TWI659565B - Mobile device - Google Patents

Abstract

A mobile device includes a metal back cover, a grounded metal portion, a feed-in radiation portion, and a dielectric substrate. The metal back cover has a slot. The ground metal part is coupled to the metal back cover. The feed-in radiation section has a feed-in point and includes a first feed-in branch, a second feed-in branch, and a third feed-in branch, wherein the second feed-in branch system and the first feed-in The branches extend in opposite directions, and the third feeding branch system extends in the same direction as the first feeding branch. The vertical projection of the feeding radiation portion on the metal back cover at least partially overlaps the slot. The dielectric substrate is adjacent to the metal back cover, wherein the ground metal portion and the feed-in radiation portion are both disposed on the dielectric substrate. The slot of the feed-in radiation part and the metal back cover together form an antenna structure.

Description

Mobile device

The present invention relates to a mobile device, and more particularly to a mobile device and an antenna structure thereof.

With the development of mobile communication technology, mobile devices have become more and more common in recent years. Common examples include: portable computers, mobile phones, multimedia players, and other portable electronic devices with mixed functions. In order to meet people's needs, mobile devices usually have the function of wireless communication. Some cover long-range wireless communication ranges, for example: mobile phones use 2G, 3G, LTE (Long Term Evolution) systems and the 700MHz, 850MHz, 900MHz, 1800MHz, 1900MHz, 2100MHz, 2300MHz, and 2500MHz frequency bands to communicate, and Some cover short-range wireless communication ranges, such as: Wi-Fi, Bluetooth systems use the 2.4GHz, 5.2GHz, and 5.8GHz bands for communication.

In order to pursue beautiful appearance, designers today often add elements of metal elements to mobile devices. However, the added metal components are likely to have a negative impact on the antenna supporting wireless communication in the mobile device, thereby reducing the overall communication quality of the mobile device. Therefore, it is necessary to propose a new mobile device and antenna structure to overcome the problems faced by traditional technologies.

In a preferred embodiment, the present invention provides a mobile device, including Including: a metal back cover with a slot; a ground metal part coupled to the metal back cover; a feed radiation part with a feed point, wherein the feed radiation part includes: a first feed A branch, wherein one end of the first feeding branch is coupled to the feeding point, the first feeding branch has a first polygon, and the first polygon has at least a long axis and a A short axis, and the long axis of the first polygon extends in a first direction; a second feeding branch, wherein one end of the second feeding branch is coupled to the feeding point, The second feeding branch has a second polygon, the second polygon has at least a long axis and a short axis, and the long axis of the second polygon extends along a second direction. The second direction is opposite to the first direction; and a third feeding branch, wherein one end of the third feeding branch is coupled to the feeding point, and the third feeding branch has a A third polygon, the third polygon having at least a major axis and a minor axis, and the major axis of the third polygon extending along the first direction; and a dielectric base , Adjacent to the metal back cover, wherein the ground metal portion and the feed-in radiation portion are both disposed on the dielectric substrate; wherein the vertical projection of the feed-in radiation portion on the metal back cover and the slot are at least partially Overlap; wherein the feed-in radiation part and the slot of the metal back cover together form an antenna structure.

In some embodiments, the slot is a closed slot and presents a rectangle, and a long axis of the slot and the long axis of the first feeding branch and the long axis of the second feeding branch The long axis and the long axis of the third feeding branch are all parallel to each other.

In some embodiments, the other end of each of the first feeding branch, the second feeding branch, and the third feeding branch is an open end.

In some embodiments, the first polygon is a rectangle.

In some embodiments, the second polygon is a rectangle or an L-shape.

In some embodiments, the third polygon is a rectangle, an L-shape, or a U-shape.

In some embodiments, the ground metal portion is a ground copper foil and extends from the dielectric substrate to the metal back cover.

In some embodiments, a first coupling gap is formed between the first feeding branch and the third feeding branch, and the width of the first coupling gap is less than or equal to the width of the slot.

