Redirection structure for electromagnetic waves

Abstract

A redirection structure (1) for electromagnetic waves includes a multilayer structure (2) and at least one antenna element (7). The multilayer structure (2) includes a first conductive element (3), a conductive substrate (5), and a dielectric substrate (6), the dielectric substrate being disposed between the first conductive element (3) and the conductive substrate (5) to form a waveguide. The antenna element (7) is disposed near the edge of the multilayer structure (2) at an interface (I), and the electromagnetic wave propagates at least partially in the waveguide (6) along a first direction (D1). The redirection structure (1) also includes at least one dielectric cavity (8) disposed along the first direction (D1) at a predetermined distance (X) from the interface (I). The dielectric cavity (8) extends at least partially through the conductive substrate (5) in a second direction (D2) away from the dielectric substrate (6). This enables the use of a 5G mmWave common-mode display-side antenna.

Description

Technical Field

[0001] The present invention relates to a redirection structure for electromagnetic waves, the redirection structure comprising a multilayer structure and at least one antenna element for transmitting electromagnetic waves. Background Technology

[0002] Mobile electronic devices such as smartphones and tablets must support an increasing number of radio signal technologies, including 5G radio technology. For 5G, the frequency range is in the so-called millimeter-wave (mmWave) frequency range, which is approximately between 30 and 300 GHz.

[0003] However, millimeter-wave antennas are currently incompatible with organic light-emitting diode (OLED) display panels, which are commonly used in mobile electronic devices. A typical implementation of an OLED panel consists of an OLED layer disposed between an indium tin oxide (ITO) layer and an electromagnetic interference (EMI) layer. The EMI layer, used to prevent electromagnetic interference, is typically composed of conductive metal strips. The OLED layer also includes metal, and a dielectric substrate lies between the OLED layer and the EMI layer. If an mmWave antenna is embedded next to a display, an electric field (e-field) will be generated between the OLED layer and the EMI layer. In other words, the energy of the millimeter waves emitted by the mmWave antenna will be partially absorbed between the OLED layer and the EMI layer; this portion of the emitted energy is effectively lost from the far field of the mmWave antenna. For example, a common-mode mmWave antenna will produce significant energy leakage between the OLED layer and the EMI strip, potentially causing a 2-5 dB decrease in the efficiency of the display-side mmWave antenna. This efficiency decrease will affect the mmWave antenna in both the transmit and receive directions.

[0004] Theoretically, this leakage can be eliminated by removing the gap between the OLED layer and the EMI strip, for example, by replacing the dielectric substrate current-closing gap with a copper strip or conductive coating. However, this could negatively impact the operation of the OLED panel, and proper shielding may be difficult to achieve. Therefore, this is not practically useful.

[0005] Another solution is to implement a high impedance surface (HIS). HIS has been used in the antenna field for many years to prevent surface waves from propagating on ground planes or metal sheets. Smooth conductive sheets have low surface impedance, but high surface impedance can be achieved by changing their geometry or adding ripples to them. Therefore, the propagation of surface waves on the surface can be stopped.

[0006] However, current HIS solutions cannot be directly implemented on devices with OLED panels without negatively impacting the performance and reliability of the OLED panels. Summary of the Invention

[0007] The objective is to provide an improved electromagnetic wave redirection structure. The above and other objectives are achieved through the features of the independent claims. Other implementations will be apparent from the dependent claims, the specification, and the drawings.

[0008] According to a first aspect, a redirection structure for electromagnetic waves is provided, comprising a multilayer structure including a first conductive element, a conductive substrate, and a dielectric substrate, the dielectric substrate being disposed between the first conductive element and the conductive substrate to form a waveguide. The redirection structure further includes at least one antenna element for emitting electromagnetic waves having a wavelength, the antenna element being disposed near an edge of the multilayer structure at an interface, and the electromagnetic waves propagating at least partially in the waveguide along a first direction. Furthermore, the redirection structure includes at least one dielectric cavity disposed along the first direction at a predetermined distance from the interface, the dielectric cavity extending in a second direction perpendicular to the first direction and extending at least partially through the conductive substrate away from the dielectric substrate.

