Antenna structure and mobile device

By designing an antenna structure including grounding elements, metal cavity, radiation part and capacitance elements, the problem of the existing antenna structure being too narrow in operation bandwidth is solved, and the effects of small size, wide band and high isolation are achieved, which are suitable for multi-band communication.

CN119864631APending Publication Date: 2025-04-22WISTRON NEWEB CORP
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Patent Information

Application Number
CN202311356006.8
Authority / Receiving Office
CN · China
Patent Type
Applications(China)
Current Assignee / Owner
Filing Date
2023-10-19
Publication Date
2025-04-22

AI Technical Summary

Technical Problem

The operating bandwidth of the existing antenna structure is too narrow, resulting in a decrease in the communication quality of the mobile device, making it difficult to meet the multi-band communication needs.

Method used

An antenna structure including a grounding element, a metal cavity, a radiating part and a capacitance element is designed, and the coverage of multi-bands is achieved through the combination of the metal cavity, a first radiating part, a second radiating part, a third radiating part and a capacitance element.

Benefits of technology

It realizes a small size, wide band and high isolation antenna structure, which can effectively support multi-band communication and is suitable for various communication devices.

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Abstract

An antenna structure and a mobile device are provided. The antenna structure comprises a grounding element, a metal cavity, a first radiation part, a second radiation part, a third radiation part and a capacitor element, the metal cavity comprises a first edge section and a second edge section which are opposite to each other, and the first edge section is coupled to the grounding element; the first radiation part is provided with a feed-in point, and the first radiation part is adjacent to the second edge section; the second radiation portion is coupled to the first edge section, wherein the second radiation portion is adjacent to the first radiation portion. The third radiation part is coupled to the second edge section; the capacitor element is coupled between the first edge section and the second edge section; the first radiation part, the second radiation part and the third radiation part are arranged between the first edge section and the second edge section. The antenna structure and the mobile device at least have the advantages of being small in size, wide in frequency band, high in isolation degree, capable of being operated in different environments and the like, and therefore the antenna structure and the mobile device are very suitable for being applied to various communication devices.
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Description

Technical Field

[0001] The present invention relates to an antenna structure, and in particular to a wideband antenna structure. Background Art

[0002] With the development of mobile communication technology, mobile devices have become increasingly popular in recent years, such as portable computers, mobile phones, multimedia players and other portable electronic devices with mixed functions. In order to meet people's needs, mobile devices usually have the function of wireless communication. Some cover long-distance wireless communication ranges, such as mobile phones using 2G, 3G, LTE (Long Term Evolution) systems and the 700MHz, 850MHz, 900MHz, 1800MHz, 1900MHz, 2100MHz, 2300MHz and 2500MHz frequency bands used for communication, while some cover short-distance wireless communication ranges, such as Wi-Fi, Bluetooth systems using 2.4GHz, 5.2GHz and 5.8GHz frequency bands for communication.

[0003] Antennas are indispensable components in the field of wireless communications. If the operational bandwidth of an antenna used to receive or transmit signals is too narrow, it is easy to cause the communication quality of the mobile device to deteriorate. Therefore, how to design a small-sized, wide-bandwidth antenna structure is an important issue for designers.

[0004] Therefore, an antenna structure and a mobile device are needed to solve the above problems. Summary of the invention

[0005] In a preferred embodiment, the present invention proposes an antenna structure, comprising: a grounding element; a metal cavity, comprising a first edge segment and a second edge segment opposite to each other, wherein the first edge segment is coupled to the grounding element; a first radiating portion, having a feeding point, wherein the first radiating portion is adjacent to the second edge segment; a second radiating portion, coupled to the first edge segment, wherein the second radiating portion is adjacent to the first radiating portion; a third radiating portion, coupled to the second edge segment; and a capacitive element, coupled between the first edge segment and the second edge segment; wherein the first radiating portion, the second radiating portion, and the third radiating portion are all arranged between the first edge segment and the second edge segment.

