Antenna structure

Abstract

Provided is an antenna structure. The antenna structure comprises a feed-in adjustment part, an asymmetric radiation part, a first winding radiation part, a second winding radiation part, a connection radiation part, a first additional radiation part, a second additional radiation part and a dielectric substrate, wherein the first winding radiation part, the second winding radiation part and the connection radiation part can jointly form a closed circulation structure; the first additional radiation part is coupled to the connection radiation part and the first winding radiation part, wherein a first open slot and a first closed slot can be formed between the first winding radiation part and the first additional radiation part; the second additional radiation part is coupled to the connection radiation part and the second winding radiation part, wherein a second open slot and a second closed slot can be formed between the second winding radiation part and the second additional radiation part. Compared with the traditional design, the antenna at least has the advantages of small size, wide frequency band, low manufacturing cost, high radiation efficiency and the like, so that the antenna is very suitable for being applied to various communication devices.

Description

Technical Field

[0001] This invention relates to an antenna structure, and more particularly to a wideband antenna structure. Background Technology

[0002] With the advancement of mobile communication technology, mobile devices have become increasingly common in recent years, such as laptops, mobile phones, multimedia players, and other portable electronic devices with multiple functions. To meet people's needs, mobile devices typically have wireless communication capabilities. Some cover long-range wireless communication ranges; for example, mobile phones use 2G, 3G, and LTE (Long Term Evolution) systems and the frequency bands they use: 700MHz, 850MHz, 900MHz, 1800MHz, 1900MHz, 2100MHz, 2300MHz, and 2500MHz. Others cover short-range wireless communication ranges; for example, Wi-Fi and Bluetooth systems use the frequency bands of 2.4GHz, 5.2GHz, and 5.8GHz.

[0003] Antennas are indispensable components in wireless communication. If the bandwidth of an antenna used for receiving or transmitting signals is insufficient, it can easily lead to a degradation in the communication quality of mobile devices. Therefore, designing small-sized, wide-bandwidth antenna components is an important task for antenna designers.

[0004] Therefore, an antenna structure is needed to solve the above-mentioned technical problems. Summary of the Invention

[0005] In a preferred embodiment, the present invention provides an antenna structure comprising: a feed adjustment section coupled to a first feed point; an asymmetric radiating section coupled to the feed adjustment section; a first meandering radiating section coupled to a second feed point; a second meandering radiating section coupled to the second feed point; a connecting radiating section coupled between the first meandering radiating section and the second meandering radiating section, wherein the first meandering radiating section, the second meandering radiating section, and the connecting radiating section together form a closed loop structure; and a first additional radiating section coupled to the connecting radiating section, wherein the first additional radiating section is further coupled to... A first meandering radiating portion, wherein a first open slot and a first closed slot are formed between the first meandering radiating portion and the first additional radiating portion; a second additional radiating portion, coupled to a connecting radiating portion, wherein the second additional radiating portion is also coupled to a second meandering radiating portion, wherein a second open slot and a second closed slot are formed between the second meandering radiating portion and the second additional radiating portion; and a dielectric substrate, wherein the feed adjustment portion, the asymmetric radiating portion, the first meandering radiating portion, the second meandering radiating portion, the connecting radiating portion, the first additional radiating portion, and the second additional radiating portion are all disposed on the dielectric substrate.

[0006] In some embodiments, the feed adjustment section is presented as a straight strip of unequal width.

[0007] In some embodiments, the feed adjustment section is disposed between the first meandering radiator and the second meandering radiator.

[0008] In some embodiments, the asymmetric radiating portion includes a rectangular portion, a tapered portion, and an extension portion, wherein the tapered portion is coupled between the rectangular portion and the extension portion.

[0009] In some embodiments, the extension of the asymmetric radiating portion is closer to the first serpentine radiating portion than the second serpentine radiating portion.

[0010] In some embodiments, the first meandering radiating portion further includes a first edge extension section, and the second meandering radiating portion further includes a second edge extension section.

[0011] In some embodiments, the first meandering radiating portion takes the shape of an inverted U to define a first gap region.

