Antenna structure and mobile device

Abstract

An antenna structure includes a feed radiation part, a first radiation part, a second radiation part, a third radiation part, a fourth radiation part, a fifth radiation part, and a switching circuit. The feed radiation part has a feed point. The second radiation part is coupled to the feed radiation part via the first radiation part. The third radiation part is coupled to the second radiation part. The fourth radiation part is coupled to the second radiation part, wherein the fourth radiation part and the third radiation part extend in different directions. The fifth radiation part has a tuning node and is coupled to the feed radiation part, wherein the feed radiation part is disposed between the first radiation part and the fifth radiation part. The switching circuit selectively couples the tuning node to a ground potential.

Description

TECHNICAL FIELD

[0001] The present application relates to an antenna structure, and more particularly, to a wideband antenna structure. BACKGROUND

[0002] With the development of mobile communication technology, mobile devices have become increasingly popular in recent years. Common mobile devices include, for example, laptop computers, mobile phones, multimedia players, and other portable electronic devices with mixed functions. In order to meet people's needs, mobile devices usually have wireless communication functions. Some cover long-distance wireless communication ranges, such as mobile phones using 2G, 3G, LTE (Long Term Evolution) systems and their used 700MHz, 850MHz, 900MHz, 1800MHz, 1900MHz, 2100MHz, 2300MHz, and 2500MHz frequency bands for communication. 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 elements in the field of wireless communication. If the operational bandwidth of an antenna used for receiving or transmitting signals is too narrow, it is easy to cause the communication quality of the mobile device to decrease. Therefore, how to design a small-size, wideband antenna structure is an important issue for designers. SUMMARY

[0004] In a preferred embodiment, an antenna structure is provided, which includes a feed radiation portion having a feed point; a first radiation portion; a second radiation portion coupled to the feed radiation portion via the first radiation portion; a third radiation portion coupled to the second radiation portion; a fourth radiation portion coupled to the second radiation portion, wherein the fourth radiation portion and the third radiation portion extend in different directions; a fifth radiation portion having an adjustment node and coupled to the feed radiation portion, wherein the feed radiation portion is disposed between the first radiation portion and the fifth radiation portion; and a switching circuit selectively coupling the adjustment node to a ground potential.

[0005] In some embodiments, the first radiation portion is substantially perpendicular to the feed radiation portion.

[0006] In some embodiments, the second radiation portion is neither parallel to nor perpendicular to the first radiation portion.

[0007] In some embodiments, the third radiation portion has a relatively long L shape.

[0008] In some embodiments, the third radiating portion comprises a first segment and a second segment perpendicular to each other.

[0009] In some embodiments, an included angle is formed between the first segment and the second radiating portion.

[0010] In some embodiments, the included angle is between 0 degree and 90 degree.

[0011] In some embodiments, the fourth radiating portion and the first segment are substantially located on the same line.

[0012] In some embodiments, the fifth radiating portion presents a short L shape.

[0013] In some embodiments, the antenna structure can cover a first frequency band, a second frequency band, and a third frequency band.

[0014] In some embodiments, the first frequency band is between 699 MHz and 894 MHz, the second frequency band is between 1710 MHz and 2000 MHz, and the third frequency band is between 2100 MHz and 2300 MHz.

[0015] In some embodiments, the total length of the feed-in radiating portion, the first radiating portion, the second radiating portion, and the third radiating portion is less than or equal to 0.25 times the wavelength of the first frequency band.

[0016] In some embodiments, the total length of the feed-in radiating portion, the first radiating portion, the second radiating portion, and the fourth radiating portion is less than or equal to 0.25 times the wavelength of the first frequency band.

[0017] In some embodiments, the total length of the feed-in radiating portion and the first radiating portion is substantially equal to 0.25 times the wavelength of the third frequency band.

[0018] In some embodiments, the switching circuit comprises a first switch having a first end and a second end, wherein the first end of the first switch is coupled to the adjustment node, and the second end of the first switch is coupled to the ground potential.

