WO2014001276A1

WO2014001276A1 - Multiple glazing furnished with an array of antennas

Info

Publication number: WO2014001276A1
Application number: PCT/EP2013/063183
Authority: WO
Inventors: Antoine LUIJCX; Xavier RADU; Christophe CRAYE
Original assignee: Agc Glass Europe; Université Catholique de Louvain
Priority date: 2012-06-28
Filing date: 2013-06-25
Publication date: 2014-01-03
Also published as: BE1020720A3

Abstract

Multiple glazing (1) able to serve as bandpass BP antenna and comprising a laminated structure (10), at least one resonant cavity (20) and at least one transmission line (30) able to excite the at least one resonant cavity (20). The laminated structure (10) comprises at least one first (11) and one second (12) dielectric sheet separated by an assemblage layer (13) as well as an earth sheet (40). The at least one resonant cavity (20) is made in the first dielectric sheet (1) and an upper dielectric sheet (50) defines with the first dielectric sheet (11) a first internal space (70). The at least one transmission line (30) is positioned in the first internal space (70).

Description

Multiple glazing with an antenna array

Technical area

The invention relates to a multiple glazing that can serve as an antenna.

State of the art

US6,388,621 B1 discloses a phased array antenna. This array antenna is flat, optically transparent and adapted to be fixed on the surface of a planar element that can itself be attached to a wall of a dwelling. Figure 6 of this document relates to a preferred embodiment. The array antenna of this embodiment comprises a first dielectric layer positioned on the upper surface of a second dielectric layer. These two dielectric layers are optically transparent. The lower surface of the second dielectric layer is covered with a transparent conductive ground sheet which is itself covered with a transparent adhesive layer. This adhesive layer allows the attachment of the network antenna to a plane support. The upper surface of the first transparent dielectric layer is covered with a transparent electrically conductive layer. This transparent electrically conductive layer comprises radiating slots oriented towards the outside of the array antenna. A beamforming network (French beamforming) comprises tracks or transmission lines that can interact with these radiating slots by electromagnetic coupling. These tracks or transmission lines are positioned between the first and second transparent dielectric layers.

The network antenna as described in US6,388,621 B1 has certain disadvantages. It requires to be fixed on a support, itself to be placed on a wall or a chimney of a dwelling. Such an antenna has a fairly narrow bandwidth BP and significant losses. Summary of the invention

One of the aims of the present invention is to provide an antenna that can be integrated into a dwelling without requiring specific support, having a wider BP bandwidth and lower losses than known antennas. For this purpose, the inventors propose the following invention:

multiple glazing capable of serving as a bandwidth antenna BP and comprising at least:

a laminated structure comprising:

at least first and second dielectric sheets each comprising a material that is optically transparent, an assembly layer located between the first and second dielectric sheets,

o a sheet of mass;

at least one resonant cavity;

at least one transmission line capable of exciting the at least one resonant cavity; characterized in that

- The multiple glazing further comprises a dielectric upper sheet comprising an optically transparent material, secured to said first dielectric sheet via at least a first spacer and defining with said first dielectric sheet a first internal space;

the at least one resonant cavity

o is formed in the first dielectric sheet,

o is filled with a medium having, in the bandwidth BP, a dielectric permittivity ε whose real part, ε ', is less than or equal to 4 ^* εο, εο being the dielectric permittivity of the vacuum, and whose ratio, tan δ, between its imaginary part, ε ", and its real part, ε ', is less than or equal to 10 ^"2;

o comprises an opening oriented towards the first internal space;

the at least one transmission line is located in the first internal space. The term optically transparent means that the light transmission in the visible (that is to say in a frequency band corresponding to a wavelength λ between 400 and 800 nm in the vacuum) is greater than 50%. The dielectric upper sheet forms with the first internal space and the laminated structure a multiple glazing that can be used as glazing for the windows of a house. Thus, the antenna proposed by the inventors can be integrated directly into a dwelling without having to provide additional support for said antenna. Thus, the inventors propose a multiple glazing that can serve as an antenna.

