PATCH ANTENNA FOR MULTI-LAYERED GLASS
Patent Information
- Authority / Receiving Office
- MX · MX
- Patent Type
- Patents
- Current Assignee / Owner
- PITTSBURGH GLASS WORKS LLC
- Filing Date
- 2022-06-02
- Publication Date
- 2026-06-12
Smart Images
Figure MX434634B0 
Figure MX434634B1
Abstract
Description
PATCH ANTENNA FOR MULTI-LAYERED GLASS TECHNICAL FIELD The invention described herein relates to a patch antenna and, more particularly, to a multi-layered patch antenna that is embedded in a laminated window glass and receives and / or transmits electromagnetic signals for connected communications in the vehicle. BACKGROUND OF THE INVENTION In automotive glazing such as windshields and tinted windows, antennas for receiving and / or transmitting radio frequency waves, such as AM, FM, TV, DAB, RKE, etc., are frequently found or integrated into the glazing. These antennas are formed by imprinting conductive lines, such as silver or copper, onto a transparent glazing material, or by laminating metal wires or strips between layers of transparent material in the vehicle's glazing. These antennas provide aerodynamic performance advantages for the vehicle as well as an aesthetically pleasing, streamlined appearance. In recent years, the automotive industry has developed vehicles capable of communicating via radio frequency signals and other communication channels. These vehicles are sometimes referred to as connected vehicles. New vehicle models offer an ever-increasing list of optional features, such as enhanced safety features and dedicated short-range communication radios (DSRCs) for vehicle-to-vehicle (V2V) and vehicle-to-infrastructure (V2I) communications. Currently, the automotive industry is transitioning from assisted driving to autonomous driving. Each new vehicle connection—whether cellular, WLAN, or DSRC—requires an antenna that supports the respective communication channel. In some cases, up to six antennas may be needed for cellular service and another six DSRC antennas for V2V and V2I communications.Designing antennas that can fit within the available space in vehicles presents a significant challenge. Integrating them. - 6 laminated glazing comprising an inner transparent layer 34 and an outer transparent layer 30. The transparent layers may be made of glass. The inner layer 34 and the outer layer 30 are bonded together by an interleaved extract 36. Preferably, the interleaved extract 36 is made of polyvinyl butyral or a similar material. The outer layer 30 has an outer surface 130 (conventionally referred to as surface number 1) that defines the exterior or outward-facing surface of the windscreen 12. The outer layer also defines an inner surface 132 (conventionally referred to as surface number 2) that is positioned opposite the outer layer 30 from the outer surface 130.The inner layer 34 has an outer surface 134 (conventionally referred to as surface number 3) that is oriented away from the passenger compartment of the vehicle and is oriented inward in the glazing unit 12 such that it is an opposing inner surface 132 of the outer transparent layer 30. The inner transparent layer 34 also defines an inner surface 136 (conventionally referred to as surface number 4) that defines the inside of the inward-facing surface of the glazing unit 12 such that it is oriented inward toward the passenger compartment of the vehicle. The gap 36 is located between surfaces 132 and 134. As shown in Figures 1 and 2, the glazing 20 may include a concealment band 32, such as a paint band applied to the outer layer 30 by opaque ink screen printing around the perimeter of the outer layer 30 surface 132 and subsequently burned off. The concealment band 32 has a closed inner edge 38 that defines the boundary of the daylight opening (DLO) of the glazing 12. The concealment band 32 is sufficiently wide to cover the described windshield antenna elements as well as any other equipment included near the outer perimeter of the glazing 12, as shown and described below. The glazing 12 further includes a first conductive layer 22 and a second conductive layer 24. The first conductive layer 22 is placed on the concealment strip 32 over the surface 132 of the outer layer 30, and the second conductive layer 24 is placed over the surface 136 of the inner layer 34. The second layer - The conductive layer 24 is substantially parallel to and separated from the first conductive layer 22. The intercalation 36 and the inner layer 34 act as a dielectric substrate for the first conductive layer 22 and the second conductive layer 24. The first conductive layer 22 and the second conductive layer 24 can be implemented in other ways, which are further illustrated herein by way of example. The conductive layers 22 