阅读说明：本技术 天线结构 (Antenna structure ) 是由 郑佳尚 于 2019-03-22 设计创作，主要内容包括：一种天线结构。该天线结构包括：一偶极天线元件以及一浮接金属部；该浮接金属部邻近于该偶极天线元件,其中该偶极天线元件的一垂直投影与该浮接金属部至少部分重叠。本发明的浮接金属部可用于微调天线结构的辐射场型并增加天线结构的操作带宽,而且本发明相较于传统设计至少具有小尺寸、宽频带、低复杂度、高增益以及低制造成本等优势,故其很适合应用于各种各式的通信装置当中。(An antenna structure. The antenna structure includes: a dipole antenna element and a floating metal part; the floating metal part is adjacent to the dipole antenna element, wherein a vertical projection of the dipole antenna element is at least partially overlapped with the floating metal part. The floating metal part of the invention can be used for finely adjusting the radiation field type of the antenna structure and increasing the operation bandwidth of the antenna structure, and compared with the traditional design, the invention has the advantages of small size, wide frequency band, low complexity, high gain, low manufacturing cost and the like, so the invention is very suitable for being applied to various communication devices.)

1. An antenna structure, comprising:

a dipole antenna element; and

a floating metal portion adjacent to the dipole antenna element, wherein a vertical projection of the dipole antenna element at least partially overlaps the floating metal portion.

2. The antenna structure of claim 1 wherein the antenna structure covers at least one operating band between 2400MHz and 2500 MHz.

3. The antenna structure of claim 1 wherein the dipole antenna element includes a first radiating portion coupled to a positive feed point and a second radiating portion coupled to a negative feed point.

4. The antenna structure according to claim 3, wherein the first radiating portion and the second radiating portion are located on the same plane.

5. The antenna structure according to claim 3, wherein the first radiating portion and the second radiating portion are located on different planes, respectively.

6. The antenna structure of claim 3, wherein the first radiating section further comprises a first end bend portion and the second radiating section further comprises a second end bend portion.

7. The antenna structure according to claim 3, wherein the first radiation portion and the second radiation portion each have a straight strip shape or an L-shape.

8. The antenna structure of claim 1 wherein the floating metal portion has a U-shape.

9. The antenna structure of claim 1 wherein the floating metal portion exhibits a circular arc shape.

10. The antenna structure of claim 2, wherein the floating metal portion includes a main portion, a first coupling portion, and a second coupling portion, and the main portion is coupled between the first coupling portion and the second coupling portion.

11. The antenna structure of claim 10, wherein the floating metal portion further includes a first end widened portion coupled to the first coupling portion.

12. The antenna structure of claim 10, wherein the floating metal portion further includes a second end widened portion coupled to the second coupling portion.

13. The antenna structure of claim 10 wherein the separation of the major portion of the floating metal portion from the perpendicular projection of the dipole antenna element is greater than or equal to 1/40 wavelengths of the operating band.

14. The antenna structure of claim 10 wherein the separation of the main portion of the floating metal portion from the perpendicular projection of the dipole antenna element is less than or equal to 1/24 wavelengths of the operating band.

15. The antenna structure of claim 10 wherein the length of the main portion of the floating metal section is between 9/40-4/15 wavelengths of the operating band.

16. The antenna structure of claim 10 wherein the length of the first coupling portion and the length of the second coupling portion of the floating metal portion are both greater than 1/30 wavelengths of the operating band.

17. The antenna structure of claim 1 wherein the dipole antenna element and the floating metal portion are spaced apart by greater than or equal to 0.2 mm.

18. The antenna structure of claim 1, further comprising:

and the dipole antenna element and the floating metal part are respectively arranged on different layers of the dielectric substrate.

19. The antenna structure of claim 18, wherein the dielectric substrate is a two-layer printed circuit board or a six-layer printed circuit board.