[0019] In some embodiments, the switching circuit further comprises a second switch having a first end and a second end, wherein the first end of the second switch is coupled to the adjustment node, and the second end of the second switch is coupled to an internal node; and a first inductor having a first end and a second end, wherein the first end of the first inductor is coupled to the internal node, and the second end of the first inductor is coupled to the ground potential.

[0020] In some embodiments, the switching circuit further comprises a second inductor having a first end and a second end, wherein the first end of the second inductor is coupled to the adjustment node and the second end of the second inductor is coupled to the ground potential.

[0021] In some embodiments, if the first switch is open and the second switch is closed, the antenna structure covers a first frequency range, and if both the first switch and the second switch are open, the antenna structure covers a second frequency range.

[0022] In some embodiments, the first frequency range is between 1710 MHz and 1850 MHz, and the second frequency range is between 1850 MHz and 2000 MHz.

[0023] In another preferred embodiment, the present application provides a mobile device, comprising: an antenna structure as described above; and a communication module coupled to the antenna structure, so that the mobile device can support wireless communication functions. BRIEF DESCRIPTION OF DRAWINGS

[0024] Figure 1 FIG. 1 is a schematic diagram showing an antenna structure according to an embodiment of the present application.

[0025] Figure 2 FIG. 2 is a circuit structure diagram showing a switching circuit according to an embodiment of the present application.

[0026] Figure 3 FIG. 3 is a circuit structure diagram showing a switching circuit according to another embodiment of the present application.

[0027] Figure 4 FIG. 4 is a return loss diagram showing an antenna structure according to an embodiment of the present application.

[0028] Figure 5 FIG. 5 is a return loss diagram showing an antenna structure according to an embodiment of the present application.

[0029] Figure 6 FIG. 6 is a return loss diagram showing an antenna structure according to an embodiment of the present application.

[0030] Figure 7 FIG. 7 is a schematic diagram showing a mobile device according to an embodiment of the present application.

[0031] REFERENCE SIGNS:

[0032] 100: antenna structure

[0033] 110: feed radiation portion

[0034] 111: first end of the feed radiation portion

[0035] 112: second end of the feed-in radiation

[0036] 120: first radiation

[0037] 121: first end of the first radiation

[0038] 122: second end of the first radiation

[0039] 130: second radiation

[0040] 131: first end of the second radiation

[0041] 132: second end of the second radiation

[0042] 140: third radiation

[0043] 141: first end of the third radiation

[0044] 142: second end of the third radiation

[0045] 144: first section of the third radiation

[0046] 145: second section of the third radiation

[0047] 150: fourth radiation

[0048] 151: first end of the fourth radiation

[0049] 152: second end of the fourth radiation

[0050] 160: fifth radiation

[0051] 161: first end of the fifth radiation

[0052] 162: second end of the fifth radiation

[0053] 170: switching circuit

[0054] 171: first switch

[0055] 172: second switch

[0056] 173: first inductor

[0057] 174: second inductor

[0058] 190: signal source

[0059] 700: mobile device

[0060] 710: communication module

[0061] FP: feed-in point

[0062] GC1: Coupling gap

[0063] L1, L2, L3: Length

[0064] LC1: Straight line

[0065] NN: Internal Nodes

[0066] NT: Adjust node

[0067] VSS: Grounding Potential

[0068] θ: included angle Detailed Implementation

[0069] 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 for detailed explanation.

[0070] Certain terms are used in this specification and the claims to refer to specific components. Those skilled in the art will understand that hardware manufacturers may use different names to refer to the same component. This specification and the claims do not distinguish components by differences in name, but by differences in function. The terms "comprising" and "including" used throughout this specification and the claims are open-ended and should be interpreted as "including 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.

[0071] The following disclosure provides many different embodiments or examples to implement the various features of this application. 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 disclosure 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 an additional feature is 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 disclosure. These repetitions are for simplification and clarity and are not intended to limit any specific relationship between the different embodiments and / or structures discussed.

[0072] Moreover, spatially relative terms are used herein for ease of description to illustrate different positions and orientations of a device under discussion. The terms are used as equivalents of the positional terms and are intended to include different orientations of the device in use or operation in addition to the orientations depicted in the figures. The device can be otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative terms will be interpreted accordingly.