The multiple glazing proposed by the inventors comprises at least one resonant cavity which is formed in the first dielectric sheet. Thus, unlike the antenna array described in US6,388,621 B1, the glazing of the invention does not include slots in an electrically conductive layer. It follows that an electromagnetic field can occupy the at least one resonant cavity of the glazing unit of the invention, that is to say a greater volume than in the case of the antenna described in US6,388,621 B1 which includes slots. An electromagnetic field may also partially penetrate the first dielectric sheet near the walls of the at least one resonant cavity, more deeply where these resonant cavities are formed in an electrically conductive material. In the latter case, the electromagnetic field indeed undergoes a greater attenuation due to the smaller skin depth which is associated with the electrically conductive materials compared to the dielectric materials (the depth of skin is a term known to those skilled in the art) . This property makes it possible to widen the bandwidth BP of the glazing of the invention that can serve as an antenna and subsequently to obtain an antenna having a bandwidth BP wider than the antenna described in US6,388,621 B1. Thus, the relatively large volume occupied by the electromagnetic field in and near the at least one resonant cavity contributes to obtaining an antenna having a large bandwidth. The at least one transmission line capable of exciting the at least one resonant cavity is located in the first internal space and the medium filling the at least one resonant cavity has low losses. The losses in a dielectric medium are in fact characterized by the ratio tan δ as defined above, that is to say as the ratio between ε "and ε '(the abbreviation tan means tangent). electromagnetic coupling between the at least one resonant cavity and the at least one transmission line is via air and a medium with low losses.In the end, the antenna of the invention presents more the condition that the real part of the dielectric permittivity, ε ', of the medium filling the at least one resonant cavity is less than or equal to 4 ^* ε0 makes it possible to obtain a BP bandwidth of appreciable width while avoiding excessive losses.

The multiple glazing of the invention can be used as transmitting or receiving antenna given the principle of electromagnetic reciprocity. In the case of the transmitting antenna application, the at least one transmission line serves to excite the at least one resonant cavity. In the case of the receiving antenna application, the at least one transmission line serves to repatriate the resonance signals originating in the at least one resonant cavity. As is known to those skilled in the art, electromagnetic reciprocity is a property that allows to interchange an elementary current dipole serving as a source and an observed electric field. The glazing of the invention can be used as an antenna for any polarization of the incident or emitted electromagnetic wave. The bandwidth BP of the multiple glazing unit of the invention is wider compared to that of the patch antennas shown in FIGS. 7 to 9 of US6,388,621 B1.

Preferably, the at least one resonant cavity is filled with air.

In this preferred embodiment, the at least one resonant cavity is in communication with the first internal space and the resonance phenomenon takes place mainly in the air which has low losses. Preferably, the bandwidth BP of the multiple glazing of the invention can serve as an antenna is between 8 and 15 GHz, preferably between 10 and 13 GHz.

The bandwidth BP of an antenna is a term known to those skilled in the art. The bandwidth BP of an antenna is generally defined as the difference between a maximum frequency e and a maximum frequency of use, BP = f max - fmin, such that the maximum and minimum frequencies, f max and f min , represent a loss of 3 dB relative to a resonance frequency of the antenna, fR. This attenuation may be due either to a lack of adaptation with respect to the transmission or reception circuits, or to a reduction in the amplitude of the radiation pattern in a direction of interest, or to losses of energy. ie (losses by Jou effect in particular) in materials constituting the antenna.

Preferably, said first and second dielectric sheets and said dielectric top sheet comprise glass.

This embodiment is particularly interesting because it uses materials commonly used for glazing homes.

Preferably, the at least one resonant cavity has a circular section in a plane parallel to the first and second dielectric sheets. Preferably, said circular section has a radius of between 5 and 10 mm.

The cylindrical shape of the at least one resonant cavity facilitates the manufacture of the multiple glazing unit of the invention.

Preferably, said at least one transmission line at least partially overhangs the opening of the at least one resonant cavity. Preferably, the ground sheet is a conductive layer deposited on the second dielectric sheet and whose surface electrical resistance is between 0 and 50 ohms / square, preferably between 2 and 20 ohms / square, and even more preferably between 7 and 15 ohms / square. Preferably, the ground sheet is an optically transparent conductive coating. Of course, according to the invention, the conductive coating may also not be optically transparent. The use of an optically transparent conductive coating makes it possible to reduce the visual impact of the antenna application of the multiple glazing unit of the invention.

Preferably, the mass sheet also has the effect of a low emissivity layer.

This embodiment makes it possible to obtain a multiple glazing with interesting thermal properties. Preferably, the assembly layer comprises a thermoplastic interlayer layer.