In some embodiments, a second coupling gap is formed between the second feeding branch and the ground metal part, and the width of the second coupling gap is less than or equal to the width of the slot.

In some embodiments, the antenna structure includes a first frequency band and a second frequency band, the first frequency band is between 2400 MHz and 2500 MHz, and the second frequency band is between 5150 MHz and 5875 MHz.

In some embodiments, the length of the slot is equal to 0.5 times the wavelength of the center frequency of the first frequency band.

In some embodiments, the length of the first feeding branch is equal to 0.25 times the wavelength of the center frequency of the first frequency band.

In some embodiments, the first feeding branch and the slot of the metal back cover are excited to generate the first frequency band.

In some embodiments, the length of the second feeding branch is equal to 0.25 times the wavelength of the center frequency of the second frequency band.

In some embodiments, the second feeding branch system is excited to produce the The second frequency band.

In some embodiments, the length of the third feeding branch is between 0.125 times and 0.25 times the center frequency of the first frequency band.

In some embodiments, the third feeding branch is used to increase the radiation efficiency and operating bandwidth of the first frequency band and the second frequency band.

100, 300, 400, 500, 600‧‧‧ mobile devices

110‧‧‧metal back cover

111‧‧‧Edge of metal back cover

120‧‧‧Slot

121, 122‧‧‧ closed end of slot

130, 330, 430, 530‧‧‧Feed into the radiation department

140, 340, 540‧‧‧‧First feeding branch

141, 341, 541‧‧‧ Open end of the first feeder branch

150, 350, 450, 550‧‧‧Second Feeder Branch

151, 351, 451, 551‧‧‧ Open end of the second feeder branch

160, 360, 560‧‧‧ Third Feeder Branch

161, 361, 561‧‧‧ Open end of the third feeding branch

170‧‧‧ Dielectric Substrate

180, 680‧‧‧ grounded metal

365‧‧‧The bent end of the third feeding branch

455‧‧‧The bent end of the second feeding branch

E1‧‧‧ the first surface of the dielectric substrate

E2‧‧‧Second surface of dielectric substrate

FB1‧‧‧First Band

FB2‧‧‧Second Band

FP‧‧‧feed point

GC1‧‧‧first coupling gap

GC2‧‧‧Second coupling gap

W1, W2‧‧‧Width

X‧‧‧X axis

Y‧‧‧Y axis

Z‧‧‧Z axis

FIG. 1A is a top view of a mobile device according to an embodiment of the present invention.

FIG. 1B is a side view showing a mobile device according to an embodiment of the present invention.

FIG. 2 is a graph showing a voltage standing wave ratio of an antenna structure of a mobile device according to an embodiment of the present invention.

FIG. 3 is a top view of a mobile device according to an embodiment of the present invention.

FIG. 4 is a top view of a mobile device according to an embodiment of the present invention.

FIG. 5 is a top view of a mobile device according to an embodiment of the present invention.

FIG. 6 is a top view of a mobile device according to an embodiment of the present invention.

In order to make the objects, features, and advantages of the present invention more comprehensible, the following specifically lists specific embodiments of the present invention and describes them in detail with the accompanying drawings. The description is as follows.

Certain terms are used in the description and the scope of patent applications to refer to specific elements. Those skilled in the art will understand that hardware manufacturers may use different terms to refer to the same component. The scope of this specification and the patent application does not use the difference in names as a way to distinguish components, but rather uses the difference in functions of components as a criterion for distinguishing components. The terms "including" and "including" mentioned throughout the specification and the scope of patent applications are open-ended terms and should be interpreted as "including but not limited to." The term "approximately" means that within the acceptable error range, those skilled in the art can solve the technical problem within a certain error range and achieve the basic technical effect. In addition, the term "coupled" includes any direct and indirect electrical connection means in this specification. Therefore, if a first device is described as being coupled to a second device, it means that the first device can be electrically connected directly to the second device, or indirectly electrically connected to the first device via other devices or connection means.二 装置。 Two devices.

