Antenna structure

Abstract

An antenna structure is disclosed. The antenna structure includes: a grounding element, a first radiating element, a second radiating element, a capacitive element, a third radiating element, an adjustable circuit, a fourth radiating element, a fifth radiating element, and a non-conductive support element. The first radiating element has a feed point; the second radiating element is coupled to the feed point; the third radiating element is coupled to the second radiating element via the capacitive element; the fourth radiating element is coupled to the grounding element via the adjustable circuit and is adjacent to the first radiating element; the fifth radiating element is coupled to the fourth radiating element; the non-conductive support element has a first surface and a second surface opposite to each other; the first radiating element, the second radiating element, the capacitive element, the third radiating element, and the fourth radiating element are all disposed on the first surface, and the fifth radiating element is disposed on the second surface. The antenna structure of the present invention has advantages such as small size, wide bandwidth, and good circuit integration, making it well-suited for application in various mobile 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. Summary of the Invention

[0004] In a preferred embodiment, the present invention provides an antenna structure comprising: a grounding element providing a ground potential; a first radiating portion having a feed point; a second radiating portion coupled to the feed point; a capacitor element; a third radiating portion coupled to the second radiating portion via the capacitor element; an adjustable circuit providing a variable impedance value according to a control signal; a fourth radiating portion coupled to the grounding element via the adjustable circuit, wherein the fourth radiating portion is adjacent to the first radiating portion; a fifth radiating portion coupled to the fourth radiating portion; and a non-conductive support element having a first surface and a second surface opposite to each other, wherein the first radiating portion, the second radiating portion, the capacitor element, the third radiating portion, and the fourth radiating portion are all disposed on the first surface of the non-conductive support element, and the fifth radiating portion is disposed on the second surface of the non-conductive support element.

[0005] In some embodiments, the grounding element and the adjustable circuit are disposed on the first or second surface of the non-conductor support element.

[0006] In some embodiments, the combination of the second radiating part, the capacitor element, and the third radiating part presents a Z-shape.

[0007] In some embodiments, the capacitor element is implemented by a lumped capacitor or a distributed capacitor.

[0008] In some embodiments, the capacitance value of the capacitor element is between 0.1pF and 8.2pF.

[0009] In some embodiments, the adjustable circuit includes: a first capacitor coupled to a ground potential; a second capacitor coupled to a ground potential; a third capacitor coupled to a ground potential; and a switch coupled to a fourth radiating section, wherein the switch switches between the first capacitor, the second capacitor, and the third capacitor according to a control signal.

[0010] In some embodiments, the capacitance value of the first capacitor is between 8.2pF and 27pF.

[0011] In some embodiments, the capacitance value of the second capacitor is between 2.8 pF and 8.2 pF.

[0012] In some embodiments, the capacitance of the third capacitor is between 1pF and 2.8pF.

[0013] In some embodiments, the adjustable circuit includes: a first capacitor coupled to a ground potential; a second capacitor coupled to a ground potential; an open path coupled to a ground potential; and a switch coupled to a fourth radiating element, wherein the switch switches between the first capacitor, the second capacitor, and the open path according to a control signal.

[0014] In some embodiments, the fourth radiating portion has a longer L-shape, while the fifth radiating portion has a shorter L-shape.

[0015] In some embodiments, a coupling gap is formed between the first radiating portion and the fourth radiating portion, and the width of the coupling gap is between 0.2 mm and 1 mm.

[0016] In some embodiments, the fifth radiating portion is adjacent to the capacitor element.

[0017] In some embodiments, the fifth radiating portion has a vertical projection on the first surface of the non-conductive support element, and the vertical projection at least partially overlaps with the capacitor element.

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

[0019] In some embodiments, the first frequency band is between 617MHz and 960MHz, the second frequency band is between 1427MHz and 1610MHz, the third frequency band is between 1710MHz and 2690MHz, and the fourth frequency band is between 3300MHz and 6000MHz.

[0020] In some embodiments, the length of the first radiating element is approximately equal to 0.25 times the wavelength of the fourth frequency band.