[0006] In some embodiments, the metal cavity is a hollow cuboid without a cover, the length of the metal cavity is between 37 mm and 45 mm, and the height of the metal cavity is between 3 mm and 9 mm.

[0007] In some embodiments, the metal cavity has an open side, and the first edge section and the second edge section are both located on the same plane near the open side.

[0008] In some embodiments, the first edge segment further includes a first protruding portion, and the second edge segment further includes a second protruding portion.

[0009] In some embodiments, the capacitive element is coupled between the first protruding portion of the first edge segment and the second protruding portion of the second edge segment.

[0010] In some embodiments, the first radiating portion is located between the second radiating portion and the third radiating portion.

[0011] In some embodiments, the first radiation portion is in an L-shape, an F-shape, or a T-shape.

[0012] In some embodiments, a first coupling gap is formed between the first radiating portion and the second edge segment, and a width of the first coupling gap is between 0.2 mm and 0.6 mm.

[0013] In some embodiments, the second radiation portion is in a straight strip shape.

[0014] In some embodiments, a second coupling gap is formed between the second radiating portion and the first radiating portion, and a width of the second coupling gap is between 0.2 mm and 0.5 mm.

[0015] In some embodiments, the third radiating portion is in a rectangular shape.

[0016] In some embodiments, the capacitive element is a distributed capacitor or a lumped capacitor.

[0017] In some embodiments, the capacitance of the capacitor is between 0.1 pF and 0.6 pF.

[0018] In some embodiments, the antenna structure covers a first frequency band, a second frequency band, and a third frequency band.

[0019] In some embodiments, the first frequency band is between 2400 MHz and 2500 MHz, the second frequency band is between 5150 MHz and 5850 MHz, and the third frequency band is between 5925 MHz and 7125 MHz.

[0020] In some embodiments, the metal cavity, the first radiation portion, and the capacitive element are jointly excited to generate a first frequency band.

[0021] In some embodiments, the first radiation portion generates a second frequency band.

[0022] In some embodiments, the second edge segment, the first radiation portion, and the third radiation portion are excited together to generate a third frequency band.

[0023] In some embodiments, the length of the first radiating portion is substantially equal to 0.25 times the wavelength of the second frequency band.

[0024] In another preferred embodiment, the present invention proposes a mobile device, comprising: a keyboard frame; a base shell; a hinge element; and an antenna structure as described above; wherein the antenna structure is disposed between the keyboard frame and the base shell; wherein the antenna structure is adjacent to the hinge element.

[0025] The present invention provides a novel antenna structure and a corresponding mobile device. Compared with the conventional design, the present invention has at least the advantages of small size, wide bandwidth, high isolation, and operability in different environments, so it is very suitable for application in various communication devices. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 A top view of an antenna structure according to an embodiment of the present invention is shown.

[0027] Figure 2 A cross-sectional view of an antenna structure according to an embodiment of the present invention is shown.

[0028] Figure 3 A voltage standing wave ratio diagram of an antenna structure according to an embodiment of the present invention is shown.

[0029] Figure 4 A top view of an antenna structure according to an embodiment of the present invention is shown.

[0030] Figure 5 A top view of an antenna structure according to an embodiment of the present invention is shown.

[0031] Figure 6 A top view of an antenna structure according to an embodiment of the present invention is shown.

[0032] Figure 7 A three-dimensional diagram of a mobile device according to an embodiment of the present invention is shown.

[0033] Main component symbols:

