Abstract: A radio frequency module that includes a first antenna terminal, a second antenna terminal, a TDD filter, a transmission filter, a filter, and a first switch. The first switch has a first common terminal, a second common terminal, a first terminal, a second terminal, and a third terminal. The filter is connected to the first terminal, the TDD filter is connected to the second terminal, and the transmission filter is connected to the third terminal. The first switch is capable of switching between a first connection state and a second connection state. The first connection state connects the first common terminal to the first terminal and the first common terminal to the second terminal simultaneously. The second connection state connects the first common terminal to the first terminal, the first common terminal to the second terminal, and the second common terminal to the third terminal simultaneously.

Abstract: A radio-frequency circuit includes an antenna connection terminal, switch circuits, a duplexer, a low-pass filter, and a high-pass filter. The switch circuit includes a port connected to the antenna connection terminal and ports. The switch circuit includes a single transmission port connected to the port, a simultaneous transmission port connected to ports. The duplexer is connected to the port. The low-pass filter is disposed on a signal path connecting the port and the simultaneous transmission port. The high-pass filter is connected to the port. No filter is disposed on a signal path connecting the port and the single transmission port.

Abstract: A high frequency circuit includes a switch that includes terminals; a switch that includes terminals; a filter that has a pass band including a first band; and a diplexer that includes terminals. The diplexer includes a filter that is connected between the terminals and has a pass band including a first frequency band group containing the first band and a filter that is connected between the terminals and has a pass band including a second frequency band group. The terminal is connected to an antenna terminal. The terminals are connected to one terminal of the filter. The terminal is connected to the terminal. The terminal is connected to the terminal.

Abstract: A radio frequency module includes: a module board that includes a first principal surface and a second principal surface on opposite sides of the module board; a power amplifier; and a first circuit component. The power amplifier includes: a first amplifying circuit element; a second amplifying circuit element; and an output transformer that includes a primary coil and a secondary coil. An end of the primary coil is connected to an output terminal of the first amplifying circuit element. Another end of the primary coil is connected to an output terminal of the second amplifying circuit element. An end of the secondary coil is connected to an output terminal of the power amplifier. The first amplifying circuit element and the second amplifying circuit element are disposed on the first principal surface. The first circuit component is disposed on the second principal surface.

Abstract: A first filter is prevented from being affected by the coplanarity of a mounting substrate and a degradation of the filter characteristics of the first filter is reduced. A first filter, a second filter, a third filter, and a first switch are mounted on a first principal surface of a mounting substrate. The first filter passes a first high-frequency signal and a second high-frequency signal, the second filter passes a third high-frequency signal, and the third filter passes a fourth high-frequency signal. The first switch is capable of simultaneously connecting the first filter and the second filter to an antenna terminal. In a plan view from a thickness direction of the mounting substrate, the first filter is larger than the second filter and the third filter and located between the second filter and the third filter. A first wire and a second wire are each shorter than a third wire.

Abstract: A decrease in isolation is suppressed when transmitting both a first transmission signal and a second transmission signal in simultaneous communication. A radio frequency module includes a first transformer and a second transformer. The first transformer is included in a first differential power amplifier to amplify the first transmission signal. The second transformer is included in a second differential power amplifier to amplify the second transmission signal to be simultaneously communicated with the first transmission signal. A direction of magnetic flux generated in the first transformer is different from a direction of magnetic flux generated in the second transformer.

Abstract: A radio frequency module includes: a module board that includes a first principal surface and a second principal surface on opposite sides of the module board; a power amplifier; and a first circuit component. The power amplifier includes: a first amplifying circuit element; a second amplifying circuit element; and an output transformer that includes a primary coil and a secondary coil. An end of the primary coil is connected to an output terminal of the first amplifying circuit element. Another end of the primary coil is connected to an output terminal of the second amplifying circuit element. An end of the secondary coil is connected to an output terminal of the power amplifier. The first amplifying circuit element and the second amplifying circuit element are disposed on the first principal surface. The first circuit component is disposed on the second principal surface.

Abstract: A radio frequency module includes: a module board that includes a first principal surface and a second principal surface on opposite sides of the module board; a power amplifier; and a first circuit component. The power amplifier includes: a first amplifying circuit element; a second amplifying circuit element; and an output transformer that includes a primary coil and a secondary coil. An end of the primary coil is connected to an output terminal of the first amplifying circuit element. Another end of the primary coil is connected to an output terminal of the second amplifying circuit element. An end of the secondary coil is connected to an output terminal of the power amplifier. The first amplifying circuit element and the second amplifying circuit element are disposed on the first principal surface. The first circuit component is disposed on the second principal surface.

Abstract: A radio frequency module includes: a module board that includes a first principal surface and a second principal surface on opposite sides of the module board; a power amplifier; and a first circuit component. The power amplifier includes: a first amplifying circuit element; a second amplifying circuit element; and an output transformer that includes a primary coil and a secondary coil. An end of the primary coil is connected to an output terminal of the first amplifying circuit element. Another end of the primary coil is connected to an output terminal of the second amplifying circuit element. An end of the secondary coil is connected to an output terminal of the power amplifier. The first amplifying circuit element and the second amplifying circuit element are disposed on the first principal surface. The first circuit component is disposed on the second principal surface.

Abstract: A communication unit includes a first input terminal to which a first transmission signal based on a first communication standard is input, a second input terminal to which a second transmission signal based on a second communication standard is input, a first transmission signal amplifier circuit outputting a first amplified transmission signal, or outputting a second amplified transmission signal, a first input-output terminal outputting the first amplified transmission signal or the second amplified transmission signal, and at least one of a first reception signal and a second reception signal inputted to the first input-output terminal, a first reception signal amplifier circuit performing at least one of operation of outputting a first amplified reception signal and operation of outputting a second amplified reception signal, a first output terminal outputting the first amplified reception signal, and a second output terminal outputting the second amplified reception signal.

Abstract: A communication unit includes a first input terminal to which a first transmission signal based on a first communication standard is input, a second input terminal to which a second transmission signal based on a second communication standard is input, a first transmission signal amplifier circuit outputting a first amplified transmission signal, or outputting a second amplified transmission signal, a first input-output terminal outputting the first amplified transmission signal or the second amplified transmission signal, and at least one of a first reception signal and a second reception signal inputted to the first input-output terminal, a first reception signal amplifier circuit performing at least one of operation of outputting a first amplified reception signal and operation of outputting a second amplified reception signal, a first output terminal outputting the first amplified reception signal, and a second output terminal outputting the second amplified reception signal.