Glazing with an antenna, its manufacturing method and its use

Abstract

The present invention provides a glazing 10 comprising a ply 11 of glazing material, an antenna 1 disposed at least partially on the ply 11 of glazing material with a feed point 3 at one end thereof for connection to an external circuit 20, an electronic device 2 located on or near the glazing 10 for emitting a frequency F, and an anti-antenna 5 connected to the antenna 1 by a bridge 6 and extending parallel to the antenna 1 towards the feed point 3 to an end 7 for at least partially cancelling the frequency F.

Description

[Technical field]

[0001] GLAZING WITH ANTENNA AND METHOD FOR MANUFACTURING SAME The present invention solves problems caused by interference from electronic devices. [Background technology]

[0002] Glazings with antennas for receiving or transmitting electromagnetic waves are known. Such glazings in vehicles are equipped with antennas for radio (AM, FM), mobile networks "Long Term Evolution" (LTE), digital audio broadcasting (DAB), television (TV), terrestrial digital video broadcasting (DVB-t), telephone (GSM), navigation (GPS), WLAN, remote keyless entry (RKE), car-to-car and car-to-infrastructure communication (car2X) and paging systems. Antennas on glazings may perform poorly due to electromagnetic interference (EMI) emitted by electronic devices (whose antennas or other conductors) located on the glazing or elsewhere.

[0003] WO2011077142 (Paulus) discloses a laminated vehicle glazing having a conductive panel defining a slot antenna and a device for emitting electromagnetic radiation. A conductive wire or conductive print electrically connected or capacitively coupled to the conductive panel and at least partially surrounding the device serves to reduce EMI at the slot antenna.

[0004] WO2014087142 (Baranski) discloses two antennas in a glazing, each connected to a coupling electrode and arranged such that AC coupling occurs between the coupling electrodes. Unwanted DC contact between the coupling electrodes and other conductors is avoided by using insulation.

[0005] EP 3534457 (Nagata) discloses a window pane to which an electronic device is placed, comprising an antenna on the pane and a linear canceller also on the pane to suppress the antenna from receiving noise from the electronic device.

[0006] It is an object of the present invention to provide a glazing having an antenna that reduces undesired interference from other antennas or electronic devices. Another object is to provide a method for manufacturing said glazing. Summary of the Invention

[0007] The invention provides in a first aspect according to claim 1 a glazing comprising a ply of glazing material, an antenna at least partially arranged on the ply of glazing material with a feed point at one end for connection to an external circuit, an electronic device located on or near the glazing for emitting frequency F, and an anti-antenna for at least partially cancelling frequency F, connected to the antenna by a bridge and extending to the end parallel to the antenna towards the feed point.

[0008] Preferably, the length A from the bridge to the end divided by the first shortening coefficient K1 of the anti-antenna is an odd integer multiple of a quarter wavelength in free space at frequency F ±25%.

[0009] Preferably, the electronic device is a second antenna having a length A' and a feed point, the length A' divided by a second shortening factor K2 of the second antenna being an odd integer multiple of a quarter wavelength in free space at frequency F ±25%.

[0010] Preferably, the distance B from the feed point to the end divided by the third shortening factor K3 between the feed point and the end is a multiple of a half wavelength in free space at frequency F ±25%.

[0011] For laminated glass, the first, second or third shortening coefficients K1, K2, K3 are typically 0.6, for monolithic tempered glass they are typically 0.7.

[0012] Preferably, the anti-antenna is a filter that cancels interference from a second antenna at frequency F, or the multiple anti-antennas are multiple filters for canceling interference from multiple electronic devices at multiple frequencies F.

[0013] In one embodiment, the length A is 300 to 500 mm, preferably 360 to 40 mm, for anti-FM function. In another embodiment, the length A is preferably 50 to 70 mm, more preferably 60 to 65 mm, for anti-LTE function.

[0014] In one embodiment, the gap G between the antenna and the anti-antenna is 20 to 40 mm, preferably 28 to 32 mm, for FM function, or the gap G between the antenna and the anti-antenna is 1 to 6 mm, preferably 3 to 4 mm, for LTE function.