[0034] 100, 400, 500, 600, 701, 702 antenna structure

[0035] 110 Grounding element

[0036] 120 Metal cavity

[0037] 126 Side wall of metal cavity

[0038] 128 Opening side of metal cavity

[0039] 130 First edge segment

[0040] 135 First protruding portion of the first edge section

[0041] 140 Second edge segment

[0042] 145 The second protruding portion of the second edge section

[0043] 150, 450, 550, 650 First radiation part

[0044] 151 first end of the first radiation portion

[0045] 152 The second end of the first radiation portion

[0046] 160 Second Radiation

[0047] 161 The first end of the second radiation portion

[0048] 162 The second end of the second radiation portion

[0049] 170 The third radiation

[0050] 171 First end of the third radiation portion

[0051] 172 The second end of the third radiation portion

[0052] 180 Carrier element

[0053] 190 Signal Source

[0054] 700 Mobile Devices

[0055] 710 Upper cover shell

[0056] 720 display frame

[0057] 730 Keyboard frame

[0058] 740 Base housing

[0059] 750 Rotating shaft element

[0060] 760 Display

[0061] 770 Keyboard

[0062] 780 Touchpad

[0063] C1 capacitor element

[0064] CP1 First connection point

[0065] CP2 Second connection point

[0066] D1, D2, D3, D4 spacing

[0067] DS Specific Distance

[0068] E1 plane

[0069] FB1 First frequency band

[0070] FB2 Second frequency band

[0071] FB3 Third frequency band

[0072] FP Feed Point

[0073] GC1 First coupling gap

[0074] GC2 Second coupling gap

[0075] HT Height

[0076] L1, L2, L3, L4, L5, L6, LT Length

[0077] LN1 Hatch Line

[0078] PA Current Path

[0079] W1, W2, W3, WT Width DETAILED DESCRIPTION

[0080] In order to make the purpose, features and advantages of the present invention more obvious and easy to understand, specific embodiments of the present invention are given below and described in detail with reference to the accompanying drawings.

[0081] Certain words are used in the specification and claims to refer to specific components. It should be understood by those skilled in the art that hardware manufacturers may use different terms to refer to the same component. The specification and claims do not use differences in names as a way to distinguish components, but use differences in the functions of components as the criteria for distinction. The words "including" and "comprising" mentioned throughout the specification and claims are open-ended terms and should be interpreted as "including but not limited to". The word "substantially" means that within an acceptable error range, those skilled in the art can solve the technical problem and achieve the basic technical effect within a certain error range. In addition, the word "coupled" in this specification includes any direct and indirect electrical connection means. Therefore, if the text describes a first device 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.

[0082] The following disclosure provides many different embodiments or examples to implement the different features of the present invention. The following disclosure describes specific examples of various components and their arrangements to simplify the description. 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 means that it may include an embodiment in which the first feature and the second feature are in direct contact, and may also include an embodiment in which an additional feature is formed between the first feature and the second feature, so that the first feature and the second feature may not be in direct contact. In addition, the same reference symbols and / or marks may be reused in different examples in the following specification. These repetitions are for the purpose of simplification and clarity, and are not intended to limit the specific relationship between the different embodiments and / or structures discussed.

[0083] In addition, spatially relative terms such as "below," "beneath," "lower," "above," "upper," and the like are used to facilitate describing the relationship between one element or feature and another element or feature in the drawings. These spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the drawings. The device may be rotated 90 degrees or in other orientations, and the spatially relative terms used herein should be interpreted accordingly.

[0084] Figure 1 A top view of an antenna structure 100 according to an embodiment of the present invention is shown. Figure 2 A cross-sectional view (along the line) of an antenna structure 100 according to an embodiment of the present invention is shown. Figure 1 Please refer to the section line LN1. Figure 1 , Figure 2 The antenna structure 100 can be applied to a mobile device, such as a smart phone, a tablet computer, or a notebook computer. Figure 1 , Figure 2 In the embodiment of the present invention, the antenna structure 100 at least includes: a ground element 110, a metal cavity 120, a first radiation part 150, a second radiation part 160, a third radiation part 170, and a capacitive element C1, wherein the ground element 110, the first radiation part 150, the second radiation part 160, and the third radiation part 170 can all be made of metal materials, such as copper, silver, aluminum, iron, or alloys thereof.

[0085] The grounding element 110 may be implemented by a ground copper foil. In some embodiments, the grounding element 110 may also be coupled to a system ground plane (not shown), but is not limited thereto.

