Patent ID: 7873326
Filing Date: 2011-01-18
Classification: G01S,G06K,H01Q,H04B

Abstract:
1. A method for deriving information from an RFID tag, comprising: transmitting RFID tag interrogation signals to an RFID tag; digitizing the signals received by each antenna element of an array of antenna elements from the RFID tag in response to the interrogation signals; performing signal processing on the digitized signals to determine relative phase and weight differences between the signals received by each of the antenna elements in the array of antenna elements from the RFID tag in response to the interrogation signals; delaying the digitized signals received from each of the antenna elements to compensate for any accumulated delay; adjusting the relative phases and weights of the digitized signals to form phase aligned and amplitude weighted signals; combining the adjusted signals to form a weighted combination of the phase aligned and amplitude weighted digitized signals, and deriving RFID tag information from the weighted combination of the phase aligned and amplitude weighted digitized signals.