Abstract: A radio frequency module includes a substrate having a mounting surface, components for transmission and a component for transmission and reception that are disposed on the mounting surface, acoustic wave filters disposed between each of the components for transmission and the component for transmission and reception, and shield electrodes each formed on a corresponding one of side surfaces of the acoustic wave filters.

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: Attenuation on a receive path side in a pass band of a second filter is improved in a case where a first filter, which passes a receive signal, is an acoustic wave filter. A multiplexer includes a common terminal, a first terminal, a second terminal, a first filter, and a second filter. The first filter is an acoustic wave filter disposed on a receive path connecting the common terminal and the first terminal and passes a receive signal. The second filter is disposed on a transmit path connecting the common terminal and the second terminal and passes a transmit signal. The multiplexer further includes an LC filter. The LC filter is disposed on the receive path connecting the common terminal and the first terminal.

Abstract: The sensitivity of a reception filter for receiving a reception signal in a second frequency band corresponding to the 4G or 5G standard is prevented from being degraded by a harmonic of a third transmission signal in a third frequency region corresponding to the 4G or 5G standard. A radio-frequency circuit includes an antenna terminal, a relay terminal, a transmission filter, a reception filter, a variable low-pass filter, and a switch. A first transmission signal in a first frequency band is input to the relay terminal. In communication using the first frequency band, the variable low-pass filter passes the first transmission signal input via the relay terminal. When another harmonic circuit performs communication using the third frequency band, the variable low-pass filter attenuates, among harmonics of the third transmission signal in the third frequency band, a harmonic input via the relay terminal.

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 frontend circuit includes a wide-band filter, a transmit filter, and switches. The wide-band filter passes both the receive frequency band of a first communication frequency band and that of a second communication frequency band which is close to or overlaps that of the first communication frequency band. The transmit filter passes the transmit frequency band of the first or second communication frequency band. The switches are capable of simultaneously bringing, into conduction, at least two of multiple filters including the wide-band filter and the transmit filter. In carrier aggregation using the receive frequency bands of the first and second communication frequency bands, the switches simultaneously bring the wide-band filter and the transmit filter into conduction. Thus, in carrier aggregation using signals of multiple communication frequencies simultaneously in communication, attenuation of signals due to signal leakage in two receive frequency bands, which are close to each other, is suppressed.

Abstract: A high-frequency module is capable of two-uplink of a transmission signal in Band A and transmission of Band C, and includes a module substrate, a metal shield plate arranged on a principal surface, power amplifiers, a transmission filter of Band A, and a transmission filter of Band C. In a plan view, the metal shield plate is arranged between a first transmission component and a second transmission component. The first transmission component is one of the power amplifier, the transmission filter, a switch circuit, and a first inductor and a first capacitor arranged in a first transmission path, and the second transmission component is one of the power amplifier, the transmission filter, a switch circuit, and a second inductor and a second capacitor arranged in a second transmission path.

Abstract: A radio frequency circuit includes a transmit filter for B66-Tx connected to a power amplifier, a transmit filter for B25-Tx connected to a power amplifier, a switch circuit having terminals, a switch circuit having a common terminal and terminals, and a switch circuit having a common terminal and terminals. The terminal is connected to the common terminal, the terminal is connected to the common terminal, the terminal is connected to the transmit filter, and the terminal is connected to the transmit filter. The switch circuit has a smaller stack number than the switch circuit, and the switch circuit has a smaller stack number than the switch circuit.

Abstract: A frontend circuit includes a wide-band filter, a transmit filter, and switches. The wide-band filter passes both the receive frequency band of a first communication frequency band and that of a second communication frequency band which is close to or overlaps that of the first communication frequency band. The transmit filter passes the transmit frequency band of the first or second communication frequency band. The switches are capable of simultaneously bringing, into conduction, at least two of multiple filters including the wide-band filter and the transmit filter. In carrier aggregation using the receive frequency bands of the first and second communication frequency bands, the switches simultaneously bring the wide-band filter and the transmit filter into conduction. Thus, in carrier aggregation using signals of multiple communication frequencies simultaneously in communication, attenuation of signals due to signal leakage in two receive frequency bands, which are close to each other, is suppressed.

Abstract: The sensitivity of a reception filter for receiving a reception signal in a second frequency band corresponding to the 4G or 5G standard is prevented from being degraded by a harmonic of a third transmission signal in a third frequency region corresponding to the 4G or 5G standard. A radio-frequency circuit includes an antenna terminal, a relay terminal, a transmission filter, a reception filter, a variable low-pass filter, and a switch. A first transmission signal in a first frequency band is input to the relay terminal. In communication using the first frequency band, the variable low-pass filter passes the first transmission signal input via the relay terminal. When another harmonic circuit performs communication using the third frequency band, the variable low-pass filter attenuates, among harmonics of the third transmission signal in the third frequency band, a harmonic input via the relay terminal.