FIG. 1A is a top view of a mobile device 100 according to an embodiment of the present invention. FIG. 1B is a side view of a mobile device 100 according to an embodiment of the present invention. Please refer to Figures 1A and 1B together. The mobile device 100 may be a smart phone, a tablet computer, or a notebook computer. In the embodiment shown in FIGS. 1A and 1B, the mobile device 100 includes: a metal back cover 110, a feeding radiation element 130, a dielectric substrate 170, and a Ground metal element 180. It must be understood that although not shown in Figures 1A and 1B, the mobile device 100 may actually include other components, such as: A processor, a touch control panel, a speaker, a battery module, and a housing. In other embodiments, the mobile device 100 is implemented in a deformable device, which can be switched between a tablet mode (notebook mode) or a notebook mode (notebook mode).

The metal back cover 110 has a slot 120, wherein the slot 120 may be a substantially rectangular opening or a rectangular opening. In detail, the slot 120 is a closed slot (Closed Slot), which has two closed ends (121, 122) away from each other. However, the present invention is not limited to this. In other embodiments, the slot 120 can also be changed to a monopole slot, which has an open end and a closed end away from each other. If the mobile device 100 is implemented in a laptop or a deformable device, an edge 111 of the metal back cover 110 may be adjacent to a hinge element (not shown) of the laptop or the deformable device. For example, the distance between the edge 111 of the metal back cover 110 and the shaft element may be less than 10 mm.

The feed-in radiation portion 130 may be made of a metal material, such as copper, silver, aluminum, iron, or an alloy thereof. The dielectric substrate 170 may be a FR4 (Flame Retardant 4) substrate, a printed circuit board (PCB), or a flexible circuit board (FCB). The dielectric substrate 170 may have a first surface E1 and a second surface E2 opposite to each other. The feed radiation portion 130 and the ground metal portion 180 are both disposed on the first surface E1 of the dielectric substrate 170, and the second surface E1 of the dielectric substrate 170 The surface E2 may be close to or directly attached to the metal back cover 110 (adjacent to the slot 120), so that the dielectric substrate 170 almost completely covers the slot 120 of the metal back cover 110. It must be noted that what is called "adjacent" in this manual Or the term "adjacent" may mean that the distance between the corresponding two components is less than a predetermined distance (for example: 5 mm or less), and may also include the case where the corresponding two components are in direct contact with each other (that is, the aforementioned distance is shortened to 0).

The ground metal part 180 is coupled to the metal back cover 110. The two can provide a ground voltage of the mobile device 100. For example, the ground metal portion 180 may be a ground copper foil (Ground Copper Foil), which may extend from the dielectric substrate 170 to the metal back cover 110. The feed radiation part 130 has a feed point FP, which can be coupled to a positive electrode of a signal source (not shown), and a negative electrode of the signal source can be coupled To the ground metal portion 180. For example, the aforementioned signal source may be a radio frequency (RF) module, which can be used to generate a transmitted signal or process a received signal. In some embodiments, the positive pole of the signal source is coupled to the feed point FP via a central lead of a coaxial cable, and the negative pole of the signal source is coupled to the ground via a conductor housing of a coaxial cable. Metal section 180. The feed-in radiation portion 130 extends across the slot 120 of the metal back cover 110. That is, the vertical projection of the feed radiation part 130 (including the first feed branch 140, the second feed branch 150, and the third feed branch 160) on the metal back cover 110 is the same as The slot 120 overlaps at least partially.