[0021] In some embodiments, the total length of the second radiating portion and the third radiating portion is between 0.125 and 0.25 times the wavelength of the second frequency band.

[0022] In some embodiments, the length of the third radiating element is approximately equal to 0.125 times the wavelength of the third frequency band.

[0023] In some embodiments, the total length of the fourth and fifth radiating portions is between 0.125 and 0.25 times the wavelength of the first frequency band.

[0024] This invention proposes a novel antenna structure. Compared with traditional designs, this invention has advantages such as small size, wide bandwidth, and good circuit integration, making it well-suited for application in a wide variety of mobile communication devices. Attached Figure Description

[0025] Figure 1 This shows a top view of an antenna structure according to an embodiment of the present invention.

[0026] Figure 2 This shows a cross-sectional view of an antenna structure according to an embodiment of the present invention.

[0027] Figure 3 This diagram shows an adjustable circuit according to an embodiment of the present invention.

[0028] Figure 4 This diagram shows the return loss of an antenna structure according to an embodiment of the present invention.

[0029] Figure 5 This diagram shows the return loss of an antenna structure according to an embodiment of the present invention.

[0030] Figure 6 This diagram shows an adjustable circuit according to another embodiment of the present invention.

[0031] Explanation of key component symbols:

[0032] 100 Antenna Structure

[0033] 110 Grounding element

[0034] 120 First Radiation Department

[0035] 121 First end of the first radiating section

[0036] 122 The second end of the first radiating section

[0037] 130 Second Radiation Section

[0038] 131 The first end of the second radiating section

[0039] 132 The second end of the second radiating section

[0040] 140 Capacitor Components

[0041] 150 Third Radiation Section

[0042] 151 The first end of the third radiating section

[0043] 152 The second end of the third radiating section

[0044] 160 and 660 adjustable circuits

[0045] 170 Fourth Radiation Department

[0046] 171 The first end of the fourth radiating section

[0047] 172 The second end of the fourth radiating section

[0048] 180 Fifth Radiation Department

[0049] 181 The first end of the fifth radiating section

[0050] 182 The second end of the fifth radiating section

[0051] 190 Non-conductor support element

[0052] 199 signal source

[0053] 165, 665 switch

[0054] 667 Opening Path

[0055] C1 First capacitor

[0056] C2 Second capacitor

[0057] C3 Third capacitor

[0058] CC1 First Curve

[0059] CC2 Second Curve

[0060] CC3 Third Curve

[0061] CC4 Fourth Curve

[0062] CC5 Fifth Curve

[0063] E1 First surface of non-conductor support element

[0064] E2 Second surface of non-conductor support element

[0065] FB1 First Band

[0066] FB2 Second Band

[0067] FB3 Third Band

[0068] FB4 Fourth Band

[0069] FP feed point

[0070] GC1 coupling gap

[0071] H1 thickness

[0072] Lengths of L1, L2, L3, and L4

[0073] LC1 section line

[0074] SC control signal

[0075] VSS ground potential

[0076] Z Variable impedance value Detailed Implementation

[0077] 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 conjunction with the accompanying drawings.

[0078] 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.

[0079] 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.

[0080] 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.

[0081] Figure 1 This shows a top view of an antenna structure 100 according to an embodiment of the present invention. Figure 2 A cross-sectional view of an antenna structure 100 according to an embodiment of the present invention is shown (along...). Figure 1 (See section line LC1 in the text). Please refer to it as well. Figure 1 , Figure 2 The antenna structure 100 can be fitted into a mobile device, such as a smartphone, a tablet computer, or a notebook computer. Figure 1 , Figure 2As shown, the antenna structure 100 includes: a ground element 110, a first radiating element 120, a second radiating element 130, a capacitive element 140, a third radiating element 150, a tunable circuit 160, a fourth radiating element 170, a fifth radiating element 180, and a nonconductive support element 190. The ground element 110, the first radiating element 120, the second radiating element 130, the third radiating element 150, the fourth radiating element 170, and the fifth radiating element 180 can all be made of metal materials, such as copper, silver, aluminum, iron, or their alloys.

