Patent Publication Number: US-2023163443-A1

Title: Light-transmitting antenna

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application claims the priority benefits of U.S. Provisional Application Ser. No. 63/278,071, filed on Nov. 10, 2021 and Taiwan application serial no. 111137587, filed on Oct. 3, 2022. The entirety of each of the above-mentioned patent applications is hereby incorporated by reference herein and made a part of this specification. 
    
    
     TECHNICAL FIELD 
     The disclosure relates to an antenna, and also relates to a light-transmitting antenna. 
     BACKGROUND 
     Currently, the relay technology is gradually adopted in the wireless communication technology to improve the wireless communication coverage area, group mobility, cell-edge throughput of base stations and provision of temporary network deployment. In the 5th generation (5G) communication system, in order to improve the coverage of signals, it is better to dispose the base stations on the middle floor of the building, rather than on the roof far from the ground. However, the urban environment is complex, and it is extremely difficult to find a place to install the antenna. If the antenna may be installed on the indoor window, and the coverage may be improved through the glass, the light-transmitting and inconspicuous design of the light-transmitting antenna is both beautiful and functional, which may save a lot of trouble of site selection and site installation. Of course, the performance of the light-transmitting antenna also directly affects the user experience of the wireless network. 
     SUMMARY 
     According to the embodiment of the disclosure, a light-transmitting antenna is provided, which has better performance. 
     According to the embodiment of the disclosure, the light-transmitting antenna includes a substrate, a first conductive pattern, and a second conductive pattern. The substrate has a first surface and a second surface opposite to each other. The first conductive pattern is disposed on the first surface, and includes a first feeder unit, a first radiation unit, a first coupling unit, a first parasitic unit, a second radiation unit, and a second coupling unit. The first feeder unit is connected to the second radiation unit. The first radiation unit and the second radiation unit are located between the first coupling unit and the second coupling unit. One side of the first parasitic unit is connected to the second coupling unit. The other side the first parasitic unit is adjacent to the first coupling unit. The second conductive pattern is disposed on the second surface, and includes a second feeder unit, a third coupling unit, a second parasitic unit, and a fourth coupling unit. An orthographic projection of the second feeder unit on the first surface overlaps the first feeder unit, the first radiation unit, and the second radiation unit. An orthographic projection of the third coupling unit on the first surface overlaps the first coupling unit. An orthographic projection of the fourth coupling unit on the first surface overlaps the second coupling unit. An orthographic projection of the second parasitic unit on the first surface overlaps the first parasitic unit. One side of the second parasitic unit is connected to the fourth coupling unit. The other side of the second parasitic unit is adjacent to the third coupling unit. 
     Based on the above, the light-transmitting antenna according to the embodiment of the disclosure has the characteristics of broadband, high gain, and multiple frequencies. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG.  1    is a schematic perspective view of a light-transmitting antenna according to an embodiment of the disclosure. 
         FIG.  2    is a schematic view of a first conductive pattern of the light-transmitting antenna of  FIG.  1   . 
         FIG.  3    is a schematic view of a second conductive pattern of the light-transmitting antenna of  FIG.  1   . 
         FIG.  4    is a schematic view of a conductive area of an electromagnetic wave reflector of the light-transmitting antenna of  FIG.  1   . 
         FIG.  5    is a schematic partial view of the first conductive pattern of the light-transmitting antenna of  FIG.  1   . 
         FIG.  6    is a schematic partial cross-sectional view of the first conductive pattern of the light-transmitting antenna of  FIG.  1   . 
         FIG.  7    is a schematic perspective view of a light-transmitting antenna according to another embodiment of the disclosure. 
         FIG.  8    is a schematic perspective view of a light-transmitting antenna according to still another embodiment of the disclosure. 
