FR3108192A1 - WINDOWS INCLUDING A GLASS ELEMENT CONTAINING A COMMUNICATION DEVICE CONFIGURED TO OPERATE BY RADIO FREQUENCIES AND SURFACE ACOUSTIC WAVES - Google Patents

Abstract

The invention relates to glazing comprising a glazed element, in particular monolithic or composite, having a unique identification number, said glazed element comprising a communication device (3) configured to operate by radio-frequency and by surface acoustic waves comprising a antenna (6), an interdigital transducer (7) and a surface acoustic wave reflection device (5) comprising reflectors (5a, 5b, 5c, 5d), said communication device (3) being intended to communicate the unique identification number of said glazing (1) to a remote reading device configured to operate in the ultra high frequency band, said glazing being characterized in that said interdigital transducer (7) and said acoustic wave reflection device surface (5) are arranged on a layer of piezoelectric substrate (4, 4a, 4b) itself arranged on said glazed element. Abstract Figure: Fig. 1

Description

GLAZING COMPRISING A GLASS ELEMENT COMPRISING A COMMUNICATION DEVICE CONFIGURED TO OPERATE BY RADIO-FREQUENCY AND BY ACOUSTIC SURFACE WAVES

The invention relates to a glazing comprising a glazed element comprising a communication device capable of operating by radio-frequency and by surface acoustic waves allowing wireless communication of a unique identification number assigned to said glazing, the communication not comprising an integrated circuit or chip.

It is known from the state of the art various means of visual identification used, in particular, by the authorities in order to identify motor vehicles. License plates, permanent or temporary stickers, removable or repositionable labels are examples of media with an identification number intended to identify each vehicle. Most of these supports can be easily removed from the vehicle and thus have a relatively limited level of security.

In order to solve this problem, the use of radio frequency identification, better known by the acronym RFID, has been proposed. This technology is implemented in various fields such as the logistics sector to easily identify items or the distribution sector for real-time stock inventory of items.

Radio-frequency identification refers to technologies allowing automated tracking using an electromagnetic field generated by a station or a reader in order to allow the remote identification of a tag or a transponder.

A transponder is defined as an electronic device that sends back a response when it receives an interrogation by radio-frequency. These tags, or transponders, generally include an RF antenna, RF meaning radio-frequency, or an induction loop depending on the frequency band and a logic unit intended in particular for data storage.

These data are then transmitted to the reader or to the station by backscatter or by means of magnetic coupling. The majority of RFID technologies include an integrated circuit as a logical unit comprising an EEPROM memory, an acronym meaning "Electrically Erasable Programmable Read Only Memory" in English, and a microcontroller to access the data recorded on the EEPROM memory and manage the backscattering of the electromagnetic field .

RFID technology uses three frequency bands depending on the applications and performance required.

The first frequency band, commonly referred to as low frequencies or LF, an acronym meaning “Low Frequencies” in English, is generally centered around the 125 kHz frequency. It is used, for example, for marking pets or for identification tags at short distances, of the order of a few centimeters.

The second frequency band, commonly referred to as high frequencies or HF, an acronym meaning “High Frequencies” in English, is generally centered around the 13.56 MHz frequency. It is used, for example, for contactless payment, for tracking objects or for exchanging data by means of a mobile phone implementing NFC technology, an acronym meaning "Near Field Communication" in English, or “Near Field Communication” in French. It allows tags to be read at a very short distance, i.e. a few centimeters.

The third frequency band, called ultra high frequencies or UHF, an acronym meaning “Ultra High Frequencies” in English, generally extends over the frequency range 300 MHz to 3000 MHz.

The frequency band centered around the 2.45 GHz frequency is used for tracking moving objects, relatively far from the RFID reader, namely up to ten meters, this distance also depending on the electromagnetic power available from the RFID reader as well as parameters such as antenna gains, power consumption, meteorological conditions, in particular taken into consideration for the application of the telecommunications equation (also called "Friis equation").

The use of RFID technology implementing ultra-high frequencies, also called UHF RFID, has enabled the development of so-called intelligent functionalities such as cryptography, anti-collision protocols that simultaneously decode signals from multiple tags arriving together, retrieval energy savings and other significant improvements in remote reading of RFID tags over traditional radio-frequency identification technologies using low and high frequencies.

The main disadvantage of UHF RFID technology is related to electromagnetic compatibility with the environment such as electromagnetic absorption by liquids or radio-frequency compatibility with metallic surfaces.

