The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jan. 25, 2005
Filed:
Sep. 27, 2002
Yoshihiro Ito, Muko, JP;
Michio Kadota, Kyoto, JP;
Koji Fujimoto, Otsu, JP;
Murata Manufacturing Co., Ltd., Kyoto, JP;
Abstract
A Shear Horizontal-type end-surface-reflection-type surface acoustic wave device includes a piezoelectric substrate having end surfaces. The most appropriate positions of the end surfaces of the piezoelectric substrate are determined. Interdigital transducers are disposed on the main surface of the piezoelectric substrate having a comparatively low relative dielectric constant ∈(for example, a relative dielectric constant of about 40 or less). The positions of the end surfaces are determined so that the distance from the center of the second electrode finger, counting from the outermost side in the surface acoustic wave propagation direction among the interdigital transducers, to the end surfaces (end surfaces for reflecting the surface acoustic wave) of the piezoelectric substrate satisfy the relationship (N+⅝)λs≦L≦(N+⅞)λs, where λs is the wavelength of the surface acoustic wave, and N is 0 or a positive integer.