[0015] Preferably, the antenna further comprises a connector extending from the feed point to a connection point on the first ply of glazing material.

[0016] Preferably, the connector is a flat cable and the anti-antenna and bridge are arranged on the flat cable.

[0017] Preferably the external circuit comprises an amplifier connected to a feed point and located on or near the glazing.

[0018] Preferably, the second antenna is located on the bumper of the vehicle or on the roof of the vehicle.

[0019] Preferably the first ply of glazing material is tempered glass.

[0020] Preferably, the glazing further comprises a second ply of glazing material joined to the first ply of glazing material by a ply of interlayer material to form laminated glass.

[0021] The glazing may have any suitable shape, for example trapezoidal, rectangular or triangular. The thickness of the glazing, including all glazing materials, interlayer materials and conductors, may be any thickness, for example 2.5 mm to 10.6 mm, preferably 2.6 mm to 3.8 mm, more preferably 2.7 mm to 3.2 mm. The glazing material may be any suitable material, for example soda-lime-silica glass or borosilicate glass. Preferably, the anti-antenna, bridge and antenna are copper wires with a diameter of 0.05 to 0.15 mm or silver printing with a thickness of 0.1 to 2 mm. The bridge and antenna may be galvanically connected or may be connected by capacitive coupling.

[0022] The first and second glass sheets may be formed by a float process and may be annealed. The glass sheets may be heat strengthened or tempered (toughened). In laminated glass, the first glass sheet may be the inner ply of glazing material and the second glass sheet may be the outer ply of glazing material, or vice versa.

[0023] The glazing may comprise one or more plies of an interlayer material, such as polyvinyl butyral (PVB), which is advantageous because it exhibits good adhesion after lamination to the glass. The interlayer material may have any thickness, such as 0.76 mm.

[0024] The present invention provides in a second aspect according to claim 14 a method for manufacturing a glazing comprising the steps of providing a ply of glazing material, arranging an antenna at least partially on the ply of glazing material with a feed point at an end of the antenna for connection to an external circuit, disposing an electronic device on or near the glazing for emitting frequency F, and providing an anti-antenna for at least partially cancelling frequency F, connected by a bridge to the antenna and extending towards the feed point and parallel to the antenna to the end.

[0025] The present invention provides in a third aspect according to claim 15 the use of a glazing as a window, windscreen, side window, rear window or roof window of a building or vehicle. Effect of the Invention

[0026] The present invention provides a glazing having an antenna at least partially disposed on the glazing and an anti-antenna for at least partially cancelling a frequency F due to an electronic device on or near the glazing. The present invention is highly advantageous because the signal at the feed point of the antenna is filtered by the anti-antenna to cancel interference, thereby improving the signal to noise ratio of an external circuit connected to the feed point.

[0027] The prior art does not disclose an anti-antenna that extends from a bridge toward a feed point, parallel to the antenna, to an end. The bridge connects the anti-antenna to a branch point of the antenna. By extending toward the feed point, the technical disadvantage of the antenna's end being far from the feed point is overcome. Surprisingly, the present invention provides an antenna with an end close to the feed point as part of the anti-antenna for canceling frequency F, and an end far from the feed point for receiving other frequencies.

[0028] The invention provides a method for manufacturing a glazing with the surprising step of extending an anti-antenna towards the feed point in order to cancel the frequency F. This method avoids the step of providing alternative signal processing components at the feed point or in external circuits.

[0029] The use of glazing according to the invention in buildings and vehicles is advantageous because standard external circuits, e.g. amplifiers, can be connected to the power supply point and less effort is required for signal processing to suppress electromagnetic interference from other electronic devices in use. [Brief description of the drawings]

