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:
Oct. 22, 2002
Filed:
Mar. 12, 2001
Shigeru Tsuzuki, Osaka, JP;
Tsutomu Igaki, Hyogo, JP;
Kazunori Nishimura, Kyoto, JP;
Ken Matsunami, Kyoto, JP;
Matsushita Electric Industrial Co., Ltd., Osaka, JP;
Abstract
A surface acoustic wave (SAW) filter is disclosed which comprises a piezoelectric substrate and at least two Interdigital Transducers (IDTs) having four fingered electrodes in a region corresponding to one-wavelength of SAW excited on the piezoelectric substrate. At least one IDT is formed of at least one pair of fingered electrodes having different electrode widths. By provision of the pair of fingered electrodes being different in electrode width, the IDT can be given unidirectionality. Thus, a SAW filter producing a low insertion loss and having good amplitude and phase characteristics in the pass-band can be realized. Further, by using such SAW filter, a high-performance and low-cost communication apparatus, such as a CDMA-system mobile telephone, can be realized.