Abstract: Provided is a multiplexer that includes a first filter (first transmission filter), a second filter (second reception filter), a third filter (third reception filter), a first inductor, and a second inductor. The first inductor is connected in series with one parallel arm resonator (second parallel arm resonator) of the first filter between the one parallel arm resonator and ground. The second inductor is connected in series with another parallel arm resonator (third parallel arm resonator) of the first filter between the other parallel arm resonator and ground. The first inductor and the second inductor have the same winding direction as each other from the first filter side toward the ground side thereof.

Abstract: Attenuation on a receive path side in a pass band of a second filter is improved in a case where a first filter, which passes a receive signal, is an acoustic wave filter. A multiplexer includes a common terminal, a first terminal, a second terminal, a first filter, and a second filter. The first filter is an acoustic wave filter disposed on a receive path connecting the common terminal and the first terminal and passes a receive signal. The second filter is disposed on a transmit path connecting the common terminal and the second terminal and passes a transmit signal. The multiplexer further includes an LC filter. The LC filter is disposed on the receive path connecting the common terminal and the first terminal.

Abstract: A frontend circuit includes a wide-band filter, a transmit filter, and switches. The wide-band filter passes both the receive frequency band of a first communication frequency band and that of a second communication frequency band which is close to or overlaps that of the first communication frequency band. The transmit filter passes the transmit frequency band of the first or second communication frequency band. The switches are capable of simultaneously bringing, into conduction, at least two of multiple filters including the wide-band filter and the transmit filter. In carrier aggregation using the receive frequency bands of the first and second communication frequency bands, the switches simultaneously bring the wide-band filter and the transmit filter into conduction. Thus, in carrier aggregation using signals of multiple communication frequencies simultaneously in communication, attenuation of signals due to signal leakage in two receive frequency bands, which are close to each other, is suppressed.

Abstract: A power amplifier circuit includes an amplifier element that amplifies a signal input to a base and outputs an amplified signal from a collector, and a variable capacitor provided between the base and the collector of the amplifier element. A power-supply voltage that varies in accordance with an envelope of amplitude of a radio-frequency signal is applied to the collector of the amplifier element, and capacitance of the variable capacitor decreases in response to an increase in the power-supply voltage input to the collector of the amplifier element.

Abstract: Provided is a multiplexer that includes a first filter (first transmission filter), a second filter (second reception filter), a third filter (third reception filter), a first inductor, and a second inductor. The first inductor is connected in series with one parallel arm resonator (second parallel arm resonator) of the first filter between the one parallel arm resonator and ground. The second inductor is connected in series with another parallel arm resonator (third parallel arm resonator) of the first filter between the other parallel arm resonator and ground. The first inductor and the second inductor have the same winding direction as each other from the first filter side toward the ground side thereof.

Abstract: On a substrate (200), a resistor (24R) is disposed between a position of an amplifier circuit (11) and a position of a duplexer (24), thereby reducing coupling occurring in a space between the amplifier circuit (11) and a path extending from a main switch (26) to a reception terminal (P24) through the duplexer (24). Even when an RX terminal (242) of the duplexer (24) is oriented toward an amplifier circuit (11) side, a high-frequency module (100) reduces the coupling and can thus prevent a harmonic of a transmission signal in a low band from leaking to the reception terminal (P24) through a path formed by the coupling. That is, the high-frequency module (100) can prevent a reduction in isolation characteristics in the low band and a high band and also provide flexibility in substrate layout.

Abstract: A multilayer substrate includes a component mounting electrode, an external mounting electrode, and a heat dissipating unit. The component mounting electrode is connected to an electronic component that is connected to an external structure. The heat dissipating unit is constituted by a plurality of via-conductors partially superposed each other in a stacking direction of the multilayer substrate and disposed continuously between the component mounting electrode and the external mounting electrode. The heat dissipating unit includes communicating portions, each in which one via-conductor is disposed per ceramic layer, and a branching portion in which a plurality of via-conductors are disposed continuously between the communicating portions per ceramic layer.

Abstract: A power amplifier circuit includes an amplifier element that amplifies a signal input to a base and outputs an amplified signal from a collector, and a variable capacitor provided between the base and the collector of the amplifier element.

Abstract: A radio-frequency module includes a first transmitter-and-receiver that transmits and receives a signal in a first band, and a second transmitter-and-receiver that transmits and receives a signal in a second band higher than the first band. The first transmitter-and-receiver includes a first amplifier circuit and a first separator circuit and the second transmitter-and-receiver includes a second amplifier circuit and a second separator circuit. The first separator is located on a substrate between the first amplifier circuit and the second separator circuit, such that the first separator circuit is spatially interposed between the first amplifier circuit and the second separator circuit.