Harsh V Bahl

US Patent:

49264737, May 15, 1990

Filed:

Apr 27, 1989

Appl. No.:

7/346322

Inventors:

Harsh V. Bahl - Bolingbrook IL
Laurence L. Sheets - St. Charles IL

Assignee:

Rockwell International Corporation - El Segundo CA

International Classification:

H04M 174

US Classification:

379416

Abstract:

A longitudinal cancellation circuit for use in circuits providing a received differential signal containing a desired differential component and an undesired longitudinal component has a first multiplier for multiplying received differential signal with the longitudinal signal to produce a first signal having at least a DC component in addition to other frequency components. The first signal is received by a low-pass filter which produces a second signal containing only the DC component. A second multiplier multiplies the second signal with the undesired longitudinal signal to produce a third signal equal to the to the undesired longitudinal component. The third signal is subtracted from the received differential signal to produce the desired differential signal which is free of undesired longitudinal component.