WO2019218167A1

WO2019218167A1 - Antenna system and terminal device

Info

Publication number: WO2019218167A1
Application number: PCT/CN2018/086931
Authority: WO
Inventors: 许志玮; 赖彦成; 余冬; 李建铭; 王汉阳; 吴鹏飞
Original assignee: 华为技术有限公司
Priority date: 2018-05-15
Filing date: 2018-05-15
Publication date: 2019-11-21
Also published as: CN111213283B; CN111213283A

Abstract

An antenna system applied to a terminal device. The terminal device comprises a frame body formed by a middle frame and a metal frame. There is a receiving space between the middle frame and the metal frame. The antenna system comprises: a first component coupled to a portion of the metal frame so as to form a loop antenna structure, and a first MIMO antenna and a second MIMO antenna disposed in the receiving space, and the loop antenna structure is located between the first MIMO antenna and the second MIMO antenna. The loop antenna structure is separated from the first MIMO antenna and the second MIMO antenna by a first interval and a second interval, respectively. A ground end of the first MIMO antenna is close to the first interval, and a ground end of the second MIMO antenna is close to the second interval, and a feed end of the first MIMO antenna and a feed end of the second MIMO antenna are respectively close to the third interval and the fourth interval between the metal frame and the middle frame.

Description

Antenna system and terminal equipment

Technical field

The present application relates to the field of terminals, and in particular, to an antenna system and a terminal device.

Background technique

With the development of the fourth generation mobile communication technology (4G), in order to improve the throughput of data services of terminal devices (for example, mobile phones), the user experience is improved. Multiple-input multiple-output (MIMO) technology and carrier aggregation (CA) are becoming more and more important. Therefore, the number of antennas in the terminal device and the supported frequency bands also increase rapidly.

In addition, the terminal device needs to take into account many appearance factors, for example, the fashion design of the industrial design (ID), the feel of the user when holding the terminal device, and the increase of the screen ratio. In recent years, the terminal device pursues an ID design with a screen ratio of more than 80%, resulting in a clearance area above the terminal device or a clearance area below the terminal device is less than 2 mm, and the space for arranging the antenna inside the terminal device becomes smaller. At the same time, the MIMO technology is used to increase the number of antennas, so that the space of the antenna is more compressed. In addition to the increase in the number of antennas, the MIMO technology also needs to consider the radiation pattern between the antennas. Under the premise of satisfying the envelope correlation coefficient (ECC), the throughput of MIMO can be effectively improved. . In addition, for the antenna disposed at the top of the terminal device, in addition to the diversity antenna and the MIMO antenna, the global positioning system (GPS) antenna placement position and the antenna field type upper hemisphere ratio must be considered in order to achieve good performance. user experience.

In the prior art, in order to implement MIMO, the metal frame constituting the antenna may be further divided to implement dividing the antenna located at the top of the terminal device into multiple antenna modules. For example, as shown in Figure 1, Module 1 and Module 2. The antenna radiator of Module 1 includes a top left slit 101 and metal branches on both sides of the top left slit 101: a metal branch 102 and a metal branch 103. The antenna radiator of Module 2 includes a top right slot 104 and metal branches on either side of the top right slot 104: a metal branch 105 and a metal branch 106. Module1 and Module2 have a metal wall 107 adjacent to them. Among them, the metal wall 107 is used to improve the isolation between Module1 and Module2. When the metal wall 107 is structurally realized, the metal frame and the front case, the metal frame and the rear case of the terminal device, and the radio frequency reference ground of the metal frame and the PCB may be connected at any two places to form a three-dimensional isolation structure, for Module1. Forms an isolation effect with Module2.

As shown in FIG. 1, Module 1 may include M ₁₁ and M ₁₂ . Wherein, M ₁₁ may MIMO1. For example, the antenna band of MIMO1 may include: a wireless-fidelity (WIFI), a middle band (MB) band, and a high band (high band) band. M ₁₂ can be a GPS antenna. Module 2 can include M ₂₁ and M ₂₂ . The antenna band covered by M ₂₁ includes: a low band (LB) band, and M ₂₂ can be MIMO2. The antenna band included in MIMO2 can be the same as MIMO1.

However, in the scheme shown in FIG. 1, the low frequency antenna is designed with an inverted-F antenna (IFA), and the performance of the antenna is deteriorated significantly. In addition, since the antenna design space is significantly reduced, how to improve the design freedom of the main antenna is a technical problem that needs to be solved in the future while ensuring the performance of the main antenna located at the bottom of the terminal device.

Summary of the invention

The embodiment of the invention provides an antenna system and a terminal device, so that the antenna at the top of the terminal device can be compatible with at least three MB bands.