20. The antenna structure of claim 18, further comprising:

a ground plane disposed on the dielectric substrate and having a clearance area, wherein the vertical projection of the dipole antenna element and the vertical projection of the floating metal portion are both located within the clearance area.

Technical Field

The present invention relates to an antenna structure, and more particularly, to a broadband antenna structure including a floating metal portion.

Background

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. To meet the demand of people, mobile devices generally have a function of wireless communication. Some cover long-range wireless communication ranges, such as: the mobile phone uses 2G, 3G, LTE (Long Term Evolution) system and its used frequency bands of 700MHz, 850MHz, 900MHz, 1800MHz, 1900MHz, 2100MHz, 2300MHz and 2500MHz for communication, while some cover short-distance wireless communication ranges, for example: Wi-Fi and Bluetooth systems use frequency bands of 2.4GHz, 5.2GHz, and 5.8GHz for communication.

An Antenna (Antenna) is an indispensable element in the field of wireless communication. If the Bandwidth (Bandwidth) of the antenna for receiving or transmitting signals is insufficient, it is easy to cause a degradation in the communication quality of the mobile device. Therefore, how to design a small-sized and wide-band antenna element is an important issue for an antenna designer.

Therefore, it is desirable to provide an Antenna Structure (Antenna Structure) to solve the above problems.

Disclosure of Invention

In a preferred embodiment, the present invention provides an antenna structure, which includes: a dipole antenna element; and a floating metal portion adjacent to the dipole antenna element, wherein a vertical projection of the dipole antenna element at least partially overlaps the floating metal portion.

In some embodiments, the antenna structure covers at least one operating band between 2400MHz and 2500 MHz.

In some embodiments, the dipole antenna element includes a first radiating portion coupled to a positive feed point and a second radiating portion coupled to a negative feed point.

In some embodiments, the first radiation portion and the second radiation portion are located on the same plane.

In some embodiments, the first radiating portion and the second radiating portion are respectively located on different planes.

In some embodiments, the first radiating portion further includes a first end bend portion, and the second radiating portion further includes a second end bend portion.

In some embodiments, the first radiating portion and the second radiating portion each have a straight strip shape or an L-shape.

In some embodiments, the floating metal portion has a U-shape.

In some embodiments, the floating metal portion exhibits a circular arc shape.

In some embodiments, the Floating Metal Element includes a main portion, a first coupling portion, and a second coupling portion, and the main portion is coupled between the first coupling portion and the second coupling portion.

In some embodiments, the floating metal portion further includes a first end widened portion coupled to the first coupling portion.

In some embodiments, the floating metal portion further includes a second end widened portion coupled to the second coupling portion.

In some embodiments, the separation of the major portion of the floating metal portion from the perpendicular projection of the dipole antenna element is greater than or equal to 1/40 wavelengths of the operating band.

In some embodiments, the separation of the major portion of the floating metal portion from the perpendicular projection of the dipole antenna element is less than or equal to 1/24 wavelengths of the operating band.

In some embodiments, the length of the main portion of the floating metal portion is between 9/40-4/15 wavelengths of the operating band.

In some embodiments, the length of the first coupling portion and the length of the second coupling portion of the floating metal portion are both greater than 1/30 wavelengths of the operating band.

In some embodiments, the dipole antenna element and the floating metal portion are spaced apart by greater than or equal to 0.2 mm.

In some embodiments, the antenna structure further comprises: and the dipole antenna element and the floating metal part are respectively arranged on different layers of the dielectric substrate.

In some embodiments, the dielectric substrate is a two-layer printed circuit board or a six-layer printed circuit board.

In some embodiments, the antenna structure further comprises: a ground plane disposed on the dielectric substrate and having a clearance area, wherein the vertical projection of the dipole antenna element and the vertical projection of the floating metal portion are both located within the clearance area.