[0073] Figure 1 is a schematic diagram showing an antenna structure (Antenna Structure) 100 according to an embodiment of the present application. The antenna structure 100 can be applied in a mobile device (Mobile Device), such as a wearable device (Wearable Device), a smart phone (Smart Phone), a tablet computer (Tablet Computer), a notebook computer (Notebook Computer). Or, the antenna structure 100 can be applied in an electronic device (Electronic Device), such as any unit in the Internet of Things (Internet of Things, IOT).

[0074] In the embodiment of FIG. 1, the antenna structure 100 includes a feeding radiation element (Feeding Radiation Element) 110, a first radiation element (Radiation Element) 120, a second radiation element 130, a third radiation element 140, a fourth radiation element 150, a fifth radiation element 160, and a switch circuit (Switch Circuit) 170, wherein the feeding radiation element 110, the first radiation element 120, the second radiation element 130, the third radiation element 140, the fourth radiation element 150, and the fifth radiation element 160 can be made of a metal material, such as copper, silver, aluminum, iron, or an alloy thereof.

[0075] The feeding radiation element 110 can generally present a relatively short straight bar shape. In detail, the feeding radiation element 110 has a first end 111 and a second end 112, wherein a feeding point (Feeding Point) FP is located at the first end 111 of the feeding radiation element 110. The feeding point FP can be coupled to a signal source (Signal Source) 190. For example, the signal source 190 can be a radio frequency (Radio Frequency, RF) module, which can be used to excite the antenna structure 100.

[0076] The first radiating portion 120 can generally present a long straight bar shape, which can be substantially perpendicular to the feed-in radiating portion 110. In detail, the first radiating portion 120 has a first end 121 and a second end 122, wherein the first end 121 of the first radiating portion 120 is coupled to the second end 112 of the feed-in radiating portion 110.

[0077] The second radiating portion 130 can be coupled to the feed-in radiating portion 110 via the first radiating portion 120. In detail, 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 second end 122 of the first radiating portion 120. In some embodiments, the second radiating portion 130 is neither substantially parallel to nor substantially perpendicular to the first radiating portion 120.

[0078] The third radiating portion 140 can generally present a long L-shaped bar. In detail, the third radiating portion 140 has a first end 141 and a second end 142, wherein the first end 141 of the third radiating portion 140 is coupled to the second end 132 of the second radiating portion 130, and the second end 142 of the third radiating portion 140 is an open end. In some embodiments, the third radiating portion 140 includes a first segment 144 and a second segment 145, which are substantially perpendicular to each other, wherein the first segment 144 is adjacent to the first end 141 of the third radiating portion 140, and the second segment 145 is adjacent to the second end 142 of the third radiating portion 140. It should be noted that the term "adjacent" or "adjacent to" in the present specification can refer to a distance between corresponding elements being less than a predetermined distance (e.g., 5 mm or less), and can also include a case where the corresponding elements are in direct contact with each other (i.e., the aforementioned distance is reduced to 0). It should be noted that an included angle θ can be formed between the first segment 144 and the second radiating portion 130. For example, the included angle θ can be an acute angle, but is not limited thereto. In some embodiments, the second segment 145 is substantially parallel to the first radiating portion 120, and a coupling gap GC1 can be formed between the second segment 145 and the first radiating portion 120.

[0079] The fourth radiating portion 150 can generally present a moderate straight bar shape. The fourth radiating portion 150 and the third radiating portion 140 can extend in different directions. In detail, the fourth radiating portion 150 has a first end 151 and a second end 152, wherein the first end 151 of the fourth radiating portion 150 is coupled to the second end 132 of the second radiating portion 130 and the first end 141 of the third radiating portion 140, and the second end 152 of the fourth radiating portion 150 is an open end. In some embodiments, the fourth radiating portion 150 and the first segment 144 are substantially located on the same straight line LC1.