In a first aspect, the present application provides an antenna system, which is applied to a terminal device, and includes a frame that is formed by a middle frame and a metal frame located at a top of the middle frame. The metal frame includes multiple frames and multiple frames. There is a first space between each adjacent two frames, and a receiving space is formed between the middle frame and the metal frame, the receiving space is in communication with the first space, wherein the receiving space is used for arranging components, and the antenna system comprises: a first component coupled to a portion of the metal frame to form a loop antenna structure, a first multiple input multiple output MIMO antenna and a second MIMO antenna disposed in the receiving space, wherein the loop antenna a structure is located between the first MIMO antenna and the second MIMO antenna, the ring antenna structure is separated from the first MIMO antenna by a first interval, and the ring antenna structure and the second MIMO antenna pass Separating the second interval; the ring antenna structure is configured to cover the first frequency band and the second frequency band, and the first MIMO antenna and the second MIMO antenna are respectively used to cover at least the second a segment, wherein the first frequency band is lower than the second frequency band, a ground end of the first MIMO antenna is close to the first interval, and a ground end of the second MIMO antenna is adjacent to the second interval, a feeding end of the first MIMO antenna is adjacent to a third interval between the metal frame and the middle frame, and a feeding end of the second MOMO antenna is adjacent to the first between the metal frame and the middle frame Four intervals.

Optionally, the frequency range of the first frequency band is: 760 MHz to 1000 MHz. The frequency range of the second frequency band is: 1450MHz ~ 2200MHz.

The antenna system provided by the embodiment of the present application has a loop antenna structure that can be used to cover the first frequency band, the global positioning system antenna frequency band, and the second frequency band between the first MIMO antenna and the second MIMO antenna, and the loop antenna structure and The first MIMO antennas are separated by a first interval, and the loop antenna structure and the second MIMO antenna are separated by a first interval. Therefore, the first MIMO antenna, the loop antenna structure, and the second MIMO antenna can be made effective in isolation on the layout. Furthermore, since the first MIMO antenna and the second MIMO antenna are respectively used to cover at least the second frequency band, and the ring antenna structure can also cover the global positioning system antenna frequency band and the second frequency band. Therefore, when the antenna system is applied to the terminal device, the top antenna region of the terminal device may be configured to include at least three second frequency bands. In addition, the terminal device generates a certain number of antenna requirements for the communication specification requirement. The antenna system provided in this embodiment of the present application is taken as an example. If the top antenna can support one antenna of the second frequency band, the antenna area located at the bottom of the terminal device is used. The antenna of the second frequency band can be reduced, that is, the antenna design space at the bottom of the terminal device is increased, and the design freedom of the antenna at the bottom is improved.

In a possible implementation, the plurality of frames include a first frame, a second frame, and a third frame between the first frame and the second frame, wherein the first component includes: a metal branch, and a matching component, wherein The first end of the metal branch is connected to the first end of the third frame, and the second end of the metal branch is connected to the middle frame through the first ground point; the first end of the matching component is connected with the second end of the third frame, the matching component The second end is connected to the middle frame through the second grounding point, and is used for the ring antenna structure to cover the first frequency band and the intermediate frequency filter (which may also be a band pass filter) to cooperate with the broadband using the low-pass filter and the broadband matching. The matching causes the loop antenna structure to cover the second frequency band. In the embodiment of the present application, the first frequency band and the GPS frequency band or the second frequency band are covered by the loop antenna structure. The first frequency band and the GPS frequency band or the second frequency band are split by using a low-pass filter and a band-pass filter, so that the common doubly-fed can improve the matching degree of freedom in the respective frequency bands.

In a possible implementation, the matching component includes: a first signal source, and a second signal source disposed in parallel with the first signal source, a first matching circuit, and a second matching circuit, wherein the first signal source The first end is connected to the second end of the third frame through the first matching circuit, and the second end of the first signal source is connected to the middle frame through a third ground point, the second signal a first end of the source is connected to the second end of the third frame through the second matching circuit, and a second end of the second signal source is connected to the middle frame through a fourth ground point, wherein The first matching circuit is configured to cover the first frequency band by the low-pass filter and the broadband matching, and the second matching circuit is configured to cover the second frequency band by using the intermediate frequency filter and the broadband matching .

In a possible implementation, the first matching circuit includes an adjustable component for tuning the working frequency band of the loop antenna structure between one or more of the following frequency bands: corresponding to the Long Term Evolution (LTE) system B12, B13, B20, B28, B5 and B8. By arranging the adjustable components in the first matching circuit, the ring antenna structure can be operated in a wide frequency range.

In a possible implementation, the adjustable component is a tunable inductor or a tunable capacitor. The circuit structure of the adjustable component can be simplified by an adjustable inductor or a tunable capacitor.

In a possible implementation, the second end of the metal branch is connected to the middle frame by a printed circuit board PCB located in the receiving space.

In a possible implementation, the metal branch is a flexible circuit board FPC or a metal sheet.