[0009] This structure helps prevent destructive electromagnetic waves from propagating through channels existing between conductive elements of a device, such as between a display and the frame of a smartphone. Electromagnetic waves propagating through these channels at mmWave frequencies, i.e., energy leakage, can lead to undesirable degradation of the radiation direction and power loss. Furthermore, this structure eliminates the need for current grounding of conductive elements such as the display, thereby reducing the risk of hot spots and heat-related issues in the display. Additionally, current grounding can be unreliable, and its location can be critical to the antenna structure itself. This solution allows electromagnetic waves to be redirected, maximizing the antenna's pointing in the desired direction. The dielectric cavity of the redirection structure prevents, for example, mmWave signals from propagating between conductive elements and the conductive substrate, and is suitable for many types of antennas, not just mmWave antennas. This enables the use of, for example, 5G mmWave common-mode display-side antennas.

[0010] In one possible implementation of the first aspect, the redirection structure further includes a second conductive element disposed between the dielectric substrate and the conductive substrate, the dielectric cavity extending through the second conductive element in a second direction. This allows the dielectric cavity to be formed within an existing component, such that the redirection structure does not require a specific separate component.

[0011] In another possible implementation of the first aspect, the dielectric substrate comprises a dielectric material with a dielectric constant Dk between 1 and 4, the dielectric material allowing the dielectric substrate to be part of a multilayer structure, for example, an OLED panel.

[0012] In another possible implementation of the first aspect, the distance is less than 2λ, thereby reducing the amount of leaked energy.

[0013] In another possible implementation of the first aspect, the distance is... and This significantly reduces the amount of energy leakage, thereby improving performance and allowing for a wide operating range.

[0014] In another possible implementation of the first aspect, the dielectric cavity has a width in the first direction, the width being less than 2λ, to avoid poor performance at 40 GHz.

[0015] In another possible implementation of the first aspect, the dielectric cavity has a width between λ / 2 and λ / 5 in the first direction, thereby providing optimal performance and a wide operating range.

[0016] In another possible implementation of the first aspect, the dielectric cavity has a height in the second direction, said height being at least 0.1 mm, preferably 0.5 mm or less. This allows for efficient redirection while keeping the height of the structure as low as possible, so that the internal dimensions of the device including the structure remain unaffected by the structure.

[0017] In another possible implementation of the first aspect, the surface forming the dielectric cavity is straight in a plane perpendicular to the second direction, which helps to improve beam steering or beam tilting.

[0018] In another possible implementation of the first aspect, the surface forming the dielectric cavity is bent in a plane perpendicular to the second direction, which helps to improve beam steering or beam tilting.

[0019] In another possible implementation of the first aspect, the first conductive element, the second conductive element, and the dielectric substrate are a display panel, optionally part of an OLED panel. The solution addresses the energy leakage problem without requiring modification to the display panel itself.

[0020] In yet another possible implementation of the first aspect, the first conductive element is an OLED layer, optionally a thin-film transistor layer. This allows for the use of a thin and simple display while still achieving the desired redirection function.

[0021] In another possible implementation of the first aspect, the second conductive element is an electromagnetic interference layer. This allows for redirection to be formed from existing components, avoiding the need for additional components specifically designed for redirection.

[0022] In another possible implementation of the first aspect, the conductive substrate is a printed circuit board, a liquid crystal polymer printed circuit board, or another element disposed between the dielectric substrate and one of the printed circuit board and the liquid crystal polymer printed circuit board. This facilitates the redirection of electromagnetic waves without requiring more components than existing components.

[0023] In another possible implementation of the first aspect, the other element is a conductive gasket or foam, allowing commonly used components to form part of the redirection structure.

[0024] In yet another possible implementation of the first aspect, the dielectric cavity is partially formed by vertical interconnect pathways extending within the printed circuit board or the liquid crystal polymer printed circuit board.