[0082] The grounding element 110 may be implemented by a ground copper foil. In some embodiments, the grounding element 110 may provide a ground voltage VSS and may be further coupled to a system ground plane (not shown) of the antenna structure 100.

[0083] For example, the first radiating section 120 may be generally in the shape of a straight strip. Specifically, the first radiating section 120 has a first end 121 and a second end 122, wherein a feed point FP is located at the first end 121 of the first radiating section 120, and the second end 122 of the first radiating section 120 is an open end. The feed point FP may also be coupled to a positive electrode of a signal source 199, while a negative electrode of the signal source 199 may be coupled to a ground element 110. For example, the signal source 199 may be a radio frequency (RF) module, which can be used to excite the antenna structure 100.

[0084] For example, the second radiating portion 130 may generally be L-shaped or another straight strip shape. Specifically, the second radiating portion 130 has a first end 131 and a second end 132, wherein the first end 131 of the second radiating portion 130 is coupled to the feed point FP, and the second end 132 of the second radiating portion 130 is coupled to one end of the capacitor element 140. In some embodiments, the first radiating portion 120 and the second radiating portion 130 may both be generally arranged on the same straight line.

[0085] The type and form of the capacitor element 140 are not particularly limited in this invention. In some embodiments, the capacitor element 140 may be implemented by a lumped capacitor. In other embodiments, the capacitor element 140 may be implemented by a distributed capacitor.

[0086] For example, the third radiating portion 150 may generally present another L-shape. Specifically, the third radiating portion 150 has a first end 151 and a second end 152, wherein the first end 151 of the third radiating portion 150 is coupled to the other end of the capacitor element 140, and the second end 152 of the third radiating portion 150 is an open-circuit end. That is, the third radiating portion 150 may be coupled to the second radiating portion 130 via the capacitor element 140. In some embodiments, the combination of the second radiating portion 130, the capacitor element 140, and the third radiating portion 150 may generally present a Z-shape. In some embodiments, the second end 122 of the first radiating portion 120 and the second end 152 of the third radiating portion 150 may extend in generally opposite and mutually distant directions.

[0087] Adjustable circuit 160 is coupled to ground potential VSS. In some embodiments, adjustable circuit 160 can provide a variable impedance value Z according to a control signal SC. For example, the aforementioned control signal SC may be generated by a processor according to a user input (not shown), but is not limited to this.

[0088] For example, the fourth radiating portion 170 may generally present an elongated L-shape. Specifically, the fourth radiating portion 170 has a first end 171 and a second end 172, wherein the first end 171 of the fourth radiating portion 170 is coupled to the adjustable circuit 160. That is, the fourth radiating portion 170 is coupled to the grounding element 110 via the adjustable circuit 160. In some embodiments, the fourth radiating portion 170 is adjacent to the first radiating portion 120, wherein a coupling gap GC1 may be formed between the first radiating portion 120 and the fourth radiating portion 170. It should be noted that the terms "adjacent" or "adjacent" in this specification may refer to a distance between two corresponding elements that is less than a predetermined distance (e.g., 10 mm or less), but generally do not include cases where the two corresponding elements are in direct contact with each other (i.e., the aforementioned distance is reduced to 0).

[0089] For example, the fifth radiating portion 180 may generally present a shorter L-shape (compared to the fourth radiating portion 170). Specifically, the fifth radiating portion 180 has a first end 181 and a second end 182, wherein the first end 181 of the fifth radiating portion 180 is coupled to the second end 172 of the fourth radiating portion 170, and the second end 182 of the fifth radiating portion 180 is an open-circuit end. In some embodiments, the fifth radiating portion 180 is adjacent to the capacitor element 140, wherein the second end 182 of the fifth radiating portion 180 may extend across the capacitor element 140. In some embodiments, the second end 152 of the third radiating portion 150 and the second end 182 of the fifth radiating portion 180 may both extend in generally the same direction.