In a possible implementation manner, the second frequency band covered by the loop antenna structure uses a double wavelength mode, and the second frequency band covered by the first MIMO antenna and the second MIMO antenna uses a composite left and right hand CRLH mode.

In a possible implementation manner, the first MIMO antenna and the second MIMO antenna use a coupled feed to generate a composite left and right hand mode to cover the second frequency band; the metal branch forms a 1/4 inverted F antenna (IFA) mode to cover 2.4 GHz or B1 Frequency band.

In a possible implementation, the ring antenna structure is further configured to cover a third frequency band, where the third frequency band is higher than the second frequency band, and the second frequency band covered by the ring antenna structure uses a 1.5 times wavelength mode.

In a second aspect, the present application provides a terminal device that includes a frame that is surrounded by a middle frame and a metal frame. The metal frame includes a plurality of frames, and each of the two frames has a space between adjacent frames. The first frame and the metal frame have a receiving space, and the receiving space is in communication with the space, wherein the receiving space is used for arranging components, and the terminal device further comprises: a first aspect or a possible implementation of the first aspect The antenna system described in the manner; the metal frame is used as the outer peripheral portion of the terminal device, the middle frame is disposed in the terminal device, and the antenna system is configured to provide the terminal device with at least three second frequency bands.

DRAWINGS

1 is a schematic structural diagram of an antenna system provided in the prior art;

2 is a schematic structural diagram 1 of an antenna system according to an embodiment of the present invention;

FIG. 3 is a schematic structural diagram 2 of an antenna system according to an embodiment of the present disclosure;

4 is a schematic structural view 3 of an antenna system according to an embodiment of the present invention;

FIG. 5 is a schematic structural diagram 4 of an antenna system according to an embodiment of the present disclosure;

6 is a return loss curve of a simulated antenna of an LB band antenna and an MB band antenna/GPS antenna according to an embodiment of the present invention;

FIG. 7 is a schematic diagram of a simulated antenna efficiency curve of a loop antenna structure according to an embodiment of the present invention; FIG.

FIG. 8 is a schematic diagram of a GPS antenna field according to an embodiment of the present invention; FIG.

FIG. 9 is a return loss curve of a simulated antenna of an antenna system according to an embodiment of the present invention;

10 is an antenna field radiation direction of an intermediate frequency band according to an embodiment of the present invention;

FIG. 11 is a schematic structural diagram 5 of an antenna system according to an embodiment of the present disclosure;

FIG. 12 is a schematic diagram of an efficiency of a simulation system according to an embodiment of the present invention;

FIG. 13 is a schematic structural diagram of a terminal device ID according to an embodiment of the present invention.

Detailed ways

In order to facilitate the clear description of the technical solutions of the embodiments of the present invention, in the embodiments of the present invention, the words “first” and “second” are used to distinguish the same items or similar items whose functions and functions are substantially the same. Personnel can understand that the words “first” and “second” do not limit the quantity and order of execution.

The antenna system provided by the embodiment of the present application can be applied to a terminal device. The terminal device has a metal frame on the top. Exemplarily, the terminal device may be: a handheld/wearable device such as a tablet computer, a mobile phone, an MP4, a tablet computer, a notebook, a computer, or a smart watch.

The embodiment of the present application does not limit the communication system to which the terminal device is applied. Exemplarily, the terminal device can be applied to a communication system: a global system for mobile communication (GSM), code division multiple access (CDMA), and wideband code division multiple access (wideband code). Division multiple access (WCDMA), general packet radio service (GPRS), long term evolution (LTE) system, LTE-advanced (A), universal mobile telecommunications system , UMTS), etc., as well as other communication systems in the future (for example, 5G communication systems).