[0012] In some embodiments, the first additional radiating portion extends into the first notch region and is coupled to a first connection point on the first meandering radiating portion.

[0013] In some embodiments, the second meandering radiating portion presents another inverted U-shape to define a second gap region.

[0014] In some embodiments, the second additional radiating portion extends into the second notch region and is coupled to a second connection point on the second meandering radiating portion.

[0015] In some embodiments, the combination of the feed adjustment section, the first meandering radiator, the second meandering radiator, the connecting radiator, the first additional radiator, and the second additional radiator presents a symmetrical pattern.

[0016] In some embodiments, the antenna structure covers a low-frequency band and a high-frequency band, wherein the high-frequency band includes a specific frequency, a first frequency range, a second frequency range, and a third frequency range.

[0017] In some embodiments, the low-frequency band is between 617 MHz and 960 MHz, while the high-frequency band is between 1450 MHz and 5925 MHz.

[0018] In some embodiments, a specific frequency is approximately 1700 MHz, a first frequency range is between 2500 MHz and 2700 MHz, a second frequency range is between 3300 MHz and 4200 MHz, and a third frequency range is between 5150 MHz and 5925 MHz.

[0019] In some embodiments, the length of the closed loop structure is approximately equal to 0.25 times the wavelength of the lowest frequency in the low-frequency band.

[0020] In some embodiments, the length of the asymmetric radiating portion is approximately equal to 0.25 times the wavelength of the lowest frequency in the high-frequency band.

[0021] In some embodiments, the length of each of the first and second opening slots is approximately equal to 0.25 times the wavelength of the center frequency of the first frequency range.

[0022] In some embodiments, the length of each of the first closed slot and the second closed slot is approximately equal to 0.25 times the wavelength of the center frequency of the second frequency range.

[0023] In some embodiments, the length of each of the first edge extension segment and the second edge extension segment is approximately equal to 0.25 times the wavelength of the center frequency of the third frequency range.

[0024] In some embodiments, the distance between the rectangular portion of the asymmetric radiator and the first or second meandering radiator is approximately equal to 0.125 times the wavelength of a specific frequency.

[0025] This invention proposes a novel antenna structure comprising at least one closed loop structure. Compared with conventional designs, this invention offers advantages such as small size, wide bandwidth, low manufacturing cost, and high radiation efficiency, making it well-suited for application in a wide variety of communication devices. Attached Figure Description

[0026] Figure 1This shows a top view of an antenna structure according to an embodiment of the present invention.

[0027] Figure 2 This diagram shows the radiation efficiency of an antenna structure according to an embodiment of the present invention.

[0028] Explanation of key component symbols:

[0029] 100 Antenna Structure

[0030] 110 Feed Adjustment Unit

[0031] 111 First end of the feed adjustment section

[0032] 112 Second end of the feed adjustment section

[0033] 120 Asymmetric Radiation Section

[0034] 121 The first end of the asymmetric radiating section

[0035] 122 The second end of the asymmetric radiating section

[0036] 124 Rectangular portion of the asymmetric radiating section

[0037] 125. The conical portion of the asymmetric radiating section.