Preferably, the multiple glazing further comprises a third dielectric sheet secured to said dielectric upper sheet by means of at least one second spacer and defining with said dielectric upper sheet a second internal space.

This preferred embodiment corresponds to a triple glazing that can serve as an antenna. The third dielectric sheet provides increased thermal and acoustic insulation compared to the case of double glazing.

Preferably, said at least one transmission line comprises a metallized electrically insulating substrate.

Utilizing as at least one transmission, a metallized electrically insulating substrate facilitates its manufacture and therefore the manufacture of multiple glazing of the invention.

Preferably, the first internal space has a thickness of between 1 and 3 cm, preferably between 1 and 2 cm.

Preferably, the upper electric light has a thickness of between 2 and 12 mm, preferably between 3 and 6 mm. Preferably, the first dielectric sheet has a thickness of between 3 and 8 mm.

Preferably, the multiple glazing unit of the invention further comprises a printed circuit electrically connected to the at least one transmission line, secured to the first dielectric sheet, positioned outside the first internal space and adjacent to the first of the at least one first spacer.

In this preferred embodiment, the electrical connection of the at least one transmission line to an electronic signal analysis device is achieved by the insertion on the edge of the multiple glazing of a printed circuit imparting l The signals originate from the at least one transmission line. The advantage is to obtain a multiple glazing that can serve as an antenna that is compact and incorporating an integrated circuit for collecting the data conveyed by the at least one transmission line. The assembly and assembly of multiple glazing in a home is facilitated. Brief description of the drawings

These and other aspects of the invention will be clarified in the detailed description of particular embodiments of the invention, with reference to the drawings of the figures, in which:

FIG. 1 illustrates a possible application of the multiple glazing unit of the invention; FIG. 2 shows a first preferred embodiment of the multiple glazing unit of the invention;

Fig.3 shows an example of the at least one transmission line;

FIG. 4 shows a view from above of a preferred embodiment of the multiple glazing unit of the invention; FIG. 5 shows a view from above of another preferred embodiment of the multiple glazing unit of the invention; Fig.6 shows a multiple glazing according to another preferred embodiment of the invention; Fig.7 shows a multiple glazing according to yet another preferred embodiment of the invention. The drawings of the figures are not to scale. Generally, similar elements are denoted by similar references in the figures. The presence of reference numbers in the drawings can not be considered as limiting, even when these numbers are indicated in the claims.

DETAILED DESCRIPTION OF PARTICULAR EMBODIMENTS OF THE INVENTION

Figure 1 shows a possible application of multiple glazing 1 of the invention. In this example, the multiple glazing unit 1 of the invention is used as receiving antenna of a signal emitted by a satellite 500. More precisely, the signal emitted by the satellite 500 is an electromagnetic wave 505 which is captured by the glazing unit. A multiple 1 which itself is electrically coupled to a signal analysis electronic device 51 0 and which can also amplify the signals provided by the multiple glazing unit 1. Preferably, the electronic device 510 is a low-noise amplifier (LNA) known to those skilled in the art. In another application, multiple glazing 1 of the invention is used as the transmitting antenna. This is possible thanks to the principle of electromagnetic reciprocity known to those skilled in the art. In both cases, it is therefore possible to define a bandwidth BP of the multiple glazing 1 serving as an antenna. The bandwidth BP of an antenna is a term known to those skilled in the art. The bandwidth BP of an antenna is generally defined as the difference between a maximum frequency and a minimum frequency of use, BP = f _max - f _m in, such that the maximum and minimum frequencies, f _max and f _min , represent a loss of 3 dB with respect to a resonance frequency of the antenna, IR. FIG. 2 shows a first embodiment of the multiple glazing unit 1 of the invention in a section along the axis AA 'of FIG. 1 which shows the multiple glazing unit 1 of the invention seen from above with a satellite 500. As illustrated in FIG. 2, the multiple glazing unit 1 of this first embodiment comprises a laminated structure 10 which itself comprises a first 1 1 and a second 1 2, the dielectrics separated by a single layer. The first and second 12 dielectric sheets comprise a material which is optically transparent. The term optically transparent means that the light transmission in the visible (that is to say in a frequency band corresponding to a wavelength λ between 400 and 800 nm in the vacuum) is greater than 50%. The laminated structure 10 also comprises a sheet of mass 40. It is not necessary, however, that the mass sheet 40 be located between the second dielectric sheet 12 and the assembly layer 13 as illustrated in FIG. other configurations are possible. Thus, by way of example, another embodiment consists in placing the mass sheet 40 on the lower surface of the second dielectric sheet 12 towards the outside of the multiple glazing unit 1. This mass light 40 acts as an electromagnetic shield blocking the propagation of electromagnetic waves 505 along the entire thickness of the multiple glazing 1. This sheet of mass 40 preferably comprises a material which is a very good electrical conductor.

