Patent Publication Number: US-2022231429-A1

Title: Antenna array, antenna device and display device including the same

Description:
CROSS-REFERENCE TO RELATED APPLICATION(S) 
     This application claims priority to Korean Patent Application No. 10-2021-0008377 filed on Jan. 20, 2021 in the Korean Intellectual Property Office (KIPO), the entire disclosure of which is incorporated by reference herein. 
     BACKGROUND 
     1. Field 
     The present invention relates to an antenna array, an antenna device and a display device including the same. 
     2. Description of the Related Art 
     Recently, according to development of the information-oriented society, wireless communication techniques such as Wi-Fi, Bluetooth, and the like are implemented, for example, in a form of smartphones by combining with display devices. In this case, an antenna may be coupled to the display device to perform a communication function. 
     Recently, with mobile communication techniques becoming more advanced, it is necessary for an antenna for performing communication in high frequency or ultra-high frequency bands to be coupled to the display device. In addition, according to development of thin, high-transparency and high-resolution display devices such as a transparent display and a flexible display, it is necessary to develop an antenna so as to also have improved transparency and flexibility. 
     As the size of a screen of the display device on which the antenna is mounted is increased, a space or area of a bezel part or light-shielding part has been decreased. In this case, the space or area in which the antenna can be embedded may also be limited. 
     Therefore, it is necessary to design an antenna capable of radiating a signal with a high antenna gain in a limited space without being viewed by a user. 
     SUMMARY 
     It is an object of the present invention to provide an antenna array, an antenna device and a display device including the same. 
     To achieve the above object, the following technical solutions are adopted in the present invention. 
     1. An antenna array including: a plurality of antenna elements arranged in a predetermined direction, wherein each antenna element includes: a first radiation body; a second radiation body disposed to be spaced apart from the first radiation body in a first direction; a third radiation body disposed to be spaced apart from the first radiation body in a second direction; a first signal pad and a second signal pad configured to supply signals to the first radiation body; a first transmission line extending in the first direction to connect the first signal pad and the first radiation body; a second transmission line extending in the second direction to connect the second signal pad and the first radiation body; a third transmission line configured to connect the first radiation body and the second radiation body; and a fourth transmission line configured to connect the first radiation body and the third radiation body. 
     2. The antenna array according to the above 1, wherein the plurality of antenna elements are arranged to share at least a portion thereof with each other. 
     3. The antenna array according to the above 2, wherein adjacent antenna elements share one radiation body with each other. 
     4. The antenna array according to the above 3, wherein the one radiation body serves as a second radiation body of one of the adjacent antenna elements and a third radiation body of the other one of the adjacent antenna elements. 
     5. The antenna array according to the above 2, further including: a bonding pad; and a ground line configured to connect the bonding pad and the radiation body shared by the adjacent antenna elements. 
     6. The antenna array according to the above 2, wherein each antenna element further includes: a first ground pad disposed around the first signal pad; and a second ground pad disposed around the second signal pad. 
     7. The antenna array according to the above 6, further comprising a ground line configured to connect the radiation body shared by the adjacent antenna elements and the first ground pad or the second ground pad. 
     8. The antenna array according to the above 1, wherein the plurality of antenna elements are arranged to be spaced apart from each other. 
     9. The antenna array according to the above 8, wherein a separation distance between the adjacent antenna elements is 0.5 mm or more. 
     10. The antenna array according to the above 8, further including: a boundary ground line disposed between the adjacent antenna elements; and a bonding pad connected to an end of the boundary ground line. 
     11. The antenna array according to the above 10, wherein the boundary ground line includes: a first segment extending in a longitudinal direction of the antenna element between the adjacent antenna elements; and a second segment connected with the first segment and surrounding the plurality of antenna elements. 
     12. The antenna array according to the above 8, wherein each antenna element further includes: a first ground pad disposed around the first signal pad; and a second ground pad disposed around the second signal pad. 
     13. The antenna array according to the above 12, further comprising a boundary ground line disposed between adjacent antenna elements. 
     14. The antenna array according to the above 13, wherein the boundary ground line includes: a first segment configured to connect a first ground pad of one of the adjacent antenna elements to a second ground pad of the other one of the adjacent antenna elements; a second segment surrounding the plurality of antenna elements; and a third segment extending between the adjacent antenna elements in the longitudinal direction of the antenna element to connect the first segment and the second segment. 
     15. The antenna array according to the above 1, wherein an angle between the first direction and the second direction is 80° to 100°. 
     16. The antenna array according to the above 1, wherein the first radiation body, the second radiation body and the third radiation body have a rhombus shape, the first transmission line and the second transmission line are connected to two adjacent sides of the first radiation body, respectively, the third transmission line connects two facing sides of the first radiation body and the second radiation body to each other; and the fourth transmission line connects two facing sides of the first radiation body and the third radiation body to each other. 
     17. The antenna array according to the above 1, wherein the first radiation body, the second radiation body and the third radiation body have a square shape, the first transmission line and the second transmission line are connected to two adjacent vertices of the first radiation body, respectively, the third transmission line connects two facing vertices of the first radiation body and the second radiation body to each other; and the fourth transmission line connects two facing vertices of the first radiation body and the third radiation body. 