[0038] 126. Extension of the asymmetric radiating section

[0039] 130 First winding radial section

[0040] 131 The first end of the first meandering radial section

[0041] 132 The second end of the first meandering radial section

[0042] 135 First Edge Extension Section

[0043] 137 First Gap Area

[0044] 140 Second winding radial section

[0045] 141 The first end of the second meandering radial section

[0046] 142 The second end of the second meandering radial section

[0047] 145 Second Edge Extension Section

[0048] 147 Second Gap Area

[0049] 150 Connecting Radiation Section

[0050] 151 The first end connected to the radiating section

[0051] 152 The second end connecting the radiating section

[0052] 160 First Additional Radiation Section

[0053] 161 First end of the first additional radiating section

[0054] 162 The second end of the first additional radiating section

[0055] 167 First Opening Slot Hole

[0056] 168 First closed slot hole

[0057] 170 Second Additional Radiation Section

[0058] 171 The first end of the second additional radiating section

[0059] 172 The second end of the second additional radiating section

[0060] 177 Second Opening Slot Hole

[0061] 178 Second Closed Groove

[0062] 180 Closed-loop structure

[0063] 190 dielectric substrate

[0064] CP1 First Connection Point

[0065] CP2 Second Connection Point

[0066] Spacing between D1 and D2

[0067] FBH high frequency band

[0068] FBL Low Frequency Band

[0069] FS specific frequency

[0070] FV1 First Frequency Range

[0071] FV2 Second Frequency Range

[0072] FV3 Third Frequency Range

[0073] FP1 First Feed Point

[0074] FP2 Second Feed Point

[0075] GC1 First Coupling Gap

[0076] GC2 Second Coupling Gap

[0077] Lengths of L1, L2, L3, L4, L5, L6, L7, and L8 Detailed Implementation

[0078] To make the objectives, features and advantages of the present invention more apparent and understandable, specific embodiments of the present invention are described below in detail with reference to the accompanying drawings.

[0079] Certain terms are used in the specification and claims to refer to specific elements. Those skilled in the art will understand that hardware manufacturers may use different names to refer to the same element. This specification and claims do not distinguish elements by differences in name, but rather by differences in function. The terms "comprising" and "including" used throughout the specification and claims are open-ended and should be interpreted as "comprising but not limited to." The term "generally" means that within an acceptable margin of error, those skilled in the art can solve the technical problem and achieve the basic technical effect within a certain margin of error. Furthermore, the term "coupled" in this specification includes any direct and indirect electrical connection means. Therefore, if a first device is described as coupled to a second device, it means that the first device can be directly electrically connected to the second device, or indirectly electrically connected to the second device via other devices or connection means.

[0080] The following disclosure provides many different embodiments or examples to implement the various features of this invention. The following disclosure describes specific examples of the various components and their arrangements for simplification. Of course, these specific examples are not intended to be limiting. For example, if this specification describes a first feature formed on or above a second feature, it indicates that it may include embodiments where the first and second features are in direct contact, or embodiments where additional features are formed between the first and second features, so that the first and second features may not be in direct contact. Furthermore, the same reference numerals and / or designations may be repeated in different examples of the following specification. These repetitions are for simplification and clarity and are not intended to limit any specific relationship between the different embodiments or / and structures discussed.

[0081] Furthermore, spatially related terms, such as "below," "below," "lower," "above," "higher," and similar terms, are used to facilitate the description of the relationship between one element or feature and another element(s) in the illustration. In addition to the orientations shown in the accompanying drawings, these spatially related terms are intended to encompass different orientations of the device in use or operation. The device may be rotated to different orientations (90 degrees or other orientations), and the spatially related terms used herein can be interpreted in the same way.

[0082] Figure 1This diagram shows a top view of an antenna structure 100 according to an embodiment of the present invention. The antenna structure 100 can be used as an external antenna element in a communication device, such as a wireless access point, but is not limited thereto. Figure 1 As shown, the antenna structure 100 includes: a feeding adjustment element 110, an asymmetrical radiation element 120, a first meandering radiation element 130, a second meandering radiation element 140, a connection radiation element 150, a first additional radiation element 160, a second additional radiation element 170, and a dielectric substrate 190. The feeding adjustment element 110, the asymmetrical radiation element 120, the first meandering radiation element 130, the second meandering radiation element 140, the connection radiation element 150, the first additional radiation element 160, and the second additional radiation element 170 can all be made of metal materials, such as copper, silver, aluminum, iron, or their alloys.

[0083] A feed adjustment section 110 is disposed between the first meandering radiator 130 and the second meandering radiator 140. It is important to note that the feed adjustment section 110 does not directly contact either the first meandering radiator 130 or the second meandering radiator 140. For example, a first coupling gap GC1 may be formed between the first meandering radiator 130 and the feed adjustment section 110, while a second coupling gap GC2 may be formed between the second meandering radiator 140 and the feed adjustment section 110. Specifically, the feed adjustment section 110 has a first end 111 and a second end 112, wherein the first end 111 of the feed adjustment section 110 is coupled to a first feeding point FP1. In some embodiments, the feed adjustment section 110 may be generally a straight strip of unequal width, and the width of its first end 111 may be greater than the width of its second end 112, but it is not limited to this.