[0090] The non-conductive support element 190 can be made of plastic material, and its shape and style are not particularly limited as described in this invention. For example, the non-conductive support element 190 can be implemented using a plastic partition element. Alternatively, the non-conductive support element 190 can also be implemented using a printed circuit board (PCB) or a flexible printed circuit (FPC). Specifically, the non-conductive support element 190 has a first surface E1 and a second surface E2 opposite to each other, wherein the first radiating portion 120, the second radiating portion 130, the capacitor element 140, the third radiating portion 150, and the fourth radiating portion 170 can all be disposed on the first surface E1 of the non-conductive support element 190, while the fifth radiating portion 180 can be disposed on the second surface E2 of the non-conductive support element 190. On the other hand, the grounding element 110 and the adjustable circuit 160 can be selectively disposed on the first surface E1 or the second surface E2 of the non-conductive support element 190. It must be understood that because both the fourth radiating portion 170 and the fifth radiating portion 180 extend to the same edge of the non-conductive support element 190, they can be easily coupled to each other. In some embodiments, the fifth radiating portion 180 has a vertical projection on the first surface E1 of the non-conductive support element 190, wherein the vertical projection of the fifth radiating portion 180 at least partially overlaps with the capacitive element 140. In other embodiments, the antenna structure 100 may further include a conductive via element (not shown) penetrating through the non-conductive support element 190, wherein the fifth radiating portion 180 can be coupled to the fourth radiating portion 170 via this conductive via element.

[0091] Figure 3 A schematic diagram of an adjustable circuit 160 according to an embodiment of the present invention is shown. Figure 3In one embodiment, the adjustable circuit 160 includes a switch element 165, a first capacitor C1, a second capacitor C2, and a third capacitor C3, wherein the first capacitor C1, the second capacitor C2, and the third capacitor C3 have different capacitance values, but they are all coupled to ground potential VSS. Specifically, one end of the switch element 165 is coupled to the first end 171 of the fourth radiator 170, while the other end of the switch element 165 switches between the first capacitor C1, the second capacitor C2, and the third capacitor C3 according to a control signal SC. That is, if the adjustable circuit 160 uses the switch element 165 to select one of the first capacitor C1, the second capacitor C2, and the third capacitor C3, the fourth radiator 170 can be coupled to ground potential VSS via the selected capacitor. In some embodiments, the capacitance value of the first capacitor C1 is greater than the capacitance value of the second capacitor C2, and the capacitance value of the second capacitor C2 is greater than the capacitance value of the third capacitor C3, but this is not a limitation.

[0092] Figure 4 This diagram shows the return loss 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 return loss (dB). Figure 4 As shown, a first curve CC1 represents the operating characteristics of the antenna structure 100 when the switch 165 of the adjustable circuit 160 switches to the first capacitor C1, a second curve CC2 represents the operating characteristics of the antenna structure 100 when the switch 165 of the adjustable circuit 160 switches to the second capacitor C2, and a third curve CC3 represents the operating characteristics of the antenna structure 100 when the switch 165 of the adjustable circuit 160 switches to the third capacitor C3. According to... Figure 4 Based on the measurement results, antenna structure 100 can cover a first frequency band FB1, a second frequency band FB2, a third frequency band FB3, and a fourth frequency band FB4. For example, the first frequency band FB1 can be between 617MHz and 960MHz, the second frequency band FB2 can be between 1427MHz and 1610MHz, the third frequency band FB3 can be between 1710MHz and 2690MHz, and the fourth frequency band FB4 can be between 3300MHz and 6000MHz. Therefore, antenna structure 100 will at least support broadband operation of GPS (Global Positioning System) and LTE (Long Term Evolution).

[0093] In some embodiments, the antenna structure 100 operates as follows. The first radiating section 120 and the second radiating section 130 can generate the aforementioned fourth frequency band FB4. The second radiating section 130, the capacitor element 140, and the third radiating section 150 can generate the aforementioned second frequency band FB2 and third frequency band FB3. The fourth radiating section 170 and the fifth radiating section 180 can generate the aforementioned first frequency band FB1. Furthermore, the adjustable circuit 160 can further increase the bandwidth of the aforementioned first frequency band FB1.

