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:
Dec. 02, 1986
Filed:
Dec. 14, 1984
Applicant:
Inventors:
Giacomo Premoli, Milan, IT;
Giacomo Cannalire, Milan, IT;
Assignee:
GTE Communication Systems Corporation, Northlake, IL (US);
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
H04M / ;
U.S. Cl.
CPC ...
379386 ; 328138 ; 34082573 ; 3701103 ;
Abstract
A digital multifrequency receiver circuit of the type employed between telephone system central offices, arranged to provide a faster response to received signals by processing the received signal tones digitally. The faster response resulting from the elimination of automatic gain control circuits and the use of a fixed gain amplifier used only when the received signal is below an acceptable level and the provision of a variable threshold to the individual frequency comparator circuits.