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. 01, 1991
Filed:
Aug. 01, 1989
Applicant:
Inventors:
Michael S Cruz, Buffalo Grove, IL (US);
Harmon P Vaughter, Evanston, IL (US);
Assignee:
Zenith Electronics Corporation, Glenview, IL (US);
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H04B / ;
U.S. Cl.
CPC ...
455189 ; 455191 ; 455285 ; 455302 ;
Abstract
A tunable/switchable notch filter adapted for use in the front end of a television receiver removes an image frequency on the low side of the UHF passband without degrading desired frequencies. The tunable/switchable notch filter can be switched out when in a VHF mode so as not to degrade VHF performance and switched in for UHF operation for filtering out a difference image frequency which varies with and is a predetermined frequency less than the desired UHF signal.