Currently, there are mainly two technologies implementing tags, also called transponders, UFH RFID.

The first technology concerns so-called passive tags comprising a logic unit powered by electromagnetic energy from RFID radio frequencies, the logic unit of a passive tag is therefore not powered by a battery.

The second technology concerns so-called active tags, also called BAP transponders, an acronym meaning “Battery Assisted Passive” in English. Compared to a passive tag, the logic unit is supplied with energy thanks to an on-board battery, thus allowing the detection of tags up to a distance of a hundred meters, this distance also being dependent on the strength of the field. electromagnetic frequency of the station, or of the reader, of the power gain of the antenna of the tag and of the other parameters mentioned above for the application of the telecommunications equation or "Friis equation".

The use of RFID technology in the automotive industry is well known. With regard to the automotive glazing industry, the prior art proposes the use of glazing in order to obtain better electromagnetic compatibility relating to radio frequencies.

For example, document WO 00/73990 A1 discloses a UHF RFID transponder in the form of a sticker intended to be stuck on a glass surface. The transponder includes a flexible circuit substrate having an antenna and a transponder circuit disposed on the substrate and coupled to the antenna.

The documents EP 1698455 A1 and WO 2006/114543 A1 are also known from the prior art. These two documents disclose laminated glazing comprising electronic labels equipped with an antenna for remote data communication.

Furthermore, document WO 2013/189577 A1 discloses the use of UHF RFID technology for laminated glazing implementing an infrared radiation reflection layer.

The main disadvantages of RFID technologies comprising an integrated circuit intended for laminated glazing are the high cost of the integrated circuit compared to identification by barcodes.

Another disadvantage is the suitability of the integrated circuit with the industrial processes for manufacturing glazing, given that these processes implement high pressures and temperatures, which are harmful to the integrated circuits.

In order to solve this problem, the state of the art offers chipless RFID technologies, as described in the work entitled “La RFID sans chip”, ISTE Editions, 2009, E. Perret and al (ISBN: 978- 1-78405-191-4).

Among the various chipless RFID technologies, there are SAW RF tags, an acronym meaning “Surface Acoustic Wave Radio Frequencies” in English, or in French radio-frequencies by surface acoustic waves.

These tags implement a Gaussian pulse emitted by a UHF reader, i.e. an electromagnetic wave, which is converted by the tag into a surface acoustic wave by means of an interdigital transducer. The surface acoustic wave propagates through a piezoelectric substrate and is reflected by several reflectors in order to obtain the coded identification number of the label and to create a train of pulses comprising phase shifts. The pulse train is then sent back to the UHF reader in which the identification number is decoded, in the same way as an RFID tag comprising an integrated circuit.

Finally, document BR MU 8502935 discloses a tag implementing SAW RF technology allowing motor vehicle identification. The label takes the form of a flexible substrate glued to a glazing and coupled to a dipole antenna.

The major drawback of the state of the art is that the label is simply stuck to the glazing. This solution presents reliability problems because the label ages over time and thus tends to peel off, in particular due to humidity or light. It can also be easily removed from the glazing on which it is affixed. It then becomes impossible to identify the glazing on which the label was stuck.

The object of the invention is therefore to overcome the drawbacks of the prior art by proposing a glazing which makes it possible to reliably identify the motor vehicle comprising this glazing, while being simple to produce, by means of the number of identification of the glazing, and this throughout the life of the motor vehicle.

For this purpose, the invention thus relates, in its broadest sense, to glazing comprising a glazed element, in particular monolithic or composite, having a unique identification number, said glazed element comprising a communication device configured to operate by radio-frequency and by surface acoustic waves comprising an antenna, an interdigital transducer and a device for reflecting surface acoustic waves comprising reflectors, said communication device being intended to communicate the unique identification number of said glazing to a remote reading device configured to operate in the ultra high frequency band, said glazing being characterized in that said interdigital transducer and said surface acoustic wave reflection device are arranged on a layer of piezoelectric substrate itself arranged on said glazed element.

Advantageously, the communication device arranged on the glazed element does not include an integrated circuit therefore allowing industrial production of said glazing.

Therefore, the production costs of such glazing are lower.

The invention also has the advantage of proposing a glazing incorporating an identification number which is difficult to remove (compared in particular with a glued label) thus offering a lasting solution.

