Determining RFID tag location
First Claim
1. An apparatus, comprising:
- multiple receive paths, each receive path to be coupled to a corresponding one of multiple antennas to process a signal from a radio frequency identification (RFID) tag as the signal is received through the corresponding antenna;
a timing calculation circuit, coupled to each of the multiple receive paths, to determine differences in the times a particular point in the signal was received at the different antennas; and
a processing circuit to determine a location of the RFID tag relative to the antennas, based on the differences in the times.
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Abstract
In some embodiments, a radio frequency identification (RFID) reader with multiple antennas may determine the location of an RFID tag relative to the reader'"'"'s antennas, by using a difference-in-time-of-arrival technique to triangulate on the RFID tag based on the difference in distances between the tag and each antenna. A given point in the signal from the RFID tag may provide a narrow point in time from which to make the calculations, while a common clock to the multiple receive paths may permit making accurate measurements of the difference in time of reception of that point at the different antennas. In some embodiments, movement of the RFID tag may be determined by calculating a series of locations over time.
83 Citations
16 Claims
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1. An apparatus, comprising:
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multiple receive paths, each receive path to be coupled to a corresponding one of multiple antennas to process a signal from a radio frequency identification (RFID) tag as the signal is received through the corresponding antenna;
a timing calculation circuit, coupled to each of the multiple receive paths, to determine differences in the times a particular point in the signal was received at the different antennas; and
a processing circuit to determine a location of the RFID tag relative to the antennas, based on the differences in the times. - View Dependent Claims (2, 3, 4, 5)
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6. A system, comprising:
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multiple antennas;
multiple receive paths, each receive path coupled to a corresponding one of the multiple antennas to process a signal from a radio frequency identification (RFID) tag as the signal is received through the corresponding antenna;
a timing calculation circuit, coupled to each of the multiple receive paths, to determine differences in the times a particular point in the signal was received at the different antennas; and
a processing circuit to determine a location of the RFID tag relative to the antennas, based on the differences in the times. - View Dependent Claims (7, 8, 9, 10)
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11. A method, comprising:
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receiving, through multiple antennas, a signal from a radio frequency identification (RFID) tag;
separately processing the signal from each antenna to determine a corresponding first point in each processed signal;
comparing the corresponding first points to determine a relative difference in times of receipt of the corresponding first points; and
determining a first location of the RFID tag, relative to the antennas, based on the relative differences in the times of receipt of the corresponding first points. - View Dependent Claims (12, 13, 14, 15, 16)
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Specification