Antenna element and display device including same

Abstract

Regarding an antenna element and a display device including the same, the antenna element according to one aspect includes a dielectric layer, a radiator formed on the dielectric layer, and a transmission line connected to the radiator on the dielectric layer and formed with a mesh structure that is a collection of unit cells defined by a plurality of conductive lines, and the width of the transmission line may be an integer multiple of the width of the unit cell within a tolerance range.

Description

[Technical Field]

[0001] The present invention relates to an antenna element and a display device including the same. [Background technology]

[0002] In recent years, with the development of the information society, wireless communication technologies such as Wi-Fi and Bluetooth (registered trademark) have been combined with display devices, for example, in the form of smartphones, in which an antenna is coupled to the display device to perform communication functions.

[0003] Recently, with the evolution of mobile communication technology, it has become necessary to combine antennas for communication in high frequency or ultra-high frequency bands with display devices. In addition, with the recent development of thin, highly transparent, and high-resolution display devices such as transparent displays and flexible displays, antennas must also be developed with improved transparency and flexibility.

[0004] As the screen size of display devices increases, the space or area of ​​bezels and light-shielding sections tends to decrease. In this case, the space or area in which an antenna can be built is also limited, and as a result, the radiator for transmitting and receiving signals included in the antenna may overlap the display area of ​​the display device. As a result, the image on the display device may be obscured by the radiator of the antenna, or the radiator may be visible to the user, degrading image quality.

[0005] Therefore, it is necessary to design an antenna that is invisible to the user and that can achieve high frequency communication with a desired antenna gain within a limited space. Summary of the Invention [Problem to be solved by the invention]

[0006] An object of the present invention is to provide an antenna element and a display device including the same. [Means for solving the problem]

[0007] 1. An antenna element comprising: a dielectric layer; a radiator formed on the dielectric layer; and a transmission line connected to the radiator on the dielectric layer and formed of a mesh structure which is a collection of unit cells defined by a plurality of conductive lines, wherein the width of the transmission line is an integer multiple of the width of the unit cell within a tolerance range.

[0008] 2. The antenna element according to item 1, wherein the width of the transmission line satisfies the following mathematical formula: [Mathematical formula] JPEG0007734181000001.jpg979 where n is an integer, b is the width of the unit cell, and a is the width of the transmission line.

[0009] 3. The antenna element according to item 1, further comprising a signal pad connected to an end of the transmission line, and a ground pad arranged around the signal pad so as to be separated from the signal pad.

[0010] 4. The antenna element according to item 3, wherein the signal pad or the ground pad is formed with a solid structure.

[0011] 5. The antenna element according to item 3, wherein the ground pad includes a pair of ground pads facing each other with the signal pad interposed therebetween.

[0012] 6. The antenna element according to item 1, further comprising a dummy pattern disposed on the dielectric layer around the radiator and the transmission line and electrically isolated therefrom.

[0013] 7. The antenna element according to item 6, wherein the radiator and the dummy pattern are formed in a mesh structure.

[0014] 8. The antenna element according to item 1, further comprising a ground layer formed on the bottom surface of the dielectric layer.

[0015] 9. A display device including an antenna element according to any of the preceding embodiments. [Effects of the Invention]

[0016] By determining the width of the transmission line taking into consideration the width of the unit cell that forms the mesh structure, signal loss in the transmission line where current flow concentrates during power supply can be prevented, thereby improving the antenna gain. [Brief explanation of the drawings]

[0017] [Figure 1] FIG. 1 is a schematic cross-sectional view showing an antenna element according to one embodiment. [Figure 2] FIG. 2 is a schematic plan view illustrating an antenna element according to one embodiment. [Figure 3] FIG. 3 is a diagram for explaining the width of the transmission line in the x direction. [Figure 4] FIG. 4 is a diagram for explaining the width of the transmission line in the x direction. [Figure 5] FIG. 5 is a schematic plan view showing an antenna element according to another embodiment. [Figure 6] FIG. 6 is a schematic plan view illustrating a display device according to an embodiment. [Figure 7] FIG. 7 is a diagram illustrating a transmission line according to Experimental Example 1. As shown in FIG. [Figure 8] FIG. 8 is a diagram showing a transmission line according to Experimental Example 2. In FIG. DETAILED DESCRIPTION OF THE INVENTION

[0018] Hereinafter, embodiments of the present invention will be described in more detail with reference to the drawings. When assigning reference numerals to components in each drawing, it should be noted that the same reference numerals are used to the same components whenever possible, even if they appear in different drawings.

