Device for measuring at least one physical quantity and related determination method

Patent metadata

Field	Value
Publication number	US-12072441-B2
Application number	US-202218057441-A
Country	US
Kind code	B2
Filing date	Nov 21, 2022
Priority date	Nov 23, 2021
Publication date	Aug 27, 2024
Grant date	Aug 27, 2024

Abstract

A device for measuring a physical quantity, including at least a transceiver unit for electromagnetic waves, an antenna-sensor including a sensor integrated into a target antenna having at least one excitation port, the antenna-sensor having a variable impedance with electromagnetic transduction, the measuring device being configured, per predetermined frequency band and independently of the angular difference between the transmission and reception of waves, for measuring the electromagnetic response of the antenna-sensor at least from an ellipticity rate of an electromagnetic field backscattered by the antenna-sensor, the ellipticity rate characterizing the polarization of the electromagnetic field configured to be measured by the transceiver unit, the electromagnetic response being representative, by electromagnetic transduction, of the at least one physical quantity to be measured.

First claim

The invention claimed is:

1. A measuring device for at least one physical quantity, the measuring device comprising:
a transceiver unit for electromagnetic waves,
an antenna-sensor including a sensor integrated into a target antenna having at least one excitation port, the antenna-sensor having a variable impedance with electromagnetic transduction,
wherein, per predetermined frequency band and independently of an angular deviation between transmission and the reception of the electromagnetic waves, the measuring device is configured to measure an electromagnetic response of the antenna-sensor at least from an ellipticity rate of an electromagnetic field backscattered by said antenna-sensor, the ellipticity rate characterizing the polarization of the electromagnetic field configured to be measured by said transceiver unit, said electromagnetic response being representative, by the electromagnetic transduction, of said at least one physical quantity to be measured.

2. The measuring device according to claim 1 , wherein the measuring device is configured to have, per predetermined frequency band, a bijective relationship between the load impedance of the sensor and the ellipticity rate of the electromagnetic field configured to be backscattered by said antenna-sensor.

3. The measuring device according to claim 2 , wherein the load impedance is passive.

4. The measuring device according to claim 2 , wherein said antenna-sensor is a radio identification antenna associated with an electronic chip configured to control said load impedance.

5. The measuring device according to claim 2 , wherein said antenna-sensor is an active antenna-sensor.

6. The measuring device according to claim 5 , wherein the functioning of the sensor depends on a constant local energy source.

7. The measuring device according to claim 5 , wherein the sensor is configured to integrate a tool for preprocessing and/or amplifying a signal provided by a local power source.

8. The measuring device according to claim 1 , wherein said antenna-sensor is further configured to optimize the amplitude and/or phase of the backscattered electromagnetic field by controlling the ellipticity rate of the backscattered electromagnetic field, by using the sensor load impedance of the antenna-sensor.

9. The measuring device according to claim 8 , wherein said antenna-sensor is configured to control said ellipticity rate with the load impedance of the sensor, said load impedance of the sensor being configured to directly vary the antenna mode of the antenna-sensor, the value of said load impedance of the sensor being configured to be adjusted by taking into account the structure mode of the antenna-sensor, said structure mode being determined by a characterization of the associated backscattered electromagnetic field.

10. The measuring device according to claim 8 , wherein said antenna-sensor includes a sensor integrated into a target antenna having at least two excitation ports, said antenna-sensor being configured to control said ellipticity rate, with the load impedance of the sensor, the load impedance of the sensor being configured to directly vary the orthogonal components of the antenna mode of the antenna-sensor, the value of the load impedance of the sensor being configured to be adjusted by taking into account the structure mode of the antenna-sensor, said structure mode being determined by a characterization of the associated backscattered electromagnetic field.

11. A method for determining the range of variation of the load impedance of the sensor of the antenna-sensor of the measuring device according to claim 1 , and for determining the incidence polarization of the transceiver unit during wave transmission, the method comprising the following steps, per predetermined frequency band:
characterization of the backscattering model of said antenna-sensor for a predetermined direction of incidence and a predetermined direction of scattering and for a predetermined plurality of polarizations of the incident plane wave transmitted by the transceiver unit,
first determination of the reactance and/or resistance of the load impedance of the sensor of the antenna-sensor associated with a first value of predetermined amplitude and/or ellipticity rate of the backscattered field associated with said backscattering model as a function of the incident plane wave polarization,
second determination of the reactance and/or resistance of the load impedance of the sensor associated with a second predetermined amplitude and/or ellipticity rate value of the backscattered field associated with said backscattering model as a function of the incident plane wave polarization,
third determination of the incidence polarization from the first determination and from the second determination.

12. The determination method according to claim 11 , wherein:
the characterization step is implemented for a predetermined plurality of linear polarizations of incident plane wave transmitted by the transceiver unit;
the first determination step corresponds to the determination of the reactance of the load impedance of the sensor of the antenna-sensor maximizing the value of the backscattered field associated with said backscattering model; and
the third determination step corresponds to the determination of the incidence polarization corresponding both to a predetermined load and to the reactance of the load impedance of the sensor of the antenna-sensor maximizing the value of the backscattered field associated with said backscattering model, and obtaining the maximum resistance value of the sensor load impedance associated with a circular polarization backscattering, said range of variation of the load impedance of the antenna-sensor corresponding to a range of variation of the resistance of the load impedance of the sensor between the zero value, associated with a maximum ellipticity rate, and said maximum resistance value, associated with a zero value of the ellipticity rate, for a constant reactance value equal to the reactance of the load impedance of the sensor of the antenna-sensor, maximizing the value of the backscattered field associated with said backscattering model.

13. The determination method according to claim 11 , wherein said step of characterization of backscattering model of said antenna-sensor comprises:
the local excitation of the antenna of said antenna-sensor and:
the measurement of the orthogonal components of the radiated field thereof;
depending on the number of excitation port(s) of said target antenna, the calculation of at least one impedance at an interface between said antenna and a load impedance of said antenna, of predetermined value;

the determination of the structure mode of the antenna of said antenna-sensor by loading said antenna by a short circuit and illuminating by a predetermined incident wave.

Assignees

• Commissariat Energie Atomique
• Centre Nat Rech Scient

Inventors

• Fonseca-Dias Luis-Felipe
• Jouvaud Camille
• Delaveaud Christophe
• Aubert Hervé

Classifications

• G06K19/07786

  the antenna being of the HF type, such as a dipole · CPC title

• H01Q15/141

  Apparatus or processes specially adapted for manufacturing reflecting surfaces · CPC title

• H01Q9/0407

  Substantially flat resonant element parallel to ground plane, e.g. patch antenna (dipole H01Q9/285; monopole H01Q9/40) · CPC title

• G06K19/07773

  Antenna details (antennas for wireless devices, e.g. RFID tags, in general H01Q1/22) · CPC title

• G06K19/0717

  the sensor being capable of sensing environmental conditions such as temperature history or pressure · CPC title