An integrated circuit includes a first base that has at least a part formed of a first semiconductor material and that includes an electric circuit (for example, a control circuit or a switching circuit), a second base that has at least a part formed of a second semiconductor material having a thermal conductivity lower than the first semiconductor material and that includes a power amplifier circuit, and a low thermal conductive member that has at least a part formed of a low thermal conductive material having a thermal conductivity lower than the second semiconductor material and that is disposed between the electric circuit and the power amplifier circuit. At least a part of the first base overlaps at least a part of the second base in plan view.

An integrated circuit includes a first base that has at least a part formed of a first semiconductor material and that includes an electric circuit (for example, a control circuit or a switching circuit), a second base that has at least a part formed of a second semiconductor material having a thermal conductivity lower than the first semiconductor material and that includes a power amplifier circuit, and a low thermal conductive member that has at least a part formed of a low thermal conductive material having a thermal conductivity lower than the second semiconductor material and that is disposed between the electric circuit and the power amplifier circuit. At least a part of the first base overlaps at least a part of the second base in plan view.

An integrated transformer arrangement for combining output signals of multiple differential power amplifiers to a single-ended load. The integrated transformer arrangement comprises a first transformer branch comprising an inductor loop. The inductor loop comprises a set of N windings connected in series. The first transformer branch further comprises a number of primary inductors. Each primary inductor comprises a winding placed concentrically to one winding of the inductor loop, and each primary inductor is configured to couple to a differential output of one of the multiple differential power amplifiers. The integrated transformer arrangement further comprises a secondary inductor comprising a winding placed concentrically to a winding of the inductor loop, and the secondary inductor is configured to couple to the single-ended load.

A high-frequency module includes a plurality of filters, a switch that commonly connects a plurality of paths, and a low noise amplifier that amplifies a high-frequency signal input from the plurality of filters with the switch interposed therebetween, wherein paths in which first and second filters are respectively provided among the plurality of paths connect the respective filters and the switch without connecting impedance elements, and each of the first and second filters has an output impedance located in a matching region between a NF matching impedance at which an NF of the low noise amplifier is minimum and a gain matching impedance at which a gain of the low noise amplifier is maximum in its respective pass band thereof on a Smith chart.

A high-frequency module includes a plurality of filters, a switch that commonly connects a plurality of paths, and a low noise amplifier that amplifies a high-frequency signal input from the plurality of filters with the switch interposed therebetween, wherein paths in which first and second filters are respectively provided among the plurality of paths connect the respective filters and the switch without connecting impedance elements, and each of the first and second filters has an output impedance located in a matching region between a NF matching impedance at which an NF of the low noise amplifier is minimum and a gain matching impedance at which a gain of the low noise amplifier is maximum in its respective pass band thereof on a Smith chart.

An amplifier circuit includes a first port, a second port, a reference potential port, and an RF amplifier device having a first terminal electrically coupled to the first port, a second terminal electrically coupled to the second port, and a reference potential terminal electrically coupled to the reference potential port. The RF amplifier device amplifies an RF signal across an RF frequency range that includes a fundamental RF frequency. An impedance matching network is electrically coupled to the first terminal and the first port. The impedance matching network includes a baseband termination circuit that presents low impedance in a baseband frequency region, a fundamental frequency matching circuit that presents a complex conjugate of an intrinsic impedance of the RF amplifier device in the RF frequency range, and a second order harmonic termination circuit that presents low impedance at second order harmonics of frequencies in the fundamental RF frequency range.

An amplifier circuit includes a first port, a second port, a reference potential port, and an RF amplifier device having a first terminal electrically coupled to the first port, a second terminal electrically coupled to the second port, and a reference potential terminal electrically coupled to the reference potential port. The RF amplifier device amplifies an RF signal across an RF frequency range that includes a fundamental RF frequency. An impedance matching network is electrically coupled to the first terminal and the first port. The impedance matching network includes a baseband termination circuit that presents low impedance in a baseband frequency region, a fundamental frequency matching circuit that presents a complex conjugate of an intrinsic impedance of the RF amplifier device in the RF frequency range, and a second order harmonic termination circuit that presents low impedance at second order harmonics of frequencies in the fundamental RF frequency range.

Provided is a high-frequency amplifier capable of making a circuit substrate small and reducing a cost. A high-frequency amplifier is provided with a first substrate including a matching unit, and a second substrate including a transistor and a first impedance converter connected to each other, in which the matching unit of the first substrate and the first impedance converter are connected to each other via a first connection. Furthermore, the high-frequency amplifier is further provided with a third substrate including a matching unit, in which the second substrate may further include a second impedance converter connected to the transistor, and the second impedance converter and the matching unit of the third substrate may be connected to each other via a second connection.

Provided is a high-frequency amplifier capable of making a circuit substrate small and reducing a cost. A high-frequency amplifier is provided with a first substrate including a matching unit, and a second substrate including a transistor and a first impedance converter connected to each other, in which the matching unit of the first substrate and the first impedance converter are connected to each other via a first connection. Furthermore, the high-frequency amplifier is further provided with a third substrate including a matching unit, in which the second substrate may further include a second impedance converter connected to the transistor, and the second impedance converter and the matching unit of the third substrate may be connected to each other via a second connection.

A Doherty amplifier includes: a transistor for a carrier amplifier; a transistor for a peak amplifier; a transmission line connected between an output terminal of the transistor for the carrier amplifier and an output terminal of the transistor for the peak amplifier; a stub that is connected in parallel to the output terminal of the transistor for the peak amplifier and that is capacitive and inductive in a working frequency band; and an output matching circuit connected to the output terminal of the transistor for the peak amplifier, the transmission line, and an output load, the output matching circuit to transform an impedance of the output load into an impedance lower than the impedance of the output load.