     18. An antenna device including: the antenna array according to the above 1; and a flexible printed circuit board (FPCB) to which the antenna array is bonded and including a plurality of circuit wirings connected to the first signal pad and the second signal pad. 
     19. The antenna device according to the above 18, wherein the FPCB further includes: a plurality of grounds disposed at positions in which respective signal pads face each other with them interposed therebetween when the antenna array is bonded. 
     20. A display device comprising the antenna array according to the above 1 or the antenna device according to the above 18. 
     The antenna array according to an exemplary embodiment may include antenna elements in which a plurality of radiation bodies are connected in series in an extension direction of each of two transmission lines. Thereby, it is possible to implement a dual polarization antenna with improved antenna gain. 
     According to an exemplary embodiment, the antenna gain may be improved by arranging the plurality of antenna elements to be spaced apart from or overlapped with each other. 
     According to an exemplary embodiment, it is possible to reduce an occurrence of unwanted coupling between the radiation body and the ground pad by omitting the ground pad of each antenna element. 
     According to an exemplary embodiment, when arranging the plurality of antenna elements to be overlapped with each other, it is possible to reduce an occurrence of unwanted cross-coupling by connecting the radiation body shared by adjacent antenna elements to the ground. 
     According to an exemplary embodiment, when arranging the plurality of antenna elements to be spaced apart from each other, it is possible to reduce an occurrence of unwanted coupling between the adjacent antenna elements by disposing the ground line between the adjacent antenna elements. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The above and other objects, features and other advantages of the present invention will be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings, in which: 
         FIG. 1  is a schematic cross-sectional view illustrating an antenna element according to an exemplary embodiment; 
         FIG. 2  is a schematic plan view illustrating an antenna element according to an exemplary embodiment; 
         FIG. 3  is a schematic plan view illustrating an antenna element according to another exemplary embodiment; 
         FIG. 4A  to  FIG. 11  are plan views illustrating antenna arrays according to exemplary embodiments; 
         FIGS. 12 and 13  are plan views illustrating antenna devices according to exemplary embodiments; and 
         FIG. 14  is a schematic plan view illustrating a display device according to an exemplary embodiment. 
     
    
    
     DETAILED DESCRIPTION 
     Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. However, since the drawings attached to the present disclosure are only given for illustrating one of preferable various embodiments of present invention to easily understand the technical spirit of the present invention with the above-described invention, it should not be construed as limited to such a description illustrated in the drawings. 
     An antenna element described in the present disclosure may be a patch antenna or a microstrip antenna manufactured in a form of a transparent film. For example, the antenna element may be applied to electronic devices for high frequency or ultra-high frequency (e.g., 3G, 4G, 5G or more) mobile communication, Wi-Fi, Bluetooth, near field communication (NFC), global positioning system (GPS), and the like, but it is not limited thereto. Herein, the electronic device may include a mobile phone, a smart phone, a tablet, a laptop computer, a personal digital assistant (PDA), a portable multimedia player (PMP), a navigation device, an MP3 player, a digital camera, a wearable device and the like. The wearable device may include a wristwatch type, a wrist band type, a ring type, a belt type, a necklace type, an ankle band type, a thigh band type, a forearm band type wearable device or the like. However, the electronic device is not limited to the above-described example, and the wearable device is also not limited to the above-described example. In addition, the antenna element may be applied to various objects or structures such as vehicles and buildings. 
     In the following drawings, two directions which are parallel to an upper surface of a dielectric layer and cross each other perpendicularly are defined as an x-direction and a y-direction, and a direction perpendicular to the upper surface of the dielectric layer is defined as a z-direction. For example, the x-direction may correspond to a width direction of the antenna element, the y-direction may correspond to a length direction of the antenna element, and the z-direction may correspond to a thickness direction of the antenna element. 
       FIG. 1  is a schematic cross-sectional view illustrating an antenna element according to an exemplary embodiment. 
     Referring to  FIG. 1 , an antenna element  100  according to an exemplary embodiment may include a dielectric layer  110  and an antenna pattern layer  120 . 
     The dielectric layer  110  may include an insulation material having a predetermined dielectric constant. According to an embodiment, the dielectric layer  110  may include an inorganic insulation material such as glass, silicon oxide, silicon nitride, or metal oxide, or an organic insulation material such as an epoxy resin, an acrylic resin, or an imide resin. The dielectric layer  110  may function as a film substrate of the antenna element  100  on which the antenna pattern layer  120  is formed. 
     According to an embodiment, a transparent film may be provided as the dielectric layer  110 . In this case, the transparent film may include a polyester resin such as polyethylene terephthalate, polyethylene isophthalate, polyethylene naphthalate, polybutylene terephthalate, etc.; a cellulose resin such as diacetyl cellulose, triacetyl cellulose, etc.; a polycarbonate resin; an acrylic resin such as polymethyl (meth)acrylate, polyethyl (meth)acrylate, etc.; a styrene resin such as polystyrene, acrylonitrile-styrene copolymer, etc.; a polyolefm resin such as polyethylene, polypropylene, cyclic polyolefin or polyolefin having a norbomene structure, ethylene-propylene copolymer, etc.; a vinyl chloride resin; an amide resin such as nylon, aromatic polyamide; an imide resin; a polyether sulfonic resin; a sulfonic resin; a polyether ether ketone resin; a polyphenylene sulfide resin; a vinylalcohol resin; a vinylidene chloride resin; a vinylbutyral resin; an allylate resin; a polyoxymethylene resin; a thermoplastic resin such as an epoxy resin and the like. These compounds may be used alone or in combination of two or more thereof. In addition, a transparent film made of a thermosetting resin or an ultraviolet curable resin such as (meth)acrylate, urethane, acrylic urethane, epoxy, silicone, and the like may be used as the dielectric layer  110 . 
