Abstract: A composite filter device includes an antenna common terminal, a first band pass filter having a first pass band, and a second band pass filter having a second pass band located at higher frequencies than the first pass band. The first band pass filter includes an elastic wave resonator. The elastic wave resonator includes a LiNbO3 substrate, an IDT electrode on the LiNbO3 substrate, and a dielectric film that covers the IDT electrode and includes a silicon oxide as a main component. When f1? is the frequency of a Sezawa wave of the first band pass filter and f2 is the center frequency of the second pass band, f1? is located at a different position from f2.

Abstract: An elastic wave device includes a piezoelectric substrate, first and second IDT electrodes disposed on a first main surface, and bumps each connected to one of the first and second IDT electrodes. First and second side portions extend in a direction perpendicular or substantially perpendicular to the polarization axis direction and to a direction normal to the piezoelectric substrate. The length of the piezoelectric substrate along the polarization axis direction at the first side portion is shorter than that at the second side portion. The first IDT electrode is located at a position closer to the first side portion than the second IDT electrode. The bumps include three or more first side bumps including first and second bumps that sandwich the first IDT electrode therebetween. The distance between the first and second bumps is the smallest distance among the distances between adjacent bumps of the first side bumps.

Abstract: A multiplexer includes a first filter disposed between an antenna common terminal and a first terminal, and a second filter that is disposed between the antenna common terminal and a second terminal and that has higher passband frequencies than the first filter. The second filter includes IDTs that are longitudinally coupled. Among IDT electrodes in the IDTs, first IDT electrodes are connected to the antenna common terminal side, and second IDT electrodes are connected to the second terminal side. The first and second IDT electrodes have different main pitches of the electrode fingers. At least one of the second IDT electrodes out of all of the electrode fingers has a maximum main pitch.

Abstract: An elastic wave resonator includes a first, second and third reflectors. The first reflector is between a portion including a first IDT electrode and a third IDT electrode and a portion including a second IDT electrode and a fourth IDT electrode and is shared by the first to fourth IDT electrodes. The second reflector is shared by the first and third IDT electrodes. The third reflector is shared by the second and fourth IDT electrodes. The first and third IDT electrodes share a first common busbar. The second and fourth IDT electrodes share a second common busbar. The first and second common busbars are connected to the first reflector. A first busbar, a second busbar, a third busbar, and a fourth busbar of the respective first to fourth IDT electrodes are electrically connected to each other.

Abstract: In an elastic wave filter device, a first filter including a first pass band and a second filter including a second pass band are common-connected at a common connection point. The first filter includes, on the common connection point side, a serial arm resonator, a parallel arm resonator, or a longitudinally coupled resonator-type elastic wave filter, and generates a fundamental wave and a high-order mode. A resonant frequency of the high-order mode on a higher frequency side relative to the first pass band of the first filter is smaller than the second pass band. On the common connection point side, a serial arm resonator in which the resonant frequency is not the highest, a parallel arm resonator, or a longitudinally coupled resonator-type elastic wave filter, is disposed.

Abstract: A switch module includes a filter that allows a signal in a first frequency range to pass therethrough, a filter that allows a signal in a second frequency range to pass therethrough, an impedance load circuit, and an antenna switch including a common terminal connected to an antenna element, a first selection terminal connected to the filter, a second selection terminal connected to the filter, and a third selection terminal connected to the impedance load circuit. When only one frequency range is selected from among the first and second frequency ranges, the antenna switch connects the common terminal to only one of the first and second selection terminals and connects the common terminal to the third selection terminal.

Abstract: A multiplexer includes a n number (n is an integer equal to three or more) of filters that are individually provided in the n number of paths commonly connected at a common junction point, and that have different pass bands from one another. In the multiplexer, (n?1) filters among the n number of filters except for the first filter have impedances of which imaginary components cancel each other at a pass band frequency of the first filter when viewed from the common junction point in a state of the n number of paths being not commonly connected.

Abstract: A multiplexer includes a n number (n is an integer equal to three or more) of filters that are individually provided in the n number of paths commonly connected at a common junction point, and that have different pass bands from one another. In the multiplexer, (n?1) filters among the n number of filters except for the first filter have impedances of which imaginary components cancel each other at a pass band frequency of the first filter when viewed from the common junction point in a state of the n number of paths being not commonly connected.

Abstract: A multiplexer includes a first filter disposed between an antenna common terminal and a first terminal, and a second filter that is disposed between the antenna common terminal and a second terminal and that has higher passband frequencies than the first filter. The second filter includes IDTs that are longitudinally coupled. Among IDT electrodes in the IDTs, first IDT electrodes are connected to the antenna common terminal side, and second IDT electrodes are connected to the second terminal side. The first and second IDT electrodes have different main pitches of the electrode fingers. At least one of the second IDT electrodes out of all of the electrode fingers has a maximum main pitch.

Abstract: In an elastic wave filter device, a first filter including a first pass band and a second filter including a second pass band are common-connected at a common connection point. The first filter includes, on the common connection point side, a serial arm resonator, a parallel arm resonator, or a longitudinally coupled resonator-type elastic wave filter, and generates a fundamental wave and a high-order mode. A resonant frequency of the high-order mode on a higher frequency side relative to the first pass band of the first filter is smaller than the second pass band. On the common connection point side, a serial arm resonator in which the resonant frequency is not the highest, a parallel arm resonator, or a longitudinally coupled resonator-type elastic wave filter, is disposed.

