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. 07, 2000
Filed:
Jul. 08, 1997
Applicant:
Inventors:
Pierre Dobrovolny, North Riverside, IL (US);
James J Wolford, Streamwood, IL (US);
Assignee:
Zenith Electronics Corporation, Glenview, IL (US);
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H04B / ;
U.S. Cl.
CPC ...
455266 ; 4551881 ; 455290 ; 334 15 ;
Abstract
A selective RF circuit for a double conversion tuner includes three double tuned bandpass circuits, each of which is tunable over approximately one-third of the tuning range. Switching diodes are used at the input and the output of each of the bandpass sections for selectively activating one of the bandpass sections and deactivating the remaining ones in response to a bandswitching signal. Operational amplifiers or other devices supply the input and output switching diodes by providing a current sink for the active bandpass and current sources for the inactive bandpasses.