Abstract: A surface acoustic wave device includes a pair of reflectors and an interdigital transducer having a cross electrode having a interdigitated portion and a dummy portion and a dummy electrode. The dummy electrode has a length different from the length of the dummy portion of the cross electrode arranged adjacent to the dummy electrode.

Abstract: An acoustic wave device includes a ladder-type filter in which resonators are connected in a ladder configuration. In the acoustic wave device, series-connected resonators are connected in a parallel line in the ladder-type filter, and the resonators connected in the parallel line have mutually different resonance frequencies.

Abstract: A surface acoustic wave device includes a pair of reflectors and an interdigital transducer having a cross electrode having a interdigitated portion and a dummy portion and a dummy electrode. The dummy electrode has a length different from the length of the dummy portion of the cross electrode arranged adjacent to the dummy electrode.

Abstract: An acoustic wave device includes a ladder-type filter in which resonators are connected in a ladder configuration. In the acoustic wave device, series-connected resonators are connected in a parallel line in the ladder-type filter, and the resonators connected in the parallel line have mutually different resonance frequencies.

Abstract: There is disclosed an acoustic wave apparatus, constructed in such a manner that a surface rotated in the range of 34° to 41° from a crystal Y axis around the crystal X axis of lithium tantalate is set as the surface of a substrate, a standardized electrode thickness (h/&lgr;) obtained by standardizing a thickness h of an electrode finger constituting at least a part of an interdigital transducer by a wavelength &lgr; of a surface acoustic wave is set to the range of 0.01 to 0.05, and a duty ratio (w/p) of the electrode finger decided based on a width w and an arraying cycle p of the electrode finger is set to the value ranging from 0.6 to just below 1.0.

Abstract: In an elastic wave device, an electrode, which is formed in a comb-like shape and is made of conductive material having a prescribed thickness, is arranged on a substrate of a piezo-electric element containing lithium niobate as a main component. Also, in this elastic wave device, a surface of the substrate is set to a plane which is obtained by rotating a plane perpendicular to a crystal Y-axis of the lithium niobate by an angle ranging from 55 degrees to 57 degrees around a crystal x-axis of the lithium niobate, and a duty ratio (a width w of an electrode finger/an arrangement interval p of a pair of electrode fingers) of each of a plurality of electrode fingers composing the electrode is equal to or higher than 0.4 and is lower than 1.0.

Abstract: A surface acoustic wave device includes a piezoelectric substrate of a single crystal LiTaO3 and an electrode pattern provided on the piezoelectric substrate. The electrode pattern contains Al as a primary component and has a thickness in a range of 0.03-0.15 times a wavelength of a surface acoustic wave excited on the piezoelectric substrate. The piezoelectric substrate has an orientation rotated about an X-axis thereof from a Y-axis thereof toward a Z-axis thereof, with a rotational angle of 38-46°.

Abstract: A surface acoustic wave device which reflects a surface acoustic wave is provided. The reflector of the surface acoustic wave device includes electrode fingers. The electrode fingers are disposed at predetermined intervals d, and are divided into five groups by the width. The widths w of the electrode fingers are varied between widths w1, w2, and w3, so that the reflectance becomes similar to the Hamming function.

Abstract: In an elastic wave device, an electrode, which is formed in a comb-like shape and is made of conductive material having a prescribed thickness, is arranged on a substrate of a piezo-electric element containing lithium niobate as a main component. Also, in this elastic wave device, a surface of the substrate is set to a plane which is obtained by rotating a plane perpendicular to a crystal Y-axis of the lithium niobate by an angle ranging from 55 degrees to 57 degrees around a crystal x-axis of the lithium niobate, and a duty ratio (a width w of an electrode finger/an arrangement interval p of a pair of electrode fingers) of each of a plurality of electrode fingers composing the electrode is equal to or higher than 0.4 and is lower than 1.0.

Abstract: A surface acoustic wave device includes a piezoelectric substrate of a single crystal LiTaO.sub.3 and an electrode pattern provided on the piezoelectric substrate. The electrode pattern contains Al as a primary component and has a thickness in a range of 0.03-0.15 times a wavelength of a surface acoustic wave excited on the piezoelectric substrate. The piezoelectric substrate has an orientation rotated about an X-axis thereof from a Y-axis thereof toward a Z-axis thereof, with a rotational angle of 39-46.degree..