Abstract: A front-end circuit includes a multiplexer, a circulator, reception ports, and variable filters. A port in the multiplexer is connected to an antenna. A port in the circulator is connected to a port in the multiplexer. The reception ports are connected to a port in the circulator with the variable filters interposed therebetween. The multiplexer outputs a communication signal having a frequency in a low band to the port and outputs a communication signal having a frequency in a middle band to a port. Each of the low band and the middle band includes a plurality of frequency bands. The middle band is a range of frequencies higher than those in the low band and does not overlap the low band.

Abstract: A filter unit of a high-frequency module includes a plurality of SAW resonators connected in series between a first series connection terminal and a second series connection terminal, first shunt connection terminals, a second shunt connection terminal, and a plurality of SAW resonators. A connection line interconnecting the SAW resonators is connected to the first shunt connection terminal through one of the SAW resonators. The first shunt connection terminal is connected to a ground through an inductor. A matching circuit is connected between the second series connection terminal and a second external connection terminal. The matching circuit is inductively or capacitively coupled to the inductor.

Abstract: A radio frequency module includes a transmission terminal, a transmission filter connected to the transmission terminal, a common terminal, a reception filter which is connected to the common terminal, a reception terminal, a branch point to which the common terminal, the transmission filter, and the reception filter are connected, a transmission path connecting the transmission terminal and the branch point, a reception path connecting the reception terminal and the branch point, a common path connecting the common terminal and the branch point, a matching circuit connected to the common path, and an inductor circuit that includes a first inductor that defines a propagation path through electromagnetic coupling to at least one of the transmission path, the common path, the matching circuit, and the reception path, and a second inductor that is positioned so as not to be electromagnetically coupled to the transmission path, the common path, the matching circuit, or the reception path.

Abstract: A transmission filter in a high frequency module includes serial arm resonators electrically connected in series to a serial arm electrically connecting a shared terminal and a transmission terminal, parallel arm resonators each electrically connected in series to each of parallel arms electrically connecting the serial arm and a ground, a first inductor electrically connected between the ground and a connection end electrically connecting at least the two parallel arm resonators of the parallel arm resonators, and a second inductor electrically connected between the ground and one parallel arm resonator different from the at least two parallel arm resonators of the parallel arm resonators. The second inductor is electromagnetic field coupled to at least one of an antenna side matching element, a transmission side matching element, and a portion of the serial arm in the transmission filter. The first and second inductors obstruct electromagnetic field coupling therebetween.

Abstract: A reflected signal detector (12) detects the amplitude and the phase of a reflected signal and outputs detection signals. A control circuit (13) adjusts first control signals and second control signals on the basis of the detection signals. A first cancel signal output portion (9) adjusts a first cancel signal so that the first cancel signal has a phase opposite to that of the reflected signal and has the same amplitude as that of the reflected signal using the first control signals. A second cancel signal output portion (10) adjusts a second cancel signal so that the second cancel signal has a phase opposite to that of a leakage signal and has the same amplitude as that of the leakage signal using the second control signals. A combining portion (11) combines a reception signal including noise signals with the first and second cancel signals.

Abstract: A high-frequency module includes a propagation path that has a simple structure and improves filter characteristics by causing an inductor and a matching network to electromagnetic field couple with each other such that attenuation characteristics outside of a frequency band of a transmission signal are improved without increasing the size of the high-frequency module. In addition, unintended electromagnetic field coupling between a first filter and the inductor is significantly reduced or prevented by a shield electrode. Therefore, unintended propagation of a high-frequency signal is significantly reduced or prevented. Therefore, the attenuation characteristics outside of the frequency band of transmission signal input to the transmission terminal are improved more effectively.

Abstract: A radio frequency module includes a transmission terminal, a transmission filter connected to the transmission terminal, a common terminal, a reception filter which is connected to the common terminal, a reception terminal, a branch point to which the common terminal, the transmission filter, and the reception filter are connected, a transmission path connecting the transmission terminal and the branch point, a reception path connecting the reception terminal and the branch point, a common path connecting the common terminal and the branch point, a matching circuit connected to the common path, and an inductor circuit that includes a first inductor that defines a propagation path through electromagnetic coupling to at least one of the transmission path, the common path, the matching circuit, and the reception path, and a second inductor that is positioned so as not to be electromagnetically coupled to the transmission path, the common path, the matching circuit, or the reception path.

Abstract: An amplitude phase parameter calculator in a control unit or circuit in a transmission-reception apparatus calculates an amplitude difference voltage and a phase difference voltage between a transmission detection signal and a reflected detection signal. Adjustment factors including a combination of an amplitude control voltage and a phase control voltage corresponding to a combination of the amplitude difference voltage and the phase difference voltage are discretely stored in an adjustment factor determination table in the control unit. An adjustment factor determiner in the control unit determines the adjustment factors using the combination of the amplitude difference voltage and the phase difference voltage and the adjustment factor determination table.