The present invention provides a novel antenna structure. By using the floating metal part, the invention can fine tune the main beam direction of the dipole antenna element and enlarge the operation bandwidth. Compared with the conventional design, the present invention has at least the advantages of small size, wide frequency band, low complexity, high gain and low manufacturing cost, so that the present invention is suitable for various communication devices.

Drawings

Fig. 1A is a top view of an antenna structure according to an embodiment of the invention.

Fig. 1B is a perspective view of an antenna structure according to an embodiment of the invention.

FIG. 1C is a diagram illustrating a return loss of an antenna structure according to an embodiment of the invention

Fig. 1D shows a radiation pattern of the antenna structure according to an embodiment of the invention.

Fig. 2A is a top view of an antenna structure according to an embodiment of the invention.

Fig. 2B shows a return loss diagram of an antenna structure according to an embodiment of the invention.

Fig. 3 is a top view of an antenna structure according to an embodiment of the invention.

Fig. 4 is a perspective view of an antenna structure according to an embodiment of the invention.

Fig. 5 is a top view of an antenna structure according to an embodiment of the invention.

Fig. 6 is a top view of an antenna structure according to an embodiment of the invention.

Fig. 7 is a top view of an antenna structure according to an embodiment of the invention.

Description of the main component symbols:

100. 200, 300, 400, 500, 600, 700 antenna structure

110. 210, 410 dipole antenna element

111. 211, 411 first radiation part

112. 212, 412 second radiation part

120. 320, 520, 620, 720 floating metal part

121. 321 first end of floating metal part

122. 322 second end of the floating metal part

130. 330, 530, 630, 730 floating metal part

140. 340, 540, 640, 740 first coupling part of a floating metal section

150. 350, 550, 650, 750 floating metal portion

160. 460 medium substrate

170 ground plane

175 headroom region

215 first end bent portion of first radiating portion

216 second end bent portion of the second radiation portion

345 first end widened portion of the floating metal portion

355 second end widening of the floating metal portion

First curve of CC1

Second curve of CC2

Distance between D1 and D2

First layer of E1 dielectric substrate

Second layer of E2 dielectric substrate

Third layer of E3 dielectric substrate

Fourth layer of E4 dielectric substrate

Fifth layer of E5 dielectric substrate

Sixth layer of E6 dielectric substrate

FP positive feed point

FN negative feed-in point

H1 thickness

L1, L2, L3, LA, LB Length

Width of W1

X X axle

Y Y axle

Z Z axle

Detailed Description

In order to make the objects, features and advantages of the present invention comprehensible, specific embodiments accompanied with figures are described in detail below.

Certain terms are used throughout the description and following claims to refer to particular components. As one skilled in the art will appreciate, manufacturers may refer to a component by different names. The present specification and claims do not intend to distinguish between components that differ in name but not function. In the following description and in the claims, the terms "include" and "comprise" are used in an open-ended fashion, and thus should be interpreted to mean "include, but not limited to. The term "substantially" means within an acceptable error range, within which a person skilled in the art can solve the technical problem to achieve the basic technical result. In addition, the term "coupled" is used herein to encompass any direct or indirect electrical connection. Thus, if a first device couples to a second device, that connection may be through a direct electrical connection, or through an indirect electrical connection via other devices and connections.

Fig. 1A shows a top view of an Antenna Structure (Antenna Structure)100 according to an embodiment of the invention. Fig. 1B is a perspective view of the antenna structure 100 according to an embodiment of the invention. Please refer to fig. 1A and fig. 1B together. The antenna structure 100 can be applied to a Communication Device (Communication Device), for example: but is not limited to, a Wireless Access Point (Wireless Access Point), a Smart Phone (Smart Phone), a tablet Computer (tablet Computer), or a Notebook Computer (Notebook Computer). In the embodiment shown in fig. 1A and 1B, the Antenna structure 100 at least includes a Dipole Antenna Element (Dipole Antenna Element)110 and a Floating Metal Element (Floating Metal Element)120, wherein the Floating Metal Element 120 is adjacent to the Dipole Antenna Element 110 but completely separated from the Dipole Antenna Element 110. It should be noted that the term "adjacent" or "adjacent" in this specification may mean that the corresponding elements are spaced apart by less than a predetermined distance (e.g., 5mm or less).