[0086] The metal cavity 120 includes a first edge segment 130 and a second edge segment 140 opposite to each other, wherein the first edge segment 130 is coupled to the grounding element 110. In detail, the metal cavity 120 may also have a sidewall 126 and an open side 128, wherein the sidewall 126 of the metal cavity 120 may be attached to the grounding element 110, and the first edge segment 130 and the second edge segment 140 may be located on the same plane E1 near the open side 128 of the metal cavity 120. For example, the aforementioned plane E1 may be substantially perpendicular to the grounding element 110. In some embodiments, the metal cavity 120 may be substantially a hollow cuboid without a cover, but is not limited thereto.

[0087] In some embodiments, the first edge segment 130 further includes a first protruding portion 135, and the second edge segment 140 further includes a second protruding portion 145, wherein the capacitor element C1 is coupled between the first protruding portion 135 of the first edge segment 130 and the second protruding portion 145 of the second edge segment 140. For example, the first protruding portion 135 of the first edge segment 130 may be substantially in the shape of a longer straight bar, and the second protruding portion 145 of the second edge segment 140 may be substantially in the shape of a shorter straight bar, but the present invention is not limited thereto.

[0088] Generally speaking, the first radiation portion 150 , the second radiation portion 160 , and the third radiation portion 170 may all be disposed between the first edge section 130 and the second edge section 140 . In addition, the first radiation portion 150 may also be located between the second radiation portion 160 and the third radiation portion 170 .

[0089] The first radiating portion 150 has a first end 151 and a second end 152, wherein a feeding point FP is located at the first end 151 of the first radiating portion 150, and the second end 152 of the first radiating portion 150 is an open end. The second end 152 of the first radiating portion 150 may extend substantially toward a direction close to the capacitor element C1. The feeding point FP may also be coupled to a signal source 190. For example, the aforementioned signal source 190 may be a radio frequency (RF) module, which may be used to excite the antenna structure 100. In some embodiments, the second end 152 of the first radiating portion 150 is adjacent to the second edge section 140, wherein a first coupling gap GC1 may be formed between the first radiating portion 150 and the second edge section 140. In some embodiments, the first radiating portion 150 may be substantially L-shaped, but is not limited thereto. It must be noted that the term "close" or "adjacent" in this specification may refer to the corresponding two elements being less than a critical distance (for example, 10 mm or shorter), but usually does not include the situation where the corresponding two elements are in direct contact with each other (that is, the aforementioned distance is shortened to 0).

[0090] The second radiating portion 160 has a first end 161 and a second end 162, wherein the first end 161 of the second radiating portion 160 is coupled to a first connection point CP1 on the first edge segment 130, and the second end 162 of the second radiating portion 160 is an open end. In some embodiments, the second end 162 of the second radiating portion 160 is adjacent to the second end 152 of the first radiating portion 150, so that a second coupling gap GC2 can be formed between the second radiating portion 160 and the first radiating portion 150. In some embodiments, the second radiating portion 160 can be substantially in the shape of a straight strip, which can be substantially parallel to the first protruding portion 135 of the first edge segment 130 and the second protruding portion 145 of the second edge segment 140, but is not limited thereto.

[0091] The third radiating portion 170 has a first end 171 and a second end 172, wherein the first end 171 of the third radiating portion 170 is coupled to a second connection point CP2 on the second edge section 140, and the second end 172 of the third radiating portion 170 is an open end. For example, the second end 172 of the third radiating portion 170 and the second end 162 of the second radiating portion 160 may extend in substantially opposite directions. In some embodiments, the third radiating portion 170 may be substantially rectangular, but is not limited thereto.

[0092] For example, the capacitor element C1 may be a distributed capacitor or a lumped capacitor. However, the present invention is not limited thereto. In other embodiments, the capacitor element C1 may also be a variable capacitor that can provide a tunable capacitance.