[0025] In another possible implementation of the first aspect, the electromagnetic wave is in the frequency range of 10 to 300 GHz and has a wavelength of 1 to 30 mm.

[0026] In another possible implementation of the first aspect, the dielectric cavity forms an impedance discontinuity, and the waveguide has a first impedance adjacent to a conductive material segment of the second conductive element or the conductive material segment of the conductive substrate, and a second impedance adjacent to the dielectric cavity, the second impedance being greater than the first impedance. The second impedance causes most of the electromagnetic waves to be reflected back to the antenna array.

[0027] In another possible implementation of the first aspect, the impedance discontinuity reflects the electromagnetic waves propagating in the waveguide back to the antenna array, thereby reducing the electric field generated in the waveguide.

[0028] In another possible implementation of the first aspect, the redirection structure includes a first dielectric cavity arranged along the first direction at a first predetermined distance from the interface; and at least one second dielectric cavity arranged along the first direction at a second predetermined distance from the interface, the first dielectric cavity and the second dielectric cavity being separated by a conductive material segment of the conductive substrate and optionally a conductive material segment of the second conductive element, thereby enabling multi-band or broadband operation.

[0029] In another possible implementation of the first aspect, the first dielectric cavity and the second dielectric cavity have the same or different widths or heights, allowing for maximum flexibility.

[0030] According to a second aspect, an apparatus is provided, comprising a redirection structure, a display, and a frame according to the above, wherein a first conductive element, a second conductive element, and a dielectric substrate of the redirection structure are part of the display, the frame includes at least a peripheral frame segment that at least partially surrounds a peripheral edge of the display, and an antenna array of the redirection structure is disposed between the peripheral frame segment and the peripheral edge of the display.

[0031] In such a device, destructive radiation fields are prevented from propagating through channels, such as those existing between the display and the device's frame. This, in turn, prevents undesirable degradation of the radiation direction and power loss. Furthermore, it reduces the risk of hot spots in the display and heat-related problems. The device can include many types of antennas, not just mmWave antennas.

[0032] These and other aspects will be apparent from the embodiments described below. Attached Figure Description

[0033] In the following detailed sections of the invention, aspects, embodiments, and implementations will be explained in more detail with reference to the examples shown in the accompanying drawings, in which:

[0034] Figure 1 A schematic side view of an example redirection structure according to an embodiment of the present invention is shown;

[0035] Figure 2 A schematic side view of an example redirection structure according to an embodiment of the present invention is shown;

[0036] Figure 3 A partial cross-sectional view of an example of a redirection structure according to an embodiment of the present invention is shown;

[0037] Figure 4a and 4b A top perspective view and a bottom perspective view of an example device according to an embodiment of the present invention are shown;

[0038] Figure 5a and 5b A schematic top view of the dielectric cavity of an example of a redirection structure according to an embodiment of the present invention is shown;

[0039] Figure 6 A schematic cross-sectional view of an example of a multilayer structure according to an embodiment of the present invention is shown. Detailed Implementation

[0040] Figures 1 to 3Different examples of a redirection structure 1 for electromagnetic waves are shown, including a multilayer structure 2, at least one antenna element 7, and at least one dielectric cavity 8. Several antenna elements 7 can be arranged in an antenna array. Several antenna arrays can be provided, such as two, as shown below. Figure 4a and 4b As shown in the figure. Electromagnetic waves can be in the frequency range of 10 to 300 GHz and have a wavelength λ of 1 to 30 mm.

[0041] The redirection structure 1 for electromagnetic waves includes a multilayer structure 2, which includes a first conductive element 3, a conductive substrate 5, and a dielectric substrate 6. The dielectric substrate 6 is disposed between the first conductive element 3 and the conductive substrate 5 and forms a waveguide. At least one antenna element 7 is used to transmit electromagnetic waves having a wavelength λ. The antenna element 7 is disposed at an interface I adjacent to the edge of the multilayer structure 2, and the electromagnetic waves propagate at least partially in the waveguide 6 along a first direction D1. At least one dielectric cavity 8 is disposed along the first direction D1 at a predetermined distance X from the interface I. The dielectric cavity 8 extends in a second direction D2, perpendicular to the first direction D1, and extends at least partially through the conductive substrate 5 away from the dielectric substrate 6.