Advantageously, the piezoelectric substrate layer comprises a piezoelectric layer and a conductive layer, said conductive layer being interposed between the piezoelectric layer and said glazed element.

Advantageously, said antenna is arranged on said glazed element.

In this way, the antenna of the communication device is integral with the glazed element and is thus less fragile. Alternatively, the antenna is placed on said layer of piezoelectric substrate.

This alternative is advantageous because it simplifies the production of the glazing. The interdigital transducer, the surface acoustic wave reflection device and the antenna are formed in a single step.

Preferably, said surface acoustic wave reflection device comprises at least a first reflector, a second reflector, a third reflector and a fourth reflector so as to encode said unique identification number on at least 16 bits.

A 16-bit coding makes it possible to generate 2 ¹⁶ , that is 65536 identification numbers. If a greater number of identification numbers is desired, it suffices to add the number n of reflectors necessary in order to generate 2 ⁿ identification numbers. SAW RFID technology allows coding up to 256 bits, thus authorizing the generation of numerous identification numbers.

According to a preferred embodiment, said reflectors each have a substantially linear shape.

The size of the device is therefore reduced and has the advantage of not disturbing the driver of the motor vehicle.

Preferably, said antenna is planar.

A planar antenna makes it possible to occupy a less important surface while increasing the gain of the antenna.

Preferably, said planar antenna comprises at least an upper layer, an intermediate layer and a lower layer, said upper layer further comprising an electrically conductive structure and said lower layer comprising a ground plane.

The miniaturization of the communication device allows it to be placed in one of the corners of the glazing. Thus, the visibility of the driver of the motor vehicle is not degraded.

Preferably, the antenna is dipole.

Advantageously, said piezoelectric substrate layer comprises one of the following materials: (Pb,La)(Zr,Ti)O ₃ , Pb(Mg,Nb)TiO ₃ -PbTiO ₃ , BiFeO ₃ , (Ba,Ca)(Ti ,Zr)O ₃ , AlN, AlN doped with Sc, ZnO, LiNbO ₃ .

Preferably, said piezoelectric substrate layer is made of Aluminum Nitride (AlN).

Advantageously, said communication device is configured so as to operate over a range of frequencies comprised between 800 MHz and 3000 MHz, and preferably around the 2.45 GHz frequency.

Preferably, the material of said surface acoustic wave reflection device, of the interdigital transducer and of the antenna is indium-tin oxide (ITO) or molybdenum (Mo) or a material comprising silver (Ag) or electrically conductive ink.

Preferably, said piezoelectric substrate layer is transparent. Thus, the driver of the motor vehicle is not bothered by this substrate and visibility is improved.

Preferably, the conductive layer of the piezoelectric substrate layer comprises Molybdenum (Mo), preferably the conductive layer placed between said glazed element and said piezoelectric layer is transparent.

Preferably, said piezoelectric substrate layer comprises one of the following materials: (Pb,La)(Zr,Ti)O ₃ , Pb(Mg,Nb)TiO ₃ -PbTiO ₃ , BiFeO ₃ , (Ba,Ca)( Ti,Zr)O ₃ , AlN, AlN doped with Sc, ZnO, LiNbO _{3 ,} preferably Aluminum nitride (AlN).

The invention also relates to a glazing intended to be integrated into a motor vehicle, in particular to form the windshield or a side window of said motor vehicle.

In the case of a side window, the window is for example a laminated side window, in particular with or without an acoustic polyvinyl butyral (PVB) sheet in the interlayer assembling the glass sheets of said laminated window.

Preferably, the piezoelectric layer has a thickness of between 1 μm and 5 μm, preferably around 2 μm, and the conductive layer has a thickness of between 10 nm and 200 nm, preferably around 100 nm.

There will be described below, by way of non-limiting examples, embodiments of the present invention, with reference to the appended figures in which:

FIG. 1 schematically illustrates a communication device according to one embodiment of the invention.

FIG. 2 represents a glazing, such as a motor vehicle windshield, comprising the communication device illustrated schematically in FIG. 1.

FIG. 3 is a cross-section view along a section plane CC illustrated in FIG. 1 (orthogonal to one of the reflectors) which represents part of the glazed element on which are arranged a conductive layer then a piezoelectric layer forming together the piezoelectric substrate layer, the representation of said layers not being proportional, not to scale.