[0030] [Figure 1] FIG. 2 is a plan view of a glazing according to the present invention with an antenna and an anti-antenna on the glazing and an electronic device near the glazing. [Diagram 2] FIG. 2 is a plan view of a glazing according to the invention with an antenna partly on the glazing and partly on the connector, with an anti-antenna on the connector. [Diagram 3] FIG. 3 is a plan view of a glazing according to the invention similar to FIG. 2, with an anti-antenna on the glazing. [Figure 4] FIG. 4 is a plan view of a glazing according to the invention similar to FIG. 3, in which the electronic device is a second antenna on the glazing. [Figure 5A] FIG. 5 is a cross-sectional view of a glazing according to the invention similar to FIGS. 1 to 4, in which the glazing is laminated glass. [Figure 5B] FIG. 5 is a cross-sectional view of a glazing according to the invention similar to FIGS. 1 to 4, in which the glazing is laminated glass. [Figure 6] FIG. 5 is a cross-sectional view of a glazing according to the invention similar to FIGS. 1 to 4, in which the glazing is monolithic glass. [Figure 7] FIG. 5 is a plan view of a glazing according to the invention similar to FIG. 4, in which the antenna and the second antenna have a complex shape; [Figure 8]1 is a graph of radiation efficiency (dB) versus frequency (GHz) for comparative example C-Ex and an embodiment of the invention having a gap G of 3 mm. [Figure 9] 1 is a graph of radiation efficiency (dB) versus frequency (GHz) for three embodiments of the present invention having gaps G of 3 mm, 2 mm, and 1 mm, respectively. [Figure 10] 1 is a graph of radiation efficiency (dB) versus frequency (GHz) for an embodiment of the present invention having a length of 100 mm. [Figure 11] 1 is a graph of radiation efficiency (dB) versus frequency (GHz) for an embodiment of the present invention having a length of 80 mm. [Figure 12] 1 is a graph of radiation efficiency (dB) versus frequency (GHz) for an embodiment of the present invention having a length of 60 mm. [Figure 13] 1 is a graph of radiation efficiency (dB) versus frequency (GHz) for an embodiment of the present invention having a length of 40 mm. [Figure 14] 14 is a graph of radiation efficiency (dB) versus frequency (GHz) for four embodiments of the present invention shown individually in FIGS. 10, 11, 12 and 13, with anti-antenna lengths of 100 mm, 80 mm, 60 mm and 40 mm, respectively. [Figure 15] FIG. 3 is a plan view of a glazing according to the invention similar to FIG. 2, in which the anti-antenna has a complex shape. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0031] The description of the invention will now be given with reference to the drawings in which like reference numbers are used, in which: Embodiments of the invention are illustrated by way of non-limiting examples, in which:

[0032] Figure 1 discloses a glazing 10 comprising a ply of glazing material 11. An antenna 1 is disposed on the ply of glazing material 11 and comprises a feed point 3 at one end for connection to an external circuit 20. An electronic device 2 is located on or near the glazing 10 for emitting a frequency F. An anti-antenna 5 for at least partially cancelling the frequency F is connected to the antenna 1 by a bridge 6 and extends parallel to the antenna 1 towards the feed point 3 to an end 7.

[0033] The anti-antenna 5 has a length A from the bridge 6 to the end 7. A distance B is from the end 7 to the feed point 3. A gap G is between the antenna 1 and the anti-antenna 5. The electronic device 2 may be a second antenna 2 having a second feed point 4 and a length A'. The electronic device (2) may be part of a building or part of a vehicle, for example on the bumper or roof.

[0034] The anti-antenna 5 may have a length A from the bridge 6 to the end 7 that, when divided by a first shortening factor K1 of the anti-antenna 5, is equal to an odd integer multiple of a quarter wavelength in free space at frequency F ±25%.

[0035] The second antenna 2 may have a length A' and a feed point 4, where the length A' divided by a second shortening factor K2 of the second antenna 2 is an odd multiple of a quarter wavelength in free space at frequency F ±25%.

[0036] The distance B from the feed point 3 to the end 7 divided by the third shortening factor K3 between the feed point 3 and the end 7 is a multiple of a half wavelength in free space at the frequency F ±25%.

[0037] Figure 2 discloses a glazing 10 similar to that of figure 1, except that the antenna 1 is partially disposed on the ply 11 of glazing material and partially disposed on the connector 8. A connection point 9 serves to connect a portion of the antenna 1 on the connector 8 with a portion of the antenna 1 on the ply 11 of glazing material. A feed point 3 is on the connector 8 and connects to an external circuit 20, which may be on the window frame of a building or the body of a vehicle. An anti-antenna 5 for at least partially cancelling the frequency F is located on the connector 8, is connected to the antenna 1 by a bridge 6 and extends parallel to the antenna 1 towards the feed point 3 to an end 7.