The multiple glazing unit 1 of the invention comprises a dielectric top sheet 50 comprising an optically transparent material. This dielectric upper sheet 50 is secured to the first dielectric sheet 1 1 via at least one spacer 60 and defines with the first dielectric sheet 1 1 a first internal space 70.

The multiple glazing unit 1 of the invention further comprises at least one resonant cavity 20. Preferably, the multiple glazing unit 1 of the invention comprises several resonant cavities 20. The multiple glazing unit 1 then corresponds to an array of antennas which enables to increase the gain of the multiple glazing 1 serving as an antenna. It also allows to privilege a direction particular in the antenna radiation pattern. More preferably, the multiple glazing 1 comprises five groups of 8x8 resonant cavities 20, that is to say three hundred twenty resonant cavities 20. These resonant cavities 20 are formed in the first dielectric sheet January 1. Preferably, the at least one resonant cavity 20 has a depth of between λ / 25 and λ / 10, where λ represents the wavelength of the electromagnetic wave 505 incident or emitted in a vacuum. More preferably, the depth of the resonant cavities 20 corresponds to the thickness of the first dielectric sheet 11 as shown in FIG. 2. Each resonant cavity 20 comprises an opening 25 oriented towards the first internal space 70. at least one resonant cavity 20 is filled with a medium having in the bandwidth BP of the multiple glazing unit 1 a dielectric permittivity ε whose real part, ε ', is less than or equal to 4 ^* εο and whose ratio, tan δ, between its imaginary part, ε ", and its real part, ε ', is less than or equal to 10 ^{" 2} . As is known to those skilled in the art, εο represents the dielectric permittivity of the vacuum which is equal to 8.854 10 ^-12 F / m. As is known to those skilled in the art, losses in a dielectric medium are generally characterized by the ratio tan δ between the imaginary part and the real part of the dielectric permittivity of the dielectric medium: tan δ = ε'7 ε 'Preferably, the medium filling the at least one resonant cavity 20 has a dielectric permittivity ε whose ratio, tan δ, between its imaginary part, ε ", and its real part, ε ', is less than or equal to 10 ^{" 3.} More preferably, the medium filling the at least one resonant cavity 20 has a dielectric permittivity ε whose real part, ε ', is less than or equal to 2 ^* εο and more preferably is equal to 1. The medium filling the at least one resonant cavity 20 may comprise a plurality of materials, ga z or components.

The multiple glazing unit 1 also comprises at least one transmission line 30 able to excite the at least one resonant cavity 20 and situated in the first internal space 70. When the multiple glazing unit 1 is used as a receiving antenna, the at least one transmission line 30 serves to collect the resonance signals originating in the at least one resonant cavity 20. The notion of the transmission line is known to those skilled in the art.

As illustrated in Figure 1, the transmission lines 30 are connected to an electronic device 51 0. The latter allows to electronically change the reception direction of the multiple glazing 1 to receive the signal of different satellites for example. This change of direction is achieved by introducing a phase shift between the signals from the different (groups of) cavities prior to their combination. We then speak of different angles of reception of multiple glazing 1. Preferably, these different reception angles are located in a plane horizontal with respect to the ground: the multiple glazing 1 then has different angles of reception in azimuth. More preferably, these different angles of reception in azimuth are between -35 ° and + 35 ° with respect to a horizontal reference direction. The reception angle in elevation or vertical reception angle of the multiple glazing unit 1 is preferably fixed. The selection of the different angles of reception in azimuth is preferably carried out using a beamforming technique (or beamforming in French) known to those skilled in the art (see for example the book by Robert C. Hansen entitled Phased Array Antennas and published by John Wiley & Sons in December 2009). The beamforming technique is a signal processing technique that constructively or destructively combines certain electromagnetic signals. Here, it is used to combine the signals from different transmission lines 30 which are coupled to different resonant cavities 20. The selection of the reception angle of the antenna (or multiple glazing 1) is performed by a choice of constructively combining the signals from the different transmission lines 30 assuming that a source (satellite 500 of Figure 1 for example) is located in a particular direction. In the context of the invention, the beamforming technique is preferably carried out on analog signals: the signals propagating on the various transmission lines 30 are then combined by means of electronic circuits without digitizing them beforehand. FIG. 3 shows a preferred embodiment of the at least one transmission line 30. In this preferred embodiment, a first conductor 31 of the transmission line is located above a second conductor 32 of the transmission line 30. transmission line, the latter 32 being fixed on the upper wall of the first dielectric sheet January 1. A dielectric layer 33 separates the two conductors 31 and 32. Preferably, the first 31 and second 32 conductors are obtained by metallization of all or part of the upper and lower surfaces of the dielectric layer 33.