As shown in FIG. 2, FIG. 2 is a schematic diagram of an antenna system provided by an embodiment of the present application. The antenna system is applied to a terminal device, including: a middle frame 10 and a metal frame 20 (20 in the figure) The solid line frame is only used for identification. The solid line is not used to represent the actual device, and the same frame is included in the following figure. The metal frame 20 includes a plurality of frames, such as the first frame 201, a second frame 202 and a third frame 203, wherein each of the plurality of frames has a space between the two adjacent frames, such as a first interval A between the first frame 201 and the third frame 203, a third frame 203 and a The second space B between the two frames 202 has a receiving space 30 between the middle frame 10 and the metal frame 20 (the solid line frame indicated by 30 in the figure is only used for identification, and the solid line is not used to indicate the actual device. The same as in the following figure, the accommodating space 30 is in communication with the first space A and the second space B, wherein the accommodating space 30 can be used for arranging components, the antenna system comprising: a first component, the first component and the metal frame a portion of the coupling is used to form the loop antenna structure 60, setting The first MIMO antenna 40 in the accommodating space 30 (the dotted line frame indicated by 40 in the figure is used to identify that the first MIMO antenna is located in the dotted frame, and the dotted line itself is not used to represent the actually existing device, the following figure In the same), the second MIMO antenna 50 (the dotted line frame indicated by 50 in the figure is used to identify that the second MIMO antenna is located in the dotted line frame, and the dotted line itself is not used to indicate the actually existing device, the same in the following figure). The ring antenna structure 60 is located between the first MIMO antenna 40 and the second MIMO antenna 50 (the dotted line frame indicated by 60 is used to identify the ring antenna structure in the dotted frame, and the dotted line itself is not used to indicate the actual existence. Device, the same in the figure below), the loop antenna structure 60 is separated from the first MIMO antenna 40 by a first interval (eg, the first interval A), and the loop antenna structure 60 and the second MIMO antenna 50 pass the first interval (eg, The second antenna B is coupled to the metal frame 20, and the ring antenna structure 60 is configured to cover the first frequency band and the second frequency band. The first MIMO antenna 40 and the second MIMO antenna 50 are respectively used by at least In the second frequency band, the ground end of the first MIMO antenna 40 is close to the first interval A, the ground end of the second MIMO antenna 50 is close to the second interval B, and the feeding end of the first MIMO 40 antenna is close to the metal frame 20 and the middle At a third interval between the frames, the feed end of the second MOMO antenna 50 is adjacent to a fourth interval between the metal frame 30 and the middle frame, wherein the third interval and the fourth interval are on different sides. Optionally, the loop antenna structure 60 can also be used to cover a global positioning system antenna band.

Optionally, in the embodiment of the present application, the metal frame 20 is located above the middle frame 10, so that the antenna system provided by the embodiment of the present application may be an antenna system applied to the top of the terminal device. Optionally, on the other hand, the metal frame 20 is located below the middle frame 10, so that the antenna system provided by the embodiment of the present application may be an antenna system applied to the bottom of the terminal device.

Optionally, the first frequency band may be an LB frequency band, and the second frequency band may be an MB frequency band. Exemplarily, the frequency range of the first frequency band is: 760 MHz to 1000 MHz. The frequency range of the second frequency band is: 1450MHz ~ 2200MHz.

It can be understood that the first MIMO antenna 40 and the second MIMO antenna 50 in the embodiment of the present application are also used to cover the third frequency band, respectively. The third frequency band is larger than the second frequency band. Exemplarily, the third frequency band may be a high frequency (HB) frequency band.

Optionally, the structures of the first MIMO antenna 40 and the second MIMO antenna 50 in the embodiment of the present application are the same. In the embodiment of the present application, the first MIMO antenna 40 and the second MIMO antenna 50 are symmetrically disposed.

For example, in the embodiment of the present application, the first MIMO antenna 40 is configured to cover the second frequency band, the third frequency band, and the WIFI frequency band.

For example, the WIFI band includes the 2.4G band and the 5G band.

It is to be understood that the positions of the first MIMO antenna 40 and the second MIMO antenna 50 in the embodiment of the present application may be interchanged, which is not limited in this embodiment of the present application.

Exemplarily, the frequency range of the LB frequency band in the embodiment of the present application is: 760 MHz to 1000 MHz frequency band. It can also be understood that the LB band corresponds to one or more of the B28 band, the B12 band, the B13 band, the B17 band, the B5 band, and the B8 band in the LTE system.

Exemplarily, the frequency range of the MB band in the embodiment of the present application is: 1450 MHz to 2200 MHz. It can also be understood that the MB band corresponds to one or more of the B32 band, the B3 band, the B1 band, the B2 band, and the B4 band in the LTE system. Specifically, the GPS band is 1575 MHz.

Optionally, a printed circuit board (PCB) is disposed in the accommodating space 30 in the embodiment of the present application (for example, the PCB is a flexible printed circuit (FPC)). This PCB is used to arrange components. For example, the components used in the first MIMO antenna 40, the second MIMO antenna 50, and the loop antenna structure 60 in the present application are located on the PCB.

Optionally, the material of the middle frame 10 in the embodiment of the present application is a metal material.

It should be noted that, in the embodiment of the present application, the middle frame 10 and the metal frame 20 may have a second interval or may not have a second interval.

It can be understood that multiple frames in the embodiment of the present application may include three or more frames. In the embodiment of the present application, the first frame 201, the second frame 202, and the third frame 203 are included in the plurality of frames. The third frame 203 is located between the first frame 201 and the second frame 202.

Exemplarily, the first frame 201 includes: a first sub-frame and a second sub-frame, wherein the first sub-frame and the second sub-frame are vertically connected. Optionally, the junction of the first sub-frame and the second sub-frame may have a curvature of a preset angle. The second frame 202 includes: a third sub-frame and a fourth sub-frame, wherein the third sub-frame and the fourth sub-frame are vertically connected. Optionally, the connection between the third sub-frame and the fourth sub-frame may have a curvature of a preset angle. The third border is a border on the same horizontal line as the first border and the second border.