     
    
    
     DETAILED DESCRIPTION OF DISCLOSED EMBODIMENTS 
       FIG.  1    is a schematic perspective view of a light-transmitting antenna according to an embodiment of the disclosure. Referring to  FIG.  1   , a light-transmitting antenna  100  of this embodiment includes a substrate  110 , a first conductive pattern  120 , and a second conductive pattern  130 . The substrate  110  has a first surface  112  and a second surface  114  opposite to each other. The first conductive pattern  120  is disposed on the first surface  112 , and includes a first feeder unit  120 A, a first radiation unit  120 B, a first coupling unit  120 D, a first parasitic unit  120 E, a second radiation unit  120 C, and a second coupling unit  120 F. The first feeder unit  120 A is connected to the second radiation unit  120 C. The first radiation unit  120 B and the second radiation unit  120 C are located between the first coupling unit  120 D and the second coupling unit  120 F. One side of the first parasitic unit  120 E is connected to the second coupling unit  120 F. The other side of the first parasitic unit  120 E is adjacent to the first coupling unit  120 D. The second conductive pattern  130  is disposed on the second surface  114 , and includes a second feeder unit  130 A, a third coupling unit  130 B, a second parasitic unit  130 C, and a fourth coupling unit  130 D. An orthographic projection of the second feeder unit  130 A on the first surface  112  overlaps the first feeder unit  120 A, the first radiation unit  120 B, and the second radiation unit  120 C. An orthographic projection of the third coupling unit  130 B on the first surface  112  overlaps the first coupling unit  120 D. An orthographic projection of the fourth coupling unit  130 D on the first surface  112  overlaps the second coupling unit  120 F. An orthographic projection of the second parasitic unit  130 C on the first surface  112  overlaps the first parasitic unit  120 E. One side of the second parasitic unit  130 C is connected to the fourth coupling unit  130 D. The other side of the second parasitic unit  130 C is adjacent to the third coupling unit  130 B. 
     In the light-transmitting antenna  100  of this embodiment, the first feeder unit  120 A of the first conductive pattern  120  and the second feeder unit  130 A of the second conductive pattern  130  are coupled to each other, so that a signal may be fed in by capacitive feeding. In addition, both the first conductive pattern  120  and the second conductive pattern  130  have high light transmittance, which are adapted to be installed indoors to improve coverage of an indoor network, avoid cable signal loss when the antenna is installed outdoors and pulled into a room with a long cable, and also do not affect indoor lighting and maintain the aesthetics. In addition, the light-transmitting antenna  100  of this embodiment has characteristics such as full-plane currents, multiple frequencies, narrow beams, and high gain. 
     In this embodiment, the substrate  110  has no conductive through holes. That is, the light-transmitting antenna  100  is not required to be provided with the conductive through hole that shields the light, but uses the first feeder unit  120 A and the second feeder unit  130 A to pull a signal feeding position to an edge of the substrate  110 , so as to avoid an opaque spot in a central area of the light-transmitting antenna  100 , which does not affect the line of sight and maintain the aesthetics. In this embodiment, the light-transmitting antenna  100  may further include a feeder  150 . The first feeder unit  120 A and the second feeder unit  130 A are respectively electrically connected to the feeder  150  at the edge of the substrate  110 . 
     In this embodiment, the substrate  110  includes a first substrate  110 A and a second substrate  110 B that are stacked with each other. A surface of the first substrate  110 A facing away from the second substrate  110 B is the first surface  112 . A surface of the second substrate  110 B facing away from the first substrate  110 A is the second surface  114 . The first substrate  110 A and the second substrate  110 B are stacked with each other, for example, in direct contact with each other without a gap substantially. Under this architecture, the first conductive pattern  120  may be formed on the first substrate  110 A by a single-sided process, and the second conductive pattern  130  may also be formed on the second substrate  110 B by the single-sided process. The overall process cost is low, and the yield is high. 
     In this embodiment, the light-transmitting antenna  100  further includes an electromagnetic wave reflector  140  that is stacked with the substrate  110  at a distance. That is, the electromagnetic wave reflector  140  is stacked with the substrate  110 , but keeps a distance from each other. Since the electromagnetic wave reflector  140  is disposed, the electromagnetic wave reflector  140  has functions of electromagnetic wave reflection and shielding, which may improve directivity of the antenna, and may further isolate the environmental influence. In this embodiment, the light-transmitting antenna  100  has an operating wavelength. A distance D 10  between the electromagnetic wave reflector  140  and the substrate  110  is, for example, between 0.25 times and 2 times the operating wavelength. For example, the distance D 10  between the electromagnetic wave reflector  140  and the substrate  110  may be 3 cm. 
     In this embodiment, the second conductive pattern  130  is located between the first conductive pattern  120  and the electromagnetic wave reflector  140 . However, in other embodiments, the first conductive pattern  120  may also be located between the second conductive pattern  130  and the electromagnetic wave reflector  140 . 
