Transponder system for use in access control gate systems has signal mirror reflectors with antennas connected to reader unit

摘要

The transponder system [8] is used for the identification of anyone passing into a limited are or gate [5]. The system has antenna [3] and a pair of identical concave mirrors [2]. Ultra high frequency signals are transmitted to a receiver/reader [4] that has a pair of switches [11] allowing the roles of transmitter and absorber antenna to be changed.