Surface acoustic wave device with specific electrode materials and quartz substrate euler angles

A surface acoustic wave device comprising:

• a quartz substrate having an angle .theta. of Euler angles (0, .theta., 90.degree.) which has a value that is greater than or equal to about 122.degree. and is less than or equal to about 131.degree.;
• and
• an interdigital transducer made of an electrode material including at least one of Ta and W and disposed on said quartz substrate;
• wherein the electrode material constituting said interdigital transducer is W, and the angle .theta. satisfies formula (2):
• .theta.=125.70+49.87.times.d.times.h/.lambda..+-.1.2 formula (2)
• where h represents a film thickness of said interdigital transducer, d represents an electrode finger metallization ratio of said interdigital transducer, and .lambda. represents a wavelength of a surface acoustic wave generated in the surface acoustic wave device.

A surface acoustic wave device comprising:

• a quartz substrate having an angle .theta. of Euler angles (0, .theta., 90.degree.) which has a value that is greater than or equal to about 122.degree. and is less than or equal to about 131.degree.;
• and
• an interdigital transducer made of an electrode material including at least one of Ta and W and disposed on said quartz substrate;
• wherein the surface acoustic wave device further includes reflectors arranged on opposite sides of said interdigital transducer along a surface acoustic wave propagation direction, so as to define a surface acoustic wave resonator, and
• the number N.sub.IDT of electrode finger pairs of said interdigital transducer has a value of up to 200.

A surface acoustic wave device comprising:

• a quartz substrate having an angle .theta. of Euler angles (0, .theta., 90.degree.) which has a value that is greater than or equal to about 122.degree. and is less than or equal to about 131.degree.;
• and
• an interdigital transducer made of an electrode material including at least one of Ta and W and disposed on said quartz substrate;
• wherein reflectors are disposed on opposite sides of said interdigital transducer along a surface acoustic wave propagation direction and the reflectors include plural electrode fingers extending in a direction that is substantially perpendicular to a surface acoustic wave propagation direction and the electrode fingers are short-circuited at opposite ends thereof, so as to define a surface acoustic wave resonator, and
• the number N.sub.REF of electrode fingers of the respective reflectors has a value of up to 20.

A surface acoustic wave filter comprising:

• a quartz substrate having an angle .theta. of Euler angles (0, .theta., 90.degree.) which has a value that is greater than or equal to about 122.degree. and is less than or equal to about 131.degree.;
• an interdigital transducer made of an electrode material including at least one of Ta and W and disposed on said quartz substrate;
• and
• reflectors arranged on opposite sides of said interdigital transducer along a surface acoustic wave propagation direction;
• wherein
• the number N.sub.IDT of electrode finger pairs of said interdigital transducer has a value of up to 200.

A longitudinally coupled surface acoustic wave filter comprising:

• a quartz substrate having an angle .theta. of Euler angles (0, .theta., 90.degree.) which has a value that is greater than or equal to about 122.degree. and is less than or equal to about 131.degree.;
• first and second interdigital transducers arranged on said quartz substrate so as to be separated by a gap and made of an electrode material including at least one of Ta and W;
• and
• reflectors arranged on opposite sides of a region where the first and second interdigital transducers are provided on the quartz substrate, along a surface wave propagation direction;
• wherein
• the first and second interdigital transducers have a number N.sub.IDT of electrode fingers up to N.sub.IDT.sup.MAX (x) defined in accordance with N.sub.IDT.sup.MAX (x)=338{x-(0.22+0.55n)}.sup.2 +25
• where x=G/.lambda., G represents a size of the gap G between the first and second interdigital transducers along the surface acoustic wave propagation direction, and n is an integer defined in accordance with -0.055+0.55n.ltoreq.x.ltoreq.0.495+0.55n, and .lambda. represents a wavelength of a surface acoustic wave generated in the surface acoustic wave filter.

A surface acoustic wave device comprising:

• a quartz substrate having an angle .theta. of Euler angles (0, .theta., 90.degree.) which has a value that is greater than or equal to about 122.degree. and is less than or equal to about 131.degree.;
• and
• an interdigital transducer made of an electrode material including at least one of Ta and W and disposed on said quartz substrate;
• wherein
• said interdigital transducer has an electrode finger cross width of up to about 40 .lambda. where .lambda. represents a wavelength of a surface acoustic wave generated in the surface acoustic wave device.

A surface acoustic wave device comprising:

• a quartz substrate having an angle .theta. of Euler angles (0, .theta., 90.degree.) which has a value that is greater than or equal to about 122.degree. and is less than or equal to about 131.degree.;
• and
• an interdigital transducer made of an electrode material including at least one of Ta and W and disposed on said quartz substrate;
• wherein the electrode material constituting said interdigital transducer is Ta, and the angle .theta. satisfies formula (1):
• .theta.=125.44+108.27.times.d.times.h/.lambda..+-.1.2 formula (1)
• where h represents a film thickness of said interdigital transducer, d represents an electrode finger metallization ratio of said interdigital transducer, and .lambda. represents a wavelength of a surface acoustic wave generated in the surface acoustic wave device.