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. 19, 1989
Filed:
Feb. 17, 1988
Applicant:
Inventor:
Masanobu Arai, Tokyo, JP;
Assignee:
NEC Corporation, Tokyo, JP;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H04B / ;
U.S. Cl.
CPC ...
370 321 ; 379410 ;
Abstract
An echo canceller for bidirectional transmission on two-wire metallic subscriber lines in an integrated service digital network employing a filter positioned in the echo path having the property that a zero point is located so as to cancel the echo path transfer function attributable to the inductance component of the line coupling transformer.