TWI689132B - Antenna structure and wireless communication device using the same - Google Patents

Abstract

An antenna structure includes a metal frame, a feeding source, and a ground point. The metal frame defines a first gap, a second gap, a first coupling portion, a second coupling portion, and a radiating portion. When a current flows from the feeding source to the radiating portion, the current will flow through the radiating portion and be coupled to the first coupling portion and the second coupling portion. The radiating portion, the first coupling portion and the second coupling portion can activate a first mode, a second mode and a third mode simultaneously to generate radiation signals in a first frequency band, a second frequency band and a third frequency band. When the current flows from the feeding source to the radiating portion and be coupled to the second coupling portion, the current will form a loop current through a first end and a second end of the second coupling portion. A wireless communication device is also provided.

Description

Antenna structure and wireless communication device with the antenna structure

The invention relates to an antenna structure and a wireless communication device with the antenna structure.

With the advancement of wireless communication technology, electronic devices such as mobile phones and personal digital assistants continue to develop toward the trend of diversified functions, thinner and thinner, and faster and more efficient data transmission. However, the space for accommodating antennas is getting smaller and smaller, and with the continuous development of Long Term Evolution (LTE) technology and LTE-Advanced (LTE-A), the frequency of antennas The width keeps increasing. Therefore, how to design an antenna with multiple frequency bands in a limited space is an important issue for antenna design.

In view of this, it is necessary to provide an antenna structure and a wireless communication device having the antenna structure.

An antenna structure includes a metal frame, a feed source, and a ground point. The metal frame is provided with a first break point, a second break point, a first coupling portion, a second coupling portion, and a radiation portion. The first breakpoint and the second breakpoint both penetrate and block the metal frame, and the metal frame between the first breakpoint and the second breakpoint constitutes the radiating portion, and the first A metal frame with a break point away from the radiation part constitutes the first coupling part, and a second break point is away from The metal frame constitutes the second coupling part, and the feed source is electrically connected to the radiating part to feed a current signal to the radiating part; when current is fed into the radiating part from the feed source, Flowing through the radiation part and coupled to the first coupling part and the second coupling part, so that the radiation part, the first coupling part and the second coupling part respectively excite the first Modes, second modes, and third modes to generate radiation signals in the first frequency band, the second frequency band, and the third frequency band, the first end of the second coupling portion is grounded through the ground point, and the first The second end of the two coupling parts is also grounded. After the current is fed into the radiating part from the feed source, it is coupled to the second coupling part, and the first end and the second end form a Loop current.

A wireless communication device includes the antenna structure described above.

The antenna structure and the wireless communication device having the antenna structure are provided with the first break point and the second break point to divide the radiation part, the first coupling part and the second coupling part from the metal frame. The antenna structure is also provided with a feed source, so that the current of the feed source is fed to the radiating part and is coupled to the first coupling part and the second coupling part, so that the radiation Part, the first coupling part and the second coupling part can excite the first mode, the second mode and the third mode to generate signals in the first frequency band, the second frequency band and the third frequency band. At the same time, when current is fed from the feed source to the radiating part and coupled to the second coupling part, a loop current can be formed by both ends of the second coupling part.

100: antenna structure

200: wireless communication device

11: Shell

12: Feed source

13: Ground point

14: Matching circuit

111: backplane

112: Metal frame

113: accommodating space

114: bottom

115: first side

116: Second side

117: Port

118: First breakpoint

119: Second breakpoint

21: substrate

22: Electronic components

A1: Radiation Department

A2: First coupling part

A3: Second coupling part

141: First matching element

142: Second matching element

17: switch circuit

171: Toggle switch

172: switching element

FIG. 1 is an assembly diagram of the wireless communication device shown in the preferred embodiment of the present invention.

FIG. 2 is a schematic diagram of an antenna structure applied to a wireless communication device according to a preferred embodiment of the present invention.

FIG. 3 is a circuit diagram of the antenna structure shown in FIG. 1.

4 is a circuit diagram of the switching circuit in the antenna structure shown in FIG. 3.

5 is a graph of S-parameters (scattering parameters) of the antenna structure when the switching circuit in FIG. 4 switches to different switching elements.

6 is a graph of the total radiation efficiency of the antenna structure shown in FIG.

The technical solutions in the embodiments of the present invention will be described clearly and completely in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, but not all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by a person of ordinary skill in the art without making creative efforts fall within the protection scope of the present invention.

It should be noted that when an element is called "electrically connected" to another element, it may be directly on the other element or there may be a centered element. When an element is considered to be "electrically connected" to another element, it may be a contact connection, for example, a wire connection, or a contactless connection, for example, a contactless coupling.

Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the technical field of the present invention. The terminology used in the description of the present invention herein is for the purpose of describing specific embodiments, and is not intended to limit the present invention.

The following describes some embodiments of the present invention in detail with reference to the accompanying drawings. In the case of no conflict, the following embodiments and the features in the embodiments can be combined with each other.

Please refer to FIG. 1, FIG. 2 and FIG. 3, the antenna structure 100 of the preferred embodiment of the present invention is applied to a wireless communication device 200 for transmitting and receiving radio waves to transmit and exchange wireless signals. The wireless communication device 200 may be a wireless communication device such as a mobile phone or a personal digital assistant.

The antenna structure 100 includes a housing 11, a feed source 12, a ground point 13 and a matching circuit 14. The casing 11 may be a casing of the wireless communication device 200. The casing 11 includes at least a back plate 111 and a metal frame 112. In this embodiment, the backplane 111 is made of non-metallic materials, such as plastic, glass, Made of ceramics. The metal frame 112 is made of metal material. The back plate 111 and the metal frame 112 constitute a casing of the wireless communication device 200.

The metal frame 112 has a substantially ring structure. In this embodiment, the metal frame 112 is disposed around the edge of the back plate 111 to form an accommodating space 113 together with the back plate 111. The accommodating space 113 is used for accommodating electronic components or circuit modules such as circuit boards and processing units of the wireless communication device 200 therein.

The metal frame 112 at least includes a bottom 114, a first side 115 and a second side 116. In this embodiment, the bottom 114 is the bottom of the wireless communication device 200. The first side portion 115 and the second side portion 116 are oppositely disposed, and the two are respectively disposed at both ends of the bottom portion 114, preferably vertically. The bottom 114, the first side 115 and the second side 116 are all vertically connected to the back plate 111.

The metal frame 112 is also provided with a port 117, a first breakpoint 118 and a second breakpoint 119. In this embodiment, the port 117 is opened at the middle of the bottom 114 and penetrates the bottom 114. In this embodiment, the first break point 118 is provided in the metal frame 112 between the port 117 and the first side 115. The second breakpoint 119 is provided in the metal frame 112 between the port 117 and the second side 116, that is, the first breakpoint 118 and the second breakpoint 119 are respectively provided in the The two sides of the port 117 are described.

The wireless communication device 200 further includes a substrate 21 and at least one electronic component 22. The substrate 21 is a printed circuit board (PCB), which can be made of dielectric materials such as epoxy glass fiber (FR4). In this embodiment, the electronic component 22 is a Universal Serial Bus (USB) interface module. The electronic component 22 is disposed in the accommodating space 113, adjacent to and electrically connected to the substrate 21. The electronic component 22 corresponds to the port 117 so that the electronic component 22 is partially exposed from the port 117. So users can borrow a USB component Inserted through the port 117 to establish an electrical connection with the first electronic component 22, the USB component can be used to charge the wireless communication device 200 and transfer data.

In this embodiment, the first breakpoint 118 and the second breakpoint 119 both penetrate and block the metal frame 112, and then divide the metal frame 112 into three parts, namely, the radiation portion A1, the first The coupling part A2 and the second coupling part A3. Wherein, the metal frame 112 between the first breakpoint 118 and the second breakpoint 119 forms the radiation portion A1. The metal frame 112 of the bottom 114 outside the first breakpoint 118 and the metal frame 112 connecting the first side 115 of the bottom 114 form the first coupling portion A2. The metal frame 112 of the bottom 114 outside the second breakpoint 119 and the metal frame 112 connecting the second side 116 of the bottom 114 form the second coupling portion A3. In this embodiment, the first side 115 and the second side 116 are both grounded, so both the first coupling portion A2 and the second coupling portion A3 are grounded.

In this embodiment, the first breakpoint 118 and the second breakpoint 119 are filled with an insulating material to separate the radiation portion A1, the first coupling portion A2, and the second coupling部A3. The insulating material is plastic, rubber, glass, wood, ceramic, etc., but not limited to this.

Please refer to FIG. 3 together. The feed source 12 is disposed in the accommodating space 113. The feed source 12 is electrically connected to the radiating portion A1 through the matching circuit 14.

It can be understood that when a current is fed from the feed source 12, the current will flow into the radiating portion A1, and are respectively coupled to the first breakpoint 118 and the second breakpoint 119 The first coupling part A2 and the second coupling part A3, so that the feed source 12, the radiation part A1, the first coupling part A2, and the second coupling part A3 constitute a coupling feed antenna, thereby exciting the first A mode, a second mode, and a third mode respectively generate radiation signals in the first frequency band, the second frequency band, and the third frequency band, respectively.