[0093] In some embodiments, the antenna structure 100 further includes a carrier element 180 located in the metal cavity 120, wherein the carrier element 180 may be adjacent to the opening side 128 of the metal cavity 120. The first edge section 130, the second edge section 140, the first radiating portion 150, the second radiating portion 160, the third radiating portion 170, and the capacitor element C1 may all be disposed on the same surface of the carrier element 180, wherein the surface may also be substantially aligned with the aforementioned plane E1. For example, the carrier element 180 may be a nonconductive support element or a dielectric substrate, but is not limited thereto. It must be understood that the carrier element 180 is only an optional element and may be removed in other embodiments.

[0094] Figure 3 The voltage standing wave ratio (VSWR) diagram of the antenna structure 100 according to an embodiment of the present invention is shown, wherein the horizontal axis represents the operating frequency (MHz) and the vertical axis represents the voltage standing wave ratio. Figure 3 According to the measurement results, the antenna structure 100 can cover a first frequency band FB1, a second frequency band FB2, and a third frequency band FB3. For example, the first frequency band FB1 can be between 2400MHz and 2500MHz, the second frequency band FB2 can be between 5150MHz and 5850MHz, and the third frequency band FB3 can be between 5925MHz and 7125MHz. Therefore, the antenna structure 100 will at least support the broadband operation of the traditional WLAN (Wireless Local Area Network) and the new generation Wi-Fi 6E.

[0095] In some embodiments, the operating principle of the antenna structure 100 may be as follows. The metal cavity 120, the first radiating portion 150, and the capacitor element C1 may be jointly excited to generate the aforementioned first frequency band FB1. In detail, the metal cavity 120 may be coupled and excited by the first radiating portion 150 to form a current path PA, wherein the current path PA may mainly contribute to the first frequency band FB1. The first radiating portion 150 may also be separately excited to generate the aforementioned second frequency band FB2, wherein the second radiating portion 160 may be used to fine-tune the impedance matching (Impedance Matching) of the aforementioned second frequency band FB2. In addition, the second edge section 140, the first radiating portion 150, and the third radiating portion 170 may be jointly excited to generate the aforementioned third frequency band FB3. According to actual measurement results, the addition of the capacitor element C1 may also be used to significantly increase the bandwidth of the aforementioned first frequency band FB1.

[0096] In some embodiments, the element dimensions and element parameters of the antenna structure 100 may be as follows. The length LT of the metal cavity 120 may be greater than or equal to 40 mm, for example, about 50 mm. The width WT of the metal cavity 120 may be between 10 mm and 20 mm, for example, about 15 mm. The height HT of the metal cavity 120 may be between 3 mm and 9 mm, for example, about 6 mm. The length L1 of the first radiating portion 150 may be substantially equal to 0.25 times the wavelength (λ / 4) of the second frequency band FB2 of the antenna structure 100. The width W1 of the first radiating portion 150 may be between 1 mm and 3 mm. The length L2 of the second radiating portion 160 may be between 2 mm and 5 mm. The width W2 of the second radiating portion 160 may be between 1 mm and 2 mm. The length L3 of the third radiating portion 170 may be between 3 mm and 5 mm. The width W3 of the third radiating portion 170 may be between 2 mm and 4 mm. The capacitance value of the capacitive element C1 may be between 0.1 pF and 0.6 pF. The length of the current path PA may be between 37 mm and 45 mm, which may be approximately equal to 0.25 times the wavelength (λ / 4) of the first frequency band FB1 of the antenna structure 100. The width of the first coupling gap GC1 may be between 0.2 mm and 0.6 mm. The width of the second coupling gap GC2 may be between 0.2 mm and 0.5 mm. The spacing D1 between the first edge segment 130 and the second edge segment 140 may be between 6 mm and 12 mm. The spacing D2 between the feed point FP and the first protruding portion 135 of the first edge segment 130 may be less than 0.25 times the wavelength (λ / 4) of the first frequency band FB1 of the antenna structure 100. The spacing D3 between the second radiating portion 160 and the first protruding portion 135 of the first edge segment 130 may be between 3 mm and 6 mm. The spacing D4 between the third radiating portion 170 and the first radiating portion 150 may be between 4 mm and 10 mm. The above ranges of component sizes and component parameters are obtained based on multiple experimental results, which help optimize the operational bandwidth and impedance matching of the antenna structure 100. In addition, if more antenna structures 100 are used together, the above ranges can also maximize the isolation between these antenna structures.

