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:
Feb. 23, 1982
Filed:
Aug. 11, 1980
Applicant:
Inventors:
Allen L Davidson, Crystal Lake, IL (US);
Jona Cohn, Morton Grove, IL (US);
Assignee:
Motorola, Inc., Schaumburg, IL (US);
Primary Examiner:
Int. Cl.
CPC ...
H04B / ;
U.S. Cl.
CPC ...
455 24 ; 455 22 ;
Abstract
Spillover of RF signal from the output of a same-frequency repeater to the input is reduced by attaching a tag to the output signal. The tag is double-sideband, suppressed carrier to place two spectral spikes, one above and one below the carrier. The tag is applied to the signal in the IF. A tagged signal of variable amplitude and phase is added to the received signal so as to cancel the tag and hence the spillover signal, leaving only the desired signal. A feedback system controls the amplitude and phase of the cancelling signal.