Abstract: An elastic wave device includes a piezoelectric substrate, an IDT electrode disposed on the piezoelectric substrate, an internal electrode disposed on the piezoelectric substrate and connected to the IDT electrode, a support pillar disposed on the piezoelectric substrate and provided around the IDT electrode, a top panel provided on the support pillar to cover a space above the IDT electrode, an insulation protector provided to cover the support pillar and the top panel, an external electrode disposed on the insulation protector, a conductor pattern disposed on the insulation protector in order to obtain inductance, and a connection electrode provided through the insulation protector, to connect the external electrode and the internal electrode to each other.

Abstract: An acoustic wave device includes a piezoelectric substrate, an interdigital transducer (IDT) electrode, a reflector electrode, and a dummy electrode. The IDT electrode includes electrode fingers extending in a predetermined direction. The reflector electrode faces the IDT electrode across a gap. The dummy electrode is situated on a straight line extending in the predetermined direction through the gap. At least one of the distance between the dummy electrode and the IDT electrode and the distance between the dummy electrode and the reflector electrode is larger than the distance between the IDT electrode and the reflector electrode. This acoustic wave device prevents a short circuit between the IDT electrode and the reflector electrode, thereby avoiding a decrease in its yield.

Abstract: A SAW filter includes a piezoelectric body, an IDT electrode on the piezoelectric body, and signal wiring electrically connected to the IDT electrode. The signal wiring has a thickness not less than a skin depth specified based on the frequency of a signal passing through the signal wiring and the electrical conductivity of the signal wiring. As a result, the signal wiring has low propagation loss of the signal passing through it, so that the SAW filter has excellent transmission characteristics.

Abstract: An acoustic wave device includes a piezoelectric substrate, an interdigital transducer (IDT) electrode, a reflector electrode, and a dummy electrode. The IDT electrode includes electrode fingers extending in a predetermined direction. The reflector electrode faces the IDT electrode across a gap. The dummy electrode is situated on a straight line extending in the predetermined direction through the gap. At least one of the distance between the dummy electrode and the IDT electrode and the distance between the dummy electrode and the reflector electrode is larger than the distance between the IDT electrode and the reflector electrode. This acoustic wave device prevents a short circuit between the IDT electrode and the reflector electrode, thereby avoiding a decrease in its yield.

Abstract: An antenna sharer with both low loss and sharp attenuation characteristic in a wide band is achieved. Antennal sharer 1 of the present invention includes first filter 3 for passing a signal in the first frequency band, and second filter 4 for passing a signal in the second frequency band higher than the first frequency band. First filter 3 includes a ladder filter that includes first series resonator 6 and second series resonator 7 with an antiresonant frequency point higher than antiresonant frequency of first series resonator. Electromechanical coupling coefficient of first series resonator 6 is smaller than electromechanical coupling coefficient of second series resonator 7.

Abstract: An elastic wave device includes a piezoelectric substrate, an IDT electrode disposed on the piezoelectric substrate, an internal electrode disposed on the piezoelectric substrate and connected to the IDT electrode, a support pillar disposed on the piezoelectric substrate and provided around the IDT electrode, a top panel provided on the support pillar to cover a space above the IDT electrode, an insulation protector provided to cover the support pillar and the top panel, an external electrode disposed on the insulation protector, a conductor pattern disposed on the insulation protector in order to obtain inductance, and a connection electrode provided through the insulation protector, to connect the external electrode and the internal electrode to each other.

Abstract: A surface acoustic wave filter which includes a first terminal at the input side, a second terminal at the output side, a plurality of resonators electrically connected between the first and the second terminals, and a piezoelectric substrate provided on the upper surfaces of first and second terminals and the plurality of resonators. The piezoelectric substrate is made to have a thickness that is not thicker than 0.2 mm. The filtering characteristic of surface acoustic wave filter can be improved by taking advantage of the above structure.

Abstract: A SAW filter includes a piezoelectric body, an IDT electrode on the piezoelectric body, and signal wiring electrically connected to the IDT electrode. The signal wiring has a thickness not less than a skin depth specified based on the frequency of a signal passing through the signal wiring and the electrical conductivity of the signal wiring. As a result, the signal wiring has low propagation loss of the signal passing through it, so that the SAW filter has excellent transmission characteristics.

Abstract: A surface acoustic wave filter which includes a first terminal at the input side, a second terminal at the output side, a plurality of resonators electrically connected between the first and the second terminals, and a piezoelectric substrate provided on the upper surfaces of first and second terminals and the plurality of resonators. The piezoelectric substrate is made to have a thickness that is not thicker than 0.2 mm. The filtering characteristic of surface acoustic wave filter can be improved by taking advantage of the above structure.