RFID reader and associated complementary device

Patent metadata

Field	Value
Publication number	US-12393799-B2
Application number	US-202218701072-A
Country	US
Kind code	B2
Filing date	Oct 11, 2022
Priority date	Oct 13, 2021
Publication date	Aug 19, 2025
Grant date	Aug 19, 2025

Abstract

A novel RFID communication device is proposed which allows the detection and electronic processing not only of the response signal backscattered at the fundamental frequency f 0 of the reader, but also at least one response signal backscattered at a harmonic frequency, before feeding them to the conventional receive chain of an RFID reader. The joint use of the signal at the fundamental frequency of the reader and at least one signal at a harmonic frequency allows the reader's performance to be improved. The RFID reader can additionally be provided with novel functionalities by virtue of suitable software processing. It is applicable to the field of communications between a reader and passive transponders in UHF RFID and to the field of the Internet of Things.

First claim

The invention claimed is:

1. A complementary RFID communication device configured to be coupled with an RFID reader operable at a fundamental frequency f 0 , the complementary device comprising:
RF antenna to receive, in response to an interrogation signal emitted at the fundamental frequency f 0 by the RFID reader, a response signal backscattered at a harmonic frequency by a transponder, the response signal backscattered at a harmonic frequency being at the frequency n×f 0 where n is an integer defining the order of the harmonic considered,
A first electronic circuit arranged at the output of the RFID reader to take an image of said interrogation signal,
A second electronic circuit, operationally connected to the first electronic circuit, to generate a signal at the frequency (n−1)×f 0 from the image of the interrogation signal, and
A third electronic circuit, operationally connected to the second electronic circuit and to the RF antenna of the complementary device, to generate a backscattered signal converted downwards, from the response signal backscattered at the harmonic frequency n×f 0 and according to the signal at the frequency (n−1)×f 0 generated before, the backscattered signal converted downwards being generated, so as to be returned to the fundamental frequency f 0 and to be injected, directly or indirectly, at the input of the RFID reader for processing, such that the RFID reader can extract information carried by the backscattered response signal.

2. The complementary device according to claim 1 , further comprising, when the backscattered signal converted downwards is to be injected indirectly at the input of the RFID reader for processing, an electronic combiner operationally connected to the third electronic circuit and arranged at the input of the RFID reader to:
receive, from an RF antenna of the RFID reader, a response signal backscattered at the fundamental frequency f 0 by the interrogated transponder,
combine the response signal backscattered at the fundamental frequency f 0 and the backscattered signal converted downwards, and
inject the signal resulting from the combination at the input of the RFID reader for processing.

3. The complementary device according to claim 2 , wherein the electronic combiner is configured for a weighted combination in module and/or in phase of the response signal backscattered at the fundamental frequency f 0 and of the backscattered signal converted downwards.

4. The complementary device according to claim 2 , wherein the electronic combiner is configured for a combination by alternating of the response signal backscattered at the fundamental frequency f 0 and of the backscattered signal converted downwards.

5. The complementary device according to claim 1 , wherein the first electronic circuit comprises an electronic coupler.

6. The complementary device according to claim 1 , wherein the second electronic circuit successively comprises:
An electronic frequency multiplier operationally connected to an output of the first electronic circuit and configured to multiply the frequency of the image of the interrogation signal by a factor equal to n−1,
An electronic amplifier to amplify the image of the multiplied interrogation signal,
A first bandpass filter configured to filter the image of the multiplied and amplified interrogation signal such as multiplied and amplified before, by letting a frequency interval pass, centred on the frequency (n−1)×f 0 , and
A bandstop filter configured to filter the image of the multiplied, amplified and filtered interrogation signal, by not letting a frequency interval pass, centred on the fundamental frequency f 0 .

7. The complementary device according to claim 1 , wherein the third electronic circuit comprises at the output, an electronic amplifier to amplify the output signal of the third electronic circuit, an output of the electronic amplifier being connectable, directly or indirectly, at the input of the RFID reader.

8. The complementary device according to claim 7 , wherein the third electronic circuit comprises a second bandpass filter configured to filter the signal passing through the third electronic circuit, by letting a frequency interval pass, centred on the fundamental frequency f 0 and successively comprises:
A low noise electronic amplifier operationally connected to the RF antenna of the complementary device and configured to amplify the response signal backscattered at the harmonic frequency n×f 0 ,
A third bandpass filter configured to filter the amplified response signal backscattered at the harmonic frequency n×f 0 , by letting a frequency interval pass, centred on the frequency n×f 0 ,
A bandstop filter configured to filter the amplified and filtered response signal backscattered at the harmonic frequency n×f 0 , by not letting a frequency interval pass, centred on the fundamental frequency f 0 ,
An electronic mixer operationally connected to an output of the second electronic circuit and configured to combine the amplified and double filtered response signal backscattered at the harmonic frequency n×f 0 , and the image of the multiplied, amplified and filtered interrogation signal,
The second bandpass filter configured to filter the output signal of the electronic mixer, and
The electronic amplifier to amplify the filtered output signal of the electronic mixer such as filtered before.

9. The complementary device according to claim 1 , wherein the third electronic circuit comprises a second bandpass filter configured to filter the signal passing through it the third electronic circuit, by letting a frequency interval pass, centred on the fundamental frequency f 0 .

10. The complementary device according to claim 1 , wherein the integer n is equal to 3, such that the harmonic frequency n×f 0 corresponds to the third harmonic backscattered signal.

11. An RFID reader operating at the fundamental frequency f 0 and comprising a complementary RFID communication device according to claim 1 to enable the detection and the processing of at least one harmonic signal backscattered by an interrogated RFID transponder, so as to extract information carried by the backscattered harmonic signal.

12. An RFID communication system comprising an RFID reader according to the claim 11 and a plurality of RFID transponders.

Assignees

• Inst Polytechnique Grenoble
• Univ Grenoble Alpes
• Univ Claude Bernard Lyon
• Inst Nat Sciences Appliquees Lyon
• Lyon Ecole Centrale
• Centre Nat Rech Scient

Inventors

• Tedjini Smail
• Allane Dahmane
• Duroc Yvan

Classifications

• H04B5/45

  Transponders · CPC title

• H04B5/20

  characterised by the transmission technique; characterised by the transmission medium · CPC title

• G06K7/10366

  the interrogation device being adapted for miscellaneous applications · CPC title

• G06K19/0726

  the arrangement including a circuit for tuning the resonance frequency of an antenna on the record carrier · CPC title

• G06K7/10316 Primary

  using at least one antenna particularly designed for interrogating the wireless record carriers (antennas in general H01Q1/22) · CPC title