[0084] The asymmetric radiating section 120 has a first end 121 and a second end 122, wherein the first end 121 of the asymmetric radiating section 120 is an open end, and the second end 122 of the asymmetric radiating section 120 is coupled to the second end 112 of the feed adjustment section 110. In some embodiments, the asymmetric radiating section 120 includes a rectangular portion 124 and a tapered portion 125 located at the first end 121, and an extension portion 126 located at the second end 122, wherein the tapered portion 125 is coupled between the rectangular portion 124 and the extension portion 126. In addition, the extension portion 126 of the asymmetric radiating section 120 may be closer to the first tapered radiating section 130 than the second meandering radiating section 140. It should be noted that the terms "adjacent" or "adjacent" in this specification may refer to the distance between two corresponding elements being less than a predetermined distance (e.g., 10 mm or less), but generally do not include the case where the two corresponding elements are in direct contact with each other (i.e., the aforementioned distance is shortened to 0).

[0085] The first meandering radiator 130 has a first end 131 and a second end 132, wherein the first end 131 of the first meandering radiator 130 is coupled to a second feed point FP2. For example, the first feed point FP1 may also be coupled to a positive electrode of a signal source (not shown), and the second feed point FP2 may also be coupled to a negative electrode of the signal source, wherein the aforementioned signal source may be a radio frequency (RF) module for exciting the antenna structure 100. In some embodiments, the first meandering radiator 130 further includes a first edge extension segment 135 adjacent to the extension portion 126 of the asymmetric radiator 120. In some embodiments, the first meandering radiator 130 may generally present an inverted U-shape to define a first notch region 137, but is not limited thereto.

[0086] The second meandering radiator 140 has a first end 141 and a second end 142, wherein the first end 141 of the second meandering radiator 140 is coupled to the second feed point FP2. In some embodiments, the second meandering radiator 140 further includes a second edge extension segment 145, wherein the second edge extension segment 145 is further away from the extension portion 126 of the asymmetric radiator 120 than the first edge extension segment 135. In some embodiments, the second meandering radiator 140 may generally present another inverted U-shape to define a second gap region 147, but is not limited thereto.

[0087] The connecting radiating portion 150 has a first end 151 and a second end 152, wherein the first end 151 of the connecting radiating portion 150 is coupled to the second end 132 of the first meandering radiating portion 130, and the second end 152 of the connecting radiating portion 150 is coupled to the second end 142 of the second meandering radiating portion 140. That is, the connecting radiating portion 150 is coupled between the first meandering radiating portion 130 and the second meandering radiating portion 140. It should be noted that the first meandering radiating portion 130, the second meandering radiating portion 140, and the connecting radiating portion 150 may together form a closed loop structure 180. In some embodiments, the connecting radiating portion 150 may be generally a straight strip of equal width, but is not limited to this.

[0088] The first additional radiating portion 160 has a first end 161 and a second end 162, wherein the first end 161 of the first additional radiating portion 160 is coupled to the first end 151 of the connecting radiating portion 150, and the second end 162 of the first additional radiating portion 160 may be a triangular open-circuit end. In some embodiments, the first additional radiating portion 160 may extend into the first notch region 137 and be coupled to a first connection point CP1 on the first meandering radiating portion 130, such that a first open slot 167 and a first closed slot 168 may be formed between the first meandering radiating portion 130 and the first additional radiating portion 160. For example, the first open slot 167 may communicate with the first notch region 137, but the first closed slot 168 may be completely independent of the first open slot 167. In some embodiments, the first additional radiating portion 160 may be generally a straight strip of unequal width, which may be generally perpendicular to the connecting radiating portion 150, but is not limited thereto.

