A transformer includes a primary coil and a secondary coil. The primary coil includes: a first shield of a first coaxial cable; a second shield of a second coaxial cable; and a conductive interconnector connecting the first shield to the second shield. The secondary coil includes: a first core of the first coaxial cable; a second core of the second coaxial cable; and a pair of conductive lines connecting the first core to the second core.

A radio frequency module includes a transmit filter of Band A and Band B, a transmit amplifier, and a switch circuit and can perform CA using a transmit signal of Band A and a receive signal of Band B, a transmit band of Band B including a receive band of Band C. The switch circuit includes a switch switching connection between a common terminal and a first selection terminal, a switch switching connection between the common terminal and a second selection terminal, and a switch switching connection between the second selection terminal and a third selection terminal. The common terminal is connected to the transmit amplifier. The first selection terminal is connected to the transmit filter of Band A. The second selection terminal is connected to the transmit filter of Band B. The third selection terminal is connected to a receive path of Band C.

A radio frequency module includes a transmit filter of Band A and Band B, a transmit amplifier, and a switch circuit and can perform CA using a transmit signal of Band A and a receive signal of Band B, a transmit band of Band B including a receive band of Band C. The switch circuit includes a switch switching connection between a common terminal and a first selection terminal, a switch switching connection between the common terminal and a second selection terminal, and a switch switching connection between the second selection terminal and a third selection terminal. The common terminal is connected to the transmit amplifier. The first selection terminal is connected to the transmit filter of Band A. The second selection terminal is connected to the transmit filter of Band B. The third selection terminal is connected to a receive path of Band C.

Improvement in heat dissipation capability is intended. A radio-frequency module includes a mounting substrate, a first transmission filter, a second transmission filter, a resin layer, and a shield layer. The second transmission filter is higher in power class than the first transmission filter. The resin layer covers at least part of an outer peripheral surface of the first transmission filter and covers at least part of an outer peripheral surface of the second transmission filter. The shield layer overlaps at least part of the second transmission filter in plan view in a thickness direction of the mounting substrate. At least part of a major surface of the second transmission filter on an opposite side to the mounting substrate side is in contact with the shield layer.

A high-frequency circuit includes a power amplifier for a communication band A, and a power amplifier for a communication band B. Transmission in the communication band A, transmission in the communication band B, and reception in the communication band C can be simultaneously used. A frequency range of intermodulation distortion generated between a second harmonic wave of a transmission signal of the communication band A and a fundamental wave of a transmission signal of the communication band B, overlaps with at least part of a reception band of the communication band C. The power amplifier includes amplifying elements and an output trans including coils. One end of the coil is connected with an output of the amplifying element, the other end of the coil is connected with an output of the amplifying element, and one end of the coil is connected with an output terminal of the power amplifier.

Described is an apparatus which comprises: a first transmission path for a first frequency band; a second transmission path for a second frequency band different from the first frequency band; a node common to the first and second transmission paths, the node to be coupled to an antenna; and a transmission-zero circuit coupled to the common node.

Radio-frequency splitter circuits, devices and methods. In some embodiments, a power splitter can include an input port, a first output port and a second output port. The power splitter can further include a first signal path implemented between the input port and the first output port, and a second signal path implemented between the input port and the second output port. Each of the first and second signal paths can include a variable capacitance configured to provide a plurality of capacitance values that result in different frequency responses of the respective signal path.

Aspects of this disclosure relate to a multiplexer with a hybrid acoustic passive filter. The multiplexer includes a plurality of filters configured to filter respective radio frequency signals, a shared filter coupled between each of the plurality of filters and a common node, and a radio frequency filter coupled to the common node. At least a first filter of the plurality of filters includes acoustic resonators and a non-acoustic passive component. Related multiplexers, wireless communication devices, and methods are disclosed.

A filter module has a first terminal, a second terminal, and at least one filter disposed along each signal path extending from the first terminal to the second terminal. The filter can include a plurality of series resonators and a plurality of shunt resonators disposed between the series resonators and a ground configured to enhance power ruggedness of the filter module. A matching circuit coupled to the filter performs impedance matching of the filter.

A filter device includes a main body, a first inductor, a second inductor, and a third inductor that are provided in the main body to transfer signals from an antenna terminal to a first terminal. The first inductor is connected to the antenna terminal and the second inductor is connected to the first terminal. The third inductor is connected to a signal transfer path between the first inductor and the second inductor. In a plan view from a normal direction of the main body, the first inductor and the second inductor are adjacent to each other.