     According to an embodiment, an adhesive film such as an optically clear adhesive (OCA), an optically clear resin (OCR), and the like may also be included in the dielectric layer  110 . 
     According to an embodiment, the dielectric layer  110  may be formed in a substantial single layer, or may be formed in a multilayer structure of two or more layers. 
     Capacitance or inductance may be generated by the dielectric layer  110 , thus to adjust a frequency band which can be driven or sensed by the antenna element  100 . When the dielectric constant of the dielectric layer  110  exceeds about 12, a driving frequency is excessively reduced, such that driving of the antenna in a desired high frequency band may not be implemented. Therefore, according to an embodiment, the dielectric constant of the dielectric layer  110  may be adjusted in a range of about 1.5 to 12, and preferably about 2 to 12. Further, according to an embodiment, the dielectric layer  110  may have a thickness of 4 μm to 1000 μm so that the antenna element  100  can be driven in a desired high frequency band. However, the present invention is not limited thereto, and the dielectric constant and thickness of the dielectric layer  110  may be variously altered according to a desired frequency band. 
     According to an embodiment, an insulation layer (e.g., an encapsulation layer, a passivation layer, etc. of a display panel) inside the display device on which the antenna element  100  is mounted may be provided as the dielectric layer  110 . 
     The antenna pattern layer  120  may be disposed on an upper surface of the dielectric layer  110 . 
     The antenna pattern layer  120  may include a low resistance metal such as silver (Ag), gold (Au), copper (Cu), aluminum (Al), platinum (Pt), palladium (Pd), chromium (Cr), titanium (Ti), tungsten (W), niobium (Nb), tantalum (Ta), vanadium (V), iron (Fe), manganese (Mn), cobalt (Co), nickel (Ni), zinc (Zn), tin (Sn), molybdenum (Mo), calcium (Ca), or an alloy including at least one thereof. These may be used alone or in combination of two or more thereof. For example, the antenna pattern layer  120  may include silver (Ag) or a silver alloy (e.g., a silver-palladium-copper (APC) alloy) to implement a low resistance. As another example, the antenna pattern layer  120  may include copper (Cu) or a copper alloy (e.g., a copper-calcium (CuCa) alloy) in consideration of low resistance and fine line width patterning. 
     According to an embodiment, the antenna pattern layer  120  may include a transparent conductive oxide such as indium tin oxide (ITO), indium zinc oxide (IZO), indium zinc tin oxide (IZTO), zinc oxide (ZnOx), or copper oxide (CuO). 
     According to an embodiment, the antenna pattern layer  120  may include a lamination structure of a transparent conductive oxide layer and metal layer, for example, may have a two-layer structure of transparent conductive oxide layer-metal layer or a three-layer structure of transparent conductive oxide layer-metal layer-transparent conductive oxide layer. In this case, resistance may be reduced to improve signal transmission speed while improving flexible properties by the metal layer, and corrosion resistance and transparency may be improved by the transparent conductive oxide layer. 
     Specific details of the antenna pattern layer  120  will be described below with reference to  FIGS. 2 and 3 . 
     According to an embodiment, the antenna element  100  may further include a ground layer  130 . Since the antenna element  100  includes the ground layer  130 , vertical radiation characteristics may be implemented. 
     The ground layer  130  may be disposed on a lower surface of the dielectric layer  110 . The ground layer  130  may be overlapped with the antenna pattern layer  120  with the dielectric layer  110  interposed therebetween. For example, the ground layer  130  may be entirely overlapped with radiation bodies (see  211 ,  212  and  213  in  FIG. 2 ) of the antenna pattern layer  120 . 
     According to an embodiment, a conductive member of the display device or display panel on which the antenna element  100  is mounted may be provided as the ground layer  130 . For example, the conductive member may include electrodes or wirings such as a gate electrode, source/drain electrodes, pixel electrode, common electrode, data line, scan line, etc. of a thin film transistor (TFT) included in the display panel; and a stainless steel (SUS) plate, heat radiation sheet, digitizer, electromagnetic wave shielding layer, pressure sensor, fingerprint sensor, etc. of the display device. 
       FIG. 2  is a schematic plan view illustrating an antenna element according to an exemplary embodiment. An antenna element  200  of  FIG. 2  may be an embodiment of the antenna element  100  shown in  FIG. 1 . 
     Referring to  FIGS. 1 and 2 , the antenna element  200  according to the exemplary embodiment includes the antenna pattern layer  120  disposed on the dielectric layer  110 , and the antenna pattern layer  120  may include a first radiation body  211 , a second radiation body  212 , a third radiation body  213 , a first transmission line  221 , a second transmission line  222 , a first signal pad  231  and a second signal pad  232 . 