[0089] The second additional radiating portion 170 has a first end 171 and a second end 172, wherein the first end 171 of the second additional radiating portion 170 is coupled to the second end 152 of the connecting radiating portion 150, and the second end 172 of the second additional radiating portion 170 may be another triangular open-circuit end. In some embodiments, the second additional radiating portion 170 may extend into the second notch region 147 and be coupled to a second connection point CP2 on the second meandering radiating portion 140, such that a second open slot 177 and a second closed slot 178 may be formed between the second meandering radiating portion 140 and the second additional radiating portion 170. For example, the second open slot 177 may communicate with the second notch region 147, but the second closed slot 178 may be completely independent of the second open slot 177. In some embodiments, the second additional radiating portion 170 may generally present another unequal-width straight strip shape, which may also be generally perpendicular to the connecting radiating portion 150, but is not limited thereto. In addition, both the first additional radiating part 160 and the second additional radiating part 170 can be completely surrounded by the aforementioned closed loop structure 180.

[0090] In some embodiments, the combination of the feed adjustment section 110, the first meandering radiator 130, the second meandering radiator 140, the connecting radiator 150, the first additional radiator 160, and the second additional radiator 170 can present a symmetrical pattern. In other words, the upper half of the antenna structure 100 can be an asymmetrical design, but the lower half of the antenna structure 100 can be a symmetrical design, thereby improving the overall impedance matching of the antenna structure 100.

[0091] The feed adjustment section 110, the asymmetric radiating section 120, the first meandering radiating section 130, the second meandering radiating section 140, the connecting radiating section 150, the first additional radiating section 160, and the second additional radiating section 170 can all be disposed on the same surface of the dielectric substrate 190. For example, the dielectric substrate 190 can be implemented by an FR4 (Flame Retardant) substrate, a printed circuit board (PCB), or a flexible printed circuit (FPC), but it is not limited to these.

[0092] Figure 2 This diagram displays the radiation efficiency of an antenna structure 100 according to an embodiment of the present invention, where the horizontal axis represents the operating frequency (MHz) and the vertical axis represents the radiation efficiency (%). Figure 2Based on the measurement results, antenna structure 100 can cover a low-frequency band (FBL) and a high-frequency band (FBH). For example, the low-frequency band (FBL) can be between 617MHz and 960MHz, while the high-frequency band (FBH) can be between 1450MHz and 5925MHz. Therefore, antenna structure 100 will at least support wideband operation in the sub-6GHz band of next-generation 5G (5th Generation Mobile Networks). It should be noted that the radiation efficiency of antenna structure 100 in both the low-frequency band (FBL) and the high-frequency band (FBH) can reach at least 60%, which is sufficient to meet the practical application requirements of general communication devices.

[0093] In detail, the high-frequency band FBH includes a specific frequency FS, a first frequency interval FV1, a second frequency interval FV2, and a third frequency interval FV3. For example, the specific frequency FS may be approximately 1700MHz, the first frequency interval FV1 may be between 2500MHz and 2700MHz, the second frequency interval FV2 may be between 3300MHz and 4200MHz, and the third frequency interval FV3 may be between 5150MHz and 5925MHz.

[0094] In some embodiments, the operating principle of the antenna structure 100 may be as follows. The closed-loop structure 180 is primarily used to generate the aforementioned low-frequency band FBL. The feed adjustment section 110, the asymmetric radiator 120, the first meandering radiator 130, the second meandering radiator 140, the connecting radiator 150, the first additional radiator 160, and the second additional radiator 170 can jointly generate the aforementioned high-frequency band FBH. The first open slot 167 and the second open slot 177 can both be used to fine-tune the impedance matching of the aforementioned first frequency range FV1. The first closed slot 168 and the second closed slot 178 can both be used to fine-tune the impedance matching of the aforementioned second frequency range FV2. Additionally, the first edge extension section 135 and the second edge extension section 145 can both be used to fine-tune the impedance matching of the aforementioned third frequency range FV3. According to actual measurement results, the addition of the first connection point CP1 and the second connection point CP2 helps to increase the operating bandwidth of the antenna structure 100. It must be understood that since antenna structure 100 is a planar antenna, its overall manufacturing cost can be further reduced.