[0019] In describing the present invention, if it is determined that a detailed description of related prior art may obscure the gist of the present invention, the detailed description will be omitted. Furthermore, the terms described below are defined in consideration of the functions of the present invention and may vary depending on the intentions or practices of users or operators. Therefore, the definitions should be based on the contents of this specification as a whole.

[0020] Terms such as "first," "second," etc., are used to describe various components, but are only used to distinguish one structural element from another. The singular includes the plural unless the context clearly dictates otherwise. The terms "comprise," "have," etc., indicate the presence of a feature, numeral, step, operation, component, part, or combination thereof stated in the specification, but do not preclude the presence or addition of one or more other features, numerals, steps, operations, components, parts, or combinations thereof.

[0021] Additionally, directional terms such as "one side," "other side," "top," and "bottom" are used in relation to the orientation of the disclosed figures. Because components of embodiments of the present invention may be positioned in a variety of orientations, directional terms are used for illustrative purposes and not as a limitation.

[0022] Furthermore, the classification of components in this specification merely refers to the main function of each component. That is, two or more components may be combined into one component, or one component may be divided into two or more sub-functions. Each component may perform some or all of the functions of other components in addition to its own main function, or some of the main functions of each component may be performed by other components.

[0023] The antenna element described herein may be a patch antenna or a microstrip antenna fabricated in the form of a transparent film. The antenna element may be applied to, but is not limited to, electronic devices for high-frequency or ultra-high-frequency (e.g., 3G, 4G, 5G, or higher) mobile communications, Wi-Fi, Bluetooth, Near Field Communication (NFC), Global Positioning System (GPS), and the like. The antenna element may also be applied to various objects or structures, such as vehicles and buildings. Here, the electronic devices may include mobile phones, smartphones, tablets, laptops, personal digital assistants (PDAs), portable multimedia players (PMPs), navigation devices, MP3 players, digital cameras, wearable devices, and the like. Wearable devices may include watches, wristbands, rings, belts, necklaces, ankle bands, thigh bands, forearm bands, and the like. However, the electronic devices are not limited to these examples, and the wearable devices are also not limited to these examples.

[0024] In the following figures, the two directions parallel to the top surface of the dielectric layer and perpendicular to each other are defined as the x-direction and the y-direction, and the direction perpendicular to the top surface of the dielectric layer is defined as the z-direction. For example, the x-direction may correspond to the width direction of the antenna element, the y-direction to the length direction of the antenna element, and the z-direction to the thickness direction of the antenna element.

[0025] FIG. 1 is a schematic cross-sectional view showing an antenna element according to an embodiment, and FIG. 2 is a schematic plan view showing an antenna element according to an embodiment.

[0026] Referring to FIGS. 1 and 2, the antenna element may include a dielectric layer 110 and an antenna conductive layer 120 .

[0027] The dielectric layer 110 may include an insulating material having a predetermined dielectric constant. According to an embodiment, the dielectric layer 110 may include an inorganic insulating material such as glass, silicon oxide, silicon nitride, or metal oxide, or an organic insulating material such as epoxy resin, acrylic resin, or imide resin. The dielectric layer 110 may function as a film substrate for the antenna element on which the antenna conductive layer 120 is formed.