In the preferred embodiments shown in FIGS. 1 and 2, the transmission lines 30 overhang the resonant cavities 20. However, this is not necessary. This is illustrated in Figure 4 which shows a view from above of another embodiment of the multiple glazing 1 of the invention. In this preferred embodiment, the entirety of the transmission lines 30 rests on the upper surface of the first dielectric sheet January 1. In such an embodiment, the smallest distance 45 between a transmission line 30 and the edge of a resonant cavity 20 is less than λ / 10 and preferably less than λ / 20 to allow electromagnetic coupling between at least one Transmission line 30 and at least one resonant cavity 20. In such a case, those skilled in the art generally speak of an electromagnetic coupling by proximity. As it is glossed in FIG. 2, the at least one transmission line 30 is preferably in contact with the first internal space 70.

Figure 5 shows a view from above of another preferred embodiment of multiple glazing 1 of the invention. In this preferred embodiment, two transmission lines 30 are able to excite each resonant cavity 20. Such a configuration makes it possible to obtain better control of the polarization of the emitted wave when the multiple glazing unit 1 is used in transmission or to obtain a better selection of the incident waves according to their polarization when the multiple glazing 1 is used in reception. The lengths of the paths traveled by the signals conveyed by the two transmission lines 30 relating to a resonant cavity 20 are different. A wise choice of the difference in length of the paths traveled along two different transmission lines 30 make it possible to select a given polarization, for example a polarization of the circular type if the difference in length of the paths traveled corresponds to a phase shift of 90 ° (λ _9/4 , where A _g is the length of d wave in the transmission line). Preferably, the at least one resonant cavity 20 is filled with air.

The air is characterized by a dielectric permittivity ε whose ratio, tan δ, between its imaginary part, ε ", and its real part ε ', is close to 0 (or less than 10 ^{" 6} in good approximation) and this, on a very large frequency range. The air also has a dielectric permittivity of which the real part ε 'is close to εο in good approximation.

Preferably, the bandwidth BP of the multiple glazing unit 1 of the invention is between 8 and 15 GHz, more preferably between 10 and 13 GHz and even more preferably between 10.75 and 12.75 GHz. The last frequency interval corresponds to what is usually called the Ku band for satellite broadcasting (including television services).

Preferably, the first 11 and second 12 dielectric sheets and the dielectric upper sheet 50 comprise glass. By glass is meant all types of glasses and equivalent transparent materials such as mineral glasses and organic glasses. The mineral glass can be constituted indifferently of one or more types of known glasses such as soda-lime glasses, boron glasses, crystalline and semi-crystalline glasses. The organic glass may be a thermosetting or rigid thermoplastic transparent polymer or copolymer such as, for example, a transparent polycarbonate, polyester or polyvinyl synthetic resin. Preferably, the resonant cavities 20 have a cylindrical shape.