[0095] In some embodiments, the component dimensions of the antenna structure 100 may be as described below. The length L1 of the closed-loop structure 180 may be approximately equal to 0.25 times the wavelength (λ / 4) of the lowest frequency of the low-frequency band FBL of the antenna structure 100. The length L2 of the asymmetric radiating portion 120 may be approximately equal to 0.25 times the wavelength (λ / 4) of the lowest frequency of the high-frequency band FBH of the antenna structure 100. The length L3 of the first open slot 167 may be approximately equal to 0.25 times the wavelength (λ / 4) of the center frequency of the first frequency interval FV1 of the high-frequency band FBH of the antenna structure 100. The length L4 of the second open slot 177 may be approximately equal to 0.25 times the wavelength (λ / 4) of the center frequency of the first frequency interval FV1 of the high-frequency band FBH of the antenna structure 100. The length L5 of the first closed slot 168 may be approximately equal to 0.25 times the wavelength (λ / 4) of the center frequency of the second frequency interval FV2 of the high-frequency band FBH of the antenna structure 100. The length L6 of the second closed slot 178 is approximately equal to 0.25 times the wavelength (λ / 4) of the center frequency of the second frequency range FV2 of the high-frequency band FBH of the antenna structure 100. The length L7 of the first edge extension section 135 is approximately equal to 0.25 times the wavelength (λ / 4) of the center frequency of the third frequency range FV3 of the high-frequency band FBH of the antenna structure 100. The length L8 of the second edge extension section 145 is approximately equal to 0.25 times the wavelength (λ / 4) of the center frequency of the third frequency range FV3 of the high-frequency band FBH of the antenna structure 100. The distance D1 between the rectangular portion 124 of the asymmetric radiating portion 120 and the first meandering radiating portion 130 is approximately equal to 0.125 times the wavelength (λ / 8) of the specific frequency FS of the high-frequency band FBH of the antenna structure 100. The distance D2 between the rectangular portion 124 of the asymmetric radiating section 120 and the second meandering radiating section 140 can be approximately equal to 0.125 times the wavelength (λ / 8) of a specific frequency FS of the high-frequency band FBH of the antenna structure 100. The width of the first coupling gap GC1 can be less than or equal to 2 mm. The width of the second coupling gap GC2 can be less than or equal to 2 mm. The dielectric substrate 190 can be approximately rectangular, with a length between 110 mm and 120 mm and a width between 20 mm and 25 mm. These dimensional ranges were determined based on multiple experimental results and help optimize the radiation efficiency, impedance matching, and operating bandwidth of the antenna structure 100.

[0096] This invention proposes a novel antenna structure comprising at least one closed loop structure. Compared with conventional designs, this invention offers advantages such as small size, wide bandwidth, low manufacturing cost, and high radiation efficiency, making it well-suited for application in a wide variety of communication devices.

[0097] It is worth noting that the component dimensions, shapes, and frequency ranges described above are not limiting factors of this invention. Antenna designers can adjust these settings according to different needs. The antenna structure of this invention is not limited to... Figure 1 , Figure 2 The state illustrated. This invention may include only... Figure 1 , Figure 2 Any one or more features of any one or more embodiments. In other words, not all the features illustrated need to be implemented simultaneously in the antenna structure of the present invention.

[0098] The ordinal numbers in this specification and claims, such as "first," "second," "third," etc., are not sequential in any particular order; they are only used to distinguish between two different elements with the same name.

[0099] While the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the scope of the invention. Any person skilled in the art should be able to make some modifications and refinements without departing from the spirit and scope of the invention. Therefore, the scope of protection of the present invention should be determined by the scope of the appended claims.