[0028] According to one embodiment, a transparent film may be provided as the dielectric layer 110. The transparent film may include thermoplastic resins such as polyester-based resins, such as polyethylene terephthalate, polyethylene isophthalate, polyethylene naphthalate, and polybutylene terephthalate; cellulose-based resins, such as diacetyl cellulose and triacetyl cellulose; polycarbonate-based resins; acrylic-based resins, such as polymethyl (meth)acrylate and polyethyl (meth)acrylate; styrene-based resins, such as polystyrene and acrylonitrile-styrene copolymers; polyolefin-based resins, such as polyethylene, polypropylene, polyolefins having a cyclo- or norbornene structure, and ethylene-propylene copolymers; vinyl chloride-based resins; amide-based resins, such as nylon and aromatic polyamides; imide-based resins; polyethersulfone-based resins; sulfone-based resins; polyetheretherketone-based resins; polyphenylene sulfide-based resins; vinyl alcohol-based resins; vinylidene chloride-based resins; vinyl butyral-based resins; arylate-based resins; polyoxymethylene-based resins; and epoxy-based resins. These may be used alone or in combination. Alternatively, the dielectric layer 110 may be a transparent film made of a thermosetting resin or an ultraviolet curable resin, such as a (meth)acrylic, urethane, acrylic urethane, epoxy, or silicone resin.

[0029] According to an embodiment, the dielectric layer 110 may include an adhesive film such as an optically clear adhesive (OCA) or an optically clear resin (OCR).

[0030] According to an embodiment, the dielectric layer 110 may be formed substantially as a single layer, or may be formed as a multi-layer structure of at least two layers.

[0031] The dielectric layer 110 forms capacitance or inductance, which can adjust the frequency band in which the antenna element can be driven or sensed. If the dielectric constant of the dielectric layer 110 exceeds about 12, the driving frequency may be too low to achieve driving in the desired high frequency band. Therefore, according to one embodiment, the dielectric constant of the dielectric layer 110 can be adjusted to a range of about 1.5 to 12, preferably a range of about 2 to 12.

[0032] According to one embodiment, the dielectric layer 110 may also provide an insulating layer within the display device in which the antenna element is implemented (eg, an encapsulation layer, passivation layer of the display panel, etc.).

[0033] The antenna conductive layer 120 is formed on the dielectric layer 110 and can include an antenna pattern 200 including a radiator 210 and a transmission line 220 , and a pad electrode 230 .

[0034] The antenna pattern 200 may include a low-resistivity 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), or calcium (Ca), or an alloy containing at least one of these. These may be used alone or in combination. For example, the antenna pattern 200 may include silver (Ag) or a silver alloy (e.g., a silver-palladium-copper (APC) alloy) to achieve low resistance. As another example, the antenna pattern 200 may include copper (Cu) or a copper alloy (e.g., a copper-calcium (CuCa) alloy) to achieve low resistance and fine linewidth patterning.

[0035] According to one embodiment, the antenna pattern 200 may include a transparent metal oxide such as indium tin oxide (ITO), indium zinc oxide (IZO), indium zinc tin oxide (ITZO), zinc oxide (ZnOx), or copper oxide (CuO).

[0036] According to one embodiment, the antenna pattern 200 may be formed as a single-layer structure of a metal layer, or as a laminate structure of a transparent conductive oxide layer and a metal layer. For example, the antenna pattern 200 may have a two-layer structure of a transparent conductive oxide layer and a metal layer, or a three-layer structure of a transparent conductive oxide layer, a metal layer, and a transparent conductive oxide layer. In this case, the metal layer can improve flexibility and reduce resistance to improve signal transmission speed, and the transparent conductive oxide layer can improve corrosion resistance and transparency.

[0037] According to an exemplary embodiment, the antenna pattern 200 may include a blackening treatment, which reduces the reflectivity on the surface of the antenna pattern 200 and reduces the visibility of the pattern due to light reflection.

[0038] According to one embodiment, a blackened layer may be formed by converting the surface of a metal layer included in the antenna pattern 200 into a metal oxide or metal sulfide. According to one embodiment, a blackened layer such as a black material coating layer or plating layer may be formed on the antenna pattern 200 or the metal layer. Here, the black material or plating layer may include silicon, carbon, copper, molybdenum, tin, chromium, molybdenum, nickel, cobalt, or an oxide, sulfide, alloy, etc. containing at least one of these elements.