Thus, in such a preferred embodiment, the resonant cavities 20 have a circular section in a plane parallel to the first and second dielectric sheets (11, 12). In such an embodiment, the resonant cavities 20 preferably have a radius of between 5 and 10 mm, more preferably a radius of between 6 and 8 mm and even more preferably a radius of 7 mm. Preferably, the ground sheet 40 is a conductive layer deposited on the second dielectric sheet 12 and whose surface electrical resistance is between 0 and 50 ohms / square, preferably between 2 and 20 ohms / square, and moreover preferred between 7 and 15 ohms / square. Preferably, the ground sheet 40 is an optically transparent conductive coating. Such coatings are for example doped oxide-based layers whose thickness is generally between 0.02 and 0.5 μιτι, preferably between 0.2 and 0.4 μιτι and whose surface resistance can vary between 10 and 80 ohms / square, preferably between 12 and 20 ohms / square. Such layers comprise, for example, indium or aluminum doped zinc oxide, fluorine or antimony doped tin oxide, or indium doped indium oxide. tin (commonly known as ITO). A coating of such a transparent conductive film may, for example, have been deposited on a dielectric sheet such as glass by the well-known technique of chemical vapor deposition (CVD), from precursors in the gas phase. Other examples of optically transparent conductive coatings for the sheet of mass 40 are silver-based layers. These conductive layers may be composed of one, two or even three layers of silver (or any other conductive material), separated by layers of dielectric. For layers comprising a total thickness of conductive material between 10 and 30 nm, the surface resistance can reach very low values of between 2 and 3 ohms / square. Such stacks are for example the result of a succession of magnetron sputtering magnetron sputtering deposits in the English literature. The stacking of layers is, for example in this case: ΤΊΟ2 /

ZnO / Ag / Ti / ZnO / SnO2. However, any other layer even more weakly conductive could be suitable.

Preferably, the mass sheet 40 also has the effect of a low emissivity layer. Such property is known to those skilled in the art of glazing. It is based on the reflection of IR (far infrared) and limits in a given direction the heat transfer between the outside and the inside of a house through a glazing. Preferably, the assembly layer 1 3 comprises a layer of thermoplastic interlayer, for example polyvinyl butyral (PVB), ethylene vinyl acetate or polyurethane.

Figure 6 shows another preferred embodiment of multiple glazing 1 of the invention. In this preferred embodiment, the multiple glazing 1 further comprises a third dielectric sheet 200 which is secured to the dielectric upper sheet 50 via at least one second spacer 210. This third dielectric sheet 200 defines with the sheet dielectric upper 50 a second internal space 220. Preferably, the first internal space 70 has a thickness of between 1 and 3 cm, and more preferably between 1 and 2 cm.

Preferably, the first internal space 70 comprises a vacuum. More preferably, the first internal space 70 comprises air. Even more preferably, the first internal space 70 comprises another gas, certain non-limiting examples of which are: argon, krypton, CO2, xenon or any other gas, in particular any thermal or acoustic insulating gas and any mixture of the aforementioned gases mentioned above.

Preferably, the dielectric top sheet 50 has a thickness of between 2 and 12 mm and more preferably between 3 and 6 mm. Preferably, the first electric light 11 has a thickness of between 3 and 8 mm.

FIG. 7 shows an example of connections that can be used and integrated with the multiple glazing unit 1 to repatriate the signals carried by the at least one transmission line 30. In this example, the multiple glazing unit 1 comprises on its wafer a printed circuit 300 which is secured to the first dielectric sheet 1 1 via an adhesive 310. Thus, in this example, the printed circuit 300 is positioned outside the first internal space 70 and is adjacent to one of the at least a first spacer 60. As shown in Figure 7, the various dielectric sheets are cut so staggered, to allow the leaf structure 10 to protrude from the dielectric upper sheet 50. This allows easy access to the circuit board 300 which is adjacent to one of the at least one spacer 60. The circuit board 300 is electrically connected to the different transmission lines 30 to repatriate the signals conveyed by these transmission lines 30 to an electronic device 510 such as an LNA.

The present invention has been described in relation to specific embodiments, which have a purely illustrative value and should not be considered as limiting. In general, the present invention is not limited to the examples illustrated and / or described above. The use of the verbs "to understand", "to include", "to include", or any other variant, as well as their conjugations, can in no way exclude the presence of elements other than those mentioned. The use of the indefinite article "a", "an", or the definite article "the", "the" or "Γ", to introduce an element does not exclude the presence of a plurality of these elements. The reference numerals in the claims do not limit their scope.