Specifically, in the embodiment of the present application, as shown in FIG. 3, the ground end G3 of the first MIMO antenna 40 is connected to the first frame 201, and the ground end G3 is close to the first interval between the first frame 201 and the third frame 203. . The feeding end 401 of the first MIMO antenna 40 is connected to the first frame 201, and the feeding end 401 is close to the second interval C between the first frame 201 and the middle frame 10. Specifically, the feeding end 401 is used for the input source of the first MIMO antenna 40. Thus, those skilled in the art know how to generate a composite left and right hand mode to cover the second frequency band at the first frame between the ground terminal G3 and the feed terminal 401. It should be noted that the circuit between the signal source 4011 and the first frame 201 is omitted in the figure, and the circuit includes a capacitor.

Exemplarily, the feeding end 401 includes a signal source 4011 on the PCB, the first end of the signal source 4011 is connected to the first frame 201, and the second end of the feeding end 401 is connected to the middle frame through the grounding end G4.

As shown in FIG. 3, the ground end G5 of the second MIMO antenna 50 in the embodiment of the present application is connected to the second frame 202, and the ground end G5 is close to the first interval between the second frame 202 and the third frame 203. The feeding end 501 of the second MIMO antenna 50 is connected to the second frame 202, and the feeding end 501 of the second MIMO antenna 50 is close to the second interval D between the second frame 202 and the middle frame 10. Specifically, the feeding end 501 is used for the input source of the second MIMO antenna 50.

Exemplarily, the feeding end 501 includes a signal source 5011 on the PCB, the first end of the signal source 5011 is connected to the second frame 202, and the second end of the feeding end 501 is connected to the middle frame 10 through the grounding end G6. .

As shown in FIG. 4, the first component provided by the embodiment of the present application includes: a metal branch 601, and a matching component 602, wherein the first end of the metal branch 601 is connected to the first end of the third frame 203, and the metal branch 601 is The second end is connected to the middle frame 10 through the first grounding point G1; the first end of the matching component 602 is connected to the second end of the third frame 203, and the second end of the matching component 602 passes through the second grounding point G2 and the middle frame 10 A connection for utilizing a low pass filter with wideband matching to cause the loop antenna structure 60 to cover the first frequency band (eg, the 760 MHz to 1000 MHz frequency band) and for utilizing the intermediate frequency filter with wideband matching to cause the loop antenna structure to cover the second frequency band (eg, 1450MHz ~ 2200MHz band).

It can be understood that the loop of the loop antenna structure 60 in the embodiment of the present application is composed of a metal branch 601, a matching component 602, and a metal branch located between the first end of the metal branch 601 and the first end of the matching component 602. That is, the loop antenna structure 60 needs to be coupled to the metal stub 601.

The circuit of the first MIMO antenna 40 in the embodiment of the present application is composed of a feeding end 401, a grounding end G3, and a metal branch located between the feeding end 401 and the grounding end G3.

The loop of the second MIMO antenna 50 in the embodiment of the present application is composed of a feeding end 501, a grounding end G5, and a metal branch located between the feeding end 501 and the grounding end G5.

Specifically, the metal branch 601 and the third frame 203 in the present application may be an integral structure, or may be connected together by other fixing methods (for example, welding).

Optionally, the second end of the metal branch 601 is connected to the middle frame 10 through a printed circuit board PCB located in the receiving space.

Optionally, the metal branch 601 is a flexible circuit board FPC or a metal sheet.

Illustratively, as shown in FIG. 5, FIG. 5 shows a specific structure of the matching component 602 provided by the present application. As shown in FIG. 5, the matching component 602 includes: a first signal source 6021 and a juxtaposition with the first signal source 6021. a second signal source 6022, a first matching circuit (MC1) 6023, and a second matching circuit 6024. The first end of the first signal source 6021 passes through the first matching circuit 6023 and the third frame 203. The second end of the first signal source 6021 is connected to the middle frame 10 through the third ground point G6, and the first end of the second signal source 6022 is connected to the second end of the third frame 203 through the second matching circuit 6024. The second end of the second signal source 6022 is connected to the middle frame 10 through the fourth grounding point G7. The first matching circuit 6023 is configured to cover the 760 MHz to 1000 MHz frequency band by using the low-pass filter and the broadband matching. The second matching circuit 6024 is configured to utilize the intermediate frequency filter in conjunction with the wideband matching to cause the loop antenna structure 60 to cover the 1450 MHz to 2200 MHz frequency band.

The specific structure of the first matching circuit and the second matching circuit is not limited in the embodiment of the present application.