     The first radiation body  211  and the second radiation body  212  may receive an electric signal from the first signal pad  231 , convert it into an electromagnetic wave signal, and radiate the converted electromagnetic wave signal. In addition, the first radiation body  211  and the third radiation body  213  may receive an electric signal from the second signal pad  232 , convert it into an electromagnetic wave signal, and radiate the converted electromagnetic wave signal. 
     The first radiation body  211 , the second radiation body  212  and the third radiation body  213  may have substantially the same resonance frequency. To this end, shapes and sizes (lengths and widths) of the first radiation body  211 , the second radiation body  212  and the third radiation body  213  may be substantially the same as each other. The lengths and widths of the first radiation body  211 , the second radiation body  212  and the third radiation body  213  may be determined according to the desired resonance frequency, radiation resistance and gain. 
     According to an exemplary embodiment, the first radiation body  211 , the second radiation body  212  and the third radiation body  213  may have a rhombus shape, and may be formed in a mesh structure, a solid structure (thin film or thick film), or a structure in which the mesh structure and the solid structure are mixed. When the first radiation body  211 , the second radiation body  212  and the third radiation body  213  are formed in a mesh structure, transmittances of the first radiation body  211 , the second radiation body  212  and the third radiation body  213  may be increased, and flexibility of the antenna element  200  may be improved. Accordingly, the antenna element  200  may be effectively applied to a flexible display device. 
     The first radiation body  211  may be connected to the first signal pad  231  through the first transmission line  221  extending in a first direction  210 , and may be connected to the second signal pad  232  through the second transmission line  222  extending in a second direction  220 . Herein, the first direction  210  and the second direction  220  may be perpendicular to a thickness direction (z-direction) of the antenna element  100  and may intersect a length direction (y-direction) of the antenna element  100 . In addition, the first direction  210  and the second direction  220  may intersect each other. For example, an angle between the first direction  210  and the second direction  220  may be 80° to 100°, and preferably 90°. By forming the extension directions of the first transmission line  221  and the second transmission line  222  to be orthogonal to each other, the dual polarization antenna may be effectively implemented. 
     The second radiation body  212  may be disposed to be spaced apart from the first radiation body  211  in the first direction  210 . The second radiation body  212  may be connected to the first radiation body  211  through the third transmission line  223  extending in the first direction  210 . Thereby, the first transmission line  221 , the first radiation body  211 , the third transmission line  223  and the second radiation body  212  may form one serial power supply antenna. 
     The third radiation body  213  may be disposed to be spaced apart from the first radiation body  211  in the second direction  220 . The third radiation body  213  may be connected to the first radiation body  211  through a fourth transmission line  224  extending in the second direction  220 . Thereby, the second transmission line  222 , the first radiation body  211 , the fourth transmission line  224  and the third radiation body  213  may form another serial power supply antenna. 
     According to an exemplary embodiment, in order to reduce an interference between the first radiation body  211  and the second radiation body  212 , and an interference between the first radiation body  211  and the third radiation body  213 , a distance between a center of the first radiation body  211  and a center of the second radiation body  212 , and a distance between a center of the first radiation body  211  and a center of the third radiation body  213  may be  212  or more. 
     According to an exemplary embodiment, the second radiation body  212  and the third radiation body  213  may be formed symmetrically based on a center line CL of the first radiation body  211 . In this case, the center line CL of the first radiation body  211  may be defined as an imaginary line passing through the center of the first radiation body  211  and parallel to a longitudinal direction (y-direction) of the antenna element  200 . 
     The first transmission line  221  may connect the first signal pad  231  and the first radiation body  211 . According to an exemplary embodiment, the first transmission line  221  may be bent. For example, the first transmission line  221  may include a first segment  221   a  extending from the first signal pad  231  in the longitudinal direction (y-direction) of the antenna element  200 , and a second segment  221   b  extending from the first segment  221   a  in the first direction  210  to be connected to the first radiation body  211 . 
     The second transmission line  222  may connect the second signal pad  232  and the first radiation body  211 . According to an exemplary embodiment, the second transmission line  221  may be curved. For example, the second transmission line  222  includes a first segment  222   a  extending from the second signal pad  232  in the longitudinal direction (y-direction) of the antenna element  200 , and a second segment  222   b  extending from the first segment  222   a  in the second direction  220  to be connected to the first radiation body  211 . 
     According to an exemplary embodiment, the first transmission line  221  and the second transmission line  222  may be connected to two adjacent sides of the first radiation body  211 , respectively. In this case, the first transmission line  221  and the second transmission line  222  may be connected to the center of each side. 
     The third transmission line  223  may connect the first radiation body  211  and the second radiation body  212 . According to an exemplary embodiment, the third transmission line  223  may extend from the first radiation body  211  in the first direction  210  to be connected to the second radiation body  212 . For example, the third transmission line  223  may connect the centers of two facing sides of the first radiation body  211  and the second radiation body  212  to each other. 
     The fourth transmission line  224  may connect the first radiation body  211  and the third radiation body  213 . According to an exemplary embodiment, the fourth transmission line  224  may extend from the first radiation body  211  in the second direction  220  to be connected to the third radiation body  213 . For example, the fourth transmission line  224  may connect the centers of two facing sides of the first radiation body  211  and the third radiation body  213  to each other. 