[0039] The composition and thickness of the blackening layer can be adjusted taking into consideration the effect of reducing reflectance and the radiation characteristics of the antenna.

[0040] The radiator 210 can transmit or receive signals externally. For example, the radiator 210 can transmit or receive signals at a resonant frequency. The length in the y direction and the width in the x direction of the radiator 210 can be determined by the desired resonant frequency, radiation resistance, and gain.

[0041] The radiator 210 may be formed in a mesh structure defined by a plurality of conductive lines, thereby increasing the transmittance of the radiator 210 and improving the flexibility of the antenna element, thereby enabling the antenna element to be effectively applied to a flexible display device.

[0042] According to one embodiment, the emitter 210 may be realized in a diamond shape as shown in Fig. 2. However, this is merely one embodiment, and the shape of the emitter 210 is not particularly limited. That is, the emitter 210 may be realized in various shapes such as a rectangle, a circle, etc.

[0043] The transmission line 220 is disposed between the radiator 210 and the signal pad 231 of the pad electrode 230, and can electrically connect the radiator 210 and the signal pad 231. For example, the transmission line 220 can branch from the center of the radiator 210 and connect to the signal pad 231.

[0044] The transmission line 220 may be formed in a mesh structure defined by a plurality of conductive lines. For example, the transmission line 220 may be formed in a mesh structure having substantially the same shape as the radiator 210 (e.g., the same line width, the same spacing, etc.).

[0045] The width of the transmission line 220 in the x direction can be determined taking into account the width of the unit cells forming the mesh structure in the x direction. For example, the width of the transmission line 220 in the x direction may be an integer multiple of the width of the unit cells forming the mesh structure in the x direction within an acceptable error range. More preferably, the width of the transmission line 220 in the x direction may be an integer multiple of the width of the unit cells in the x direction.

[0046] In a mesh-structured electrode, the more intersections of multiple conductive lines there are (for example, dotted circles in FIGS. 3 and 4), the higher the electrical conductivity becomes. Therefore, by forming the width of the transmission line 220 in the x direction to be an integer multiple of the width of the unit cell in the x direction so that the transmission line 220 includes as many intersections as possible, signal loss in the transmission line 220 can be prevented.

[0047] The width of the transmission line 220 in the x direction will be described in detail later with reference to FIGS.

[0048] According to one embodiment, transmission line 220 may comprise substantially the same conductive material as radiator 210. Additionally, transmission line 220 may be integrally connected to radiator 210 and provided as a substantially single member, or may be provided as a separate member from radiator 310.

[0049] 2, the radiator 210 and the transmission line 220 may include a frame conductive line 201 formed on the frame of the radiator 210 and the transmission line 220, but is not limited to this. That is, the frame conductive line 201 does not have to be formed on the frame of the radiator 210 and / or the transmission line 220. For example, as will be described later, a dummy pattern may be disposed around the radiator 210 and the transmission line 220, or the frame may be formed without a separate frame conductive line 201 by separating the radiator 210 and the transmission line 220 from the dummy pattern.

[0050] The pad electrodes 230 may include a signal pad 231 and a ground pad 232 .

[0051] The signal pad 231 is connected to an end of the transmission line 220 and can be electrically connected to the radiator 210 via the transmission line 220. This allows the signal pad 231 to electrically connect a driving circuit unit (e.g., an IC chip) to the radiator 210. For example, a circuit board such as a flexible printed circuit board (FPCB) can be bonded onto the signal pad 231, and the driving circuit unit can be mounted on the circuit board. This allows the radiator 210 to be electrically connected to the driving circuit unit.

[0052] The ground pads 232 can be arranged around the signal pads 231 so as to be electrically and physically separated from the signal pads 231. For example, a pair of ground pads 232 can be arranged so as to face each other with the signal pad 231 in between.