In this embodiment, the frequency of the third frequency band is higher than the frequency of the second frequency band, and the frequency of the second frequency band is higher than the frequency of the first frequency band. Specifically, the first mode is the LTE-A low-frequency mode, and the first frequency band is the 699-960 MHz frequency band. The second mode is the LTE-A intermediate frequency mode, and the The second frequency band is the 1710-2170MHz frequency band. The third mode is the LTE-A high-frequency mode, and the third frequency band is the 2300-2690MHz frequency band.

Please refer to FIG. 4 together. In this embodiment, the antenna structure 100 further includes a switching circuit 17. The switching circuits 17 are all disposed in the accommodating space 113 and located between the feed source 12 and the electronic component 22. In this embodiment, one end of the switching circuit 17 is electrically connected to the radiating portion A1. The other end of the switching circuit 17 is grounded.

The switching circuit 17 includes a switching switch 171 and a plurality of switching elements 172. The changeover switch 171 is electrically connected to the radiation part A1. Each of the switching elements 172 may be an inductor, a capacitor, or a combination of an inductor and a capacitor. The switching elements 172 are connected in parallel with each other, and one end of the switching element 172 is electrically connected to the switching switch 171 and the other end is grounded. In this way, by controlling the switching of the switching switch 171, the radiating portion A1 can be switched to a different switching element 172. Since each switching element 172 has a different impedance, the first frequency band of the first mode can be effectively adjusted by the switching of the switching switch 171. For example, the plurality of switching elements 172 may include four inductors connected in parallel, and the inductance values of the four inductors are 5.1 nH, 10 nH, 12 nH, and 27 nH, respectively.

Please refer to FIG. 3 again. It can be understood that in this embodiment, when a current is fed from the feed source 12, a part of the current will flow through the radiation portion A1, thereby exciting the first mode to generate the first Radiated signal in a frequency band (see path P1). A part of the current will flow through the radiation part A1 and be coupled to the first coupling part A2, thereby exciting the second mode to generate a radiation signal in a second frequency band (see path P2). The second coupling portion A3 includes a first end electrically connected to the ground point 13 and a second end located on the second side portion 116. The first end of the second coupling portion A3 is grounded through the grounding point 13, and the second end of the second coupling portion A3 is also grounded. A part of the current fed by the feed source 12 will flow through the radiating portion A1 and be coupled to the second coupling portion A3, and a loop current is formed by the first end and the second end, and further The third mode is excited to generate a radiation signal in the third frequency band (see path P3).

FIG. 5 is a graph of S-parameters (scattering parameters) when the antenna structure 100 works in the LTE-A low-medium-high-frequency mode. Obviously, when the switching switch 171 in the switching circuit 17 switches to different switching elements 172 (for example, four different switching elements 172, the inductance of each switching element 172 is 5.1nH, 10nH, 12nH, 27nH), since each switching element 172 has a different impedance, the first frequency band can be effectively adjusted by the switching of the switching switch 171. Wherein, the curve S601 is an S-parameter (scattering parameter) curve diagram when the antenna structure 100 works in the LTE-A low-medium-high-frequency mode when the inductance value is 5.1 nH. Curve S602 is a graph of S-parameters (scattering parameters) when the antenna structure 100 works in the low-medium-high mode of LTE-A when the inductance value is 10 nH. The curve S603 is a graph of S-parameters (scattering parameters) when the antenna structure 100 works in the low-medium-high mode of the LTE-A when the inductance value is 12 nH. Curve S604 is a graph of S-parameters (scattering parameters) when the antenna structure 100 works in the low-medium-high mode of LTE-A when the inductance value is 27 nH.

FIG. 6 is a graph of the total radiation efficiency of the antenna structure 100 when operating in the low, medium and high modes of LTE-A. Wherein, curve S701 is a graph of the total radiation efficiency when the antenna structure 100 works in the LTE-A low, medium and high modes when the inductance value is 5.1 nH. Curve S702 is a graph of the total radiation efficiency of the antenna structure 100 when the inductance value is 10 nH when the antenna structure 100 works in the low, medium and high LTE-A mode. Curve S703 is a graph of the total radiation efficiency of the antenna structure 100 when the antenna structure 100 works in the low, medium and high modes of LTE-A when the inductance value is 12 nH. Curve S704 is a graph of the total radiation efficiency of the antenna structure 100 when the antenna structure 100 works in the low, medium, and high modes of LTE-A when the inductance value is 27 nH.

Obviously, as can be seen from FIG. 5, the antenna structure 100 can work in the corresponding LTE-A low-frequency band, for example, the 699-960 MHz band. In addition, the antenna structure 100 can also work in the LTE-A intermediate frequency band (1710-2170MHz band) and LTE-A high frequency band (2300-2690MHz), that is, covering the low, medium and high frequency bands, the frequency range is relatively It is wide, and when the antenna structure 100 works in the above frequency band, it can meet the antenna design requirements and has better radiation efficiency.