The reference numerals which are identical in the different figures represent similar or identical elements.

Referring to Figure 1, there is shown schematically a communication device 3 according to an embodiment of the present invention.

The communication device 3 comprises a radio-identification system, also known by the acronym RFID or “Radio Frequency Identification” in English, in order to identify a glazing 1 as shown in FIG. 2. The glazing 1 has a number unique identifier, assigned beforehand, for example by a computer system integrated into the glazing production process.

In the embodiment presented, the glazing 1 is a motor vehicle windshield comprising a glazed element 2. A vehicle windshield is however only one example given here without limitation.

The glazed element 2 of the glazing 1 can be monolithic, that is to say made up of a single sheet of material, or be composite, that is to say made up of several sheets of material between which is inserted at least one layer of adherent material, in the case of laminated glazing. The sheet(s) of material may (or may) be mineral(s), in particular glass, or organic(s), in particular plastic.

The invention can also be implemented on other types of glazing, such as side glazing or rear glazing or glazing forming all or part of the roof of the motor vehicle.

The communication device 3 comprises a dipole antenna 6, called “dipole antenna” in English. There is shown in Figure 1 a dipole antenna 6 having a first metal strand 6a and a second metal strand 6b.

In another embodiment of the present invention, the communication device 3 has a planar antenna, also sometimes called a planar antenna, instead of the dipole antenna 6. In English, the planar antenna is called a “patch antenna”. ".

The 6 dipole antenna is configured to operate in the ultra high frequency band, also known as UHF or “Ultra High Frequencies” in English.

Thus, the dipole antenna 6 is capable of operating over a range of radio frequencies between 300 MHz and 3000 MHz, preferably between 800 MHz and 3000 MHz, even in the band of the radio spectrum centered around the frequency 2.45 GHz.

The communication device 3 makes it possible to communicate by radio-frequency and, consequently, does not require a wire to transmit or receive information. The communication device 3 further comprises an RFID system without integrated circuit, which can also be called “chipless”, implementing a technology based on surface acoustic waves.

This technology is also known by the acronym SAW or “Surface Acoustic Wave” in English. SAW technology uses a Gaussian pulse emitted by a UHF RFID reader converted via an interdigital transducer 7, integrated into the communication device 3, into a surface acoustic wave.

The interdigital transducer 7 is connected to the dipole antenna 6. The interdigital transducer 7, also called IDT, acronym meaning "Interdital Transducer" in English, is a device comprising two rows of metal electrodes in the form of a comb which intersect, like a zipper.

The function of the interdigital transducer 7 is to convert the electromagnetic waves coming from the UHF RFID reader into surface acoustic waves generating periodically distributed mechanical stresses. Conversely, the interdigital transducer 7 converts the surface acoustic waves, generating mechanical stresses, into electromagnetic waves sent to the UHF RFID reader via the dipole antenna 6.

The electromagnetic waves are therefore picked up by the dipole antenna 6 and then propagate through a layer of piezoelectric substrate 4 applied to the glazed element 2, the layer of piezoelectric substrate 4 being arranged so as to transform the electromagnetic waves emitted by the UHF RFID reader in surface acoustic waves. The electromagnetic waves are reflected by means of a surface acoustic wave reflection device 5 making it possible to code the identification information specific to the glazing 1.

The surface acoustic wave reflection device 5 thus creates a train of pulses having phase shifts. The pulse train is then converted by the UHF reader in which the identifier is decoded.

In a particular embodiment, the surface acoustic wave reflection device 5 comprises seventy-five locations from which are selected a first reflector 5a, a second reflector 5b, a third reflector 5c and a fourth reflector 5d in order to code the 16-bit identification information and assign a unique identification number to glazing 1.

The first, second, third and fourth reflectors 5a, 5b, 5c, 5d generate reflections in the direction of the dipole antenna 6. These reflections are converted into electromagnetic waves and sent to the UHF RFID reader.

In the particular embodiment of the invention shown in Figure 1, the first, second, third and fourth reflectors 5a, 5b, 5c, 5d each have a substantially linear shape and are arranged parallel to one another. other. The reflectors 5a, 5b, 5c, 5d are substantially of the same length and are arranged substantially parallel with respect to the dipole antenna 6 and to the fingered transducer 7. The surface acoustic wave reflection device 5 comprising the four reflectors 5a, 5b, 5c, 5d makes it possible to encode a unique identification number on 16 bits.

