this invention relates to dynamically controlled , electronic article surveillance systems whereby an array of antenna elements is digitally phased and actively driven for concurrent transmission , and digitally phased and combined in the receiver unit to improve detection . in particular , the individual frequency and phase of the plurality of the transmit / receive signals are rapidly varied to allow for automated manipulation of the transmit field pattern and receive field sensitivity . the invention achieves the following features via means of digital phasing and dynamic computer control : sufficient far - field cancellation , null - free detection and uncompromised detection performance regardless of tag &# 39 ; s orientation while using single transmission drivers to drive entire antenna structures , whether loop antenna or ferrite core antenna , using a phase coupler , thereby allowing more efficient system operation or additional features such as deactivator antenna operation .