Abstract: A transmission-reception device includes an antenna duplexer, an antenna, and first and second transmission-reception circuits. A demultiplexer is connected between the first transmission-reception circuit and the antenna duplexer, and a multiplexer is connected between the second transmission-reception circuit and the antenna duplexer. A signal adjusting unit is connected between the demultiplexer and the multiplexer. The amplitude and phase of a third harmonic signal of a first transmission signal reflected by the antenna are detected. The signal adjusting unit adjusts the amplitude and phase of the third harmonic signal demultiplexed by the demultiplexer on the basis of the detection results, and outputs a cancel signal. The multiplexer synthesizes and hence cancels the third harmonic signal reflected by the antenna and the cancel signal with each other.

Abstract: A transmission filter allows a signal in the frequency band of a transmission signal to pass through the transmission filter and blocks signals in other frequency bands. The transmission signal output from the transmission filter is supplied to an antenna via an antenna sharing device and transmitted to the outside. A reflected-signal detector senses the amplitude and the phase of a reflected signal from the antenna and outputs detection signals (DA and DP). A control circuit adjusts control signals (CA and CP) on the basis of the detection signals (DA and DP). A cancellation-signal-output circuit adjusts a cancellation signal in such a manner that the cancellation signal has a phase opposite to that of the reflected signal and an amplitude the same as that of the reflected signal by using the control signals (CA and CP). A multiplexer combines the cancellation signal with a received signal including a noise signal.

Abstract: A filter unit of a high-frequency module includes a plurality of SAW resonators connected in series between a first series connection terminal and a second series connection terminal, first shunt connection terminals, a second shunt connection terminal, and a plurality of SAW resonators. A connection line interconnecting the SAW resonators is connected to the first shunt connection terminal through one of the SAW resonators. The first shunt connection terminal is connected to a ground through an inductor. A matching circuit is connected between the second series connection terminal and a second external connection terminal. The matching circuit is inductively or capacitively coupled to the inductor.

Abstract: A front-end circuit includes a multiplexer, a circulator, reception ports, and variable filters. A port in the multiplexer is connected to an antenna. A port in the circulator is connected to a port in the multiplexer. The reception ports are connected to a port in the circulator with the variable filters interposed therebetween. The multiplexer outputs a communication signal having a frequency in a low band to the port and outputs a communication signal having a frequency in a middle band to a port. Each of the low band and the middle band includes a plurality of frequency bands. The middle band is a range of frequencies higher than those in the low band and does not overlap the low band.

Abstract: A high-frequency front-end circuit includes a first variable filter and a second variable filter. One end of each of the variable filters is connected to a common terminal. The other end of the first variable filter is connected to a transmission individual terminal and the other end of the second variable filter is connected to a reception individual terminal. At the time of transmission of a transmission signal, the impedance of the second variable filter is adjusted such that the impedance seen on the second variable filter side from a connection point between the variable filters is open. At the time of transmission of a reception signal, the impedance of the first variable filter is adjusted such that the impedance seen on the first variable filter side from a connection point between the variable filters is open.

Abstract: A transmission filter allows a signal in the frequency band of a transmission signal to pass through the transmission filter and blocks signals in other frequency bands. The transmission signal output from the transmission filter is supplied to an antenna via an antenna sharing device and transmitted to the outside. A reflected-signal detector senses the amplitude and the phase of a reflected signal from the antenna and outputs detection signals (DA and DP). A control circuit adjusts control signals (CA and CP) on the basis of the detection signals (DA and DP). A cancellation-signal-output circuit adjusts a cancellation signal in such a manner that the cancellation signal has a phase opposite to that of the reflected signal and an amplitude the same as that of the reflected signal by using the control signals (CA and CP). A multiplexer combines the cancellation signal with a received signal including a noise signal.

Abstract: A reflected signal detector (12) detects the amplitude and the phase of a reflected signal and outputs detection signals. A control circuit (13) adjusts first control signals and second control signals on the basis of the detection signals. A first cancel signal output portion (9) adjusts a first cancel signal so that the first cancel signal has a phase opposite to that of the reflected signal and has the same amplitude as that of the reflected signal using the first control signals. A second cancel signal output portion (10) adjusts a second cancel signal so that the second cancel signal has a phase opposite to that of a leakage signal and has the same amplitude as that of the leakage signal using the second control signals. A combining portion (11) combines a reception signal including noise signals with the first and second cancel signals.

Abstract: A high-frequency front-end circuit includes a first variable filter and a second variable filter. One end of each of the variable filters is connected to a common terminal. The other end of the first variable filter is connected to a transmission individual terminal and the other end of the second variable filter is connected to a reception individual terminal. At the time of transmission of a transmission signal, the impedance of the second variable filter is adjusted such that the impedance seen on the second variable filter side from a connection point between the variable filters is open. At the time of transmission of a reception signal, the impedance of the first variable filter is adjusted such that the impedance seen on the first variable filter side from a connection point between the variable filters is open.