[0053] According to one embodiment, the signal pad 231 and the ground pad 232 may be formed as a solid structure including the aforementioned metal or alloy to reduce signal resistance, or may be formed as a multi-layer structure including the aforementioned metal or alloy layer and a transparent conductive oxide layer.

[0054] According to an embodiment, the antenna element may further include a ground layer 105. By including the ground layer 105 in the antenna element, vertical radiation characteristics can be achieved.

[0055] The ground layer 105 can be formed on the bottom surface of the dielectric layer 110. The ground layer 105 can be arranged to overlap entirely or partially with the antenna conductive layer 120 across the dielectric layer 110. For example, the ground layer 105 can overlap with the radiator of the antenna conductive layer 120.

[0056] According to an embodiment, a conductive member of a display device or a display panel on which an antenna element is mounted may be provided as the ground layer 105. For example, the conductive member may include electrodes or wiring such as a gate electrode, source / drain electrode, pixel electrode, common electrode, data line, scan line, etc. of a thin film transistor (TFT) included in the display panel, as well as a stainless steel (SUS) plate, a heat dissipation sheet, a digitizer, an electromagnetic wave shielding layer, a pressure sensor, a fingerprint sensor, etc. of the display device.

[0057] 2 shows only one antenna element for convenience of explanation, a plurality of antenna elements may be arranged in an array on the dielectric layer 110. The arrangement of the antenna elements may include a linear arrangement or a non-linear arrangement.

[0058] 3 and 4 are diagrams illustrating the width of the transmission line in the x direction. Specifically, Fig. 3 shows a case where the tilt angle of the unit cell with respect to the y direction is 0, and Fig. 4 shows a case where the tilt angle of the unit cell with respect to the y direction is not 0.

[0059] 2-4, the mesh structure forming the radiator 210 and the transmission line 220 may be formed by a plurality of conductive lines 310 that cross each other.

[0060] The mesh structure includes unit cells 330 defined by a plurality of conductive lines 310 intersecting in a substantially honeycomb configuration, and a plurality of unit cells 330 may collectively define the mesh structure.

[0061] According to one embodiment, the unit cell 330 may have a substantially diamond shape.

[0062] As described above, the width a in the x direction of the transmission line 220 can be determined in consideration of the width b in the x direction of the unit cells 330 that form the mesh structure. For example, the width a in the x direction of the transmission line 220 may be an integer multiple of the width b in the x direction of the unit cells 330 that form the mesh structure, and may be within the tolerance range.

[0063] More specifically, the width a of the transmission line 220 in the x direction can be determined within a range that satisfies mathematical formula 1.

[0064] [Mathematical formula 1] JPEG0007734181000002.jpg979

[0065] Here, n is an integer, b may be the width of the unit cell 330, and a may be the width of the transmission line 220. Also, 0.2 takes into consideration process errors and may be a value for setting an allowable error range.

[0066] More preferably, the width a of the transmission line 220 in the x direction may be an integer multiple of the width b of the unit cell 330 in the x direction that forms the mesh structure.

[0067] More specifically, the width a of the transmission line 220 in the x direction can be determined so as to satisfy mathematical formula 2.

[0068] [Mathematical formula 2] JPEG0007734181000003.jpg927

[0069] According to one embodiment, by determining the width a in the x direction of the transmission line 220 so as to satisfy the above-mentioned mathematical formula 1, more preferably mathematical formula 2, signal loss in the transmission line 220 where the current flow concentrates during power supply can be prevented, thereby improving the antenna gain.

[0070] FIG. 5 is a schematic plan view showing an antenna element according to another embodiment.

[0071] 1 and 5, the antenna element includes an antenna conductive layer 120 formed on a dielectric layer 110, and the antenna conductive layer 120 may include an antenna pattern 200 including a radiator 210 and a transmission line 220, a pad electrode 230, and a dummy pattern 510. Here, the radiator 210, the transmission line 220, and the pad electrode 230 are the same as those described with reference to FIGS. 1 to 4, and therefore detailed description thereof will be omitted.

[0072] The dummy pattern 510 may be arranged around the antenna pattern 200 including the radiator 210 and the transmission line 220 .

