Surface acoustic wave device and manufacturing method therefor
AssigneeMurata Manufacturing Co., Ltd.
InventorsTakeshi Nakao, Koji Fujimoto, Michio Kadota, Toshimaro Yoneda
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Abstract
In a surface acoustic wave device using a Shear Horizontal type surface acoustic wave, at least one interdigital transducer (IDT) is made of a material having a larger mass-load effect than that of aluminum. The metallization ratio of the IDT and the normalization film thickness h/λ of the IDT are controlled such that ripple caused by a transversal mode wave is about 0.5 dB or less, where “h” indicates the film thickness of the electrodes and “λ” indicates the wavelength of a surface acoustic wave.
Claims24
A surface acoustic wave device using a Shear Horizontal type surface acoustic wave, comprising:
- a quartz substrate;
- and
- at least one interdigital transducer disposed on the quartz substrate and including electrodes having a larger mass-load effect than that of aluminum;
- wherein a metallization ratio “d” and a normalized film thickness h/λ of the at least one interdigital transducer are within specific ranges such that a ripple caused by a transversal mode wave is about 0.5 dB or less, where “λ” is the wavelength of the surface acoustic wave and “h” is the film thickness of the electrodes of the at least one interdigital transducer.
A surface acoustic wave device using a Shear Horizontal type surface acoustic wave, comprising:
- a quartz substrate;
- and
- at least one interdigital transducer disposed on the quartz substrate and made from tantalum;
- wherein a normalized film thickness h/λ of the at least one interdigital transducer is within a range of about 0.6d+1.65 to about 0.6d+1.81, where “d” is the metallization ratio of the interdigital transducer, “λ” is the wavelength of the surface acoustic wave, and “h” is the film thickness of the electrodes of the at least one interdigital transducer.
A surface acoustic wave device using a Shear Horizontal type surface acoustic wave, comprising:
- a quartz substrate;
- and
- at least one interdigital transducer disposed on the quartz substrate and made from tungsten;
- wherein a normalized film thickness h/λ of the at least one interdigital transducer is within a range of about 0.6d+0.85 to about 0.6d+1.30, where “d” is the metallization ratio of the interdigital transducer, “λ” is the wavelength of the surface acoustic wave, and “h” is the film thickness of the electrodes of the at least one interdigital transducer.
Dependencies are inferred from the claim text.