       FIG.  2    is a schematic view of the first conductive pattern  120  of the light-transmitting antenna  100  of  FIG.  1   . Referring to  FIG.  2   , in this embodiment, the first radiation unit  120 B and the second radiation unit  120 C are trapezoidal. In addition, the first coupling unit  120 D and the second coupling unit  120 F may also be trapezoidal. In this embodiment, two base angles of the trapezoids of the radiation units are not equal, but the disclosure is not limited thereto. The first radiation unit  120 B is not connected to the first coupling unit  120 D, and the second radiation unit  120 C is also not connected to the second coupling unit  120 F. The first radiation unit  120 B is located between the second radiation unit  120 C and the first coupling unit  120 D. The second radiation unit  120 C is located between the first radiation unit  120 B and the second coupling unit  120 F. 
     In this embodiment, a shape of the first radiation unit  120 B and a shape of the second radiation unit  120 C are line-symmetrical patterns with a boundary line L 10  therebetween as a symmetrical line. In this embodiment, although the shape of the first radiation unit  120 B is not completely line-symmetrical to the shape of the second radiation unit  120 C because the second radiation unit  120 C has a small gap in the middle, the shape of the first radiation unit  120 B is still substantially line-symmetrical to the shape of the second radiation unit  120 C. In this embodiment, a shape of the first coupling unit  120 D and a shape of the second coupling unit  120 F are line-symmetrical patterns with the boundary line L 10  therebetween as the symmetrical line. Similarly, the shape of the first coupling unit  120 D and the shape of the second coupling unit  120 F is not required to be completely line-symmetrical, and may only be substantially line-symmetrical. In addition, in this embodiment, the shape of the first radiation unit  120 B is substantially the same as the shape of the first coupling unit  120 D, but the disclosure is not limited thereto. 
     In this embodiment, the first conductive pattern  120  further has a third parasitic unit  120 G. The third parasitic unit  120 G is connected to the first coupling unit  120 D. The other side of the first parasitic unit  120 E is adjacent to the first coupling unit  120 D and the third parasitic unit  120 G. 
       FIG.  3    is a schematic view of the second conductive pattern  130  of the light-transmitting antenna  100  of  FIG.  1   . Referring to  FIGS.  2  and  3   , in this embodiment, the third coupling unit  130 B and the fourth coupling unit  130 D are trapezoidal. In this embodiment, two base angles of the trapezoids of the radiation units are not equal, but the disclosure is not limited thereto. In this embodiment, the second conductive pattern  130  further has a fourth parasitic unit  130 E. The fourth parasitic unit  130 E is connected to the third coupling unit  130 B. The other side of the second parasitic unit  130 C is adjacent to the third coupling unit  130 B and the fourth parasitic unit  130 E. An orthographic projection of the fourth parasitic unit  130 E on the first surface  112  overlaps the third parasitic unit  120 G. 
       FIG.  4    is a schematic view of a conductive area  142  of the electromagnetic wave reflector  140  of the light-transmitting antenna of  FIG.  1   . Referring to  FIGS.  1  and  4   , in this embodiment, the electromagnetic wave reflector  140  has the conductive area  142 . Orthographic projections of the second conductive pattern  130  and the first conductive pattern  120  on the electromagnetic wave reflector  140  all fall on the conductive area  142 . Of course, portions at edges of the first feeder unit  120 A and the second feeder unit  130 A may not fall on the conductive area  142 . 
     The following data are obtained after simulation with the light-transmitting antenna  100  of  FIGS.  1  and  2   . Dimensions of the three substrates are all 100 mm×100 mm. A thickness of the conductive pattern is 0.7 mm. The distance between the electromagnetic wave reflector  140  and the substrate  110  is 3 cm. A length of one side of the second feeder unit  130 A close to the fourth coupling unit  130 D is 51 mm, and a length of one side of the second feeder unit  130 A close to the third coupling unit  130 B is 25 mm. Front-back ratios of the light-transmitting antenna  100  at 1.8 GHz, 2.1 GHz, and 3.5 GHz are 21.9 dB, 52.07 dB, and 3330.4 dB, respectively. Peak gains of the light-transmitting antenna  100  at the XZ section and the YZ section at 1.8 GHz are 7.92 dB and 7.96 dB, respectively. The peak gains of the light-transmitting antenna  100  at the XZ section and the YZ section at 2.1 GHz are 7.15 dB and 7.2 dB, respectively. The peak gains of the light-transmitting antenna  100  at the XZ section and the YZ section at 3.5 GHz are 6.28 dB and 8.13 dB, respectively. An available frequency of the light-transmitting antenna  100  in the vicinity of 1.8 GHz is between 1.6 GHz and 2.2 GHz, and a converted antenna bandwidth is 32%, that is, it has a broadband characteristic. The available frequency of the light-transmitting antenna  100  in the vicinity of 3.5 GHz is between 1.2 GHz and 4.4 GHz, and the converted antenna bandwidth is 32%, that is, it has the broadband characteristic. 