[0073] The dummy pattern 510 is formed in a mesh structure having substantially the same shape (e.g., the same line width and the same spacing) as the radiator 210 or the transmission line 220, and may contain the same metal as the radiator 210 or the transmission line 220. According to one embodiment, some of the conductive lines forming the dummy pattern 510 may be segmented.

[0074] The dummy pattern 510 may be arranged to be electrically and physically separated from the antenna pattern 200 and the pad electrode 230. For example, a separation region 511 may be formed along the side line or contour of the antenna pattern 200 to separate the dummy pattern 510 from the antenna pattern 200. That is, the dummy pattern 510 may be arranged around the antenna pattern 200, and the antenna pattern 200 and the dummy pattern 510 may be separated from each other to form the separation region 511. As a result, the antenna pattern 200 may form a frame without a separate frame conductive line.

[0075] As described above, by arranging the dummy pattern 510 having a mesh structure substantially identical to that of the radiator 210 or the transmission line 220 around the antenna pattern 200, it is possible to prevent the antenna pattern from being visible to a user of a display device equipped with an antenna element due to differences in the arrangement of electrodes at different positions.

[0076] 5 shows only one antenna pattern, a plurality of antenna patterns may be arranged in an array on the dielectric layer 110. The arrangement of the antenna elements may include a linear arrangement or a non-linear arrangement.

[0077] 6 is a schematic plan view illustrating a display device according to an embodiment, more specifically, an external shape including a window of the display device.

[0078] 6, the display device 600 may include a display area 610 and a peripheral area 620. The display area 610 may refer to an area where visual information is displayed, and the peripheral area 620 may refer to opaque areas disposed on both sides and / or both ends of the display area 610. For example, the peripheral area 620 may correspond to a light-shielding portion or a bezel portion of the display device 600.

[0079] According to an embodiment, the above-described antenna element may be mounted on a display device 600. For example, the antenna pattern 200 of the antenna element may be arranged to at least partially correspond to a display area 610 of the display device 600, and the pad electrode 230 may be arranged to correspond to a peripheral area 620 of the display device 600. In this case, the antenna pattern 200, particularly a portion of the transmission line 220, may be arranged to correspond to the peripheral area 620 of the display device 600.

[0080] The peripheral area 620 may include a driver circuit such as an IC chip for the display device 600 and / or an antenna element.

[0081] By arranging the pad electrode 230 of the antenna element adjacent to the drive circuit, the signal transmission / reception path can be shortened and signal loss can be reduced.

[0082] If the antenna element includes a dummy pattern 510 , the dummy pattern 510 may be positioned to at least partially correspond to a display area 610 of the display device 600 .

[0083] The antenna element includes an antenna pattern and / or a dummy pattern formed in a mesh structure, which improves transparency and significantly reduces or suppresses visibility of the electrodes, thereby improving image quality in the display area 610 while maintaining or improving desired communication reliability.

[0084] The above description focuses on preferred embodiments of the present invention. Those skilled in the art will understand that the present invention can be embodied in various modified forms without departing from the essential characteristics of the present invention. Therefore, the scope of the present invention is not limited to the above-described embodiments, but should be interpreted as including various embodiments within the scope equivalent to the content of the claims.

[0085] [Experimental Example 1] Using the designs shown in Figures 2 and 7, a 1x2 array antenna was fabricated with a mesh structure in which the unit cells had a zero tilt angle. Specifically, a mesh-structured electrode layer was formed on the top surface of a glass (0.7T) dielectric layer using an alloy of silver (Ag), palladium (Pd), and copper (Cu) (APC), and a ground layer was formed by vapor deposition on the bottom surface of the dielectric layer. The conductive lines in the mesh structure had a line width of 3 μm, and the electrodes had a thickness (or height) of 2000 Å. The distance between the electrodes and the ground layer was 380 μm. Example 1, Comparative Example 1, and Comparative Example 2 were fabricated with a fixed unit cell width of 100 μm and transmission line widths of 300 μm, 260 μm, and 340 μm, respectively, and the antenna gain at 28 GHz was measured. The results are shown in Table 1.