In order to make the second frequency band covered by the loop antenna structure 60 different from the second frequency band radiation field direction covered by the first MIMO antenna 40 and the second MIMO antenna 50. In the embodiment of the present application, the second frequency band covered by the loop antenna structure 60 and the second frequency band covered by the first MIMO antenna 40 and the second MIMO antenna 50 use different modes.

For example, the second frequency band covered by the loop antenna structure 60 uses a double wavelength mode (which may also be referred to as a balanced mode). The second frequency band covered by the first MIMO antenna 40 and the second MIMO antenna 50 uses a composite right/left-handed (CRLH) mode.

Since the first MIMO antenna 40 and the second MIMO antenna 50 and the loop antenna structure 60 respectively use different modes, the first MIMO antenna 40 and the second MIMO antenna 50 and the loop antenna structure 60 respectively cover the second frequency band radiation pattern. The direction is different. Thus, when the upper half of the terminal device has three second frequency bands, the antenna far-field envelope correlation coefficient (ECC) between the first MIMO antenna 40 and the second MIMO antenna 50 and the loop antenna structure 60 is used. ) Still better than 0.155. At the same time, the GPS antenna also uses a loop antenna balancing mode to optimize the GPS upper hemisphere ratio (greater than 60%). Among them, the ECC is used to judge the similarity of the two antenna field types. 0 means that the two antenna fields are completely independent, and 1 means that the two antenna fields are completely coincident.

The double wavelength mode in the embodiment of the present application means that the working (resonant) frequency of the antenna is one wavelength on the metal radiator (taking the loop antenna structure as an example, the feeding end from the antenna ground point will go from the current strong point to the current zero point to The current is strong to the current zero point to the current strong point).

Among them, CRLH refers to the antenna feeding in the large voltage region at the end, so that the current density is concentrated from the feeding end to the grounding end, and the resonant length of the antenna can be reduced to nearly one-eighth wavelength.

Optionally, as another embodiment of the present application, the first MIMO antenna and the second MIMO antenna respectively generate a composite left and right hand mode to cover the second frequency band by using the coupled feed. The metal branch forms a 1/4IFA antenna pattern covering the 2.4 GHz or B1 band, and the coupling unit below the side slit covers the B7 band.

The IFA antenna in the embodiment of the present application is also referred to as an inverted F antenna, and the shape of the antenna is an inverted "F". The IFA antenna includes a grounding point and a feeding point. Generally, the IFA antenna radiating portion is flat or linear, and the IFA antenna further includes a grounding leg connected between the grounding point and the radiating portion and a feeding portion connected between the feeding point and the radiating portion. The feed point and the grounding leg can be parallel to each other, and both can be perpendicular to the radiating portion.

Optionally, as another embodiment of the present application, the loop antenna structure in the present application is further used to cover the third frequency band.

As another embodiment of the present application, the second interval of the two terminal devices has a slot (for example, the slot E and the slot F shown in FIG. 3 to FIG. 5) to form a parasitic structure, the A MIMO antenna covers the second frequency band and the third frequency band using a composite left and right hand mode, a quarter IF A and a parasitic mode, the second MIMO antenna covering the second frequency band using a composite left and right hand mode, a quarter IF A and a parasitic mode And the third frequency band.

Optionally, the antenna system in the embodiment of the present application is further configured to provide two channels of HB MIMO, GPS, and 2×2 WIFI.

The following embodiment will take the first frequency band as the LB frequency band and the second frequency band as the MB frequency band as an example:

In FIG. 6 , the embodiment of the present application only considers the return loss curve of the simulated antenna of the top LB band and the MB band/GPS antenna band. As shown in FIG. 6 , since the LB band uses a low pass filter in the first matching circuit, The MB band/GPS antenna band uses a bandpass (high pass) filter in the second matching circuit, so as shown by the line labeled C in Figure 6, the isolation of the ring antenna structure can be better than -10 dB.

FIG. 7 shows a simulated antenna efficiency curve according to an embodiment of the present application. The efficiency of the LB frequency band (the line labeled as 1 in FIG. 7) is 760 MHz to 1000 MHz, and the efficiency is about -7.5 to -8.5 dBi. -8.5dB efficiency bandwidth is 250MHz; MB band / GPS antenna band (marked as 2 lines in Figure 7) The efficiency of the 1450MHz ~ 2170MHz band is about -2.0 ~ -6.1dBi, can cover B1 including GPS antenna and LTE system Bands such as the band/B2 band/B3 band/B4 band/B32 band.

In addition, since the MB band/GPS band uses the one-time wavelength mode of the ring antenna structure, referring to FIG. 8 , the GPS antenna field pattern of the embodiment of the present application is shown, and the GPS antenna antenna field type concentrates on the top of the mobile phone (the GPS upper hemisphere accounts for More than about 60 to 65%), improve GPS wireless performance.