[0038] FIG. 3 discloses a glazing 10 similar to FIG. 2, except that an anti-antenna 5 for at least partially cancelling the frequency F is located on a ply 11 of glazing material, connected to the antenna 1 by a bridge 6 and extends parallel to the antenna 1 towards the feed point 3 to an end 7.

[0039] Figure 4 discloses a glazing 10 similar to that of figure 3, except that the electronic device 2 is a second antenna 2, located on the glazing 10. The shortening factors K1, K2 of the antenna 1 and the second antenna 2 are similar in this embodiment, and therefore the lengths A, A' are also similar.

[0040] Figure 5A discloses a cross section along line XX of a glazing 10 similar to Figure 4, where a first ply 11 of glazing material is joined to a second ply 12 of glazing material by a ply 13 of interlayer material to form a laminated glass, and antenna 1 is an embedded wire. Figure 5B is similar to Figure 5A, but antenna 1 is printed on surface 4 and numbered from the outside.

[0041] FIG. 6 discloses a cross-section along line XX of a glass (10) similar to that of FIG. 4, in which the first ply of glazing material 11 is a monolithic (single ply) of tempered glass.

[0042] FIG. 7 discloses a glazing 10 similar to that of FIG. 4, except that the antenna 1 and the second antenna 2 have a complex shape.

[0043] For example, antenna 1 may extend away from feed point 3 through multiple inflection points. Figure 7 shows three inflection points: connection point 9, a point between connection point 9 and end 7 of anti-antenna 5, and a branch point where bridge 6 connects to antenna 1. EXAMPLES

[0044] (Example 1 and Comparative Example) Examples of the present invention will be described below. The present invention is not limited to these examples. Comparative examples will also be described.

[0045] FIG. 8 shows the radiation performance of a comparative example (C-Ex) of a glazing 10 with a monopole antenna 1 and of an example 1 according to the invention further comprising an anti-antenna 5 and a gap G of 3 mm.

[0046] The antenna 1 has a length equivalent to 0.725 m in free space. For the comparative example (C-Ex) and example 1, the lowest frequency at which the peak radiation efficiency occurs is when the length is a quarter wavelength, i.e., the wavelength is 2.900 m and the frequency is 103 MHz, i.e., FM radio waves.

[0047] For the comparative example (C-Ex), a similar peak radiation efficiency also occurs at a harmonic frequency of about 720 MHz. The harmonic frequency peak is undesirable because the LTE signal transmitted by the electronic device 2, e.g. a cellular phone antenna, will be received as interference at the feed point 3 of the antenna 1. The LTE band is nominally 700 MHz. User equipment transmits from 703 to 748 MHz and receives from 758 to 803 MHz.

[0048] Example 1 includes an anti-antenna 5 having a length A equivalent to 0.100 m in free space. The lowest frequency at which resonance occurs in the anti-antenna 5 is when the length A is a quarter of the wavelength, i.e., the wavelength is 0.400 m and the frequency is 750 MHz.

[0049] The anti-antenna 5, located adjacent to the antenna 1 and separated therefrom by a gap G of 3 mm, causes a peak attenuation of the radiation efficiency of -22 dB at 720 MHz. The attenuation occurs from 630 to 810 MHz, i.e. the filter bandwidth is 180 MHz.

[0050] (Examples 2 and 3) FIG. 9 discloses the radiation efficiency (dB) of Example 1, Example 2 and Example 3 having gaps G of 3 mm, 2 mm and 1 mm, respectively.

[0051] The narrower the gap G, the stronger the attenuation. In Example 3 with a gap G of 1 mm, the radiation efficiency drops to -29 dB.

[0052] As the gap G becomes narrower, the attenuation occurs in a narrower frequency range. In the third embodiment, the attenuation occurs between 690 and 810 MHz, i.e., the filter bandwidth is 120 MHz.

