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. 04, 1994
Filed:
May. 01, 1992
Applicant:
Inventors:
Oscar E Agazzi, Florham Park, NJ (US);
Steven R Norsworthy, Emmanus, PA (US);
Assignee:
AT&T Bell Laboratories, Murray Hill, NJ (US);
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H04B / ;
U.S. Cl.
CPC ...
375 59 ; 375 28 ; 341 77 ; 341143 ;
Abstract
A transmitter suitable for ISDN use feeds the 2B1Q transmit signals directly into a sigma-delta modulator. The input word is two or three bits and the datapath within the sigma-delta modulator need be only six bits wide. The sigma-delta modulator has sample-hold means which has some filtering effect. The additional filtering requirements are met with an analog filter. No digital interpolation filter is required.