[0094] Figure 5 This diagram illustrates the return loss 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 return loss (dB). Figure 5 As shown, a fourth curve CC4 represents the operating characteristics of the antenna structure 100 without the capacitor element 140, while a fifth curve CC5 represents the operating characteristics of the antenna structure 100 with the capacitor element 140. According to... Figure 5 The comparison results show that the proposed capacitor element 140 helps improve the impedance matching of the antenna structure 100 in the second frequency band FB2. Furthermore, if the fifth radiating section 180 and the capacitor element 140 at least partially overlap, the stability of the antenna structure 100 can be further enhanced. It must be noted that regardless of the switching operation of the adjustable circuit 160, the antenna structure 100 of the present invention can cover the required GPS frequency band.

[0095] In some embodiments, the component dimensions and parameters of the antenna structure 100 may be as described below. The length L1 of the first radiating portion 120 may be approximately equal to 0.25 times the wavelength (λ / 4) of the fourth frequency band FB4 of the antenna structure 100. The total length L2 of the second radiating portion 130 and the third radiating portion 150 may be between 0.125 times and 0.25 times the wavelength (λ / 8 to λ / 4) of the second frequency band FB2 of the antenna structure 100. It must be understood that because the capacitor element 140 is relatively small, its length is almost negligible. The length L3 of the third radiating portion 150 may be approximately equal to 0.125 times the wavelength (λ / 8) of the third frequency band FB3 of the antenna structure 100. The total length L4 of the fourth radiating portion 170 and the fifth radiating portion 180 may be between 0.125 times and 0.25 times the wavelength (λ / 8 to λ / 4) of the first frequency band FB1 of the antenna structure 100. The thickness H1 of the non-conductive support element 190 may be between 0.6 mm and 3 mm. The width of the coupling gap GC1 can be between 0.2 mm and 1 mm. The capacitance value of capacitor element 140 can be between 0.1 pF and 8.2 pF. The capacitance value of the first capacitor C1 can be between 8.2 pF and 27 pF. The capacitance value of the second capacitor C2 can be between 2.8 pF and 8.2 pF. The capacitance value of the third capacitor C3 can be between 1 pF and 2.8 pF. The above component dimensions and parameter ranges are determined based on the results of multiple experiments, which helps to optimize the operating bandwidth and impedance matching of antenna structure 100, and also improves the operational flexibility of adjustable circuit 160.

[0096] The following embodiments will describe different configurations and detailed structural features of the antenna structure 100. It must be understood that these figures and descriptions are merely examples and are not intended to limit the scope of the invention.

[0097] Figure 6 A schematic diagram of an adjustable circuit 660 according to another embodiment of the present invention is shown. Figure 6In this embodiment, the adjustable circuit 660 includes a switch 665, a first capacitor C1, a second capacitor C2, and an open-circuited path 667, wherein the first capacitor C1, the second capacitor C2, and the open-circuited path 667 are all coupled to ground potential VSS. For example, the open-circuited path 667 can be considered as a resistor with infinite resistance. Specifically, one end of the switch 665 is coupled to the first end 171 of the fourth radiator 170, while the other end of the switch 665 switches between the first capacitor C1, the second capacitor C2, and the open-circuited path 667 according to a control signal SC. That is, if the adjustable circuit 660 uses the switch 665 to select one of the first capacitor C1, the second capacitor C2, and the open-circuited path 667, the fourth radiator 170 can be coupled to ground potential VSS via the selected capacitor or path. According to actual measurement results, if the adjustable circuit 660 is applied to the aforementioned antenna structure 100, the aforementioned antenna structure 100 can also support wideband operation of GPS and LTE.

[0098] This invention proposes a novel antenna structure. Compared with traditional designs, this invention has advantages such as small size, wide bandwidth, and good circuit integration, making it well-suited for application in a wide variety of mobile communication devices.

[0099] It is worth noting that the component dimensions, shapes, parameters, 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... Figures 1-6 The state illustrated. This invention may include only... Figures 1-6 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.

[0100] The ordinal numbers in this specification and the scope of the claims, such as "first", "second", "third", etc., are not sequential in any way; they are only used to distinguish two different elements with the same name.