[0097] Figure 4 A top view of an antenna structure 400 according to an embodiment of the present invention is shown. Figure 4 and Figure 1 Similar. Figure 4 In the embodiment, a first radiating portion 450 of the antenna structure 400 may be substantially F-shaped, wherein a partial length L4 of the first radiating portion 450 may be substantially equal to 0.25 times the wavelength (λ / 4) of the second frequency band FB2 of the antenna structure 400 . Figure 4 The remaining features of the antenna structure 400 are the same as Figure 1The antenna structure 100 is similar, so the two embodiments can achieve similar operating effects.

[0098] Figure 5 A top view of an antenna structure 500 according to an embodiment of the present invention is shown. Figure 5 and Figure 1 Similar. Figure 5 In the embodiment, a first radiating portion 550 of the antenna structure 500 may be substantially T-shaped, wherein a partial length L5 of the first radiating portion 550 may be substantially equal to 0.25 times the wavelength (λ / 4) of the second frequency band FB2 of the antenna structure 500 . Figure 5 The remaining features of the antenna structure 500 are the same as Figure 1 The antenna structure 100 is similar, so the two embodiments can achieve similar operating effects.

[0099] Figure 6 A top view of an antenna structure 600 according to an embodiment of the present invention is shown. Figure 6 and Figure 1 Similar. Figure 6 In the embodiment, a first radiating portion 650 of the antenna structure 600 can be implemented by a planar inverted F antenna (PIFA), wherein a partial length L6 of the first radiating portion 650 can also be approximately equal to 0.25 times the wavelength (λ / 4) of the second frequency band FB2 of the antenna structure 600. Figure 6 The remaining features of the antenna structure 600 are the same as Figure 1 The antenna structure 100 is similar, so the two embodiments can achieve similar operating effects.

[0100] Figure 7 A perspective view of a mobile device 700 according to an embodiment of the present invention is shown. Figure 7In the embodiment of the present invention, the mobile device 700 may include one or more antenna structures 701 and 702 as described in the previous embodiment, and the mobile device 700 may be a notebook computer, which may include an upper cover housing 710, a display frame 720, a keyboard frame 730, and a base housing 740. It should be understood that the upper cover housing 710, the display frame 720, the keyboard frame 730, and the base housing 740 are respectively equivalent to the so-called "A part", "B part", "C part", and "D part" in the field of mobile devices. In addition, the mobile device 700 may also include a hinge element 750, a display device 760, a keyboard 770, and a click panel 780. The aforementioned antenna structures 701 and 702 can be disposed between the keyboard frame 730 and the base housing 740, and can both be adjacent to the hinge element 750 of the mobile device 700. According to actual measurement results, since the noise at the hinge element 750 is usually relatively large, the use of the metal cavity can avoid the negative impact on the radiation performance of the aforementioned antenna structures 701 and 702. In addition, if a specific distance DS between the aforementioned antenna structures 701 and 702 is less than or equal to 8 mm, it is sufficient to enhance the overall antenna isolation.

[0101] The present invention provides a novel antenna structure and a corresponding mobile device. Compared with the conventional design, the present invention has at least the advantages of small size, wide bandwidth, high isolation, and operability in different environments, so it is very suitable for application in various communication devices.

[0102] It is worth noting that the above-mentioned element size, element shape, element parameters, and frequency range are not limiting conditions of the present invention. Antenna designers can adjust these settings according to different needs. The antenna structure and mobile device of the present invention are not limited to Figure 1-Figure 7 The present invention may only include Figure 1-Figure 7 In other words, not all the features shown in the figure need to be implemented in the antenna structure and mobile device of the present invention at the same time.