[0080] The fifth radiating portion 160 can generally present a short L-shape. In detail, the fifth radiating portion 160 has a first end 161 and a second end 162, wherein the first end 161 of the fifth radiating portion 160 is coupled to the second end 112 of the feeding radiating portion 110, and a tuning node NT is located at the second end 162 of the fifth radiating portion 160. In some embodiments, the feeding radiating portion 110 is disposed between the first radiating portion 120 and the fifth radiating portion 160.

[0081] The switching circuit 170 can selectively couple the tuning node NT to a ground potential VSS (e.g., 0V). In some embodiments, the ground potential VSS can be provided by a system ground plane (not shown). By using the switching circuit 170, the antenna structure 100 can cover a first frequency band, a second frequency band, and a third frequency band. For example, the first frequency band can be between 699MHz and 894MHz, the second frequency band can be between 1710MHz and 2000MHz, and the third frequency band can be between 2100MHz and 2300MHz, but not limited thereto. Thus, the antenna structure 100 can support at least the wideband operation of LTE (Long Term Evolution).

[0082] In terms of antenna principles, the feeding radiating portion 110, the first radiating portion 120, the second radiating portion 130, and the third radiating portion 140 can be used to excite the first frequency band. In addition, the feeding radiating portion 110, the first radiating portion 120, the second radiating portion 130, and the fourth radiating portion 150 can be used to increase the bandwidth of the first frequency band. Due to the frequency doubling effect, the feeding radiating portion 110, the first radiating portion 120, the second radiating portion 130, and the third radiating portion 140 can also excite the second frequency band. In addition, the feeding radiating portion 110 and the first radiating portion 120 can be used to excite the third frequency band. It must be understood that the fifth radiating portion 160 and the switching circuit 170 can be used to adjust the impedance matching of the first frequency band, the second frequency band, and the third frequency band of the antenna structure.

[0083] Different circuit structures of the switching circuit 170 will be described below. It must be understood that these figures and descriptions are only examples and are not intended to limit the scope of the present application.

[0084] Figure 2Figure 2 shows a circuit diagram of a switching circuit 170 according to an embodiment of the present invention. In the embodiment of Figure 2, the switching circuit 170 includes a first switch element 171. Specifically, the first switch element 171 has a first terminal and a second terminal, wherein the first terminal of the first switch element 171 is coupled to the adjustment node NT of the fifth radiating section 160, and the second terminal of the first switch element 171 is coupled to the ground potential VSS. For example, if the first switch element 171 is turned on, the main operating frequency of the antenna structure 100 will decrease; conversely, if the first switch element 171 is turned off, the main operating frequency of the antenna structure 100 will increase.

[0085] Figure 3 This is a circuit structure diagram showing the switching circuit 170 according to another embodiment of the present invention. Figure 3 In one embodiment, the switching circuit 170 includes a first switch 171, a second switch 172, a first inductor 173, and a second inductor 174. Specifically, the first switch 171 has a first terminal and a second terminal, wherein the first terminal of the first switch 171 is coupled to the adjustment node NT of the fifth radiating section 160, and the second terminal of the first switch 171 is coupled to ground potential VSS. The second switch 172 has a first terminal and a second terminal, wherein the first terminal of the second switch 172 is coupled to the adjustment node NT, and the second terminal of the second switch 172 is coupled to an internal node NN. The first inductor 173 has a first terminal and a second terminal, wherein the first terminal of the first inductor 173 is coupled to the internal node NN, and the second terminal of the first inductor 173 is coupled to ground potential VSS. The second inductor 174 has a first terminal and a second terminal, wherein the first terminal of the second inductor 174 is coupled to the adjustment node NT, and the second terminal of the second inductor 174 is coupled to the ground potential VSS. For example, the inductance of the second inductor 174 may be more than twice the inductance of the first inductor 173. For the high-frequency current of the antenna structure 100, the second inductor 174 can be approximated as an open-circuited element.