     According to an exemplary embodiment, the first transmission line  221 , the second transmission line  222 , the third transmission line  223  and the fourth transmission line  224  may include substantially the same conductive material as the first radiation body  211 , the second radiation body  212  and the third radiation body  213 . In addition, the first transmission line  221 , the second transmission line  222 , the third transmission line  223  and the fourth transmission line  224  may be integrally connected to the first radiation body  211 , the second radiation body  212  and the third radiation body  213  to be formed as a substantial single member, or may be formed as a separate member from the first radiation body  211 , the second radiation body  212  and the third radiation body  213 . 
     According to an exemplary embodiment, the first transmission line  221 , the second transmission line  222 , the third transmission line  223  and the fourth transmission line  224  may be formed in a mesh structure, a solid structure (thin film or thick film), or a structure in which the mesh structure and the solid structure are mixed. 
     According to an exemplary embodiment, the first transmission line  221  and the second transmission line  222  may be formed symmetrically based on the center line CL of the first radiation body  211 . In addition, the third transmission line  223  and the fourth transmission line  224  may be formed symmetrically based on the center line CL of the first radiation body  211 . 
     The first signal pad  231  may be connected to the first transmission line  221  and may be electrically connected to the first radiation body  211  through the first transmission line  221 . The second signal pad  232  may be connected to the second transmission line  222  and may be electrically connected to the first radiation body  211  through the second transmission line  222 . Thereby, the first signal pad  231  and the second signal pad  232  may electrically connect an antenna driving unit (e.g., a radio frequency integrated circuit (RFIC), etc.) and the first radiation body  211 , respectively. For example, a flexible printed circuit board (FPCB) is bonded to the first signal pad  231  and the second signal pad  232 , and a circuit wiring of the FPCB may be electrically connected to the first signal pad  231  and the second signal pad  232 . For example, the first signal pad  231  and the second signal pad  232  may be electrically connected to the FPCB using an anisotropic conductive film (ACF) bonding technique, which is a bonding method that allows electrical conduction up and down and insulates left and right using an anisotropic conductive film (ACF), or using a coaxial cable, but it is not limited thereto. The antenna driving unit may be mounted on the FPCB or a separate printed circuit board (PCB) to be electrically connected to the circuit wiring of the FPCB. Accordingly, the first radiation body  211  and the antenna driving unit may be electrically connected. 
     According to an exemplary embodiment, the first signal pad  231  and the second signal pad  232  may include substantially the same conductive material as the first transmission line  221  and the second transmission line  222 . In addition, the first signal pad  231  and the second signal pad  232  may be integrally connected to the first transmission line  221  and the second transmission line  222  to be formed as a substantial single member, respectively, or may be formed as separate members from the first transmission line  221  and the second transmission line  222 . 
     According to an exemplary embodiment, the first signal pad  231  and the second signal pad  232  may be formed in a solid structure. In addition, the first signal pad  231  and the second signal pad  232  may be formed symmetrically based on the center line CL of the first radiation body  211 . 
     According to an exemplary embodiment, the antenna pattern layer  120  may further include a first ground pad  241  and a second ground pad  242 . 
     The first ground pad  241  may be disposed around the first signal pad  231  to be electrically and physically spaced apart from the first signal pad  231 . For example, the first ground pad  241  may include two first ground pads  241   a  and  241   b  which are disposed to face each other with the first signal pad  231  interposed therebetween. 
     The second ground pad  242  may be disposed around the second signal pad  232  to be electrically and physically spaced apart from the second signal pad  232 . For example, the second ground pad  242  may include two second ground pads  242   a  and  242   b  disposed to face each other with the second signal pad  232  interposed therebetween. 
     The first ground pad  241  and the second ground pad  242  may be formed in a solid structure including the above-described metal or alloy. 
     Meanwhile,  FIG. 2  illustrates an example in which the first transmission line  221  and the second transmission line  222  are bent, but this is only an exemplary embodiment. That is, the first transmission line  221  may include only the second segment  221   b,  and the first segment  221   a  may be included in the first signal pad  231 . Similarly, the second transmission line  222  may include only the second segment  222   b,  and the first segment  222   a  may be included in the second signal pad  232 . 
     In addition, according to an exemplary embodiment, when the antenna pattern layer  120  includes the first ground pad  241  and the second ground pad  242 , the first ground pad  241   b  and the second ground pad  242   a  may also be connected to each other to form one ground pad. 
     Further, according to an exemplary embodiment, when the radiation bodies  211 ,  212  and  213 , and the transmission lines  221 ,  222 ,  223  and  224  are formed in a mesh structure, a dummy pattern (not shown) may be formed around the radiation bodies  211 ,  212  and  213 , and the transmission lines  221 ,  222 ,  223  and  224 . The dummy pattern may be electrically and physically separated from the radiation bodies  211 ,  212  and  213 , and the transmission lines  221 ,  222 ,  223  and  224 . Furthermore, the dummy pattern may include substantially the same conductive material as the radiation bodies  211 ,  212  and  213  and/or the transmission lines  221 ,  222 ,  223  and  224 . According to an exemplary embodiment, the dummy pattern may be formed in a segmented mesh structure. 