In a preferred embodiment of the present invention, the reflectors are configured so as to be compatible with the EPC standards, an acronym meaning "Electronic Product Code" in English, and more particularly with the labels according to the "Alternative Class 1" standard of EPC Global, Inc.

In a particular embodiment of the present invention, the layer of piezoelectric substrate 4 is directly applied to one of the faces of a composite glazed element 2.

Advantageously, the piezoelectric substrate layer 4 comprises a piezoelectric layer 4a and a conductive layer 4b which, preferably made of Molybdenum (Mo), is interposed between the face of the glazed element 2 and said piezoelectric layer 4a.

Preferably, the piezoelectric layer 4a is made of aluminum nitride (AlN), said piezoelectric layer 4a being a thin layer having for example a thickness of approximately 2 μm.

Preferably, the conductive layer 4b of Molybdenum (Mo) has a thickness of 100 nm.

Preferably, the piezoelectric substrate layer 4 is transparent. As a variant, the layer of piezoelectric substrate 4 is opaque, or even non-transparent.

The term "transparent" defines a total transmission (direct and diffuse) greater than 1%, and preferably greater than 40%, for wavelengths visible to the human eye, from a spectrum composed of discrete lines and/or continue. These visible wavelengths are between 350 and 800 nm.

The layer of piezoelectric substrate 4 comprises a piezoelectric material capable of transforming a mechanical movement, such as vibrations, into an electric signal and vice versa. Thus, the layer of piezoelectric substrate 4 makes it possible not to obstruct the view or the light transmission through the glazed element 2 and can be arranged anywhere on the glazed element 2.

In an alternative embodiment, the transparent piezoelectric substrate layer 4 is deposited on a transparent glass substrate. A transparent conductive layer is first deposited on the transparent glass substrate and then the layer of transparent piezoelectric substrate 4 is deposited. The transparent conductive layer can be deposited by sol-gel, ALD, CVD, magnetron sputtering, or else PECVD.

The transparent conductive layer is, for example, SiO ₂ , TiO ₂ , SiN, AlN, HfO2, Al ₂ O ₃ , Y ₂ O ₃ , SiON, ZrO ₂ , Ta ₂ O ₅ , SnO _{2 ,} or else SnZnO _x . The transparent glass substrate is made of organic or inorganic glass.

The thickness of the transparent glass substrate is between 10 μm and 10 mm, preferably between 10 μm and 500 μm for an organic glass and preferably between 500 μm and 5 mm, or even between 1 mm and 3 mm for an inorganic glass .

In one embodiment, the glazing 1 is a motor vehicle windshield, the layer of piezoelectric substrate 4 is placed in one of its corners. The piezoelectric substrate layer 4 is preferably made of lead titanium-zirconate, such as lead titanium-zirconate doped with lanthanum (Pb,La)(Zr,Ti)O ₃ or Pb(Mg,Nb)TiO ₃ -PbTiO ₃ or BiFeO ₃ or (Ba,Ca)(Ti,Zr)O ₃ or Aluminum Nitride (AIN), or Aluminum Nitride doped with Scandium (AIN doped Sc) or Aluminum Oxide Zinc or Lithium Niobate (LiNbO ₃ ).

The layer of piezoelectric substrate 4 is preferably a thin layer having a thickness of between 1 nm and 10 μm, preferably between 0.5 and 5 μm.

The surface acoustic wave reflection device 5, the interdigital transducer 7 and the dipole antenna 6 are preferably directly deposited on the piezoelectric substrate layer 4 and are made of a layer of conductive ink, a layer of indium tin oxide (ITO) or any transparent or opaque conductive layer. The thickness of these layers is between 1 nm and 10 µm.

In a particular embodiment of the invention, the surface acoustic wave reflection device 5, the interdigital transducer 7 and the dipole antenna 6 are made of the same material, for example indium-tin oxide. (ITO).

Alternatively, the surface acoustic wave reflector 5 is made of a conductive ink layer, and the interdigital transducer 7 and the dipole antenna 6 are each made of an indium-tin oxide layer. .

In another embodiment of the invention, the communication device 3 comprises a planar antenna instead of a dipole antenna so as to reduce its size.

The implementation of a planar antenna also has the advantage of improving the gain, i.e. its passive application power.

The planar antenna includes a substrate having at least a top layer, an intermediate layer, and a bottom layer. The upper layer has a top side and a bottom side and the bottom layer also has a top side and a bottom side.

