Abstract: At least some embodiments of the present invention are directed to RFID reader systems configured to estimate a directional bearing of an RFID tag. In an embodiment, the present invention is an RFID system configured in a way that upon a detection of a variance in the direction of a maximum RSSI value for a given RFID tag in response to a plurality of interrogation signals transmitted by an RFID reader over a respective plurality of different directions, the RFID reader retransmits the plurality of interrogation signals over the respective plurality of different directions with successively lower power levels until the only response(s) being received no longer exhibit the previously detected variance.

Abstract: Systems and methods for enhanced fault tolerance for a radio frequency identification (RFID) phased array antenna are provided. The systems include a RFID reader that includes (i) a phased array antenna having N antenna elements; and (ii) a controller operatively connected to the phased array antenna. The controller is configured to (1) monitor a characteristic for each antenna element of a set of the N antenna elements; (2) based on the characteristic, detect a fault of a faulty antenna element of the set of the N antenna elements; and (3) responsive to detecting the fault of the faulty antenna element of the set of the N antenna elements, adjust a parameter of at least one other antenna element of the N antenna elements, wherein the parameter is a weight applied to a signal that is transmitted to or received at an antenna element.

Abstract: At least some embodiments of the present invention are directed to RFID reader systems configured to estimate a directional bearing of an RFID tag. In an embodiment, the present invention is an RFID system configured in a way that upon a detection of a variance in the direction of a maximum RSSI value for a given RFID tag in response to a plurality of interrogation signals transmitted by an RFID reader over a respective plurality of different directions, the RFID reader retransmits the plurality of interrogation signals over the respective plurality of different directions with successively lower power levels until the only response(s) being received no longer exhibit the previously detected variance.

Abstract: At least some embodiments of the present invention are directed to RFID reader systems configured to estimate a directional bearing of an RFID tag. In an embodiment, the present invention is an RFID system configured in a way that upon a detection of a variance in the direction of a maximum RSSI value for a given RFID tag in response to a plurality of interrogation signals transmitted by an RFID reader over a respective plurality of different directions, the RFID reader retransmits the plurality of interrogation signals over the respective plurality of different directions with successively lower power levels until the only response(s) being received no longer exhibit the previously detected variance.

Abstract: At least some embodiments of the present invention are directed to RFID reader systems, readers, and/or arrangements configured to estimate a directional bearing of an RFID tag. In an embodiment, the present invention is an RFID arrangement configured communicate with an RFID tag via a primary transmit and receive signals and to contemporaneously determine a plurality of RSSI levels of the RFID tag over a 360-degree azimuth range via a plurality of secondary receive signals.

Abstract: At least some embodiments of the present invention are directed to RFID reader systems, readers, and/or arrangements configured to estimate a directional bearing of an RFID tag. In an embodiment, the present invention is an RFID arrangement configured communicate with an RFID tag via a primary transmit and receive signals and to contemporaneously determine a plurality of RSSI levels of the RFID tag over a 360-degree azimuth range via a plurality of secondary receive signals.

Abstract: At least some embodiments of the present invention are directed to RFID reader systems configured to estimate a directional bearing of an RFID tag. In an embodiment, the present invention is an RFID system configured in a way that upon a detection of a variance in the direction of a maximum RSSI value for a given RFID tag in response to a plurality of interrogation signals transmitted by an RFID reader over a respective plurality of different directions, the RFID reader retransmits the plurality of interrogation signals over the respective plurality of different directions with successively lower power levels until the only response(s) being received no longer exhibit the previously detected variance.

Abstract: An RFID tag reading system and method accurately and rapidly determine true bearings of RFID tags associated with items in a controlled area. An RFID reader has an array of antenna elements and a plurality of RF transceivers. A controller controls the transceivers by steering a primary transmit beam over the controlled area to each tag, by steering a primary receive beam at a primary steering angle from each tag, by steering a plurality of secondary receive beams at different secondary steering angles that are offset from the primary steering angle by receiving secondary receive signals from each tag, and by processing the secondary receive signals to determine a true bearing for each tag. Bidirectional communication between the reader and a tag is conducted over a single inventory round in which the tag is read a plurality of times by the primary and the secondary receive beams.

Abstract: An RFID tag reading system and method estimate bearings of RFID tags. When the RSSI of a primary and/or secondary RFID receive signal is below a threshold, a primary receive beam is steered in a limited scan to an array of locations distributed around the location at which the RSSI of the primary receive signal is a maximum, and the RSSI of the primary receive signal is recorded at each location. The recorded RSSIs are processed to determine an effective weighted center of distribution of the recorded RSSIs, and the bearing for the tag based on the weighted center of distribution is thus estimated.

Abstract: A radio frequency identification (RFID) tag reading system and method accurately and rapidly determine, in real-time, true bearings of RFID tags associated with items in a controlled area. Primary transmit and receive beams are steered over the area, and multiple secondary receive beams are substantially simultaneously steered to a plurality of bearings in the area. The highest signal strength of secondary receive signals from the secondary receive beams determines an approximate tag bearing of each tag. Two secondary receive beams at opposite sides of the approximate tag bearing in elevation are selected to obtain a pair of elevation offset signals, and two secondary receive beams at opposite sides of the approximate tag bearing in azimuth are selected to obtain a pair of azimuth offset signals. The elevation offset signals and the azimuth offset signals are processed to determine a true bearing for each tag in real-time.

