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:
Feb. 19, 1991
Filed:
Sep. 01, 1989
R Keith Harman, Kanata, CA;
Senstar Corporation, Ontario, CA;
Abstract
A continuous wave (CW) leaky cable sensor for an intrusion detector uses a pair of elongated parallel cables, one for establishing an RF field and the other for receiving the field. A modulator is connected at an intermediate location of the receiving (or transmitting) cable, subdividing a detection zone into detection regions on each side of the modulator. The modulator selectively modifies a signal received by a portion of the receiving cable connected to its input. By processing the signal at the output of the receiving cable, the detection region for either side of the modulator in which an intrusion has occurred can be determined. The resolution of a CW sensor is thus increased at low cost. Multiple modulators can be used at spaced locations increasing the number of detection regions, and thus the resolution.