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:
Jul. 20, 2010
Filed:
Apr. 04, 2005
Teruhisa Shibahara, Kanazawa, JP;
Masakazu Tani, Hakusan, JP;
Yasuaki Shin, Hakusan, JP;
Murata Manufacturing Co., Ltd., Kyoto, JP;
Abstract
An elastic wave filter includes two longitudinally coupled resonator type elastic wave filter elements that are cascade connected with each other, each longitudinally coupled resonator type elastic wave filter element including three IDTs (interdigital transducers) arranged on a piezoelectric substrate in a transmitting direction of an elastic wave. In at least one of the longitudinally coupled resonator type elastic wave filter elements, electrode fingers of the IDTs that are cascade connected are arranged at a pitch that is smaller than a pitch of electrode fingers of the remaining IDT. The adverse effect of a parasitic capacitance in cascade connected wires disposed between the longitudinally coupled resonator type elastic wave filter elements is reduced so as to improve impedance matching of a cascade connected portion and to improve the VSWR characteristics of input-output terminals of the elastic wave filter.