Patent ID: 7605684
Filing Date: 2009-10-20
Classification: G01S

Abstract:
1. A method for interrogating an RFID tag using an antenna array, comprising the steps of: transmitting a data signal having an amplitude and a time delay, wherein said data signal causes said RFID tag to respond to said antenna array; transmitting one or more scramble signals each having an amplitude and a time delay, wherein said one or more scramble signals do not cause said RFID tag to respond to said antenna array; selecting said data signal amplitude, said data signal time delay, said one or more scramble signal amplitudes, and said one or more scramble signal time delays so that said data signal overshadows said one or more scramble signals in a region and said one or more scramble signals overshadow said data signal outside said region, wherein said region is a one-sided region; and, receiving a response from said RFID tag when said RFID tag is located within said region.