       FIG.  5    is a schematic partial view of the first conductive pattern of the light-transmitting antenna of  FIG.  1   . Referring to  FIGS.  1  and  5   , in this embodiment, the first conductive pattern  120  and the second conductive pattern  130  are mesh metal. That is to say, within a range of the first conductive pattern  120  and the second conductive pattern  130  seen in  FIG.  1   , in an enlarged state, it may be seen that the first conductive pattern  120  and the second conductive pattern  130  are formed by the mesh metal. Therefore, the light may pass through a mesh of the mesh metal, so that the first conductive pattern  120  and the second conductive pattern  130  may transmit the light. In this embodiment, the mesh metal has a line width W 12  and a mesh width W 14 . Considering the light transmittance, the line width W 12  is, for example, between 0.05 times and 0.1 times the mesh width W 14 . In addition, if a manufacturing process is feasible, meshes of the first conductive pattern  120  and the second conductive pattern  130  may be completely overlapped as much as possible to improve the light transmittance. 
       FIG.  6    is a schematic partial cross-sectional view of the first conductive pattern  120  of the light-transmitting antenna of  FIG.  1   . Referring to  FIG.  6   , in this embodiment, the light-transmitting antenna  100  further includes a protective layer  160  covering the first conductive pattern  120  and the second conductive pattern  130 . The protective layer  160  may protect the first conductive pattern  120  and the second conductive pattern  130 . In addition, by properly selecting a material of the protective layer  160 , a function of index matching may be exerted to improve the light transmittance of the light-transmitting antenna  100 . Furthermore, the protective layer  160  may also have conductivity to reduce impedance of the overall first conductive pattern  120  and second conductive pattern  130 , thereby improving efficiency of signal transmission. When the protective layer  160  has the conductivity, the protective layer  160  does not cover the entire first surface  112  and second surface  114 . An area covered by the protective layer  160  is substantially equal to an area where the first conductive pattern  120  is distributed and an area where the second conductive pattern  130  is distributed, so as to avoid changing an appearance of the radiation unit and affecting transmission and reception of the signal. 
       FIG.  7    is a schematic perspective view of a light-transmitting antenna according to another embodiment of the disclosure. In  FIG.  7   , a dimension and scale of each element have been adjusted for convenience only, and are not actual dimensions and scales. Referring to  FIG.  7   , a light-transmitting antenna  200  of this embodiment is substantially the same as the light-transmitting antenna  100  of  FIG.  1   , and only the difference between the two is described here. A substrate  210  of this embodiment further includes an optical adhesive layer  270  disposed between the first substrate  110 A and the second substrate  110 B. The optical adhesive layer  270  may improve the accuracy of alignment of the first conductive pattern  120  and the second conductive pattern  130 . In addition, it may also improve the light transmittance of the substrate  210  to select a material with an appropriate refractive index as the optical adhesive layer  270 . The light-transmitting antenna  200  of this embodiment may further include an outer frame  280  configured to fix the electromagnetic wave reflector  140 , the first substrate  110 A, and the second substrate  110 B. 
       FIG.  8    is a schematic perspective view of a light-transmitting antenna according to still another embodiment of the disclosure. In  FIG.  8   , a dimension and scale of each element have been adjusted for convenience only, and are not actual dimensions and scales. Referring to  FIG.  8   , a light-transmitting antenna  300  of this embodiment is substantially the same as the light-transmitting antenna  100  of  FIG.  1   , and the difference is that a substrate  310  of this embodiment is a single substrate, not formed by two or more substrates. Therefore, the light transmittance of the light-transmitting antenna  300  is better. 
     Based on the above, the light-transmitting antenna of the disclosure may be installed indoors to reduce the cable signal loss, and further has the characteristics such as the full-plane currents, multiple frequencies, narrow beams, and high gain. 
     It will be apparent to those skilled in the art that various modifications and variations may be made to the structure of the disclosed embodiments without departing from the scope or spirit of the disclosure. In view of the foregoing, it is intended that the disclosure cover modifications and variations of this disclosure provided they fall within the scope of the following claims and their equivalents.