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:
Mar. 20, 1990
Filed:
Sep. 26, 1988
Takaya Watanabe, Tokyo, JP;
Shigeo Fushimi, Tokyo, JP;
NEC Corporation, Tokyo, JP;
Abstract
In a three-transducer surface acoustic wave device, an apodized electrode member is interposed between two interdigital electrode members, each having first and second ends and comprising interdigital electrodes between the first and the second ends either with a uniform density distribution or with a density distribution varied according to a prescribed rule of selective withdrawal of the interdigital electrodes. The apodized electrode member has first and second extremities and is given substantially minimum-phase and maximum-phase impulse responses for surface acoustic waves which are propagated either into or out of the apodized electrode member through one and the other of the extremities. Alternatively, an interdigital electrode member is interposed between two apodized electrode members. Each of the interdigital and the apodized electrode members is of the type described above. One of the apodized electrode member should have a substantially minimum-phase impulse response. The other should have a substantially maximum-phase impulse response.