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. 10, 1983
Filed:
Jul. 02, 1981
Applicant:
Inventor:
Allen L Davidson, Crystal Lake, IL (US);
Assignee:
Motorola, Inc., Schaumburg, IL (US);
Primary Examiner:
Int. Cl.
CPC ...
H04B / ;
U.S. Cl.
CPC ...
455 24 ; 455 22 ;
Abstract
A same-frequency repeater used in a system that has at least one other same-frequency repeater is protected against oscillation resulting from feedback of signals broadcast by the same-frequency repeater, either directly or after reception and rebroadcast by another same-frequency repeater. A tag is added to the signal to be broadcast from the first SFR, and one tag detection and canceling system is added to the first SFR for each SFR, in the system. Each tag detector senses the presence of tagged signal received by the first SFR and adjusts amplitude and phase of an appropriately delayed signal that is fed back to cancel the signal containing tag.