[0042] Antenna element 7 or antenna array is used to transmit electromagnetic waves with wavelength λ when the wave propagates through a substrate such as dielectric substrate 6, which will be discussed further below. Antenna element 7 or antenna array is arranged at interface I near the edge of multilayer structure 2, as follows: Figure 1 and 2 As shown in the image.

[0043] The electromagnetic wave propagates in waveguide 6 at least partially along the first direction D1, which is the direction that reduces the performance of antenna element 7 or antenna array. This is also known as energy leakage.

[0044] The multilayer structure 2 includes a first conductive element 3, a conductive substrate 5, and a dielectric substrate 6. The dielectric substrate 6 is disposed between the first conductive element 3 and the conductive substrate 5 and forms a waveguide for electromagnetic waves. The dielectric substrate 6 may have a dielectric constant Dk between 1 and 4. Furthermore, the dielectric substrate 6 may include a foam or adhesive material.

[0045] The conductive substrate 5 can be a printed circuit board 5a or a liquid crystal polymer printed circuit board 5b, such as... Figure 1 As shown. The conductive substrate can also be as follows. Figure 2Another element 5c is shown, disposed between the dielectric substrate 6 and one of the printed circuit boards (PCBs) or liquid crystal polymer (LCD) PCBs. In other words, the conductive substrate 5 can be either the PCB 5a or the LCD PCB 5b, or connected to either PCB 5a or the LCD PCB 5b. The other element 5c can be a conductive gasket or foam. For example, a gasket made of tape is used to attach the display panel to the PCB or the LCD PCB. The thickness of the gasket is typically 0.125 to 0.5 mm.

[0046] At least one dielectric cavity 8 is arranged along a first direction D1 at a predetermined distance X from the interface I. The dielectric cavity 8 needs to be located at a certain distance away from the edge of the antenna element 7 or the antenna array. The distance X can be less than twice the wavelength, i.e., 2λ, and is preferably located at... and between.

[0047] The dielectric cavity 8 has a height, extending in a second direction D2 perpendicular to the first direction D1. The dielectric cavity 8 is located away from the dielectric substrate 6, extending from the bottom of the dielectric substrate 6 and at least partially passing through the conductive substrate 5, i.e., forming a recess or opening in the conductive substrate 5. This prevents the dielectric cavity 8 from affecting the performance or reliability of the first conductive element 3.

[0048] The dielectric cavity 8 creates an impedance discontinuity. Waveguide 6 has a first impedance in the adjacent waveguide region, for example, as described above. Figures 1 to 3 As shown, "adjacent" refers to the conductive material segment of the conductive substrate 5 and, optionally, the conductive material segment of the second conductive element 4. The waveguide 6 also has a second impedance in the adjacent waveguide region, for example, as described above. Figures 1 to 3 As shown, "proximity" refers to dielectric cavity 8. The second impedance is greater than the first impedance. This difference in impedance creates an impedance discontinuity that partially reflects electromagnetic waves propagating in waveguide 6 back to antenna array 7, thereby reducing the electric field in waveguide 6 and thus reducing absorption loss. The actual values ​​of the first and second impedances depend on dielectric substrate 6, and particularly on the height of dielectric substrate 6.

[0049] The dielectric cavity 8 may be partially formed by vertical interconnect pathways extending within the printed circuit board 5a or the liquid crystal polymer printed circuit board 5b.

[0050] The dielectric cavity 8 may have a width W in the first direction D1, which is less than 2λ, preferably between λ / 2 and λ / 5. Furthermore, the dielectric cavity 8 may have a height H in the second direction D2, which is at least 0.1 mm, preferably 0.5 mm or less.

[0051] like Figure 5a and 5bAs shown, the surface forming the dielectric cavity 8 can be straight and / or curved in a plane perpendicular to the second direction D2.