The dipole antenna element 110 may be made of a conductive material, such as: and (3) a metal material. The detailed shape of the dipole antenna element 110 is not particularly limited in the present invention. In detail, the dipole antenna element 110 includes a first radiation portion 111 and a second radiation portion 112, wherein the first radiation portion 111 is coupled to a Positive Feeding Point (FP), and the second radiation portion 112 is coupled to a Negative Feeding Point (FN). The first radiation portion 111 and the second radiation portion 112 may each substantially exhibit a straight bar shape. The Positive feed point FP and the Negative feed point FN may be respectively coupled to a Positive Electrode (Positive Electrode) and a Negative Electrode (Negative Electrode) of a Signal Source (Signal Source) (not shown). For example, the signal source may be a Radio Frequency (RF) module, which may be used to excite the antenna structure 100. A Coupling Effect (Coupling Effect) may be generated between the dipole antenna element 110 and the floating metal part 120, so that the floating metal part 120 may be used to improve the radiation performance of the dipole antenna element 110. To enhance the coupling effect, a Vertical Projection (Vertical Projection) of the dipole antenna element 110 is required to at least partially overlap the floating metal part 120. That is, if the floating metal part 120 is disposed on a specific plane, the perpendicular projection of the first radiation part 111 or (and) the second radiation part 112 on the specific plane will at least partially overlap with the floating metal part 120.

The floating metal part 120 may substantially have a U-shape. The floating metal portion 120 has a first End 121 and a second End 122, which are two Open ends (Open ends). In detail, the floating metal part 120 includes a main Portion (main Portion)130, a first Coupling Portion (Coupling Portion)140, and a second Coupling Portion 150, wherein the main Portion 130 is coupled between the first Coupling Portion 140 and the second Coupling Portion 150. The main portion 130, the first coupling portion 140, and the second coupling portion 150 may each have a substantially straight bar shape, wherein the main portion 130 and the dipole antenna element 110 may be substantially parallel to each other, and the first coupling portion 140 and the second coupling portion 150 may be substantially perpendicular to the main portion 130. In the floating metal part 120, the length L1 of the main portion 130 may be the longest of the three portions, and the length L3 of the second coupling portion 150 may be substantially equal to the length L2 of the first coupling portion 140. In addition, a perpendicular projection of the first radiation part 111 may at least partially overlap with the first coupling portion 140 of the floating metal part 120, and a perpendicular projection of the second radiation part 112 may at least partially overlap with the second coupling portion 150 of the floating metal part 120. In general, the length L1 of the main portion 130 is used to determine the Resonant Frequency (Resonant Frequency) of the antenna structure 100, while the length L2 of the first coupling portion 140 and the length L3 of the second coupling portion 150 are used to determine the amount of coupling between the floating metal portion 120 and the dipole antenna element 110.

In some embodiments, the antenna structure 100 further includes a Dielectric Substrate (Dielectric Substrate)160, wherein the dipole antenna element 110 and the floating metal part 120 may be disposed on different layers of the Dielectric Substrate 160, respectively. For example, if the dielectric substrate 160 is a six-layer Printed Circuit Board (PCB), the first radiation part 111 may be disposed on a first layer E1 (i.e., the uppermost layer) of the dielectric substrate 160, the second radiation part 112 may be disposed on a fourth layer E4 (i.e., between the uppermost layer and the lowermost layer) of the dielectric substrate 160, and the floating metal part 120 may be disposed on a sixth layer E6 (the lowermost layer) of the dielectric substrate 160, but is not limited thereto. In other embodiments, the total number of layers of the dielectric substrate 160 can be adjusted according to different requirements.