     As the dummy pattern is disposed around the radiation bodies  211 ,  212  and  213 , and the transmission lines  221 ,  222 ,  223  and  224 , optical uniformity of the pattern may be improved, thereby preventing the antenna pattern from being viewed by the user. 
       FIG. 3  is a schematic plan view illustrating an antenna element according to another exemplary embodiment. An antenna element  300  of  FIG. 3  may be an embodiment of the antenna element  100  shown in  FIG. 1 . Details of the contents substantially the same as those of the structures and configurations described with reference to  FIGS. 1 and 2  will not be described. In addition, a first radiation body  311 , a second radiation body  312  and a third radiation body  313  are the same as the first radiation body  211 , the second radiation body  212  and the third radiation body  213 , and therefore will not be described in detail within the overlapping range. 
     Referring to  FIG. 3 , the first radiation body  311 , the second radiation body  312  and the third radiation body  313  of the antenna element  300  may have a square shape, respectively. 
     In this case, a first transmission line  221  and a second transmission line  222  may be respectively connected to two adjacent vertices of the first radiation body  311 . Also, a third transmission line  223  may connect two facing vertices of the first radiation body  311  and the second radiation body  312  to each other, and a fourth transmission line  224  may connect two facing vertices of the first radiation body  311  and the third radiation body  313  to each other. 
     Meanwhile,  FIG. 2  illustrates an example in which the radiation bodies  211 ,  212  and  213  have a rhombus shape, and  FIG. 3  illustrates an example in which the radiation bodies  311 ,  312 , and  313  have a square shape, but these are only exemplary embodiments. That is, there is no particular limitation on the shapes of the radiation bodies  211 ,  212 ,  213 ,  311 ,  312  and  313 , and these radiation bodies may have various planar shapes such as a circle and a polygon. 
       FIG. 4A  to  FIG. 11  are plan views illustrating antenna arrays according to exemplary embodiments. In the description of  FIGS. 4A  to  FIG. 11 , details of the contents substantially the same as those of the structures and configurations described with reference to  FIGS. 1 to 3  will not be described. 
     Referring to  FIGS. 4A and 4B , an antenna array  400  according to an exemplary embodiment may include a plurality of antenna elements  100  arranged while sharing at least a portion thereof with each other in the width direction (x-direction) of the antenna element  100 . In this case, the antenna element  100  may include ground pads  241  and  242 . 
     Adjacent antenna elements  100   a  and  100   b  may share one radiation body  215  with each other. For example, the radiation body  215  may be a second radiation body  212  of a first antenna element  100   a  and a third radiation body  213  of a second antenna element  100   b.  That is, the radiation body  215  may serve as the second radiation body  212  of the first antenna element  100   a  and as the third radiation body  213  of the second antenna element  100   b.    
     Referring to  FIG. 5 , unlike the embodiment shown in  FIGS. 4A and 4B , the ground pads  241  and  242  may be omitted in an antenna array  500  according to an exemplary embodiment. 
     When the radiation bodies  211 ,  212  and  213  are located close to the ground pads  241  and  242 , unwanted coupling may occur between the radiation bodies  211 ,  212  and  213 , and the ground pads  241  and  242 . Such the unwanted coupling may affect isolation and radiation efficiency of the antenna. Therefore, according to an exemplary embodiment, the ground pads  241  and  242  of the antenna element  100  may be removed so as to reduce an occurrence of the unwanted coupling between the radiation bodies  211 ,  212 ,  213 ,  311 ,  312  and  313 , and the ground pads  241  and  242 . 
     Referring to  FIG. 6 , an antenna array  600  according to an exemplary embodiment may further include a ground line  610  in the embodiment shown in  FIGS. 4A and 4B . 
     The ground line  610  may be disposed on the dielectric layer  110  to connect the radiation body  215  shared by the adjacent antenna elements  100   a  and  100   b  to at least one of ground pads  241  and  242 . For example, as shown in  FIG. 6 , the ground line  610  may include a first segment extending in the width direction (x-direction) of the antenna element  100  to connect a second ground pad  242   b  of a first antenna element  100   a  and a first ground pad  241   a  of a second antenna element  100   b  adjacent to the first antenna element  100   a,  and a second segment extending in the longitudinal direction (y-direction) of the antenna element  100  to connect the first segment and the radiation body  215 . In this case, the second segment may be connected to a vertex of the radiation body  215 . 
     In the case of a dual polarization antenna such as the antenna array  400  shown in  FIGS. 4A and 4B , in which one radiation body  215  is shared by adjacent antenna elements  100   a  and  100   b,  polarization separation may be difficult due to an influence of unwanted cross-coupling or isolation. Therefore, according to an exemplary embodiment, the antenna array  600  may connect the radiation body  215  shared by the adjacent antenna elements  100   a  and  100   b  to the at least one of the ground pads  241  and  242  through a ground line  610 , thereby reducing an occurrence of the unwanted cross-coupling. 
     According to an exemplary embodiment, the ground line  610  may include substantially the same conductive material as the radiation body  215  and/or the ground pads  241  and  242 . In addition, the ground line  610  may be integrally connected with the radiation body  215  and/or the ground pads  241  and  242  to form a substantially single member, or may be formed as a separate member from the radiation body  215  and/or the ground pads  241  and  242 . 
     According to an exemplary embodiment, the ground line  610  may be formed in a mesh structure or a solid structure (thin film or thick film). 
