Systems and methods to determine motion parameters using RFID tags

• US 10,650,200 B2
• Filed: 05/07/2019
• Issued: 05/12/2020
• Est. Priority Date: 06/05/2008
• Status: Active Grant

• Current Assignee: Micron Technology, Inc.
• Original Assignee: Micron Technology, Inc.
• Inventors: Tuttle, John R.
• Primary Examiner(s): Nguyen, Nam V
• Application Number:
  US16/405,946
• Publication Number:
  US 20190266366A1
• Time in Patent Office: 371 Days
• Field of Search: 340 564
• CPC Class Codes: G01S 11/10 using Doppler effect
• CPC Class Codes: G01S 13/756 using a signal generator for modifying the reflectivity of the reflector G01S13/758 takes precedence
• CPC Class Codes: G06K 7/0008 General problems related to the reading of electronic memory record carriers, independent of its reading method, e.g. power transfer
• CPC Class Codes: G06K 7/10019 resolving collision on the communication channels between simultaneously or concurrently interrogated record carriers. collision between the communication channels used by wireless communication devices, where the solution is not particularly adapted for RFIDs or the like, H04W74/08
• CPC Class Codes: G06K 7/10316 using at least one antenna particularly designed for interrogating the wireless record carriers antennas in general H01Q1/22
• CPC Class Codes: G06K 7/10366 the interrogation device being adapted for miscellaneous applications
• CPC Class Codes: H04Q 2213/13095 PIN / Access code, authentication

Abstract

Systems and methods to determine motion parameters of physical objects using radio frequency identification (RFID) tags attached to the objects. In one embodiment, a method implemented in a radio frequency identification (RFID) system includes determining a motion parameter of the RFID tag based on detecting a Doppler frequency shift in a radio frequency signal received from the RFID tag.

Claims

1. A reader, comprising:

a transceiver coupled with an antenna;

an oscillator to generate a signal;

a modulator coupled between the oscillator and the transceiver to modulate the signal transmitted via the antenna;

a modulation remover coupled with the transceiver to remove modulations from a reflected version of the signal received in the transceiver and generate a modulation-free version of the signal received in the transceiver;

a frequency detector coupled with the modulation remover to determine a Doppler frequency shift between the signal generated by the oscillator and the modulation-free version of the signal received in the transceiver; and

wherein the reader determines an identity of a device reflecting the signal transmitted via the antenna and a position of the device based on the Doppler frequency shift.

2. A method implemented in a reader, the method comprising:

generating, by an oscillator of the reader, a signal;

modulating, by a modulator coupled between the oscillator and a transceiver of the reader, the signal transmitted via an antenna coupled with the transceiver;

removing, by a modulation remover coupled with the transceiver, modulations from a reflected version of the signal received in the transceiver to generate a modulation-free version of the signal received in the transceiver;

determining, by a frequency detector coupled with the modulation remover, a Doppler frequency shift between the signal generated by the oscillator and the modulation-free version of the signal received in the transceiver; and

determining, by the reader, an identity of a device reflecting the signal transmitted via the antenna and a position of the device based on the Doppler frequency shift.

3. A system, comprising:

a plurality of devices in a field, each of the devices having a unique identification among the plurality of devices; and

a reader, including;

a transceiver coupled with an antenna;

an oscillator to generate a signal;

a modulator coupled between the oscillator and the transceiver to modulate the signal transmitted via the antenna;

a modulation remover coupled with the transceiver to remove modulations from a reflected version of the signal received in the transceiver and generate a modulation-free version of the signal received in the transceiver;

a frequency detector coupled with the modulation remover to determine a Doppler frequency shift between the signal generated by the oscillator and modulation-free version of the signal received in the transceiver; and

wherein the reader determines an identity of a device, among the plurality of devices, reflecting the signal transmitted via the antenna and a position of the device based on the Doppler frequency shift.

4. The system of claim 3, wherein the identity of the device is determined based at least in part on the modulations in the reflected version of the signal received in the transceiver.

5. The system of claim 4, wherein the modulations produced by the modulator on the signal transmitted via the antenna represent a command to request the device having the identity to reflect the signal.

6. The system of claim 4, wherein the modulations are provided by the device in response to a communication from the reader.

7. The system of claim 6, wherein the communication is made via the signal modulated by the modulator and transmitted by the transceiver via the antenna;

and the modulations provided by the device encode identification data stored in the device.