Abstract: Isolation between a first path and a second path is improved. A radio frequency module is capable of operating in a first mode in which simultaneous transmission, simultaneous reception, or simultaneous transmission and reception using both a first filter and a second filter is possible, and in a second mode in which transmission or reception using only the first filter is possible. A first switching element is provided in a first path that is usable between an antenna terminal and the first filter in the first mode, and a second switching element is provided between the first path and a ground. A third switching element is provided in a second path that is usable between the antenna terminal and the first filter in the second mode, and a fourth switching element is provided between the second path and the ground. The radio frequency module further includes a phase shifter.

Abstract: A radio-frequency signal receiver/transmitter circuit includes a power amplifying circuit that amplifies a radio-frequency transmit signal for output, at least one duplexer including a transmit filter for passing the radio-frequency transmit signal and a receive filter for passing a radio-frequency receive signal, a switch that electrically connects between the power amplifying circuit and the transmit filter, and a control circuit that controls enabling/disabling the power amplifying circuit, that controls connection of the switch, and that controls switching the receive filter between first bandpass characteristics and second bandpass characteristics. The receive filter switches between the first bandpass characteristics and the second bandpass characteristics, in which attenuation is relatively less than that in the first bandpass characteristics.

Abstract: A transmission and reception module includes a substrate including a transmission signal input terminal, a reception signal output terminal, and an antenna terminal, a duplexer that is provided on the substrate, outputs a transmission signal input from the transmission signal input terminal to the antenna terminal, and outputs a reception signal input from the antenna terminal to the reception signal output terminal, a first inductor included in a first matching circuit provided between the duplexer and the antenna terminal, and a second inductor included in a second matching circuit provided between the duplexer and the reception signal output terminal. On the substrate, a winding axis direction of a conductor of the first inductor and a winding axis direction of a conductor of the second inductor are different from each other.

Abstract: A transmission/reception module includes a substrate including a transmission signal input terminal, a reception signal output terminal, and an antenna terminal, an antenna switch circuit provided on the substrate and configured to output a transmission signal input from the transmission signal input terminal to the antenna terminal and configured to output a reception signal input from the antenna terminal to the reception signal output terminal, and a first inductor included in an input/output filter circuit provided between the antenna switch circuit and the antenna terminal. The first inductor includes a conductor whose winding axis direction is orthogonal to the substrate.

Abstract: The present disclosure facilitates impedance matching between a power amplifier and filters. A radio-frequency circuit includes a power amplifier, a plurality of transmit filters, a switch, a plurality of first matching networks, and a second matching network. The switch switches the plurality of transmit filters to be coupled to the power amplifier. The plurality of first matching networks are coupled between the plurality of transmit filters and the switch. The second matching network is coupled between the power amplifier and the switch. The second matching network includes a transmission line transformer.

Abstract: An output switch includes; a plurality of input terminals and output terminals each of the plurality of input terminals is electrically connected to at least one of the plurality of output terminals; a first low noise amplifier that amplifies a signal of a predetermined frequency band input through an antenna and outputs a first signal to a first input terminal among the plurality of input terminals, and a second low noise amplifier that amplifies a signal of a predetermined frequency band input through an antenna and outputs a second signal to a second input terminal different from the first input terminal among the plurality of input terminals. A filter that attenuates a signal of a frequency band higher than a frequency band of the second signal is electrically connected between the second input terminal and the second low noise amplifier.

Abstract: A radio-frequency signal receiver/transmitter circuit includes a power amplifying circuit that amplifies a radio-frequency transmit signal for output, at least one duplexer including a transmit filter for passing the radio-frequency transmit signal and a receive filter for passing a radio-frequency receive signal, a switch that electrically connects between the power amplifying circuit and the transmit filter, and a control circuit that controls enabling/disabling the power amplifying circuit, that controls connection of the switch, and that controls switching the receive filter between first bandpass characteristics and second bandpass characteristics. The receive filter switches between the first bandpass characteristics and the second bandpass characteristics, in which attenuation is relatively less than that in the first bandpass characteristics.

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: 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.