Abstract: An RFID tag reading system and method estimate true bearings of RFID tags associated with items in a controlled area. A plurality of secondary receive beams are rotated in a cycle about a boresight axis of a primary receive beam to generate a plurality of secondary receive signals. A controller processes all the secondary receive signals received in the cycle to estimate a true bearing for each tag in the controlled area.

Abstract: A radio frequency identification (RFID) tag reading system and method read RFID tags in a controlled area in real time with an enhanced performance. An RFID reader reads a mixed tag population of interesting RFID tags and of uninteresting RFID tags in the controlled area at a read rate. A controller dynamically and continuously monitors the read rate in real time, dynamically selects the interesting RFID tags, or deselects the uninteresting RFID tags, in real time when the read rate is below a reading threshold, and dynamically controls the RFID reader in real time to only read the interesting RFID tags when the read rate is below the reading threshold.

Abstract: A radio frequency identification (RFID) tag reading system and method accurately and rapidly determine, in real-time, true bearings of RFID tags associated with items in a controlled area. Primary transmit and receive beams are steered over the area, and multiple secondary receive beams are substantially simultaneously steered to a plurality of bearings in the area. The highest signal strength of secondary receive signals from the secondary receive beams determines an approximate tag bearing of each tag. Two secondary receive beams at opposite sides of the approximate tag bearing in elevation are selected to obtain a pair of elevation offset signals, and two secondary receive beams at opposite sides of the approximate tag bearing in azimuth are selected to obtain a pair of azimuth offset signals. The elevation offset signals and the azimuth offset signals are processed to determine a true bearing for each tag in real-time.

Abstract: A radio frequency (RF) identification (RFID) tag reading system and method accurately determine true bearings of RFID tags associated with items in a controlled area. An RFID reader has an array of antenna elements and a plurality of RF transceivers. A controller controls the transceivers by steering a primary transmit beam over the controlled area by transmitting a primary transmit signal to each tag, and steering a primary receive beam at a primary steering angle by receiving a primary receive signal from each tag. The controller thereupon steers a plurality of secondary receive offset beams at different secondary steering angles that are offset from the primary steering angle by receiving secondary receive offset signals from each tag, and by processing the offset signals to determine a true bearing for each tag.

Abstract: Radio frequency identification (RFID) tag readers are integrated with individual RFID tags to form integrated RFID units that are initially deployed to cover a controlled area with radio frequency (RF) coverage. A controller determines whether the RF coverage optimally covers the controlled area by controlling at least one of the integrated RFID units in the initial deployment to read the RFID tag integrated with at least another of the integrated RFID units. An interface reports when the RF coverage does not optimally cover the controlled area, and responsively guides a redeployment of at least one of initially deployed integrated RFID units to a subsequent deployment in which the RF coverage provided by the integrated RFID units optimally covers the controlled area.

Abstract: An RFID tag reading system and method estimate bearings of RFID tags. When the RSSI of a primary and/or secondary RFID receive signal is below a threshold, a primary receive beam is steered in a limited scan to an array of locations distributed around the location at which the RSSI of the primary receive signal is a maximum, and the RSSI of the primary receive signal is recorded at each location. The recorded RSSIs are processed to determine an effective weighted center of distribution of the recorded RSSIs, and the bearing for the tag based on the weighted center of distribution is thus estimated.

Abstract: An RFID tag reading system and method estimate true bearings of RFID tags associated with items in a controlled area. A plurality of secondary receive beams are rotated in a cycle about a boresight axis of a primary receive beam to generate a plurality of secondary receive signals. A controller processes all the secondary receive signals received in the cycle to estimate a true bearing for each tag in the controlled area.

Abstract: An RFID tag reading system and method accurately and rapidly determine true bearings of RFID tags associated with items in a controlled area. An RFID reader has an array of antenna elements and a plurality of RF transceivers. A controller controls the transceivers by steering a primary transmit beam over the controlled area to each tag, by steering a primary receive beam at a primary steering angle from each tag, by steering a plurality of secondary receive beams at different secondary steering angles that are offset from the primary steering angle by receiving secondary receive signals from each tag, and by processing the secondary receive signals to determine a true bearing for each tag. Bidirectional communication between the reader and a tag is conducted over a single inventory round in which the tag is read a plurality of times by the primary and the secondary receive beams.

Abstract: A radio frequency identification (RFID) tag reading system having a phased antenna array accurately locates RFID tags in a controlled area, by steering an interrogating beam over the controlled area to interrogate the tags and generate return modulated RF signals. A primary receiver steers a primary receive beam at a primary steering angle that is fixed during each tag interrogation. A primary demodulator demodulates and reconstructs the received return modulated signals. A secondary receiver, independently of the primary receiver, steers a secondary receive beam at a plurality of secondary steering angles. A secondary correlator/demodulator demodulates the combined return modulated signals, and utilizes the reconstructed signal reconstructed by the primary demodulator at each of the secondary steering angles. Both the primary and the secondary receivers cooperate to accurately locate the same tag.

Abstract: A radio frequency (RF) identification (RFID) tag reading system and method accurately determine true bearings of RFID tags associated with items in a controlled area. An RFID reader has an array of antenna elements and a plurality of RF transceivers. A controller controls the transceivers by steering a primary transmit beam over the controlled area by transmitting a primary transmit signal to each tag, and steering a primary receive beam at a primary steering angle by receiving a primary receive signal from each tag. The controller thereupon steers a plurality of secondary receive offset beams at different secondary steering angles that are offset from the primary steering angle by receiving secondary receive offset signals from each tag, and by processing the offset signals to determine a true bearing for each tag.