In some embodiments, the antenna structure 100 further includes a Ground Plane (Ground Plane)170, which is made of metal and disposed on the dielectric substrate 160. For example, if the dielectric substrate 160 is a six-layer printed circuit board, the ground plane 170 may be simultaneously distributed on the first layer E1 to the sixth layer E6 of the dielectric substrate 160. The ground plane 170 has a Clearance Region (Clearance Region)175, which may substantially exhibit a rectangular Notch. Both the vertical projection of the dipole antenna element 110 and a vertical projection of the floating metal portion 120 may be located entirely within the clearance area 175 of the ground plane 170. The addition of the floating metal portion 120 may make the dipole antenna element 110 less susceptible to interference from the metal portion of the ground plane 170, based on actual measurements. It should be understood that the dielectric substrate 160 and the ground plane 170 are optional elements (optional elements) of the antenna structure 100, and may be omitted or removed in other embodiments.

Fig. 1C shows a Return Loss (Return Loss) diagram of the antenna structure 100 according to an embodiment of the invention, wherein a first curve CC1 represents the operating characteristics of the antenna structure 100 when the floating metal part 120 is not used, and a second curve CC2 represents the operating characteristics of the antenna structure 100 when the floating metal part 120 is used. According to the measurement results shown in fig. 1C, the addition of the floating metal part 120 can greatly improve the Bandwidth (Bandwidth) of the antenna structure 100, so that the antenna structure 100 can cover at least an operating frequency band between 2400MHz and 2500 MHz. Under this design, the antenna structure 100 will support at least 2.4GHz broadband operation for Bluetooth and WLAN (Wireless Local Area networks).

Fig. 1D shows a radiation pattern (radiation pattern) diagram of the antenna structure 100 according to an embodiment of the present invention. As can be seen from the measurement results shown in fig. 1D, the antenna structure 100 can provide an approximately symmetrical radiation pattern on the XY plane, and the Main Beam (Main Beam) direction thereof substantially coincides with the U-shaped opening direction of the floating metal portion 120 (i.e., the + X axis direction). It should be noted that if a conventional inverted-F antenna is used, the radiation pattern is usually asymmetric and the main beam is shifted to one side (i.e., + Y-axis direction). Therefore, the addition of the floating metal portion 120 can also fine tune the radiation pattern of the antenna structure 100 to meet various application requirements.

In some embodiments, the element dimensions of the antenna structure 100 may be as follows. The length LA of the first radiating portion 111 of the dipole antenna element 110 may be approximately equal to 1/4 wavelengths of the operating frequency band of the antenna structure 100. The length LB of the second radiating portion 112 of the dipole antenna element 110 may be substantially equal to 1/4 wavelengths of the operating frequency band of the antenna structure 100. The separation D1 of the perpendicular projection of the main portion 130 of the floating metal portion 120 and the dipole antenna element 110 may be greater than or equal to 1/40 wavelengths of the operating band of the antenna structure 100. The separation D1 of the perpendicular projection of the main portion 130 of the floating metal portion 120 and the dipole antenna element 110 may be less than or equal to 1/24 wavelengths of the operating band of the antenna structure 100. The length L1 of the main portion 130 of the floating metal portion 120 is between 9/40 and 4/15 wavelengths of the operating band of the antenna structure 100. The length L2 of the first coupling portion 140 of the floating metal section 120 may be greater than 1/30 wavelengths of the operating band of the antenna structure 100. For example, the length L2 of the first coupling section 140 may be between 1/24 and 3/40 wavelengths of the operating band of the antenna structure 100. The length L3 of the second coupling section 150 of the floating metal section 120 may be greater than 1/30 wavelengths of the operating band of the antenna structure 100. For example, the length L3 of the second coupling section 150 may be between 1/24 and 3/40 wavelengths of the operating band of the antenna structure 100. The floating metal part 120 may have an equal width, and the width W1 may be between 0.1mm and 2 mm. The separation D2 between the dipole antenna element 110 (or the second radiating portion 112) and the floating metal portion 120 may be greater than or equal to 0.2 mm. The separation D2 between the dipole antenna element 110 and the floating metal part 120 may be less than or equal to the thickness H1 (e.g., 1.1mm) of the dielectric substrate 160. The length of the clearance area 175 of the ground plane 170 can be at least 30mm and the width of the clearance area 175 of the ground plane 170 can be at least 10 mm. The above ranges of element sizes are found from multiple experimental results, which can be used to optimize the operating bandwidth (OperationBandwidth) and Impedance Matching (Impedance Matching) of the antenna structure 100.