In detail, the feed radiation unit 130 includes a first feeding branch 140, a second feeding branch 150, and a third feeding branch 160. The combination of the first feeding branch 140, the second feeding branch 150, and the third feeding branch 160 may include a Y-shaped connection portion surrounding the feeding point FP. The first feeding branch 140 has a first polygon (Polygon), which may be substantially rectangular or L-shaped. One end of the first feeding branch 140 is coupled to the feeding Point FP, and the other end of the first feeding branch 140 is an Open End 141. The first polygon of the first feeding branch 140 has at least a long axis and a short axis. The long axis of the first polygon extends along a first direction, for example, : + X axis direction. For example, the long axis of the first polygon may be a first virtual straight line passing through the open end 141 and parallel to the + X axis. The second feeding branch 150 has a second polygon, which can be substantially rectangular or L-shaped. One end of the second feeding branch 150 is coupled to the feeding point FP, and the other end of the second feeding branch 150 is an open end 151. The second polygon of the second feeding branch 150 has at least a long axis and a short axis, wherein the long axis of the second polygon extends along a second direction, for example, the -X axis direction. For example, the long axis of the second polygon may be a second virtual straight line passing through the open end 151 and parallel to the -X axis. In other words, the aforementioned second direction may be opposite to the aforementioned first direction, so that the first feeding branch 140 and the second feeding branch 150 may extend substantially in opposite directions. For example, the open end 141 of the first feeding branch 140 may extend toward the + X axis direction, and the open end 151 of the second feeding branch 150 may extend toward the -X axis direction. The third feeding branch 160 may have a third polygon, which may be substantially rectangular or L-shaped. One end of the third feeding branch 160 is coupled to the feeding point FP, and the other end of the third feeding branch 160 is an open end 161. The third polygon of the third feeding branch 160 has at least a long axis and a short axis, and the long axis of the third polygon also extends along the aforementioned first direction, for example, the + X axis direction. For example, the long axis of the third polygon may be a third virtual straight line passing through the open end 161 and parallel to the + X axis. In other words, the first feeding branch 140 and the third feeding branch 160 may extend substantially in the same direction. For example, the open end 141 of the first feeding branch 140 may extend toward the + X axis direction, and the open end 161 of the third feeding branch 160 may also extend toward the + X axis direction. For extension. Each of the first feeding branch 140, the second feeding branch 150, and the third feeding branch 160 is at least partially parallel to the slot 120 of the metal back cover 110. In some embodiments, one of the long axes of the slot 120 (through the two closed ends 121, 122) is connected to the long axis of the first feeding branch 140, the long axis of the second feeding branch 150, and the third The long axes of the feeding branches 160 are all parallel to each other. In addition, a first coupling gap GC1 may be formed between the first feeding branch 140 and the third feeding branch 160, and a gap between the second feeding branch 150 and the ground metal portion 180 may be formed. Second coupling gap GC2. In a preferred embodiment, the metal back cover 110, the slot 120, and the feed-in radiation portion 130 collectively form an antenna structure.

FIG. 2 shows a Voltage Standing Wave Ratio (VSWR) diagram of the antenna structure of the mobile device 100 according to an embodiment of the present invention, where the horizontal axis represents the operating frequency (MHz) and the vertical axis represents the voltage Standing wave ratio. According to the measurement results in FIG. 2, when receiving or transmitting wireless signals, the antenna structure of the mobile device 100 may cover a first frequency band FB1 and a second frequency band FB2. The first frequency band FB1 may be between about 2400 MHz and 2500 MHz. The second frequency band FB2 may be between approximately 5150 MHz and 5875 MHz. Therefore, the antenna structure of the mobile device 100 can support at least 2.4GHz / 5GHz broadband operation of Bluetooth and WLAN (Wireless Local Area Network). According to the actual measurement results, the antenna efficiency of the antenna structure of the mobile device 100 in the first frequency band FB1 is about -3.88 dB, and the antenna efficiency in the second frequency band FB2 is about -3.95 dB (its Compared with the traditional slot antenna, the antenna efficiency is improved by about 2 to 4dB), which can meet the practical application requirements of general mobile communication devices.