     Referring to  FIG. 7 , an antenna array  700  according to an exemplary embodiment may further include a ground line  710  and a bonding pad  720  in the embodiment shown in  FIG. 5 . 
     The ground line  710  may be disposed on the dielectric layer  110  and may extend in the longitudinal direction (y-direction) of the antenna element  100  to be connected to the radiation body  215 . The bonding pad  720  bonded to a ground (see  1222  of  FIG. 12 ) of the FPCB may be disposed at an end of the ground line  710 . 
     The bonding pad  720  is bonded to the ground of the FPCB, and the ground line  710  is connected to the ground of the FPCB, such that the radiation body  215  may be connected to the ground of the FPCB. Thereby, it is possible to reduce an occurrence of the unwanted cross-coupling. 
     According to an exemplary embodiment, the ground line  710  may include the above-described metal or alloy, and may be formed in a mesh structure or a solid structure (thin film or thick film). Also, the bonding pad  720  may include the above-described metal or alloy, and may be formed in a solid structure (thin film or thick film). 
     Referring to  FIGS. 8A and 8B , an antenna array  800  according to an exemplary embodiment may include a plurality of antenna elements  100  arranged to be spaced apart from each other in the width direction (x-direction) of the antenna element  100 . In this case, the antenna element  100  may include ground pads  241  and  242 . 
     When the adjacent antenna elements  100  are located close to each other, unwanted coupling may occur between adjacent antenna elements  100 , in particular, a second radiation body  212  of a first antenna element  100   c  and a third radiation body  213  of a second antenna element  100   d  adjacent to the first antenna element  100   c.  Such the coupling may affect the isolation and radiation efficiency of the antenna. Therefore, according to an exemplary embodiment, a separation distance b of the adjacent antenna elements  100  may be 0.5 mm or more, so as to reduce an occurrence of the unwanted coupling between the adjacent antenna elements  100 . 
     Unlike the embodiment shown in  FIGS. 4A and 4B , since the adjacent antenna elements  100  of  FIGS. 8A and 8B  do not share the radiation body, it is possible to reduce an occurrence of the unwanted cross-coupling. 
     Referring to  FIG. 9 , unlike the embodiment shown in  FIGS. 8A and 8B , the ground pads  241  and  242  may be omitted in an antenna array  900  according to an exemplary embodiment. 
     When the radiation bodies  211 ,  212  and  213  are located close to the ground pads  241  and  242 , unwanted coupling may occur between the radiation bodies  211 ,  212  and  213 , and the ground pads  241  and  242 . Such the coupling may affect the isolation and radiation efficiency of the antenna. Therefore, according to an exemplary embodiment, the ground pads  241  and  242  of the antenna element  100  may be removed, so as to reduce an occurrence of the unwanted coupling between the radiation bodies  211 ,  212 ,  213 ,  311 ,  312  and  313 , and the ground pads  241  and  242 . 
     Referring to  FIG. 10 , an antenna array  1000  according to an exemplary embodiment may further include a boundary ground line  1010  in the embodiment shown in  FIGS. 8A and 8B . The boundary ground line  1010  may be disposed between adjacent antenna elements  100  on the dielectric layer  110  to be connected to ground pads  241  and  242 . For example, as shown in  FIG. 10 , the boundary ground line  1010  may include a first segment extending in the width direction (x-direction) of the antenna element  100  to connect the ground pads  241  and  242  of the adjacent antenna elements  100 , a second segment surrounding the antenna elements  100 , and a third segment extending in the longitudinal direction (y-direction) of the antenna element  100  between the adjacent antenna elements  100  to connect the first segment and the second segment. In this case, ends of the second segment may be connected to the ground pads  241  and  242  of the antenna elements  100 . 
     When the adjacent antenna elements  100  are located close to each other, unwanted coupling may occur between the adjacent antenna elements  100 . Such the coupling may affect the isolation and radiation efficiency of the antenna. Therefore, according to an exemplary embodiment, the boundary ground line  1010  may be disposed between the adjacent antenna elements  100 , thereby reducing an occurrence of the unwanted coupling between the adjacent antenna elements  100 . 
     According to an exemplary embodiment, the boundary ground line  1010  may include substantially the same conductive material as the radiation bodies  211 ,  212  and  213  and/or the ground pads  241  and  242 . Further, the boundary ground line  1010  may be integrally connected with the radiation bodies  211 ,  212  and  213  and/or the ground pads  241  and  242  to form a substantially single member, or may be formed as a separate member from the radiation bodies  211 ,  212  and  213  and/or the ground pads  241  and  242 . 
     According to an exemplary embodiment, the boundary ground line  1010  may be formed in a mesh structure or a solid structure (thin film or thick film). 
     Referring to  FIG. 11 , an antenna array  1100  according to an exemplary embodiment may further include a boundary ground line  1110  and a bonding pad  1120  in the embodiment shown in  FIG. 9 . 
     The boundary ground line  1110  may be disposed between adjacent antenna elements  100  on the dielectric layer  110 . For example, the boundary ground line  1110  may include a first segment extending in the longitudinal direction (y-direction) of the antenna element  100  between adjacent antenna elements  100  to be connected to a second segment, and a second segment surrounding the antenna elements  100 . 