[0086] Figure 4 This is a graph showing the return loss of the 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 4In an embodiment, if the first switch 171 is turned on, it will form a short-circuited path between the adjustment node NT and the ground potential VSS, so that the effects of the second switch 172, the first inductor 173, and the second inductor 174 can be ignored. According to the measurement results of Figure 4 The antenna structure 100 can cover a relatively low first frequency band and a relatively high third frequency band.

[0087] Figure 5 is a return loss diagram of the antenna structure 100 according to an embodiment of the present application, in which the horizontal axis represents the operating frequency (MHz), and the vertical axis represents the return loss (dB). In the embodiment, if the first switch 171 is turned on, the antenna structure 100 can cover a first frequency interval between 1710 MHz and 1850 MHz, which can correspond to the first half of the second frequency band of the antenna structure. Figure 5

[0088] Figure 6 is a return loss diagram of the antenna structure 100 according to an embodiment of the present application, in which the horizontal axis represents the operating frequency (MHz), and the vertical axis represents the return loss (dB). In the embodiment, if the first switch 171 is turned on, the antenna structure 100 can cover a first frequency interval between 1710 MHz and 1850 MHz, which can correspond to the first half of the second frequency band of the antenna structure. Figure 6

[0089] ​​In some embodiments, the element size and element parameter of the antenna structure 100 can be as follows. The total length L1 of the feed radiation part 110, the first radiation part 120, the second radiation part 130, and the third radiation part 140 can be less than or equal to 0.25 times the wavelength (λ / 4) of the first frequency band of the antenna structure 100. The total length L2 of the feed radiation part 110, the first radiation part 120, the second radiation part 130, and the fourth radiation part 150 can be less than or equal to 0.25 times the wavelength (λ / 4) of the first frequency band of the antenna structure 100. The total length L3 of the feed radiation part 110 and the first radiation part 120 can be substantially equal to 0.25 times the wavelength (λ / 4) of the third frequency band of the antenna structure 100. The width of each of the feed radiation part 110, the first radiation part 120, the second radiation part 130, the third radiation part 140, the fourth radiation part 150, and the fifth radiation part 160 can be between 0.5 mm and 2 mm. The included angle θ can be between 0 degrees and 90 degrees. The width of the coupling gap GC1 can be less than or equal to 5 mm. The inductance value of the first inductor 173 can be between 10 nH and 14 nH, and preferably about 12 nH. The inductance value of the second inductor 174 can be between 30 nH and 36 nH, and preferably about 33 nH. The above size and parameter ranges are derived from multiple experimental results, which help to optimize the operational bandwidth and impedance matching of the antenna structure 100.

[0090] Figure 7 is a schematic diagram showing a mobile device 700 according to an embodiment of the present application. As shown in Figure 7 the mobile device 700 includes an antenna structure 100 and a communication module 710, where various features of the antenna structure 100 can be as described in the embodiments of the previous FIGS. 1-6. On the other hand, the communication module 710 is coupled to the antenna structure 100, so that the mobile device 700 can support the function of wireless communication. For example, the communication module 710 can include a signal source, a radio frequency circuit (RF circuit), a filter, an amplifier, or (and) a processor, but is not limited thereto. Figure 7 The remaining features of the mobile device 700 are similar to the antenna structure 100 of FIG. 1, so both embodiments can achieve similar operational effects.

[0091] The present application proposes a novel antenna structure and mobile device. Compared with conventional designs, the present application has at least the advantages of small size, wide frequency band, and low manufacturing cost, so it is very suitable for application in various mobile communication devices or Internet of Things.

[0092] It is noted that the element sizes, element shapes, and frequency ranges described above are not limiting conditions of the present application. Antenna designers can adjust these settings according to different needs. The antenna structure and mobile device of the present application are not limited to Figures 1-7 the illustrated state. The present application can include only Figures 1-7 one or more features of any one or more embodiments. In other words, not all of the illustrated features need be implemented in the antenna structure and mobile device of the present application.

[0093] In this specification and the claims, ordinal numbers such as "first", "second", "third", etc. do not have a sequential order between them, and are used only to distinguish two different elements having the same name.

