Location sensing for analytical applications
First Claim
1. A radio frequency identification (RFID) tag comprising:
- at least one receiver configured to receive a first RFID signal comprising a first frequency and a second RFID signal comprising a second frequency; and
logic configured to;
select, in response to receiving the first and second RFID signals, one of the first and second frequencies by determining which of the first or second RFID signal has the greater signal strength, andoutput a reply message comprising a tag ID using the selected frequency.
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Accused Products
Abstract
Embodiments herein describe RFID systems that include multiple RFID tag readers that each use a different frequency to communicate with an RFID tag. For example, each of the tag readers may transmit a tag query command using different modulated frequencies. In one embodiment, the RFID tag includes multiple receivers each tuned to one of the different frequencies generated by the tag readers. For example, one receiver in the tag is tuned to receive 200 MHz signals while another receiver is tuned to receive 900 MHz signals. To provide location information, the RFID tag compares power values associated with the received signals to determine which of the RFID tag readers is closest to the tag. The RFID tag conveys this location information to the tag readers by selecting one of the frequencies of the tag readers to use when generating a reply message.
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Citations
20 Claims
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1. A radio frequency identification (RFID) tag comprising:
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at least one receiver configured to receive a first RFID signal comprising a first frequency and a second RFID signal comprising a second frequency; and logic configured to; select, in response to receiving the first and second RFID signals, one of the first and second frequencies by determining which of the first or second RFID signal has the greater signal strength, and output a reply message comprising a tag ID using the selected frequency. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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9. A method of operating a RFID tag, the method comprising:
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receiving a first RFID signal at the RFID tag at a first frequency; receiving a second RFID signal at the RFID tag at a second frequency; selecting one of the first and second RFID signals based on which has a greater signal strength; and transmitting a reply message from the RFID tag using a frequency corresponding to the selected RFID signal. - View Dependent Claims (10, 11, 12, 13, 14, 15)
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16. An RFID tag, comprising:
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a first receiver tuned to receive a first RFID signal; a second receiver tuned to receive a second RFID signal, wherein the first and second receivers are tuned to different frequencies; a comparator configured to determine which of the first and second RFID signals has a greater signal strength; and a transmitter configured to transmit a reply message using a frequency corresponding to the first or second RFID signal with the greater signal strength. - View Dependent Claims (17, 18, 19, 20)
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Specification