Fig. 2A is a top view of an antenna structure 200 according to an embodiment of the invention. Fig. 2A is similar to fig. 1A. In the embodiment of fig. 2A, a dipole antenna element 210 of the antenna structure 200 includes a first radiation Portion 211 and a second radiation Portion 212, wherein the first radiation Portion 211 further includes a first Terminal Bending Portion (Terminal Bending Portion)215, and the second radiation Portion 212 further includes a second Terminal Bending Portion 216, so that the first radiation Portion 211 and the second radiation Portion 212 each substantially present an L-shape. A perpendicular projection of the first terminal bent portion 215 at least partially overlaps the first coupling portion 140 of the floating metal part 120. A perpendicular projection of the second terminal bent portion 216 at least partially overlaps the second coupling portion 150 of the floating metal part 120. This design may further enhance the coupling effect between the dipole antenna element 210 and the floating metal part 120. Fig. 2B shows a return loss diagram of the antenna structure 200 according to an embodiment of the invention. According to the measurement results of fig. 2B, the addition of the first end bend 215 and the second end bend 216 helps to expand the operating bandwidth of the antenna structure 200 (e.g., from originally 320MHz to over 400 MHz). The remaining features of the antenna structure 200 of fig. 2A are similar to those of the antenna structure 100 of fig. 1A and 1B, so that similar operation effects can be achieved in both embodiments.

Fig. 3 is a top view of an antenna structure 300 according to an embodiment of the invention. Fig. 3 is similar to fig. 2A. In the embodiment of fig. 3, a floating metal portion 320 of the antenna structure 300 is a non-uniform width structure, which includes a main portion 330, a first coupling portion 340, a first end widened portion 345, a second coupling portion 350, and a second end widened portion 355. The first end widened portion 345 may substantially assume a rectangular shape or a square shape. The first end widened portion 345 is coupled to the first coupling portion 340 and located at a first end 321 of the floating metal portion 320, wherein a vertical projection of the first end bent portion 215 of the first radiation portion 211 may at least partially overlap with the first end widened portion 345. The second end widened portion 355 may substantially assume a rectangular or a square shape. The second end widened portion 355 is coupled to the second coupling portion 350 and located at a second end 322 of the floating metal portion 320, wherein a vertical projection of the second end bent portion 216 of the second radiation portion 212 may at least partially overlap with the second end widened portion 355. Based on practical measurements, such a design can further enhance the coupling effect between the dipole antenna element 210 and the floating metal portion 320, thereby further expanding the operating bandwidth of the antenna structure 300. The remaining features of the antenna structure 300 of fig. 3 are similar to those of the antenna structure 200 of fig. 2A, so that similar operation effects can be achieved in both embodiments.

