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:
Aug. 31, 2004
Filed:
Sep. 20, 1999
Robin Paul Rickard, Bishop's Stortford, GB;
Nortel Networks Limited, St. Laurent, CA;
Abstract
An apparatus for coupling signals to a transmission line, such as a power line ( ). The apparatus comprises an input for receiving a wanted signal; a first coupler for coupling the wanted signal (V ) onto the line at a first position (Y); a cancelling means (W , W , W ), coupled to the input, for deriving a cancelling signal (V ) from the wanted signal; a second coupler for coupling the cancelling signal onto the line at a second position (X), spaced from the first position; wherein the wanted signal and the cancelling signal destructively combine in a single direction of propagation along the line while enabling the wanted signal to propagate in the other direction along the line. The apparatus can be used to minimise radiation from an unshielded part of an electricity distribution network, such as substation ( ), or to allow re-use of a frequency band on other power lines.