Abstract: An elastic wave resonator includes a first, second and third reflectors. The first reflector is between a portion including a first IDT electrode and a third IDT electrode and a portion including a second IDT electrode and a fourth IDT electrode and is shared by the first to fourth IDT electrodes. The second reflector is shared by the first and third IDT electrodes. The third reflector is shared by the second and fourth IDT electrodes. The first and third IDT electrodes share a first common busbar. The second and fourth IDT electrodes share a second common busbar. The first and second common busbars are connected to the first reflector. A first busbar, a second busbar, a third busbar, and a fourth busbar of the respective first to fourth IDT electrodes are electrically connected to each other.

Abstract: An elastic wave filter includes a transmission circuit provided on a first main surface of a first piezoelectric substrate and a reception circuit provided on a second main surface of a second piezoelectric substrate. A mounting board on which the elastic wave filter is mounted includes a first ground electrode opposed to the transmission circuit; a first rear surface ground electrode overlapped with the transmission circuit in plan view of a rear surface; a second ground electrode opposed to the reception circuit; a second rear surface ground electrode overlapped with the reception circuit in plan view of the rear surface; a line electrode used for connection between the first ground electrode and the second ground electrode; and a first via electrode and a second via electrode passing through the mounting board. An amount of heat transfer per unit time of the second via electrode is greater than an amount of heat transfer per unit time of the first via electrode.

Abstract: An elastic wave device includes elastic wave filters connected in parallel between an input and an output, and has reduced size and insertion loss, and improved electric power handling capability. An elastic wave filter chip is mounted on a die-attach surface of a wiring board and includes an input signal terminal and output signal terminals. At least one of the input and output signal terminals includes a plurality of signal terminals. A common connection wiring line to commonly connect the plurality of signal terminals of the elastic wave filter chip is provided in the wiring board.

Abstract: An elastic wave device includes a piezoelectric substrate, first and second IDT electrodes disposed on a first main surface, and bumps each connected to one of the first and second IDT electrodes. First and second side portions extend in a direction perpendicular or substantially perpendicular to the polarization axis direction and to a direction normal to the piezoelectric substrate. The length of the piezoelectric substrate along the polarization axis direction at the first side portion is shorter than that at the second side portion. The first IDT electrode is located at a position closer to the first side portion than the second IDT electrode. The bumps include three or more first side bumps including first and second bumps that sandwich the first IDT electrode therebetween. The distance between the first and second bumps is the smallest distance among the distances between adjacent bumps of the first side bumps.

Abstract: An elastic wave device includes a piezoelectric substrate, first and second IDT electrodes on a first main surface, and electrode lands each connected to one of the first and second IDT electrodes. First and second side portions extend in a direction perpendicular or substantially perpendicular to a polarization axis direction and to a direction normal to the piezoelectric substrate. The length of the piezoelectric substrate along the polarization axis direction at the first side portion is shorter than that at the second side portion. The first IDT electrode is closer to the first side portion than the second IDT electrode. The electrode lands include a first electrode land connected to the first busbar of the first IDT electrode without having the second IDT electrode interposed therebetween, and a second electrode land being at the same potential as the first busbar of the first IDT electrode.

Abstract: An elastic wave filter device includes a one-port elastic wave resonator and an elastic wave filter unit connected in series to the one-port elastic wave resonator. The one-port elastic wave resonator is connected in parallel to an inductance. In the elastic wave filter device, fr1>f0 is satisfied, where f0 is the center frequency of a passband of the elastic wave filter unit, and fr1 is a resonant frequency of the one-port elastic wave resonator.

Abstract: An elastic wave device includes a piezoelectric substrate, an IDT electrode, wiring, a pad, an under bump metal, a first dielectric layer, and a second dielectric layer. At least a portion of the IDT electrode includes a first electrically conductive film, at least a portion of the wiring includes a multilayer body including the first electrically conductive film and a second electrically conductive film, and at least a portion of the pad includes the second electrically conductive film. The second dielectric layer covers the region other than the contact region between the second electrically conductive film and the under bump metal. Consequently, the second electrically conductive film is covered with the second dielectric layer and the under bump metal and is not exposed to air.

Abstract: An elastic wave filter includes a transmission circuit provided on a first main surface of a first piezoelectric substrate and a reception circuit provided on a second main surface of a second piezoelectric substrate. A mounting board on which the elastic wave filter is mounted includes a first ground electrode opposed to the transmission circuit; a first rear surface ground electrode overlapped with the transmission circuit in plan view of a rear surface; a second ground electrode opposed to the reception circuit; a second rear surface ground electrode overlapped with the reception circuit in plan view of the rear surface; a line electrode used for connection between the first ground electrode and the second ground electrode; and a first via electrode and a second via electrode passing through the mounting board. An amount of heat transfer per unit time of the second via electrode is greater than an amount of heat transfer per unit time of the first via electrode.

Abstract: An elastic wave filter device includes a one-port elastic wave resonator and an elastic wave filter unit connected in series to the one-port elastic wave resonator. The one-port elastic wave resonator is connected in parallel to an inductance. In the elastic wave filter device, fr1>f0 is satisfied, where f0 is the center frequency of a passband of the elastic wave filter unit, and fr1 is a resonant frequency of the one-port elastic wave resonator.

Abstract: A dual-band surface acoustic wave filter is mounted on a circuit board together with a high-frequency switch, constitutes a composite high-frequency component together with the high-frequency switch, and significantly reduces and prevents deterioration of filter characteristics of the composite high-frequency component. A first input terminal is located on a first corner portion of a second principal surface of a wiring board. A second input terminal is located on the second principal surface of the wiring board and along a first long side or a first short side so as to be next to the first input terminal. First and second output terminals are arranged on an edge portion of the second principal surface of the wiring board on a second long side and along the second long side.