Abstract: A first receiving band and a first transmission band in band A and a second transmission band and a second receiving band in band B are listed in frequency order. A radio frequency module includes: first and second boards; a first filter having a passband that is the first transmission band; second and sixth filters each having a passband that is the first receiving band; third and fifth filters each having a passband that is the second receiving band; a first power amplifier connected to the first filter; a fourth filter having a passband that is the second transmission band; and a second power amplifier connected to the fourth filter. The first to third filters and the first power amplifier are disposed on the first board, and the fourth to sixth filters and the second power amplifier are disposed on the second board.

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 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 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 transmit/receive module includes plural duplexers, a power amplifier, and a sending transmission line. The plural duplexers operate in bands different from each other and each includes a transmit filter and a receive filter. The power amplifier amplifies signals of pass bands of the plural transmit filters and outputs the amplified signals. The sending transmission line is connected to the plural transmit filters. The signals of the pass bands of the plural transmit filters output from the power amplifier are transmitted through the sending transmission line.

Abstract: A surface acoustic wave demultiplexer includes a first surface acoustic wave filter, a second surface acoustic wave filter having a higher center frequency than the first surface acoustic wave filter, and a one-port surface acoustic wave resonator connected to an input terminal of the first surface acoustic wave filter in series and having an anti-resonant frequency in the stop band of the first surface acoustic wave filter. A first piezoelectric substrate that constitutes the first surface acoustic wave filter and a second piezoelectric substrate that constitutes the second surface acoustic wave filter are made from different piezoelectric materials.

Abstract: A duplexer includes a transmitting filter and a receiving filter which are connected in parallel to an antenna terminal, and a matching circuit connected between the antenna terminal and at least one of the transmitting filter and the receiving filter. A portion of the matching circuit defines a trap circuit for harmonic suppression.

Abstract: A surface acoustic wave demultiplexer includes a first surface acoustic wave filter, a second surface acoustic wave filter having a higher center frequency than the first surface acoustic wave filter, and a one-port surface acoustic wave resonator connected to an input terminal of the first surface acoustic wave filter in series and having an anti-resonant frequency in the stop band of the first surface acoustic wave filter. A first piezoelectric substrate that constitutes the first surface acoustic wave filter and a second piezoelectric substrate that constitutes the second surface acoustic wave filter are made from different piezoelectric materials.

Abstract: A duplexer includes a transmitting filter and a receiving filter which are connected in parallel to an antenna terminal, and a matching circuit connected between the antenna terminal and at least one of the transmitting filter and the receiving filter. A portion of the matching circuit defines a trap circuit for harmonic suppression.