one line has a center line having a length of 10 ?m to 1 mm, a width of the at least one line is ? or less of a width of the first plane, and a pattern ratio is 1 or more.

Abstract: A frequency includes an input terminal, an output terminal, a transistor having a gate terminal which receives input of a signal including a first frequency from the input terminal, a source terminal and a drain terminal connected to the output terminal by a main line, an output matching circuit provided in the main line, the output matching circuit shutting off the first frequency while allowing an output frequency multiplied from the first frequency to pass therethrough, a branch line including a power supply terminal for connection to a power supply, the branch line branching off from a branch point in the main line, and a first diode provided in the branch line, the first diode having an anode connected to the power supply terminal and a cathode connected on the branch point side.