In summary, the invention can also be described as follows. Multiple glazing 1 that can serve as a bandwidth antenna BP and comprising a laminated structure 10, at least one resonant cavity 20 and at least one transmission line 30 capable of exciting the at least one resonant cavity 20. The laminated structure 10 comprises at least a first 1 1 and a second 12 dielectric sheets separated by an assembly layer 13 and a sheet of mass 40. The at least one resonant cavity 20 is formed in the first dielectric sheet 1 1 and a top sheet dielectric 50 defines with the first dielectric sheet 1 1 a first internal space 70. The at least one transmission line 30 is positioned in the first internal space 70.

Claims

claims

1. Multiple glazing (1) that can serve as a bandwidth antenna BP and comprising at least:

a laminated structure (10) comprising:

at least a first (1 1) and a second (12) dielectric sheet each comprising a material that is optically transparent,

an assembly layer (13) located between the first (1 1) and second (12) dielectric sheets,

a mass sheet (40);

at least one resonant cavity (20);

at least one transmission line (30) capable of exciting the at least one resonant cavity (20); characterized in that: - the multiple glazing (1) further comprises a dielectric upper sheet (50) comprising an optically transparent material, secured to said first dielectric sheet (1 1) via at least one intermediate interlayer ( 60) and defining with said first dielectric sheet (1 1) a first internal space (70);

the at least one resonant cavity (20):

o is formed in the first dielectric sheet (1 1), o is filled with a medium having, in the bandwidth BP, a dielectric permittivity ε whose real part, ε ', is less than or equal to 4 ^* εο, εο being the dielectric permittivity of the vacuum, and whose ratio, tan δ, between its imaginary part, ε ", and its real part, ε ', is less than or equal to 10 ^"2;

o comprises an opening (25) oriented towards the first internal space (70);

the at least one transmission line (30) is located in the first internal space (70).

2. Multiple glazing (1) according to claim 1 characterized in that the at least one resonant cavity (20) is filled with air.

3. Multiple glazing (1) according to claim 1 or 2 characterized in that the bandwidth BP is between 8 and 15 GHz, preferably between 10 and 13 GHz.

4. Multiple glazing (1) according to any one of the preceding claims characterized in that said first (1 1) and second (12) dielectric sheets and said dielectric upper sheet (50) comprise glass.

5. multiple glazing (1) according to any one of the preceding claims characterized in that the at least one resonant cavity (20) has a circular section in a plane parallel to the first and second dielectric sheets (1 1, 12).

6. Multiple glazing (1) according to the preceding claim characterized in that said circular section has a radius of between 5 and 10 mm.

7. multiple glazing (1) according to any one of the preceding claims characterized in that said at least one transmission line (30) at least partially overhangs the opening (25) of the at least one resonant cavity (20) .

8. multiple glazing (1) according to any one of the preceding claims characterized in that the ground sheet (40) is a conductive layer deposited on the second dielectric sheet (12) and whose surface electrical resistance is between 0 and 50 ohms / square, preferably between 2 and 20 ohms / square, and more preferably between 7 and 15 ohms / square.

9. Multiple glazing (1) according to any one of the preceding claims characterized in that the ground sheet (40) is an optically transparent conductive coating.

10. Multiple glazing (1) according to any one of the preceding claims characterized in that the mass sheet (40) also has the effect of a low emissivity layer.

1 1. Multiple glazing (1) according to any preceding claim characterized in that said assembly layer (13) comprises a thermoplastic interlayer layer.

12. multiple glazing (1) according to any one of the preceding claims further comprising a third dielectric sheet (200) secured to said dielectric upper sheet (50) via at least one second spacer (210) and defining with this dielectric upper sheet (50) a second internal space (220).

13. Multiple glazing (1) according to any one of the preceding claims characterized in that said at least one transmission line (30) comprises a metallized electrically insulating substrate.

14. Multiple glazing (1) according to any one of the preceding claims characterized in that the first internal space (70) has a thickness of between 1 and 3 cm, preferably between 1 and 2 cm.

15. Multiple glazing (1) according to any one of the preceding claims characterized in that the dielectric upper sheet (50) has a thickness of between 2 and 12 mm, preferably between 3 and 6 mm.

16. Multiple glazing (1) according to any one of the preceding claims characterized in that the first dielectric sheet (1 1) has a thickness of between 3 and 8 mm.

17. multiple glazing (1) according to any one of the preceding claims further comprising a printed circuit (300) electrically connected to the at least one transmission line (30), secured to the first dielectric sheet (1 1), positioned outside the first inner space (70) and adjacent to one of the at least one spacer (60).