In addition, in the embodiment of the present application, since the first MIMO antenna and the second MIMO antenna are disposed on the left and right sides of the ring antenna structure, both the first MIMO antenna and the second MIMO antenna can be designed to include the second frequency band (for example, the intermediate frequency band) The antenna of the segment and the antenna of the third frequency band (for example, the high frequency band) and the WIFI frequency band, and the return loss curve of the specific simulated antenna is as shown in FIG. The first MIMO antenna and the second MIMO antenna IF band radiation field type radiate toward the lower side (as shown in FIG. 9), and the GPS antenna band/second band uses the ring antenna structure to double the wavelength mode (balance mode), reference map 10 It can be seen that even if a MIMO antenna of three intermediate frequency bands is arranged at the top of the terminal device, the antenna pattern of the intermediate frequency band can still radiate in different directions. Table 1 lists the ECC results between the first MIMO antenna and the second MIMO antenna after adding the GPS/MB antenna. The ECC of the second frequency band is less than 0.155, which is better than the main operator ECC index (less than 0.3).

The line labeled 5 in Figure 9 represents the return loss curve of the LB band, the line labeled 6 indicates the return loss curve for the MB band/GPS antenna band, and the line labeled 7 indicates the return loss of the first MIMO band. The curve, the line labeled 8 indicates the return loss curve of the second MIMO antenna, and the line labeled 3 indicates the isolation comparison between the antenna of the LB band and the GPS antenna. The line labeled 4 represents the isolation of the GPS antenna and the isolation between the second MIMO antenna.

Table 1

As another embodiment of the present application, as shown in FIG. 11, the first matching circuit 6023 in the present application includes an adjustable component 6025 for enabling the ring antenna structure 60 to operate in a long-term evolution LTE system. Tuning between B12 band/B13 band/B20 band/B28 band/B5 band/B8 band.

As an example, the adjustable component 6025 is a tunable inductor, or a tunable capacitor.

As shown in FIG. 12, FIG. 12 is a simulation system efficiency of another possible embodiment of an antenna system according to an embodiment of the present application, and the antenna working frequency is tuned by the tunable matching circuit component, wherein the difference between FIG. 11 and the above embodiment is: low frequency An adjustment component 6025 is also included in the matching circuit (e.g., the first matching circuit 6023 described in the above embodiments). In this way, the operating frequency band of the antenna system can be tuned between the corresponding B12 band/B13 band/B20 band/B28 band/B5 band/B8 band in the LTE system by the selection of the adjustable component 6025. The line identified as 10 in Figure 12 represents the efficiency of the LB band. The line labeled 11 indicates that the corresponding band of the LB band in the LTE system is the B20 band/B28 band. The line labeled 12 indicates that the corresponding band of the LB band in the LTE system is the B8 band.

It should be noted that the setting of the adjustable component 6025 in the first matching circuit 6023 is only to realize that the operating frequency band of the antenna system is tuned between the B12 frequency band/B13 frequency band/B20 frequency band/B28 frequency band/B5 frequency band/B8 frequency band corresponding to LTE. In the actual implementation, in the actual process, in order to make the working frequency band of the antenna system be tuned in the B12 frequency band/B13 frequency band/B20 frequency band/B28 frequency band/B5 frequency band/B8 frequency band corresponding to the LTE, other methods may be used, and the present application does not repeat here. .

The embodiment of the present application provides a terminal device, which includes a frame formed by a middle frame and a metal frame located at the top of the middle frame, the metal frame includes a plurality of frames, and each of the plurality of frames Between the two adjacent frames, there is a first space between the first frame and the metal frame, and the receiving space is in communication with the first space, wherein the receiving space is used for arranging elements The device further includes: an antenna system as described in the above embodiment; wherein a metal frame is used as a peripheral portion of the terminal device, the middle frame is disposed in the terminal device, and the antenna system is used by the antenna system Providing at least three second frequency bands for the terminal device.

Optionally, the antenna system provided by the embodiment of the present application is further configured to provide two third frequency bands for the terminal device.

The embodiment of the present invention can be applied to a plurality of terminal devices designed by ID. As shown in FIG. 13, the metal frame located at the top of the terminal device and the metal frame at the bottom of the terminal device respectively have four intervals. That is, two spaces (for example, C and D) between the joint of the top metal frame 11 and the middle frame 21, the first interval A and the first interval B on the metal frame 11 at the top, and the metal frame 31 at the bottom. The third interval E and the third interval F are two intervals (for example, G and H) at the junction of the metal frame 31 and the middle frame 21 at the bottom.

It can be understood that the back shell of the terminal device in the embodiment of the present application may be a metal material or a scrap metal material, which is not limited in this application.

The size of the terminal device is not limited in the embodiment of the present application. Exemplarily, the size of the terminal device in the embodiment of the present application is 146×74×8.5 mm ³ . Exemplarily, the third frame in the embodiment of the present application has a length of 50 mm.

