Antenna system of monitring electronic article, and its configuration

Abstract

An antenna system for an electronic article surveillance system comprising: a first antenna and the second antenna mounted for use in an substantially overlapping manner, the first antenna configured as a loop, the second antenna configured in a "figure-8"; a control circuit for selectively activating one of the first and second antennas. The first and second antennas each operate as a transmit and receive antenna. The control circuit further comprises a switch to selectively enable operation of one of the antennas when the other is open circuit. One of the antennas transmits and receives while the other circuit, the vice versa. The loop antenna substantially detects markers oriented substantially perpendicular to an elongated axis when entering into a surveillance area. The "figure-8" antenna substantially detects markers oriented substantially parallel to an elongated axis when entering into a surveillance area.

Description

[0001] This application claims priority under 35 U.S.C. Section 119(e) to: Co-pending U.S. Provisional Patent Application Serial No. 60 / 374,920, filed April 22, 2002, entitled "Antenna System for Electronic Article Surveillance" Methods and Arrangements," and Serial No. 60 / 376,236, filed April 26, 2002, entitled "Methods and Arrangements for Antenna Systems for Electronic Article Surveillance." These two patents are also incorporated by reference into the application. technical field

[0002] The present invention relates to the field of Electronic Article Surveillance (EAS) systems, and more particularly to ESA antenna systems for omnidirectional transmission and reception of signals. Background technique

[0003] Antenna systems generally consist of two components located on either side of a store entrance or checkpoint corridor, usually referred to as gates, racks, panels or detectors. In many systems, one anten...

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