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:
May. 15, 1979
Filed:
Oct. 31, 1977
Frank Sandy, Lexington, MA (US);
Manfred B Schulz, Sudbury, MA (US);
Raytheon Company, Lexington, MA (US);
Abstract
A surface acoustic wave low loss filter device having input and output transducers located along opposed sides of a rectangular propagation path with frequency selective reflective gratings at each of the four corners of the rectangle. Two traveling surface waves traverse the device along opposed paths encountering frequency filtering at the gratings. The two waves arrive at the output transducer additively in phase eliminating the bidirectionality loss normally associated with surface acoustic wave devices. At frequencies for which the gratings are reflective there can be nearly lossless transmission from input to output. At all other frequencies, transmission between input and output transducers is negligible. The device has high sidelobe rejection, adjustable passband skirt slopes, and an adjustable bandwidth.