In some embodiments, the operation of the antenna structure of the mobile device 100 The principle can be described as follows. The first feeding branch 140 and the slot 120 of the metal back cover 110 are used to excite the aforementioned first frequency band FB1. The second feeding branch 150 is used for exciting and generating the aforementioned second frequency band FB2. The third feeding branch 160 can be coupled and excited by the first feeding branch 140 to increase the radiation efficiency and the operation bandwidth of the first frequency band FB1 and the second frequency band FB2 at the same time. Since the feed-in radiation part 130 has a meandering shape (for example, three different feed-in branches), it can greatly reduce the overall area of the antenna structure of the mobile device 100.

In some embodiments, the component dimensions of the mobile device 100 may be as described below. The length of the slot 120 (that is, the length from the closed end 121 to the other closed end 122) may be approximately equal to 0.5 times the wavelength (λ / 2) of the central frequency of the aforementioned first frequency band FB1. The length of the first feeding branch 140 (that is, the length from the feeding point FP to the open end 141) may be approximately equal to the wavelength (λ / 4) of the center frequency of the aforementioned first frequency band FB1. The length of the second feeding branch 150 (that is, the length from the feeding point FP to the open end 151) may be approximately equal to 0.25 times the wavelength (λ / 4) of the center frequency of the aforementioned second frequency band FB2. The length of the third feeding branch 160 (that is, the length from the feeding point FP to the open end 161) may be between 0.125 times and 0.25 times the wavelength of the center frequency of the aforementioned first frequency band FB1 (λ / 8 ~ λ / 4). In order to strengthen the coupling effect between the components, the width of the first coupling gap GC1 may be less than or equal to the width W1 of the slot 120, and the width of the second coupling gap GC2 is also less than or equal to the width W1 of the slot 120. The above element size range is obtained based on the results of multiple experiments, which helps to optimize the operating frequency band and impedance matching of the antenna structure of the mobile device 100.

It must be understood that the shape of the above-mentioned feeding radiation portion 130 may be determined according to Fine-tune for different needs. For example, the Y-shaped connecting portion between the first feeding branch 140, the second feeding branch 150, and the third feeding branch 160 (that is, near the feeding point FP) may be modified to be smoother Shape to remove discontinuous jagged edges without affecting the effect of the present invention. The following embodiments will introduce different configurations of the proposed antenna structure, but the drawings and descriptions thereof are merely examples, and are not intended to limit the scope of the present invention.

FIG. 3 is a top view of a mobile device 300 according to an embodiment of the present invention. Figure 3 is similar to Figure 1A. In the embodiment of FIG. 3, one of the feed radiation portions 330 of the mobile device 300 includes a first feed branch 340, a second feed branch 350, and a third feed branch 360. The three-feed branch 360 further includes an end bending portion 365, so that one open end 361 of the third feed branch 360 is closer to an open end 341 of the first feed branch 340. The end bent portion 365 may be substantially perpendicular to the rest of the third feeding branch 360. The third feeding branch 360 (ie, the third polygon) having the end bent portion 365 may be roughly U-shaped. The addition of the end bent portion 365 can reduce the equivalent width of the first coupling gap GC1 between the first feeding branch 340 and the third feeding branch 360 to strengthen the first feeding branch 340 and the third Coupling effect between feeding branches 360. Under this design, the radiation efficiency of the antenna structure of the mobile device 300 in the first frequency band FB1 can be further improved. The remaining features of the mobile device 300 in FIG. 3 are similar to those of the mobile device 100 in FIGS. 1A and 1B, so similar operation effects can be achieved in both embodiments.

