Portable radio frequency identification (RFID) reader
First Claim
1. A portable radio frequency identification (RFID) reader, comprising:
- an antenna array including a plurality of antenna elements to receive one or more RFID signals from each of a plurality of RFID devices, wherein each of the plurality of antenna elements include control circuitry to control a beam pattern generated by the antenna array;
sum circuitry operable to determine a sum signal based on a sum of the one or more RFID signals received from each of the plurality of RFID devices by at least two of the plurality of antenna elements;
difference circuitry operable to determine a difference signal based on a difference of the one or more RFID signals received from each of the plurality of RFID devices by at least two of the plurality of antenna elements; and
a controller to;
electronically steer the beam pattern in a direction of a particular RFID device of the plurality of RFID devices using the control circuitry of the plurality of antenna elements; and
determine the direction of the particular RFID device of the plurality of RFID devices to steer the beam pattern based on the sum signal and the difference signal.
1 Assignment
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Accused Products
Abstract
A particular portable radio frequency identification (RFID) reader includes an active antenna array including a plurality of antenna elements to receive RFID signals from RFID devices. The antenna elements include control circuitry to control a beam pattern generated by the active antenna array. The portable RFID reader further includes sum circuitry and difference circuitry. The sum circuitry is operable to determine a sum signal by summing the RFID signals received by at least two of the plurality of antenna elements. The difference circuitry is operable to determine a difference signal between the RFID signals received by at least two of the plurality of antenna elements. The portable RFID reader also includes a controller to electronically steer the beam pattern and to determine a direction from the RFID reader to a particular RFID device.
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Citations
18 Claims
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1. A portable radio frequency identification (RFID) reader, comprising:
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an antenna array including a plurality of antenna elements to receive one or more RFID signals from each of a plurality of RFID devices, wherein each of the plurality of antenna elements include control circuitry to control a beam pattern generated by the antenna array; sum circuitry operable to determine a sum signal based on a sum of the one or more RFID signals received from each of the plurality of RFID devices by at least two of the plurality of antenna elements; difference circuitry operable to determine a difference signal based on a difference of the one or more RFID signals received from each of the plurality of RFID devices by at least two of the plurality of antenna elements; and a controller to; electronically steer the beam pattern in a direction of a particular RFID device of the plurality of RFID devices using the control circuitry of the plurality of antenna elements; and determine the direction of the particular RFID device of the plurality of RFID devices to steer the beam pattern based on the sum signal and the difference signal. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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11. A portable radio frequency identification (RFID) reader, comprising:
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an antenna array including a plurality of antenna elements to receive one or more RFID signals from each of a plurality of RFID devices, the one or more received RFID signals having a characteristic wavelength, wherein the plurality of antenna elements include at least a first antenna element and a second antenna element, wherein the first antenna element and the second antenna element are spaced apart at a distance of less than one half of the characteristic wavelength; sum circuitry coupled to the first antenna element and to the second antenna element to determine a sum signal based on a sum of an RFID signal received from each of the plurality of RFID devices by the first antenna element and the second antenna element; difference circuitry coupled to the first antenna element and to the second antenna element to deter mine a difference signal based on a difference of an RFID signal received from each of the plurality of RFID devices by the first antenna element and the second antenna element; and circuitry to; electronically steer a beam pattern in a direction of a particular RFID device of the plurality of RFID devices; and determine the direction of the particular RFID device of the plurality of RFID devices to steer the beam pattern based on the sum signal and the difference signal. - View Dependent Claims (12)
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13. A method comprising:
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sending at least one first radio frequency identification (RFID) interrogation signal to each of a plurality of RFID devices via an antenna array of a portable RFID reader, wherein the antenna array includes a plurality of antenna elements; receiving a first plurality of response signals by at least a first antenna element of the antenna array and a second antenna element of the antenna array, wherein each of the first plurality of response signals is received from one of the plurality of RFID devices; determining a sum signal based on a sum of the first plurality of response signals received from the plurality of RFID devices; determining a difference signal based on a difference of the first plurality of response signals received from the plurality of RFID devices; determining a direction from the portable RFID reader to a targeted RFID device of the plurality of RFID devices based on the sum signal and the difference signal; and activating an indicator of the portable RFID reader, wherein the indicator indicates the direction to the targeted RFID device. - View Dependent Claims (14, 15, 16, 17, 18)
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Specification