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:
Nov. 05, 2002
Filed:
Apr. 06, 2001
Shigeru Tsuzuki, Osaka, JP;
Tsutomu Igaki, Hyogo, JP;
Ken Matsunami, Kyoto, JP;
Kazunori Nishimura, Kyoto, JP;
Hiroyuki Nakamura, Osaka, JP;
Toru Yamada, Osaka, JP;
Matsushita Electric Industrial Co., Ltd., Osaka, JP;
Abstract
A SAW filter comprising a piezoelectric substrate and at least two filter tracks formed on the substrate, each having at least two IDT electrodes for input and output. The two filter tracks have substantially the same phase within a pass band, while it is substantially inverse-phased outside the pass band. For realizing the above-described conditions, input IDT electrode of one filter track is connected in parallel with input IDT electrode of the other filter track, while output IDT electrode of one filter track is connected in parallel with output IDT electrode of the other filter track. Furthermore, frequency values of said two filter tracks substantially coincide at a point dB lower from the peak transfer function value. Thus the above-configured SAW filter of the present invention is smaller in the overall size and offers a broad pass band and a steep attenuation characteristic.