[0094] Although the present application has been disclosed with reference to the preferred embodiments, it is not intended to limit the scope of the present application, and any person skilled in the art, without departing from the spirit and scope of the present application, can make some changes and modifications, and therefore the scope of the present application is defined by the following claims.

Claims

1. An antenna structure, comprising: a feed radiation portion having a feed point, wherein the feed point is located at a first end of the feed radiation portion; a first radiation portion having a first end coupled to a second end of the feed radiation portion; a second radiation portion coupled to the feed radiation portion via the first radiation portion, the second radiation portion having a first end coupled to a second end of the first radiation portion; a third radiation portion coupled to a second end of the second radiation portion, wherein the third radiation portion exhibits a longer L-shape; a fourth radiation portion having a first end coupled to a second end of the second radiation portion, wherein the fourth radiation portion and the third radiation portion extend in different directions; a fifth radiation portion having an adjustment node, the fifth radiation portion exhibiting a shorter L-shape, and the fifth radiation portion having a first end coupled to a second end of the feed radiation portion, the adjustment node being located at a second end of the fifth radiation portion, wherein the feed radiation portion is disposed between the first radiation portion and the fifth radiation portion; and a switching circuit selectively coupling the adjustment node to a ground potential.

2. The antenna structure of claim 1, wherein the first radiation portion is perpendicular to the feed radiation portion.

3. The antenna structure of claim 1, wherein the second radiation portion is neither parallel nor perpendicular to the first radiation portion.

4. The antenna structure of claim 1, wherein the third radiation portion includes a first segment and a second segment that are perpendicular to each other.

5. The antenna structure of claim 4, wherein an included angle is formed between the first segment and the second radiation portion.

6. The antenna structure of claim 5, wherein the included angle is between 0 degrees and 90 degrees.

7. The antenna structure of claim 5, wherein the fourth radiation portion and the first segment are located on a same line.

8. The antenna structure of claim 1, wherein the antenna structure is capable of covering a first frequency band, a second frequency band, and a third frequency band.

9. The antenna structure of claim 8, wherein the first frequency band is between 699 MHz and 894 MHz, the second frequency band is between 1710 MHz and 2000 MHz, and the third frequency band is between 2100 MHz and 2300 MHz.

10. The antenna structure of claim 8, wherein a total length of the feed radiation portion, the first radiation portion, the second radiation portion, and the third radiation portion is less than or equal to 0.25 times a wavelength of the first frequency band.

11. The antenna structure of claim 8, wherein a total length of the feed radiation portion, the first radiation portion, the second radiation portion, and the fourth radiation portion is less than or equal to 0.25 times a wavelength of the first frequency band.

12. The antenna structure of claim 8, wherein a total length of the feed radiation portion and the first radiation portion is equal to 0.25 times a wavelength of the third frequency band.

13. The antenna structure of claim 1, wherein the switching circuit includes: a first switch having a first end and a second end, wherein the first end of the first switch is coupled to the adjustment node, and the second end of the first switch is coupled to the ground potential. ​ 14. The antenna structure of claim 13, wherein the switching circuit further comprises: a second switch having a first terminal and a second terminal, wherein the first terminal of the second switch is coupled to the tuning node and the second terminal of the second switch is coupled to an internal node; and a first inductor having a first terminal and a second terminal, wherein the first terminal of the first inductor is coupled to the internal node and the second terminal of the first inductor is coupled to the ground potential.

15. The antenna structure of claim 14, wherein the switching circuit further comprises: a second inductor having a first terminal and a second terminal, wherein the first terminal of the second inductor is coupled to the tuning node and the second terminal of the second inductor is coupled to the ground potential.

16. The antenna structure of claim 15, wherein if the first switch is open and the second switch is closed, the antenna structure covers a first frequency range, and if both the first switch and the second switch are open, the antenna structure covers a second frequency range.

17. The antenna structure of claim 16, wherein the first frequency range is between 1710 MHz and 1850 MHz and the second frequency range is between 1850 MHz and 2000 MHz.

18. A mobile device, comprising: the antenna structure of claim 1 ; and a communication module coupled to the antenna structure such that the mobile device is capable of supporting wireless communication.

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