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:
Aug. 10, 2004
Filed:
Aug. 05, 2002
Seiko Epson Corporation, Tokyo, JP;
Abstract
The invention provides a surface acoustic wave device which uses an in-plane rotated ST cut quartz crystal plate around the Z′-axis, and which has a large reflection coefficient of the Rayleigh wave. Comb teeth-like IDT electrodes are provided and reflectors to trap the Rayleigh wave are provided on both sides of the IDT electrodes on the principal surface of the in-plane rotated ST cut quartz crystal plate. The electrode width and pitch at the IDT electrodes are defined as L , P , the width and pitch of short-circuit electrodes at the reflectors as L , P , and the thickness of the IDT electrodes and the short-circuit electrodes side as H and H . If the electrode widths and pitches are set up so that either or both of L /P and L /P become 0.32±0.1, this enables maximizing the reflection coefficient and achieving the miniaturization of device itself by reducing the number of the short-circuit electrodes.