FIG. 4 is a top view of a mobile device 400 according to an embodiment of the present invention. Figures 4 and 3 are similar. In the embodiment of FIG. 4, one of the feed-in radiation portions 430 of one of the mobile devices 400 further includes a second feed branch 450. The bent end portion 455 makes one of the open ends 451 of the second feeding branch 450 closer to the ground metal portion 180. The bent end portion 455 may be substantially perpendicular to the rest of the second feeding branch 450. The second feeding branch 450 (ie, the second polygon) having the end bent portion 455 may be roughly L-shaped. The addition of the end bent portion 455 can reduce the equivalent width of the second coupling gap GC2 between the second feeding branch 450 and the ground metal portion 180 to fine-tune Impedance matching. Under this design, the radiation efficiency of the antenna structure of the mobile device 400 in the second frequency band FB2 can be further improved. The remaining features of the mobile device 400 in FIG. 4 are similar to those of the mobile device 300 in FIG. 3, so similar operation effects can be achieved in both embodiments.

FIG. 5 is a top view of a mobile device 500 according to an embodiment of the present invention. Figure 5 is similar to Figure 1A. In the embodiment of FIG. 5, one of the feed radiation portions 530 of the mobile device 500 includes a first feed branch 540, a second feed branch 550, and a third feed branch 560. The width W2 of a feeding branch 540 is significantly increased (for example, the width W2 of FIG. 5 may be about twice as large as the width W2 of FIG. 1A), so that the first feeding branch 540 is on the metal back cover 110. The vertical projection system at least partially overlaps the slot 120. For example, the width W2 of the first feeding branch 540 may be greater than or equal to the width W1 of the slot 120, but it is not limited thereto. The widening of the first feeding branch 540 can reduce the equivalent width of the first coupling gap GC1 between the first feeding branch 540 and the third feeding branch 560 to strengthen the first feeding branch 540 and Coupling effect between the third feeding branches 560. Under this design, the radiation efficiency of the antenna structure of the mobile device 500 in the first frequency band FB1 can be further improved. The remaining features of the mobile device 500 in Fig. 5 are similar to the mobile device 100 in Figs. 1A and 1B, so the two embodiments can achieve similar operating effects. fruit.

FIG. 6 is a top view of a mobile device 600 according to an embodiment of the present invention. Figures 6 and 5 are similar. In the embodiment of FIG. 6, one ground metal part 680 of the mobile device 600 moves closer to the second feeding branch 550, so that the vertical projection system of the ground metal part 680 on the metal back cover 110 and The slot 120 overlaps at least partially. The movement of the ground metal portion 680 can reduce the equivalent width of the second coupling gap GC2 between the second feeding branch 550 and the ground metal portion 680 to fine-tune the impedance matching between the second feeding branch 550 and the ground metal portion 680 . Under this design, the radiation efficiency of the antenna structure of the mobile device 600 in the second frequency band FB2 can be further improved. The remaining features of the mobile device 600 in FIG. 6 are similar to those of the mobile device 500 in FIG. 5. Therefore, the two embodiments can achieve similar operating effects.

The invention proposes a novel antenna structure, which includes a slot. When this antenna structure is applied to a mobile device with a metal back cover, the metal back cover can be regarded as an extension of the antenna structure, which can effectively avoid metal The back cover has a negative impact on the communication quality of the mobile device. It should also be noted that the present invention can further improve the appearance design of the mobile device without using any Antenna Window on the metal back cover. Compared with the traditional design, the present invention has at least the advantages of small size, wide frequency band, improved high and low frequency antenna efficiency, increased device stability, and beautifying the appearance of the device. .

It is worth noting that the above-mentioned component size, component shape, and frequency range are not the limiting conditions of the present invention. The antenna designer can adjust these settings according to different needs. The mobile device and antenna structure of the present invention are not Only in the state shown in Figures 1-6. The invention may include only any one or more features of any one or more of the embodiments of FIGS. 1-6. In other words, not all the illustrated features must be implemented in the mobile device and antenna structure of the present invention at the same time.

The ordinal numbers in this specification and the scope of patent application, such as "first", "second", "third", etc., do not have a sequential relationship with each other, they are only used to indicate that two have the same Different components of the name.