The upper face of the upper layer comprises an electrically conductive structure called a “patch” and the lower face of the lower layer comprises a ground plane, called a “ground plane”.

In a preferred embodiment, the planar antenna is miniaturized.

In an alternative embodiment, the antenna 6 is directly deposited on a glass substrate or on the glazed element 2, that is to say in particular outside the layer of piezoelectric substrate 4.

The antenna 6 is configured to operate in the frequency band advantageously centered around 2.45 GHz and in such a way as to take into account the dielectric permittivities of the laminated glazing and of the layer of piezoelectric substrate 4.

Claims (15)

Glazing (1) comprising a glazed element (2), in particular monolithic or composite, having a unique identification number, said glazed element (2) comprising a communication device (3) configured to operate by radio-frequency and by acoustic waves surface comprising an antenna (6), an interdigital transducer (7) and a surface acoustic wave reflection device (5) comprising reflectors (5a, 5b, 5c, 5d), said communication device (3) being intended to communicate the unique identification number of said glazing (1) to a remote reading device configured to operate in the ultra high frequency band, said glazing (1) being characterized in that said interdigital transducer (7) and said surface acoustic wave reflection device (5) are arranged on a layer of piezoelectric substrate (4, 4a, 4b) itself arranged on said glazed element (2). Pane (1) according to Claim 1, characterized in that the layer of piezoelectric substrate (4) comprises a piezoelectric layer (4a) and a conductive layer (4b), the said conductive layer (4b) being interposed between the piezoelectric layer (4a ) and said glazed element (2). Glazing (1) according to Claim 1 or 2, characterized in that the said antenna (6) is arranged on the said glazed element (2). Glazing (1) according to any one of Claims 1 to 3, characterized in that the said surface acoustic wave reflection device (5) comprises at least a first reflector (5a), a second reflector (5b), a third reflector (5c) and a fourth reflector (5d) so as to encode said unique identification number on at least 16 bits. Glazing (1) according to any one of Claims 1 or 4, characterized in that the said reflectors (5a, 5b, 5c, 5d) each have a substantially linear shape. Glazing (1) according to any one of Claims 1 to 5, characterized in that the said antenna (6) is planar. Glazing (1) according to Claim 6, characterized in that the said planar antenna (6) comprises at least an upper layer, an intermediate layer and a lower layer, the said upper layer further comprising an electrically conductive structure and the said lower layer including a ground plane. Glazing (1) according to any one of Claims 1 to 5, characterized in that the antenna (6) is dipole. Pane (1) according to any one of Claims 1 to 8, characterized in that the said layer of piezoelectric substrate (4, 4a) comprises one of the following materials: (Pb,La)(Zr,Ti)O ₃ , Pb(Mg,Nb)TiO ₃ -PbTiO ₃ , BiFeO ₃ , (Ba,Ca)(Ti,Zr)O ₃ , AlN, AlN doped with Sc, ZnO, LiNbO _3, preferably Aluminum nitride (AlN). Glazing (1) according to any one of Claims 2 to 9, characterized in that the conductive layer (4b) of the layer of piezoelectric substrate (4) comprises Molybdenum (Mo), preferably the said conductive layer (4b) arranged between said glazed element and said layer of piezoelectric substrate is transparent. Glazing (1) according to any one of the preceding claims, characterized in that the said communication device (3) is configured in such a way as to operate on a range of frequencies comprised between 800 MHz and 3000 MHz, and preferably around the frequency 2.45GHz. Pane (1) according to any one of the preceding claims, characterized in that the material of said surface acoustic wave reflection device (5), of the interdigital transducer (7) and of the antenna (6) is indium tin oxide (ITO) or molybdenum (Mo) or a material comprising silver (Ag) or an electrically conductive ink. Glazing (1) according to any one of the preceding claims, characterized in that the said layer of piezoelectric substrate (4) is transparent. Pane (1) according to any one of the preceding claims, characterized in that the piezoelectric layer (4a) has a thickness of between 1 µm and 5 µm, preferably approximately 2 µm, and the conductive layer (4b) has a thickness comprised between 10 nm and 200 nm, preferably around 100 nm. Glazing (1) according to any one of the preceding claims, characterized in that it is intended to be integrated into a motor vehicle, in particular to form the windscreen or a side window of the said motor vehicle.