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. 26, 1976
Filed:
Dec. 31, 1975
Adrian J DeVries, Elmhurst, IL (US);
Zenith Radio Corporation, Chicago, IL (US);
Abstract
An acoustic surface wave filter has offset transmitting and receiving transducers formed on a wave propagating surface of a piezoelectric substrate. A multistrip coupler interposed between the transducers on the propagating surface includes a plurality of identical conductor groups forming coupler elements uniformly spaced on the surface and selectively attenuates either of the symmetrical or anti-symmetrical mode components of coupled waves within a predetermined range of acoustic wavelengths. In one embodiment, each conductor group includes electrically connected pairs which attenuates the symmetrical mode component while in another embodiment each conductor group includes a first continuous filamentary conductor and a second filamentary conductor having a discontinuity at its approximate center which attenuates the anti-symmetrical mode component.