Although the present invention is disclosed as above with a preferred embodiment, it is not intended to limit the scope of the present invention. Any person skilled in the art can make some modifications and decorations without departing from the spirit and scope of the present invention. The protection scope of the present invention shall be determined by the scope of the attached patent application.

Claims (16)

A mobile device includes: a metal back cover having a slot; a ground metal portion coupled to the metal back cover; a feed radiation portion having a feed point, wherein the feed radiation portion includes: a A first feeding branch, wherein one end of the first feeding branch is coupled to the feeding point, the first feeding branch has a first polygon, and the first polygon has at least one A long axis and a short axis, and the long axis of the first polygon extends along a first direction; a second feeding branch, wherein one end of the second feeding branch is coupled to the Feed point, the second feed branch has a second polygon, the second polygon has at least a long axis and a short axis, and the long axis of the second polygon is along a second The direction is extended, and the second direction is opposite to the first direction; and a third feeding branch, wherein one end of the third feeding branch is coupled to the feeding point, and the third feeding The branch has a third polygon, the third polygon has at least a major axis and a minor axis, and the major axis of the third polygon extends along the first direction. And a dielectric substrate adjacent to the metal back cover, wherein the ground metal portion and the feed radiation portion are both disposed on the dielectric substrate; wherein the vertical projection of the feed radiation portion on the metal back cover is related to the The slot holes are at least partially overlapped; wherein the feeding radiation portion and the slot hole of the metal back cover together form an antenna structure; wherein a first feeding branch and a third feeding branch form a first A coupling gap, and the width of the first coupling gap is less than or equal to the width of the slot. The mobile device according to item 1 of the scope of patent application, wherein the slot is a closed slot and presents a rectangle, and a long axis of the slot and the long axis of the first feeding branch, the The long axis of the second feeding branch and the long axis of the third feeding branch are all parallel to each other. The mobile device according to item 1 of the scope of patent application, wherein the other end of each of the first feeding branch, the second feeding branch, and the third feeding branch is an open circuit. end. The mobile device according to item 1 of the scope of patent application, wherein the first polygon is a rectangle. The mobile device according to item 1 of the scope of patent application, wherein the second polygon is a rectangle or an L-shape. The mobile device according to item 1 of the scope of patent application, wherein the third polygon is a rectangle, an L-shape, or a U-shape. The mobile device according to item 1 of the scope of patent application, wherein the ground metal part is a ground copper foil and extends from the dielectric substrate to the metal back cover. The mobile device according to item 1 of the scope of patent application, wherein a second coupling gap is formed between the second feeding branch and the ground metal part, and the width of the second coupling gap is less than or equal to the slot Of its width. The mobile device according to item 1 of the patent application scope, wherein the antenna structure covers a first frequency band and a second frequency band, the first frequency band is between 2400MHz and 2500MHz, and the second frequency band is between 5150MHz To 5875MHz. The mobile device according to item 9 of the scope of patent application, wherein the length of the slot is equal to 0.5 wavelength of the center frequency of the first frequency band. The mobile device according to item 9 of the scope of patent application, wherein the length of the first feeding branch is equal to 0.25 times the wavelength of the center frequency of the first frequency band. The mobile device according to item 9 of the scope of patent application, wherein the first feeding branch and the slot of the metal back cover are excited to generate the first frequency band. The mobile device according to item 9 of the scope of patent application, wherein the length of the second feeding branch is equal to 0.25 times the wavelength of the center frequency of the second frequency band. The mobile device according to item 9 of the scope of patent application, wherein the second feeding branch is excited to generate the second frequency band. The mobile device according to item 9 of the scope of patent application, wherein the length of the third feeding branch is between 0.125 times and 0.25 times the center frequency of the first frequency band. The mobile device according to item 9 of the scope of patent application, wherein the third feeding branch is used to increase the radiation efficiency and operating bandwidth of the first frequency band and the second frequency band.