[0053] Due to its narrow bandwidth, anti-antenna 5 has no effect on FM / DAB / TV.

[0054] (Examples 4, 5, 6 and 7) The set of four examples uses a ply 11 of glazing material with a thickness of 3.15 mm and an antenna 1 deposited as a silver print with a thickness of 0.01 mm, width 1 mm and length 0.7 m. An anti-antenna 5 is placed parallel to it with a gap G of 10 mm.

[0055] 10, 11, 12 and 13 disclose examples 4, 5, 6 and 7, respectively, in which the length A of the anti-antenna is 100 mm, 80 mm, 60 mm and 40 mm, respectively.

[0056] FIG. 14 shows four examples together to assist in selecting a suitable length A for a given frequency F to be filtered. For example, the digital TV band is nominally 800 MHz, but the user equipment receives 791-821 MHz. To attenuate the interference from the digital TV, an anti-antenna length A of 40 mm should be selected to achieve an attenuation of -15 dB.

[0057] When 40 mm is selected (Example 7), the individual graphs in FIG. 13 confirm that the anti-antenna has no effect on FM radio (88-108 MHz) or DAB (174-240 MHz).

[0058] When the TV transmission is 750 to 800 MHz, from FIG. 14 it can be estimated that the anti-antenna length A is about 50 mm, which is intermediate between 60 mm (590 to 720 MHz, Example 6) and 40 mm (760 to 1,000 MHz, Example 7).

[0059] The length A depends on the dielectric constant of the ply 11 of glazing material or the connector 8 that serves as the substrate for the anti-antenna 5. To create a sample, the first shortening factor K1 may be estimated as 0.7 for tempered glass, 0.6 for laminated glass, or 0.5 for coated glass using laser-etched lines. The sample should be tested in an anechoic chamber to measure the actual filtered frequency. To create a prototype, the actual filtered frequency should be compared with a given frequency F and length A, shortened or lengthened according to the revised estimate of the first shortening factor K1. Similar estimations and tests may be used for the length A', distance B and the corresponding second and third shortening factors K2, K3 of the second antenna 2.

[0060] Example 8 Example 8 is the laminated glazing 10 of Figure 1. The distance B from the edge 7 to the feed point 3 divided by the third shortening factor K3 is n multiples of half wavelength in free space of frequency F ±25%, where n is any integer (0, 1, 2...). To attenuate the LTE signal, the distance B is 125 mm, which when divided by 0.6 is 208 mm, the full wavelength is 0.416 m, i.e. a frequency of 720 MHz.

[0061] (Multiple anti-antennas) There may be provided on the antenna 1 a number of anti-antennas 5, each having a length A1, A2 etc. which cancels a given frequency F1, F2 etc. This is advantageous for filtering out a number of undesired frequencies at the feed point 3 to the amplifier 20.

[0062] (Anti-antenna with complex shape) FIG. 15 discloses a glazing 10 similar to that of FIG. 2, except that the anti-antenna 5 has a complex shape that corresponds to the complex shape of the antenna 1.

[0063] WO2017194961 (Baranski), which is incorporated by reference, discloses glazing with multiple bend points where the antenna forms a complex shape over the connector.

[0064] In Figure 15, the antenna 1 comprises a connector (8) which extends from a feed point 3 on a ply 11 of a first glazing material to a connection point 9. According to the invention, an anti-antenna 5 is located on the connector 8, having a bending point corresponding to the bending point of the antenna 1.

[0065] The total length of the anti-antenna 5 having a complex shape is the sum of the parts, for example the sum of two parts having lengths A1, A2. The length A1 is from the bridge 6 to the bending point. The length A2 is from the bending point to the end 7 of the anti-antenna 5. The bending point means the curved part between two straight parts. [Explanation of symbols]