The above is only a specific embodiment of the present invention, but the scope of the present invention is not limited thereto, and any person skilled in the art can easily think of changes or substitutions within the technical scope of the present invention. It should be covered by the scope of the present invention. Therefore, the scope of the invention should be determined by the scope of the appended claims.

Claims

An antenna system, which is applied to a terminal device, the terminal device includes a frame formed by a middle frame and a metal frame, the metal frame includes a plurality of frames, and each of the plurality of frames is adjacent There is a space between the two frames, and an accommodation space is formed between the middle frame and the metal frame. The antenna system includes:

a first component, the first component is coupled to a portion of the metal frame to form a loop antenna structure, a first multiple input multiple output MIMO antenna and a second MIMO antenna disposed in the receiving space, wherein the ring An antenna structure is located between the first MIMO antenna and the second MIMO antenna, the ring antenna structure is separated from the first MIMO antenna by a first interval, the ring antenna structure and the second MIMO antenna Separating by the second interval; the ring antenna structure is configured to cover the first frequency band and the second frequency band, and the first MIMO antenna and the second MIMO antenna are respectively used to cover at least the second frequency band, where The first frequency band is lower than the second frequency band, the ground end of the first MIMO antenna is close to the first interval, and the ground end of the second MIMO antenna is close to the second interval, the first MIMO antenna The feeding end is adjacent to a third interval between the metal frame and the middle frame, and a feeding end of the second MOMO antenna is adjacent to a fourth interval between the metal frame and the middle frame.
The antenna system according to claim 1, wherein the plurality of frames comprise a first frame, a second frame, and a third frame between the first frame and the second frame, wherein The first component includes: a metal branch, and a matching component;

The first end of the metal branch is connected to the first end of the third frame, and the second end of the metal branch is connected to the middle frame through a first ground point; the first end of the matching component Connected to the second end of the third frame, the second end of the matching component is connected to the middle frame through a second ground point for covering the loop antenna structure with a low-pass filter and broadband matching The first frequency band and the use of an intermediate frequency filter in conjunction with wideband matching cause the loop antenna structure to cover the second frequency band.
The antenna system according to claim 2, wherein the matching component comprises: a first signal source, and a second signal source, a first matching circuit, and a second matching circuit disposed in parallel with the first signal source The first end of the first signal source is connected to the second end of the third frame through the first matching circuit, and the second end of the first signal source passes through the third ground point and the a middle frame is connected, a first end of the second signal source is connected to a second end of the third frame through the second matching circuit, and a second end of the second signal source passes through a fourth ground point The middle frame connection, wherein the first matching circuit is configured to cover the first frequency band by using a low pass filter and broadband matching, and the second matching circuit is configured to use an intermediate frequency filter to cooperate with a broadband The matching causes the loop antenna structure to cover the second frequency band.
The antenna system according to claim 3, wherein said first matching circuit comprises an adjustable component for tuning said ring antenna structure operating frequency band between one or the following frequency bands: corresponding to a Long Term Evolution (LTE) system B12, B13, B20, B28, B5 and B8.
The antenna system according to claim 4, wherein the adjustable component is a tunable inductor or a tunable capacitor.
The antenna system according to any one of claims 2 to 5, wherein the second end of the metal branch is connected to the middle frame by a printed circuit board PCB located in the receiving space.
The antenna system according to any one of claims 2 to 6, wherein the metal branch is a flexible circuit board FPC or a metal sheet.
The antenna system according to any one of claims 1 to 7, wherein the second frequency band covered by the loop antenna structure uses a double wavelength mode, and the first MIMO antenna and the second MIMO antenna are covered. The second frequency band uses a composite left and right hand CRLH mode.
The antenna system according to any one of claims 1 to 7, wherein the first MIMO antenna and the second MIMO antenna use a coupled feed to generate a composite left and right hand mode to cover the second frequency band;

The metal branch forms a 1/4 inverted F antenna pattern covering the 2.4 GHz or B1 frequency band.
The antenna system according to any one of claims 1 to 7, wherein the loop antenna structure is further configured to cover a third frequency band, the third frequency band is higher than the second frequency band, and the loop antenna structure The second frequency band covered uses a 1.5x wavelength mode.
The antenna system according to any one of claims 1 to 7, wherein the loop antenna structure is further used to cover a global positioning system GPS antenna band.
A terminal device, comprising: a frame body surrounded by a middle frame and a metal frame, wherein the metal frame comprises a plurality of frames, and each of the plurality of frames has an adjacent frame between the two frames Between the first frame and the metal frame, there is a receiving space, the receiving space is in communication with the space, wherein the receiving space can be used for arranging components, and the terminal device further includes: The antenna system of any one of claims 1 to 10;

The metal frame is used as a peripheral portion of the terminal device, the middle frame is disposed in the terminal device, and the antenna system is configured to provide at least three second frequency bands for the terminal device.