and 24 can consist of conductive paint, metallic film deposited by electrodeposition or vapor deposition, and a silver paste mesh bonded to a non-conductive panel. Alternatively, the conductive layers 22 and 24 can be formed on the surfaces of single-layer non-conductive glass, such as a tempered glass window, or on other surfaces of any layer in a transparent, multi-layered laminated material of glass or plastic. The conductive layers 22 and 24 can also be bonded to the surfaces of the non-conductive body panel, such as an interior or exterior fiberglass panel. The first conductive layer 22 is sometimes referred to as a patch. In the described mode, the patch (conductive layer 22) is the main radiating element of the antenna. The first conductive layer 22 can have any given profile shape, such as rectangular, circular, triangular, or elliptical. In the example of the described mode, a rectangular profile shape is preferred. The second conductive layer 24 acts as a grounded electrical plane. The first conductive layer 22 cooperates with the second conductive layer 24, the interlayer 36, and the inner layer 34 to define a patch antenna. The second conductive layer 24 further defines a slot 42. The slot 42 can have various profile shapes, such as a straight, L-shaped, or U-shaped slot. Power is electromagnetically coupled through the slot 42 in the second conductive layer 24.The slot 42 is preferably oriented with respect to the center of the first conductive layer 22 because this is the location of the patch antenna's maximum magnetic field. For maximum coupling, the slot 42 is preferably parallel to the two radiating edges 46 and 48 of the first conductive layer 22, as illustrated in Figure 5. The patch antenna described with the electromagnetic coupling slot 42 is advantageous in that it eliminates the need for a feed hole in the windscreen 12. - 8 the antenna. The manufacture of vehicle glazing and other perforated glass windows involves difficulties in terms of cost, performance and reliability. When slot 42 is excited by electromagnetic waves, the electric field distribution in slot 42 can be described by a set of orthogonal modes. When slot 42 is relatively large and narrow, the electric field amplitudes of the modes have sinusoidal periodicity with an integer multiple of the slot length, as shown in Figure 6. For a relatively large and narrow slot, a set of these modes may be excited preferentially to the others. The operating frequency is also a consequence. Figure 6 illustrates the electric field distribution amplitude of the odd-numbered modes (specifically, TE10 and TE30) at their maximum value at the center of slot 42. Conversely, the even-numbered modes (specifically, TE20 and TE40) reach their minimum value at the center of slot 42.When slot 42 is excited in the middle, TE10 and TE30 modes are at their maximum value and therefore provide strong coupling for these modes. At the same time, TE20 and TE40 modes are at their minimum value, so the coupling to these modes is close to zero. With reference to Figure 3, the described patch antenna is fed by a microstrip line 44 etched into the bottom of a thin substrate 40. The patch antenna is driven by two very similar coupling mechanisms: one coupling mechanism between the microstrip line 44 and the slot 42, and a second coupling mechanism between the slot 42 and the first conductive layer 22. The characteristic impedance and width of the microstrip line 44 affect the electromagnetic coupling to the slot 42. For maximum coupling, the microstrip line 44 is oriented with respect to the slot 42 such that its longitudinal dimension is perpendicular to the longitudinal centerline of the slot 42, which is defined as the midpoint between the long lateral edges of the slot 42.When the microstrip line 44 is skewed away from the right-angle orientation (i.e., the microstrip line 44 forms an oblique angle) with respect to the longitudinal center line of the groove 42 or when the microstrip line 44 is. - 9 located near one end of slot 42 (i.e., one end of slot 42 width formed between the larger sides) compared to the opposite end, reduces the coupling to the fundamental TE 10 mode of the patch antenna. The patch antenna currently described includes an additional antenna feed substrate 40. Due to the curvature of the windscreen layers 30 and 34, the windscreen may not readily accommodate the antenna feed substrate 40. Furthermore, the first conductive layer 22 is embedded within the windscreen and, for improved aesthetics, is often covered by a hiding band 32, which makes the preferred alignment between the microstrip line 44 and the first conductive layer 22 more difficult. Therefore, other designs may sometimes be preferable due to