Abstract: In an elastic wave device, a first piezoelectric substrate and a second piezoelectric substrate are joined to each other with a joining portion so as to face each other across a cavity. A first set of a plurality of filters located on a facing surface of the first piezoelectric substrate and a second set of a plurality of filters located on a facing surface of the second piezoelectric substrate define a plurality of pairs of filters and face each other across the cavity. An absolute value of a difference between center frequencies of a filter of the first set of filters and a filter of the second set of filters in each pair of filters is larger than a minimum value among absolute values of differences between center frequencies of pairs of filters selected from a group including the first set of filters and the second set of filters.

Abstract: In an elastic wave device, a first piezoelectric substrate and a second piezoelectric substrate are joined to each other with a joining portion so as to face each other across a cavity. A first set of a plurality of filters located on a facing surface of the first piezoelectric substrate and a second set of a plurality of filters located on a facing surface of the second piezoelectric substrate define a plurality of pairs of filters and face each other across the cavity. An absolute value of a difference between center frequencies of a filter of the first set of filters and a filter of the second set of filters in each pair of filters is larger than a minimum value among absolute values of differences between center frequencies of pairs of filters selected from a group including the first set of filters and the second set of filters.

Abstract: A surface acoustic wave resonator includes a rotated Y-cut quartz substrate with a cut angle ? of about ?53° to about ?52° and an IDT electrode made of aluminum or an alloy primarily including aluminum provided on the quartz substrate. The propagation direction of surface acoustic waves is within a range of about 90°±5° with respect to the X axis. A SiO2 film is arranged to cover the quartz substrate and the IDT electrode. The thickness of the IDT electrode is in a range of about 6.0% to about 6.5% of ?, where ? is the wavelength of surface acoustic waves, and the duty ratio of the IDT electrode is in a range of about 0.62 to about 0.66.

Abstract: A surface acoustic wave resonator includes a rotated Y-cut quartz substrate with a cut angle ? of about ?53° to about ?52° and an IDT electrode made of aluminum or an alloy primarily including aluminum provided on the quartz substrate. The propagation direction of surface acoustic waves is within a range of about 90°±5° with respect to the X axis. A SiO2 film is arranged to cover the quartz substrate and the IDT electrode. The thickness of the IDT electrode is in a range of about 6.0% to about 6.5% of ?, where ? is the wavelength of surface acoustic waves, and the duty ratio of the IDT electrode is in a range of about 0.62 to about 0.66.

Abstract: A surface acoustic wave filter includes a surface acoustic wave substrate, an input transducer, and an output transducer. The input and output transducers are arranged on a surface of the surface acoustic wave substrate. Each of the input and output transducers includes a plurality of electrode fingers that is slanted in a direction that is substantially perpendicular to a surface acoustic wave propagation direction such that an electrode finger pitch changes in the direction that is substantially perpendicular to the surface acoustic wave propagation direction. An electrode finger pitch of a portion of the input transducer is different from an electrode finger pitch of a portion of the output transducer that corresponds to the portion of the input transducer in the surface acoustic wave propagation direction.

Abstract: In a surface acoustic wave filter, an input-side IDT electrode and an output-side IDT electrode are arranged on a piezoelectric substrate so as to be separated from each other in the propagation of a surface acoustic wave. The thickness of the IDT electrodes is set so that the first coefficient of the velocity-dispersion has a negative value.

Abstract: In a method for manufacturing a transversal surface acoustic wave filter device, measurement pads for use in probe measurement are formed on a wafer, and are shared by adjacent transversal surface acoustic wave filter devices. The number of measurement pads is reduced to about half the standard, thereby reducing the area occupied per device.

Abstract: A surface acoustic wave filter includes a first acoustic channel which has first input/output transducers and which is configured so as to define a first transfer function by the first input/output transducers, and a second acoustic channel which has second input/output transducers and which is configured so as to define a second transfer function by the second input/output transducers. The first and second acoustic channels are electrically connected in parallel. The first and second transfer functions are substantially in phase within a pass band, while they have substantially opposite phases outside the pass band. The bandwidth of the second acoustic channel is narrower than that of the first acoustic channel. A first side lobe of the second transfer function has a phase opposite to that of a main lobe of the first acoustic channel.

Abstract: A surface acoustic wave filter includes a surface acoustic wave substrate, an input transducer, and an output transducer. The input and output transducers are arranged on a surface of the surface acoustic wave substrate. Each of the input and output transducers includes a plurality of electrode fingers that is slanted in a direction that is substantially perpendicular to a surface acoustic wave propagation direction such that an electrode finger pitch changes in the direction that is substantially perpendicular to the surface acoustic wave propagation direction. An electrode finger pitch of a portion of the input transducer is different from an electrode finger pitch of a portion of the output transducer that corresponds to the portion of the input transducer in the surface acoustic wave propagation direction.

Abstract: In a surface acoustic wave filter, an input-side IDT electrode and an output-side IDT electrode are arranged on a piezoelectric substrate so as to be separated from each other in the propagation of a surface acoustic wave. The thickness of the IDT electrodes is set so that the first coefficient of the velocity-dispersion has a negative value.

Abstract: A surface acoustic wave filter includes a first acoustic channel which has first input/output transducers and which is configured so as to define a first transfer function by the first input/output transducers, and a second acoustic channel which has second input/output transducers and which is configured so as to define a second transfer function by the second input/output transducers. The first and second acoustic channels are electrically connected in parallel. The first and second transfer functions are substantially in phase within a pass band, while they have substantially opposite phases outside the pass band. The bandwidth of the second acoustic channel is narrower than that of the first acoustic channel. A first side lobe of the second transfer function has a phase opposite to that of a main lobe of the first acoustic channel.

Abstract: A unidirectional surface acoustic wave transducer includes a plurality of interdigital transducers and a plurality of reflectors disposed on a piezoelectric substrate. The directivity of a first group of the plurality of reflectors is opposite relative to the directivity of a second group of the plurality of reflectors.