[0052] like Figure 3 As shown, the redirection structure 1 may include: a first dielectric cavity 8a disposed along a first direction D1 at a first predetermined distance X1 from the interface I; and at least one second dielectric cavity 8b disposed along the first direction D1 at a second predetermined distance X2 from the interface I. "At least one second dielectric cavity" refers to any suitable number of dielectric cavities. The first dielectric cavity 8a and the second dielectric cavity 8b are separated by a conductive material segment of the conductive substrate 5, and optionally by a conductive material segment of the second conductive element 4.

[0053] The first dielectric cavity 8a and the second dielectric cavity 8b may have the same or different widths W1, W2 and / or heights H1, H2.

[0054] like Figures 1 to 3 As shown, the redirection structure may further include a second conductive element 4 disposed between the dielectric substrate 6 and the conductive substrate 5. In these examples of the redirection structure, the dielectric cavity 8 extends not only partially through the conductive substrate 5 in the second direction D2, but also through the second conductive element 4. That is, the dielectric cavity 8 forms an opening in the second conductive element 4. The second conductive element 4 may be an electromagnetic interference layer, such as a metal strip made of copper. The electromagnetic interference layer is used to prevent electromagnetic interference.

[0055] The first conductive element 3, the second conductive element 4, and the dielectric substrate 6 can be a display panel, optionally as follows: Figure 6 This is a portion of the OLED panel shown. The first conductive element 3 may be an OLED layer, including metal and optionally a thin-film transistor layer. The OLED panel may include additional dielectric layers, such as an OLED polarizer, OLED black band, OLED EMBO, OLED pad, OLED PI, and one or more optically clear adhesives. The OLED panel may also include a glass cover layer for forming an outer protective surface of the OLED panel.

[0056] Figure 4a and 4b An apparatus 9 is shown, including the aforementioned redirection structure 1, a display 10, and a frame 11. The first conductive element 3, the second conductive element 4, and the dielectric substrate 6 of the redirection structure 1 are part of the display 10. The frame 11 includes at least a peripheral frame segment that at least partially surrounds the peripheral edge of the display 10, and the antenna element 7 or antenna array of the redirection structure 1 is arranged between the peripheral frame segment and the peripheral edge of the display 10.

[0057] This document has described various aspects and implementations in conjunction with various embodiments. However, those skilled in the art, upon studying the accompanying drawings, disclosure, and appended claims, will be able to understand and implement other variations of the disclosed embodiments in practicing the claimed subject matter. In the claims, the word "comprising" does not exclude other elements or steps, and "a" or "an" does not exclude a plurality. The enumeration of certain measures in dissimilar dependent claims does not imply that combinations of these measures cannot be used advantageously.

[0058] The reference numerals used in the claims should not be construed as limiting the scope. Unless otherwise stated, the drawings (e.g., cross shading, component arrangements, scale, degrees, etc.) should be read in conjunction with the specification and should be considered an integral part of the entire written description of the invention. As used in the description, the terms “horizontal,” “vertical,” “left,” “right,” “up,” and “down,” and their adjective and adverbial derivatives (e.g., “horizontally,” “to the right,” “up,” etc.) simply refer to the orientation of the illustrated structure when the particular drawing is facing the reader. Similarly, the terms “inward” and “outward” generally refer to the orientation of a surface relative to its axis of elongation or axis of rotation, as appropriate.

Claims

1. A redirection structure (1) for electromagnetic waves, characterized in that, include - A multilayer structure (2) comprising a first conductive element (3), a conductive substrate (5), and a dielectric substrate (6), The dielectric substrate (6) is disposed between the first conductive element (3) and the conductive substrate (5) and forms a waveguide; - At least one antenna element (7) for transmitting electromagnetic waves with wavelength λ, The antenna element (7) is arranged near the edge of the multilayer structure (2) at interface I. The electromagnetic wave propagates at least partially in the waveguide along the first direction D1; - At least one dielectric cavity (8) is arranged along the first direction D1 at a predetermined distance X from the interface I. The dielectric cavity (8) extends in the second direction D2, perpendicular to the first direction D1, and at least partially through the conductive substrate (5) away from the dielectric substrate (6). The redirection structure (1) further includes a second conductive element (4) disposed between the dielectric substrate (6) and the conductive substrate (5), and the dielectric cavity (8) extends through the second conductive element (4) in the second direction D2.