Claims

1. An antenna structure, comprising: a feed adjusting portion coupled to a first feed point; an asymmetric radiating portion coupled to the feed adjusting portion; a first meandered radiating portion coupled to a second feed point; a second meandered radiating portion coupled to the second feed point; a connecting radiating portion coupled between the first meandered radiating portion and the second meandered radiating portion, wherein the first meandered radiating portion, the second meandered radiating portion, and the connecting radiating portion collectively form a closed loop structure; a first additional radiating portion coupled to the connecting radiating portion, wherein the first additional radiating portion is further coupled to the first meandered radiating portion, and a first open slot and a first closed slot are formed between the first meandered radiating portion and the first additional radiating portion; a second additional radiating portion coupled to the connecting radiating portion, wherein the second additional radiating portion is further coupled to the second meandered radiating portion, and a second open slot and a second closed slot are formed between the second meandered radiating portion and the second additional radiating portion; and a dielectric substrate, wherein the feed adjusting portion, the asymmetric radiating portion, the first meandered radiating portion, the second meandered radiating portion, the connecting radiating portion, the first additional radiating portion, and the second additional radiating portion are disposed on the dielectric substrate.

2. The antenna structure of claim 1, wherein the feed adjusting portion presents an unequal-width straight bar shape.

3. The antenna structure of claim 1, wherein the feed adjusting portion is disposed between the first meandered radiating portion and the second meandered radiating portion.

4. The antenna structure of claim 1, wherein the asymmetric radiating portion includes a rectangular portion, a tapered portion, and an extended portion, and the tapered portion is coupled between the rectangular portion and the extended portion.

5. The antenna structure of claim 4, wherein the extended portion of the asymmetric radiating portion is closer to the first meandered radiating portion than the second meandered radiating portion.

6. The antenna structure of claim 4, wherein the first meandered radiating portion further includes a first edge extension segment, and the second meandered radiating portion further includes a second edge extension segment.

7. The antenna structure of claim 1, wherein the first meandered radiating portion presents an inverted U-shape to define a first notched region.

8. The antenna structure of claim 7, wherein the first additional radiating portion extends into the first notched region and is coupled to a first connection point on the first meandered radiating portion.

9. The antenna structure of claim 1, wherein the second meandered radiating portion presents another inverted U-shape to define a second notched region.

10. The antenna structure of claim 9, wherein the second additional radiating portion extends into the second notched region and is coupled to a second connection point on the second meandered radiating portion.

11. The antenna structure of claim 1, wherein a combination of the feed adjusting portion, the first meandering radiating portion, the second meandering radiating portion, the connecting radiating portion, the first additional radiating portion, and the second additional radiating portion presents a symmetrical pattern.

12. The antenna structure of claim 6, wherein the antenna structure covers a low frequency band and a high frequency band, and the high frequency band includes a specific frequency, a first frequency interval, a second frequency interval, and a third frequency interval.

13. The antenna structure of claim 12, wherein the low frequency band is between 617 MHz and 960 MHz, and the high frequency band is between 1450 MHz and 5925 MHz.

14. The antenna structure of claim 12, wherein the specific frequency is about 1700 MHz, the first frequency interval is between 2500 MHz and 2700 MHz, the second frequency interval is between 3300 MHz and 4200 MHz, and the third frequency interval is between 5150 MHz and 5925 MHz.

15. The antenna structure of claim 12, wherein a length of the closed loop structure is substantially equal to 0.25 times a wavelength of a lowest frequency of the low frequency band.

16. The antenna structure of claim 12, wherein a length of the asymmetric radiating portion is substantially equal to 0.25 times a wavelength of a lowest frequency of the high frequency band.

17. The antenna structure of claim 12, wherein a length of each of the first open slot and the second open slot is substantially equal to 0.25 times a wavelength of a center frequency of the first frequency interval.

18. The antenna structure of claim 12, wherein a length of each of the first closed slot and the second closed slot is substantially equal to 0.25 times a wavelength of a center frequency of the second frequency interval.

19. The antenna structure of claim 12, wherein a length of each of the first edge extension and the second edge extension is substantially equal to 0.25 times a wavelength of a center frequency of the third frequency interval.

20. The antenna structure of claim 12, wherein a distance between the rectangular portion of the asymmetric radiating portion and the first meandering radiating portion or the second meandering radiating portion is substantially equal to 0.125 times a wavelength of the specific frequency.

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