Fig. 4 is a perspective view of an antenna structure 400 according to an embodiment of the invention. FIG. 4 is similar to FIG. 1B. In the embodiment of fig. 4, a dipole Antenna element 410 of the Antenna structure 400 is a Coplanar Antenna (Coplanar Antenna). That is, the dipole antenna element 410 includes a first radiation portion 411 and a second radiation portion 412, wherein the first radiation portion 411 and the second radiation portion 412 are located on the same plane. If a dielectric substrate 460 of the antenna structure 400 is a dual-layer printed circuit board, the first radiation portion 411 and the second radiation portion 412 may be disposed on a first layer E1 (the uppermost layer) of the dielectric substrate 460, and the floating metal portion 120 may be disposed on a second layer E2 (the lowermost layer) of the dielectric substrate 460, but is not limited thereto. Based on practical measurements, this design allows the overall size of the antenna structure 400 to be reduced without adversely affecting its radiation pattern and operational bandwidth. The remaining features of the antenna structure 400 of fig. 4 are similar to those of the antenna structure 100 of fig. 1A and 1B, so that similar operation effects can be achieved in both embodiments.

Fig. 5 is a top view of an antenna structure 500 according to an embodiment of the invention. Fig. 5 is similar to fig. 2A. In the embodiment of fig. 5, a floating metal part 520 of the antenna structure 500 includes a main portion 530, a first coupling portion 540, and a second coupling portion 550, wherein the main portion 530 substantially exhibits a relatively short circular arc shape (compared to fig. 6), and the first coupling portion 540 and the second coupling portion 550 each substantially exhibits a straight strip shape. For example, the length of the main portion 530 may be approximately equal to 9/40 wavelengths of the operating band of the antenna structure 500. The remaining features of the antenna structure 500 of fig. 5 are similar to those of the antenna structure 200 of fig. 2A, so that similar operation effects can be achieved in both embodiments.

Fig. 6 is a top view of an antenna structure 600 according to an embodiment of the invention. Fig. 6 is similar to fig. 2A. In the embodiment of fig. 6, a floating metal part 620 of the antenna structure 600 includes a main portion 630, a first coupling portion 640, and a second coupling portion 650, wherein the main portion 630 substantially exhibits a relatively long circular arc shape (compared to fig. 5), and the first coupling portion 640 and the second coupling portion 650 each substantially exhibits a straight strip shape. For example, the length of the main portion 630 may be approximately equal to 4/15 wavelengths of the operating band of the antenna structure 600. The remaining features of the antenna structure 600 of fig. 6 are similar to those of the antenna structure 200 of fig. 2A, so that similar operation effects can be achieved in both embodiments.

Fig. 7 is a top view of an antenna structure 700 according to an embodiment of the invention. Fig. 7 is similar to fig. 2A. In the embodiment of fig. 7, a floating metal portion 720 of the antenna structure 700 includes a main portion 730, a first coupling portion 740, and a second coupling portion 750, wherein a combination of the main portion 730, the first coupling portion 740, and the second coupling portion 750 substantially exhibits a relatively smooth circular arc shape (compared to fig. 5 and 6). The remaining features of the antenna structure 700 of fig. 7 are similar to those of the antenna structure 200 of fig. 2A, so that similar operation effects can be achieved in both embodiments.

The present invention provides a novel antenna structure. By using the floating metal part, the invention can fine tune the main beam direction of the dipole antenna element and enlarge the operation bandwidth. Compared with the conventional design, the present invention has at least the advantages of small size, wide frequency band, low complexity, high gain, and low manufacturing cost, so it is very suitable for various communication devices.

It is noted that the sizes, shapes and frequency ranges of the above-mentioned components are not limitations of the present invention. The antenna designer can adjust these settings according to different needs. The antenna structure of the present invention is not limited to the states illustrated in fig. 1A to 7. The present invention may include only any one or more features of any one or more of the embodiments of fig. 1A-7. In other words, not all illustrated features may be implemented in the antenna structure of the present invention at the same time.

Ordinal numbers such as "first," "second," "third," etc., in the specification and claims are not to be given a sequential order, but are merely used to identify two different elements having the same name.

Although the present invention has been described with reference to the preferred embodiments, it should be understood that various changes and modifications can be made therein by those skilled in the art without departing from the spirit and scope of the invention as defined in the appended claims.