     The bonding pad  1120  bonded to the ground (see  1222  of  FIG. 12 ) of the FPCB may be connected to an end of the boundary ground line  1110 . 
     The bonding pad  1120  may be bonded to the ground of the FPCB, such that the boundary ground line  1110  may be connected to the ground of the FPCB. Thereby, it is possible to reduce an occurrence of the unwanted coupling between the adjacent antenna elements  100 . 
     According to an exemplary embodiment, the boundary ground line  1110  may include the above-described metal or alloy, and may be formed in a mesh structure or a solid structure (thin film or thick film). In addition, the bonding pad  1120  may include the above-described metal or alloy, and may be formed in a solid structure (thin film or thick film). 
       FIGS. 12 and 13  are plan views illustrating antenna devices according to exemplary embodiments. In the description of  FIGS. 12 and 13 , details of the contents substantially the same as those of the structures and configurations described with reference to  FIGS. 1 to 11  will not be described. 
     Referring to  FIGS. 12 and 13 , antenna devices  1200  and  1300  according to exemplary embodiments may include an antenna array  1210  and an FPCB  1220 . 
     Herein, the antenna array  1210  may be the antenna arrays  500 ,  700 ,  900  and  1100  which are described above with reference to  FIGS. 5, 7, 9 and 11 . That is, the antenna array  1210  may be an antenna array from which the ground pads  241  and  242  are removed. 
     The FPCB  1220  may include a plurality of circuit wirings  1221  electrically connected to the respective signal pads  231  and  232 . In this case, the FPCB  1220  may include grounds  1222  corresponding to the ground pads  241  and  242  removed from the antenna array  1210  (see  FIG. 12 ) or may not include the same (see  FIG. 13 ). As shown in  FIG. 12 , if the FPCB  1220  includes the grounds  1222 , each ground  1222  may be disposed at a position of the FPCB  1220 , in which the signal pads  231  and  232  of the antenna array  1210  face each other with it interposed therebetween, when the antenna array  1210  is bonded to the FPCB  1220 . 
     Meanwhile, when the antenna array  1210  is the antenna array  700  or  1100  shown in  FIG. 7 or 11 , the bonding pads  720  and  1120  may be bonded to the grounds  1222  of the FPCB  1220 . Thereby, the ground line  710  and the boundary ground line  1110  may be connected to the ground  1222  of the FPCB  1220 . 
       FIG. 14  is a schematic plan view illustrating a display device according to an exemplary embodiment. More specifically,  FIG. 14  is a plan view illustrating an external shape including a window of the display device. 
     Referring to  FIG. 14 , a display device  1400  may include a display region  1410  and a peripheral region  1420 . 
     The display region  1410  may indicate a region in which visual information is displayed, and the peripheral region  1420  may indicate an opaque region disposed on both sides and/or both ends of the display region  1410 . For example, the peripheral region  1420  may correspond to a light-shielding part or a bezel part of the display device  1400 . 
     According to an embodiment, the above-described antenna elements  100 ,  200  and  300 , the antenna arrays  400 ,  500 ,  600 ,  700 ,  800 ,  900 ,  1000  and  1100 , or the antenna devices  1200  and  1300  may be mounted on the display device  1400 . For example, the radiation bodies  211 ,  212 ,  213 ,  311 ,  312  and  313 , the transmission lines  221 ,  222 ,  223  and  224 , the ground line  710  and the boundary ground line  1110  of the antenna elements  100 ,  200  and  300 , the antenna arrays  400 ,  500 ,  600 ,  700 ,  800 ,  900 ,  1000  and  1100 , and the antenna devices  1200  and  1300  may be disposed so as to at least partially correspond to the display region  1410 , and the signal pads  231  and  232 , the ground pads  241  and  242 , and the bonding pads  720  and  1120  may be arranged so as to correspond to the peripheral region  1420 . 
     The FPCB or PCB may be disposed in the peripheral region  1420  together with an antenna driving unit (e.g., RFIC). By arranging the antenna elements  100 ,  200  and  300 , the antenna arrays  400 ,  500 ,  600 ,  700 ,  800 ,  900 ,  1000  and  1100 , and the signal pads  231  and  232  of the antenna devices  1200  and  1300  so as to be adjacent to the antenna driving unit, signal loss may be suppressed by shortening a path for transmitting and receiving signals. 
     The antenna elements  100 ,  200  and  300 , the antenna arrays  400 ,  500 ,  600 ,  700 ,  800 ,  900 ,  1000  and  1100 , and the antenna devices  1200  and  1300  include the radiation bodies  211 ,  212 ,  213 ,  311 ,  312  and  313 , the transmission lines  221 ,  222 ,  223  and  224  and/or the dummy pattern, which are formed in the mesh structure, such that it is possible to significantly reduce or suppress the patterns from being viewed while improving the transmittance. Accordingly, image quality in the display region  1410  may also be improved while maintaining or improving desired communication reliability. 
     The present invention has been described with reference to the preferred embodiments above, and it will be understood by those skilled in the art that various modifications may be made within the scope without departing from essential characteristics of the present invention. Accordingly, it should be interpreted that the scope of the present invention is not limited to the above-described embodiments, and other various embodiments within the scope equivalent to those described in the claims are included within the present invention.