cost and ease of commercial manufacturing. An alternative preferred embodiment is shown in Figure 4. In the embodiment of Figure 4, the patch antenna is fed directly through the coupling slot 42 using a coaxial cable 50 having a center conductor 54 and an outer jacket 52. The center conductor 54 extends over the slot 42 and is galvanically connected to the far side of the slot 42 at a solder pad 56 on the second conductive layer 24. The outer jacket 52 is galvanically connected to the near side of the slot 42 at a solder pad 58 on the second conductive layer 24. The coaxial cable 50 and the slot 42 transmit electromagnetic energy to the first conductive layer 22 and receive electromagnetic energy from the first conductive layer 22.One advantage of the currently described invention is that it combines the advantageous electrical characteristics of the antenna with physical constituent parts of the antenna that can be more easily incorporated into current windshield designs or other transparent material designs using existing manufacturing processes. Another advantage of the currently described antenna is that it is more easily and conveniently connected by conductive connections to electronic circuitry external to the antenna. Figure 7 illustrates another preferred patch antenna and includes illustrative dimensions for the mode. The first conductive layer 22, the second conductive layer 24, and the slot 42 are all sized relative to the dimensions. - 10 listed in Figure 2. The length Lp of the first conductive layer 22 determines the resonant frequency of the patch antenna. The width Wp of the first conductive layer 22 alters the resonant resistance of the patch antenna, with a wider patch producing lower resistance. The patch antenna's matching level is primarily determined by the total length Ls = Ls1 + Ls2 + Ls3 of the U-shaped matching slot 42, as well as the backradiation level. Therefore, the slot 42 is no longer required for impedance matching. The width Ws of the slot 42 also alters the matching level, but to a much lesser degree than the slot length Ls. A preferred ratio of slot width (Ws) to length (Ls) is typically 1 / 10. A variant of the patch antenna shown in Figures 4 through 7, with dimensions specified in Figure 8, was fabricated on a convertible vehicle windshield as shown in Figure 9. The patch antenna is located at the bottom of the third viewing area of the windshield. Figure 10 is a graph comparing the return loss (Sil) between actual measured results and simulation results obtained using the FEKO simulation tool. Of the energy supplied to the antenna, the return loss (Sil) is a measure of the amount of energy reflected from the antenna and the amount received and radiated. Figure 10 shows that the return loss is less than -10 dB in the 5.1 to 6.1 GHz frequency range. This means that the antenna can be used in UNII, ISM, IEEE 802.11, and 802.11.1 lac, radio local area networks (RLAN), fixed wireless access systems (FWA), WiMAX and MESH wireless networks from 5.18 to 5.85 GHz as well as the DSRC band from 5.85 to 5.925 GHz. The vehicle antenna gain pattern is measured over an external antenna span. Figure 11 shows the vehicle antenna radiation pattern for vertical polarization at frequencies of 5.3 GHz, 5.6 GHz, and 5.85 GHz, respectively. The elevation angle is -5°. The maximum gain of the patch antenna is approximately 0 dBi, and it is directed toward the front of the vehicle. The average beamwidth in the azimuth plane is approximately 70°. Figure 12 shows the radiation pattern of the vehicle antenna -11 for vertical polarization at an elevation angle of 0°. The maximum patch antenna gain is approximately 3 dBi and is directed towards the front of the vehicle. A patch antenna embedded in the windshield, at a greater elevation angle, results in a wider beamwidth, with maximum gain. Therefore, data is only shown at elevation angles of 0° to -5°. Antenna gain and beamwidth also depend on the angle of the windshield relative to the vehicle. The antenna will perform better on a vertical windshield than on one that is tilted away from the vertical plane. The windshield antenna provides better coverage in the direction of the vehicle when facing forward (10) compared to the rear or side directions.The antenna can be embedded in the windshield, rear window and side windows by a variety of systems with an omnidirectional far-field radiation pattern in the ground direction. Although several preferred embodiments of the described invention have been shown and presented in this document, those skilled in the field 15 will recognize that various modifications can be adopted without departing from the spirit of the described invention, as set forth in the following claims.