[0086] [Table 1]

[0087] From FIG. 7 and Table 1, it can be seen that in Comparative Example 1, where the ratio of the width of the transmission line to the width of the unit cell is 2.6, and Comparative Example 2, where the ratio is 3.4, the antenna gains are 2.71 and 2.92, respectively, whereas in Example 1, where the ratio of the width of the transmission line to the width of the unit cell is an integer 3, the antenna gain is 3.12.

[0088] Furthermore, although Example 1 and Comparative Example 2 have the same number of intersections (dotted lines in FIG. 7) included in the transmission lines, the area occupied by the transmission lines in Comparative Example 2 is larger than that in Example 1, and it can be seen that the antenna gain is reduced.

[0089] It can be confirmed that by forming the width of the transmission line to be an integral multiple of the width of the unit cell, signal loss in the transmission line can be prevented and the antenna gain can be improved.

[0090] [Experimental Example 2] Using the designs shown in Figures 2 and 8, a 1x2 array antenna was fabricated with a mesh structure in which the unit cells were tilted at a 4° angle. Specifically, a mesh-structured electrode layer was formed on the top surface of a glass (0.7T) dielectric layer using an alloy of silver (Ag), palladium (Pd), and copper (Cu) (APC), and a ground layer was formed by vapor deposition on the bottom surface of the dielectric layer. The conductive lines in the mesh structure had a line width of 3 μm, and the electrodes had a thickness (or height) of 2000 Å. The distance between the electrodes and the ground layer was 380 μm. Example 2, Comparative Example 3, and Comparative Example 4 were fabricated with a fixed unit cell width of 100 μm and transmission line widths of 300 μm, 260 μm, and 340 μm, respectively, and the antenna gain at 28 GHz was measured. The results are shown in Table 2.

[0091] [Table 2]

[0092] Referring to FIG. 8 and Table 2, in the cases of Comparative Example 3 in which the ratio of the width of the transmission line to the width of the unit cell is 2.6, and Comparative Example 4 in which the ratio is 3.4, the antenna gains are 2.22 and 2.50, respectively, whereas in the case of Example 2 in which the ratio of the width of the transmission line to the width of the unit cell is an integer 3, the antenna gain is 2.67.

[0093] Furthermore, in Comparative Example 4, the number of intersections (dotted lines in FIG. 7) included in the transmission lines is greater than in Example 2, but the area occupied by the transmission lines in Comparative Example 4 is larger than in Example 2, and it can be seen that the antenna gain is inferior.

[0094] It can be confirmed that by forming the width of the transmission line to be an integral multiple of the width of the unit cell, signal loss in the transmission line can be prevented and the antenna gain can be improved.

Claims

1. a dielectric layer; a radiator formed on the dielectric layer; a transmission line connected to the radiator on the dielectric layer and formed of a mesh structure that is a collection of unit cells defined by a plurality of conductive lines; When the width of the transmission line is a and the width of the unit cell is b, the relationship 2.8≦a / b≦3.2 is satisfied, The antenna element, wherein the radiator and the unit cell have a diamond shape.

2. a signal pad connected to an end of the transmission line; The antenna element according to claim 1 , further comprising: a ground pad arranged around the signal pad so as to be separated from the signal pad.

3. The antenna element according to claim 2 , wherein the signal pad or the ground pad is formed with a solid structure.

4. The ground pad is The antenna element according to claim 2 , further comprising a pair of ground pads facing each other with the signal pad therebetween.

5. The antenna element according to claim 1 , further comprising a dummy pattern disposed on the dielectric layer around the radiator and the transmission line in an electrically isolated manner.

6. The antenna element according to claim 5 , wherein the radiator and the dummy pattern are formed in a mesh structure.

7. The antenna element according to claim 1 , further comprising a ground plane formed on a bottom surface of the dielectric layer.

8. A display device comprising the antenna element of claim 1.

Images