[0066] 1 Antenna 2. Electronic Devices 3 Antenna feed point 4. Power supply points for electronic devices 5. Anti-antenna 6 Bridge 7 Anti-antenna end 8 Connectors 9 Connection points 10 Glazing 11 First ply of glazing material 12 Second ply of glazing material 13 Ply of intermediate layer material 15 Frames 20 External circuit A Anti-antenna length Length of A1 section Length of A2 section A' Length of electronic device B Distance from the feed point to the end of the anti-antenna F is the frequency emitted by an electronic device G Gap between antenna and anti-antenna K1 First shortening factor K2 Second shortening factor K3 Third shortening factor

Claims

1. A glazing 10, A ply 11 of glazing material; an antenna 1 at least partially disposed on a ply 11 of glazing material and provided at one end with a feed point 3 for connection to an external circuit 20; an electronic device 2 located on or near the glazing 10 for emitting a frequency F; Equipped with an anti-antenna 5 connected to the antenna 1 by a bridge 6 and for at least partially cancelling a frequency F extending parallel to the antenna 1 towards the feeding point 3 to an end 7; Equipped with The anti-antenna 5 is a filter that cancels interference from the electronic device 2 at the frequency F. Glazing 10.

2. 2. The glazing 10 according to claim 1, wherein the length A from the bridge 6 to the end 7 divided by the first shortening coefficient K1 of the anti-antenna 5 is an odd integer multiple of a quarter wavelength in free space of the frequency F + / - 25%.

3. 2. The glazing 10 of claim 1, wherein the electronic device 2 is a second antenna having a length A' and a feed point 4, wherein the length A' divided by a second shortening factor (K2) of the second antenna is an odd integer multiple of a quarter wavelength in free space of the frequency F + / - 25%.

4. A glazing 10 as claimed in any one of claims 1 to 3, wherein the distance B from the feed point 3 to the end 7 divided by a third shortening coefficient K3 between the feed point 3 and the end 7 is a multiple of a half wavelength in free space of the frequency F + / - 25%.

5. Glazing 10 as described in any one of claims 1 to 4, wherein the multiple anti-antennas 5 are multiple filters for canceling interference from multiple electronic devices 2 at multiple frequencies F.

6. The glazing 10 according to claim 2, wherein the length A is between 300 and 500 mm, preferably between 360 and 450 mm for FM functionality or between 50 and 70 mm, preferably between 60 and 65 mm for LTE functionality.

7. Glazing according to any one of claims 1 to 6, wherein the gap G between the antenna and the anti-antenna is 20 mm to 40 mm, preferably 28 mm to 32 mm, for FM functionality, or the gap G between the antenna 1 and the anti-antenna 5 is 1 to 6 mm, preferably 3 to 4 mm, for LTE functionality.

8. A glazing as claimed in any one of the preceding claims, wherein the antenna (1) further comprises a connector (8) extending from the feed point (3) to a connection point (9) on a first ply (11) of the glazing material.

9. The glazing according to claim 8, wherein the connector (8) is a flat cable, and the anti-antenna (5) and the bridge (6) are arranged on the flat cable (8).

10. The glazing (10) according to any one of claims 1 to 9, wherein the external circuit (20) comprises an amplifier connected to the power supply point (3) and located on or near the glazing (10).

11. The glazing (10) according to claim 3, wherein the second antenna (2) is arranged on a vehicle bumper or on a vehicle roof.

12. A glazing according to any one of the preceding claims, wherein the first ply of glazing material (11) is toughened glass.

13. 13. The glazing of any one of claims 1 to 12, further comprising a second ply of glazing material (12) joined to the first ply of glazing material (11) by a ply of interlayer material (13) to form laminated glass.

14. Providing a ply of glazing material 11; Positioning an antenna 1 at least partially on said ply of glazing material 11, said antenna 1 comprising: The antenna 1 has a power supply point 3 at its end for connection to an external circuit 20. - placing an antenna 1 at least partially on said ply 11 of glazing material; - placing an electronic device 2 on or near said glazing 10 for emitting a frequency F; Including, providing an anti-antenna 5 connected to the antenna 1 by a bridge 6 for at least partially cancelling a frequency F extending to an end 7 in parallel with the antenna 1 towards the feed point 3, A method for producing the glazing (10) of claim 1.

15. Use of a glazing 10 according to claim 1 as a window, windscreen, side window, rear window or roof window in a building or vehicle.

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