2. The redirection structure (1) according to claim 1, characterized in that, The dielectric substrate (6) comprises a dielectric material with a dielectric constant Dk between 1 and 4.

3. The redirection structure (1) according to claim 2, characterized in that, The distance X is less than 2λ.

4. The redirection structure (1) according to claim 3, characterized in that, The distance X is in and between.

5. The redirection structure (1) according to any one of claims 1-4, characterized in that, The dielectric cavity (8) has a width W in the first direction D1, and the width W is less than 2λ.

6. The redirection structure (1) according to claim 5, characterized in that, The width W is between λ / 2 and λ / 5.

7. The redirection structure (1) according to any one of claims 1-4, characterized in that, The surface forming the dielectric cavity (8) is straight in a plane perpendicular to the second direction D2.

8. The redirection structure (1) according to any one of claims 1-4, characterized in that, The surface forming the dielectric cavity (8) is curved in a plane perpendicular to the second direction D2.

9. The redirection structure (1) according to any one of claims 1-4, characterized in that, The first conductive element (3) and the dielectric substrate (6) are part of the display panel.

10. The redirection structure (1) according to any one of claims 1-4, characterized in that, The first conductive element (3) is an OLED layer.

11. The redirection structure (1) according to claim 10, characterized in that, The first conductive element (3) is a thin-film transistor layer.

12. The redirection structure (1) according to any one of claims 1-4, characterized in that, The second conductive element (4) is an electromagnetic interference layer.

13. The redirection structure (1) according to any one of claims 1-4, characterized in that, The conductive substrate (5) is a printed circuit board (5a), a liquid crystal polymer printed circuit board (5b), or another element (5c) disposed between the dielectric substrate (6) and one of the printed circuit board and the liquid crystal polymer printed circuit board.

14. The redirection structure (1) according to claim 13, characterized in that, The other element (5c) is a conductive gasket or foam.

15. The redirection structure (1) according to claim 13, characterized in that, The dielectric cavity (8) is partially formed by vertical interconnect pathways extending within the printed circuit board (5a) or the liquid crystal polymer printed circuit board (5b).

16. The redirection structure (1) according to any one of claims 1-4, characterized in that, The dielectric cavity (8) forms an impedance discontinuity, and the waveguide has a first impedance adjacent to a conductive material segment of the second conductive element (4) or a conductive material segment of the conductive substrate (5), and a second impedance adjacent to the dielectric cavity (8), the second impedance being greater than the first impedance.

17. The redirection structure (1) according to any one of claims 1-4, characterized in that, include: The first dielectric cavity (8a) is arranged along the first direction D1 at a first predetermined distance X1 from the interface I. At least one second dielectric cavity (8b) is arranged along the first direction D1 at a second predetermined distance X2 from the interface I. The first dielectric cavity (8a) and the second dielectric cavity (8b) are separated by a conductive material segment of the conductive substrate (5) and optionally a conductive material segment of the second conductive element (4).

18. The redirection structure (1) according to claim 17, characterized in that, The first dielectric cavity (8a) and the second dielectric cavity (8b) have the same or different widths or heights.

19. An apparatus (9), characterized in that, Including the redirection structure (1), display (10), and frame (11) according to any one of claims 1 to 18, The first conductive element (3), the second conductive element (4), and the dielectric substrate (6) of the redirection structure (1) are part of the display (10). The frame (11) includes at least a peripheral frame segment that at least partially surrounds the peripheral edge of the display (10). The antenna element (7) of the redirection structure (1) is arranged between the peripheral frame segment and the peripheral edge of the display (10).

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