As described in the previous embodiments, the antenna structure 100 defines the first break point 118 and the second break point 119 to divide the radiation part A1, the first coupling part A2 and the Second coupling section A3. The antenna structure 100 is further provided with a feed source 12, so that the current of the feed source 12 is fed to the radiation part A1 and is coupled to the first coupling part A2 and the second coupling part A3 In this way, the radiation part A1, the first coupling part A2 and the second coupling part A3 can excite the first mode, the second mode and the third mode to generate the first frequency band, the second frequency band and Radiated signal in the third frequency band. At the same time, when current is fed from the feed source 12 to the radiating portion A1 and is coupled to the second coupling portion A3, the first end and the second end of the second coupling portion A3 may be formed The loop current.

In addition, the antenna structure 100 is provided with the casing 11, and the first breakpoint 118 and the second breakpoint 119 on the casing 11 are both provided on the metal frame 112, but are not provided on the On the backplane 111. In this way, the antenna structure 100 can only use the metal frame 112 to set the corresponding low, medium and high frequency antennas, so that the entire back plate 111 can be made of non-metallic materials, which is more complete and beautiful, and can be effectively adapted The mobile phone antenna clearance area is getting smaller and smaller, and it can effectively ensure the stability of wireless signal reception.

In summary, this creation meets the requirements of the invention patent, and the patent application is filed in accordance with the law. However, the above are only the preferred embodiments of this creation, and the scope of this creation is not limited to the above embodiments. For those who are familiar with the skills of this case, the equivalent modifications or changes made by the spirit of this creation are all It should be covered by the following patent applications.

100: antenna structure

11: Shell

12: Feed source

13: Ground point

111: backplane

112: Metal frame

113: accommodating space

114: bottom

115: first side

116: Second side

117: Port

21: substrate

22: Electronic components

A1: Radiation Department

A2: First coupling part

A3: Second coupling part

17: switch circuit

Claims (8)

An antenna structure includes a metal frame, a feed source, and a ground point. The metal frame is provided with a first break point, a second break point, a first coupling portion, a second coupling portion, and a radiation portion. The first breakpoint and the second breakpoint both penetrate and block the metal frame, and the metal frame between the first breakpoint and the second breakpoint constitutes the radiating portion, and the first The metal frame on the side with a break point away from the radiation portion constitutes the first coupling portion, and the metal frame on the side with the second break point away from the radiation portion constitutes the second coupling portion, so The feed source is electrically connected to the radiating part to feed the radiating part with a current signal, the ground point is provided on the side of the second coupling part; when current is fed into the radiation from the feed source After the unit, it will flow through the radiating part and be coupled to the first coupling part and the second coupling part, so that the radiating part, the first coupling part and the second coupling part are simultaneously The first mode, the second mode, and the third mode are excited to generate radiation signals in the first frequency band, the second frequency band, and the third frequency band, and the first end of the second coupling portion is grounded through the ground point , The second end of the second coupling part is also grounded, and after the current is fed into the radiating part from the feed source, it is coupled to the second coupling part, and through the first end and the first A loop current forms at both ends. The antenna structure according to item 1 of the patent application scope, wherein the frequency of the third frequency band is higher than the frequency of the second frequency band, and the frequency of the second frequency band is higher than the frequency of the first frequency band. The antenna structure according to item 1 of the patent application scope, wherein the first break point and the second break point are filled with an insulating material. The antenna structure according to item 1 of the patent application scope, wherein the second break point is located between the feed source and the ground point. The antenna structure according to item 1 of the patent application scope, wherein the antenna structure further includes a switching circuit, and the switching circuit includes a switching switch and a plurality of switching elements. The change-over switch is electrically connected to the radiating portion, the switching elements are connected in parallel with each other, and one end of the switching element is electrically connected to the change-over switch, and the other end is grounded. Each switching element has a different impedance, by controlling the change-over switch The switching of the switch causes the switch to switch to different switching elements, thereby adjusting the first frequency band. A wireless communication device includes the antenna structure as described in any one of items 1-5 of the patent application scope. The wireless communication device according to item 6 of the patent application scope, wherein the metal frame is a part of a casing of the wireless communication device, the casing further includes a back plate, and the metal frame surrounds the back plate The edge is set, the back plate is made of non-metallic material. The wireless communication device according to item 6 of the patent application scope, wherein the wireless communication device further includes a USB component, and a port is opened on the metal frame, and the port corresponds to the USB component to make The USB component is partially exposed from the port.

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