[0101] 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 grounding element that provides a grounding potential; A first radiating section having a feed point; A second radiating section is coupled to the feed point; A capacitor component; A third radiating section is coupled to the second radiating section via the capacitor element; An adjustable circuit that provides a variable impedance value based on a control signal; A fourth radiating part, which is coupled to the grounding element via the adjustable circuit, wherein the fourth radiating part is adjacent to the first radiating part; A fifth radiating section, which is coupled to the fourth radiating section; as well as A non-conducting support element has a first surface and a second surface opposite to each other, wherein a first radiating portion, a second radiating portion, a capacitor element, a third radiating portion, and a fourth radiating portion are all disposed on the first surface of the non-conducting support element, and a fifth radiating portion is disposed on the second surface of the non-conducting support element.

2. The antenna structure as claimed in claim 1, wherein the grounding element and the adjustable circuit are disposed on the first surface or the second surface of the non-conductive support element.

3. The antenna structure as claimed in claim 1, wherein the combination of the second radiating part, the capacitor element, and the third radiating part forms a Z-shape.

4. The antenna structure as claimed in claim 1, wherein the capacitor element is implemented by a lumped capacitor or a distributed capacitor.

5. The antenna structure as claimed in claim 1, wherein the capacitance value of the capacitor element is between 0.1pF and 8.2pF.

6. The antenna structure as claimed in claim 1, wherein the adjustable circuit comprises: A first capacitor, the first capacitor being coupled to the ground potential; A second capacitor, which is coupled to the ground potential; A third capacitor is coupled to the ground potential; as well as A switcher coupled to the fourth radiating section, wherein the switcher switches between the first capacitor, the second capacitor, and the third capacitor according to the control signal.

7. The antenna structure as claimed in claim 6, wherein the capacitance value of the first capacitor is between 8.2 pF and 27 pF.

8. The antenna structure as claimed in claim 6, wherein the capacitance value of the second capacitor is between 2.8 pF and 8.2 pF.

9. The antenna structure as claimed in claim 6, wherein the capacitance value of the third capacitor is between 1pF and 2.8pF.

10. The antenna structure of claim 1, wherein the adjustable circuit comprises: A first capacitor, the first capacitor being coupled to the ground potential; A second capacitor, which is coupled to the ground potential; An open-circuit path that is coupled to the ground potential; as well as A switcher coupled to the fourth radiating section, wherein the switcher switches between the first capacitor, the second capacitor, and the open path according to the control signal.

11. The antenna structure as claimed in claim 1, wherein the fourth radiating part has an elongated L-shape, and the fifth radiating part has a shorter L-shape.

12. The antenna structure as claimed in claim 1, wherein a coupling gap is formed between the first radiating part and the fourth radiating part, and the width of the coupling gap is between 0.2 mm and 1 mm.

13. The antenna structure as claimed in claim 1, wherein the fifth radiating portion is adjacent to the capacitor element.

14. The antenna structure of claim 1, wherein the fifth radiating portion has a vertical projection on the first surface of the non-conductive support element, and the vertical projection at least partially overlaps with the capacitor element.

15. The antenna structure of claim 1, wherein the antenna structure covers a first frequency band, a second frequency band, a third frequency band, and a fourth frequency band.

16. The antenna structure of claim 15, wherein the first frequency band is between 617MHz and 960MHz, the second frequency band is between 1427MHz and 1610MHz, the third frequency band is between 1710MHz and 2690MHz, and the fourth frequency band is between 3300MHz and 6000MHz.

17. The antenna structure of claim 15, wherein the length of the first radiating part is approximately equal to 0.25 times the wavelength of the fourth frequency band.

18. The antenna structure of claim 15, wherein the total length of the second radiating part and the third radiating part is between 0.125 times and 0.25 times the wavelength of the second frequency band.

19. The antenna structure of claim 15, wherein the length of the third radiating part is approximately equal to 0.125 times the wavelength of the third frequency band.

20. The antenna structure of claim 15, wherein the total length of the fourth radiating part and the fifth radiating part is between 0.125 times and 0.25 times the wavelength of the first frequency band.

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