[0103] In the present specification and claims, ordinal numbers, such as "first", "second", "third", etc., have no sequential relationship with each other, and are only used to distinguish two different components with the same name.

[0104] Although the present invention is disclosed as above in terms of preferred embodiments, it is not intended to limit the scope of the present invention. Any technician in this field should be able to make some changes and modifications without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention should be based on the scope defined by the attached claims.

Claims

1. An antenna structure, comprising: a grounding element; a metal cavity, the metal cavity comprising a first edge section and a second edge section opposite to each other, wherein the first edge section is coupled to the ground element; a first radiating portion, the first radiating portion having a feeding point, wherein the first radiating portion is adjacent to the second edge section; a second radiating portion, the second radiating portion coupled to the first edge section, wherein the second radiating portion is adjacent to the first radiating portion; a third radiating portion, the third radiating portion coupled to the second edge section; as well as a capacitive element coupled between the first edge section and the second edge section; The first radiation portion, the second radiation portion, and the third radiation portion are all disposed between the first edge section and the second edge section. 2 . The antenna structure as claimed in claim 1 , wherein the metal cavity is a hollow cuboid without a cover, the length of the metal cavity is between 37 mm and 45 mm, and the height of the metal cavity is between 3 mm and 9 mm. 3 . The antenna structure as claimed in claim 1 , wherein the metal cavity has an open side, and the first edge section and the second edge section are both located on the same plane near the open side. 4 . The antenna structure as claimed in claim 1 , wherein the first edge section further comprises a first protruding portion, and the second edge section further comprises a second protruding portion. 5 . The antenna structure as claimed in claim 4 , wherein the capacitive element is coupled between the first protruding portion of the first edge section and the second protruding portion of the second edge section. The antenna structure as claimed in claim 1 , wherein the first radiating portion is located between the second radiating portion and the third radiating portion. 7 . The antenna structure as claimed in claim 1 , wherein the first radiating portion is in an L-shape, an F-shape, or a T-shape. 8 . The antenna structure as claimed in claim 1 , wherein a first coupling gap is formed between the first radiating portion and the second edge section, and a width of the first coupling gap is between 0.2 mm and 0.6 mm. 9 . The antenna structure as claimed in claim 1 , wherein the second radiating portion is in a straight strip shape. 10 . The antenna structure as claimed in claim 1 , wherein a second coupling gap is formed between the second radiating portion and the first radiating portion, and a width of the second coupling gap is between 0.2 mm and 0.5 mm. The antenna structure as claimed in claim 1 , wherein the third radiating portion has a rectangular shape. 12 . The antenna structure as claimed in claim 1 , wherein the capacitive element is a distributed capacitor or a lumped capacitor. 13 . The antenna structure as claimed in claim 1 , wherein a capacitance value of the capacitor element is between 0.1 pF and 0.6 pF. 14 . The antenna structure as claimed in claim 1 , wherein the antenna structure covers a first frequency band, a second frequency band, and a third frequency band. 15 . The antenna structure of claim 14 , wherein the first frequency band is between 2400 MHz and 2500 MHz, the second frequency band is between 5150 MHz and 5850 MHz, and the third frequency band is between 5925 MHz and 7125 MHz. 16 . The antenna structure as claimed in claim 14 , wherein the metal cavity, the first radiating portion, and the capacitor element are jointly excited to generate the first frequency band. The antenna structure as claimed in claim 14 , wherein the first radiating portion is excited to generate the second frequency band. 18 . The antenna structure as claimed in claim 14 , wherein the second edge section, the first radiating portion, and the third radiating portion are excited together to generate the third frequency band.

19. The antenna structure as claimed in claim 14, wherein a length of the first radiating portion is substantially equal to 0.25 times the wavelength of the second frequency band.

20. A mobile device, comprising: A keyboard frame; a base housing; a rotating shaft element; as well as An antenna structure as claimed in claim 1; The antenna structure is disposed between the keyboard frame and the base housing; The antenna structure is adjacent to the rotating shaft element.