Claims
1. A glazing including a patch antenna, characterized in that it comprises: an inner transparent layer having first and second surfaces positioned oppositely; an outer transparent layer having first and second surfaces positioned oppositely; an interlayer located between the first surface of the inner transparent layer and the second surface of the outer transparent layer; a first conductive extract defining an outer perimeter edge, the first conductive extract being located between the second surface of the outer transparent layer and the interlayer;a second conductive extract located on the second surface of the inner transparent layer, the second conductive extract defining an outer perimeter edge and also defining an opening located within the outer perimeter edge of the second conductive substrate, the second conductive substrate is laterally aligned with respect to the first conductive substrate such that the outer perimeter edge of the first conductive substrate aligns within the outer perimeter of the second conductive substrate and also such that the opening of the second conductive substrate aligns within the outer perimeter edge of the first conductive substrate, the opening of the second conductive substrate is separated from the first conductive substrate such that electrical signals applied to the edges of the opening are electromagnetically coupled to the first conductive substrate.
2. The glazing according to claim 1, characterized in that the first conductive substrate is the main radiating element of the patch antenna.
3. The glazing according to claim 2, characterized in that the second conductive substrate is the grounded electrical element of the patch antenna.
4. The glazing according to claim 2, characterized in that the interlayer and the inner transparent layer form a dielectric substrate for the patch antenna.
5. The glazing according to claim 1, characterized in that the opening of the second conductive substrate is laterally aligned with respect to the first conductive substrate such that the center of the opening is aligned with the center of the first conductive substrate.
6. The glazing according to claim 5, characterized in that the maximum electromagnetic field in the opening of the second conductive substrate occurs at the center of the opening and wherein the maximum magnetic field of the first conductive substrate occurs at the center of the first conductive layer.
7. The glazing according to claim 5, characterized in that the energy is electromagnetically coupled between the opening of the second conductive substrate and that of the first conductive substrate.
8. The glazing according to claim 5, characterized in that the opening of the second conductive substrate is a slot having a length equal to half the wavelength in the fundamental frequency mode TE 10.
9. The glazing according to claim 8, characterized in that the groove is rectangular, L-shaped or U-shaped.
10. The glazing according to claim 8, characterized in that the groove supports a set of orthogonally oriented even and odd modes.
11. The glazing according to claim 10, characterized in that the odd modes have a maximum field strength that occurs at the center of the slot.
12. The glazing according to claim 8, characterized in that the patch antenna includes a coaxial cable having a central conductor that is surrounded by an outer sheath with the outer sheath of the coaxial cable being connected to one side of the slot and the central conductor of the coaxial cable is - 14 connected to the opposite side of the slot.
13. The glazing according to claim 12, characterized in that the coaxial cable and the slot transmit electromagnetic energy to the first conductive layer and receive electromagnetic energy from the first conductive layer.
14. The glazing according to claim 1, characterized in that the length of the first conductive layer determines the resonant frequency of the patch antenna and the width of the first conductive layer affects the resonant resistance of the patch antenna.
15. The glazing according to claim 8 characterized in that the length of the slot determines the coupling level and the backradiation level of the patch antenna.
16. The glazing according to claim 2 characterized in that the patch antenna bandwidth covers Wi-Fi under the IEEE 802.1 la / ac standard from 5.18 to 5.85 GHz and the DSRC band from 5.85 to 5.925 GHz.
17. The glazing according to claim 2, characterized in that the patch antenna is fed by a microstrip line that is etched onto a substrate located on the second side of the inner transparency layer.
18. The glazing according to claim 17, characterized in that the patch antenna is excited through two coupling stages, one coupling stage between the microstrip line and the slot and another coupling stage between the slot and the first conductive layer.
19. The glazing according to claim 18, characterized in that the characteristic impedance of the microstrip line and the width of the microstrip line affect the coupling with the groove.
20. The glazing according to claim 18, characterized in that the microstrip line is oriented at right angles to the center line of the groove.
21. The glazing according to claim 2, characterized in that the patch antenna is embedded in a windshield, a rear window or a side window to produce a diversity antenna system having an omnidirectional ground-directed far-field radiation pattern.