CN108123213B

CN108123213B - Antenna of terminal

Info

Publication number: CN108123213B
Application number: CN201611068480.0A
Authority: CN
Inventors: 薛宗林
Original assignee: Beijing Xiaomi Mobile Software Co Ltd
Current assignee: Beijing Xiaomi Mobile Software Co Ltd
Priority date: 2016-11-26
Filing date: 2016-11-26
Publication date: 2021-01-29
Anticipated expiration: 2036-11-26
Also published as: CN108123213A

Abstract

The disclosure relates to an antenna of a terminal, belonging to the field of antenna technology application. The antenna includes: the terminal comprises a metal frame of the terminal, wherein the metal frame is divided into a bottom frame and a side frame, a circuit board positioned in the metal frame, at least two radiation units arranged on the circuit board and at least one variable element, and the at least two radiation units comprise a first radiation unit and a second radiation unit; the circuit board is provided with a signal feed point and at least two first grounding points, and the signal feed point is connected with the bottom frame through a first radiation unit; the at least two first grounding points are connected with the bottom frame through the second radiation unit, the second radiation unit and the bottom frame form first gap coupling, and low-frequency resonance is generated through the first gap coupling; among the at least two first grounding points, at least one first grounding point is connected with the second radiating unit in series, and a variable element is connected between the at least one first grounding point and the second radiating unit in series. The antenna frequency adjusting method and device solve the problem that the effect of adjusting the antenna frequency is poor, the effect of adjusting the antenna frequency is improved, and the antenna performance is improved. The present disclosure is for transceiving signals.

Description

Antenna of terminal

Technical Field

The present disclosure relates to the field of antenna technology application, and in particular, to an antenna for a terminal.

Background

An Antenna is a device for transmitting and receiving signals in a terminal, and when the Antenna in the terminal is designed, electronic elements inside the terminal need to be avoided so as to avoid interference on the signals of the Antenna, and generally, a Planar Inverted F-shaped Antenna (PIFA) Antenna, an Inverted F-shaped Antenna (IFA) Antenna, a Loop Antenna, or the like is used as the Antenna in the terminal.

In practical applications, signals of an antenna of a terminal are often affected by changes of a use environment of the terminal, and in related technologies, the frequency of the antenna is adjusted by adjusting attributes of variable electronic elements connected in series between a ground point and a radiation unit, so that the performance of the antenna is improved to adapt to changes of the environment.

In the course of implementing the present disclosure, the inventors found that the prior art has at least the following problems:

when the antenna frequency is adjusted, the traditional antenna of the terminal has poor adjusting effect and weak effect of improving the antenna performance.

Disclosure of Invention

In order to solve the problems of poor adjusting effect and poor antenna performance when adjusting the frequency of an antenna, the embodiment of the disclosure provides an antenna of a terminal. The technical scheme is as follows:

the present disclosure provides an antenna of a terminal, the antenna including:

the antenna comprises a metal frame of a terminal, a circuit board positioned in the metal frame, at least two radiation units arranged on the circuit board and at least one variable element, wherein the at least two radiation units comprise a first radiation unit and a second radiation unit;

the metal frame is provided with two broken joints on one side with shorter length, and the two broken joints divide the metal frame into a bottom frame and a side frame;

a signal feed point is arranged on the circuit board and connected with the bottom frame through the first radiation unit;

the circuit board is also provided with at least two first grounding points which are positioned at the same side of the signal feed point and are connected with the bottom frame through the second radiation unit, the second radiation unit and the bottom frame form first gap coupling, and low-frequency resonance is generated through the first gap coupling;

there is at least one first grounding point among the at least two first grounding points and a variable element connected in series between the second radiating unit.

According to the antenna of the terminal, the second radiation unit and the bottom frame form the first gap coupling, low-frequency resonance is generated through the first gap coupling, and when the low-frequency resonance is adjusted through adjusting at least one variable element in the antenna, compared with the antenna of the traditional terminal, a better adjusting effect can be achieved, and meanwhile the antenna performance is improved.

Optionally, a universal serial bus USB is further disposed on the circuit board, and two sides of the universal serial bus USB are connected to each of the two first grounding points respectively.

The antenna of the terminal provided by the disclosure reduces the influence of the USB on the antenna signal by connecting the two sides of the USB with each of the two first grounding points.

Optionally, the antenna further includes:

and the third radiation unit is connected with the first radiation unit, forms second gap coupling with the bottom frame, and generates intermediate frequency resonance through the second gap coupling.

According to the antenna of the terminal, the third radiation unit and the bottom frame form second gap coupling, medium-frequency resonance is generated, the frequency range of the antenna is widened, and the performance of the antenna is improved.

Optionally, a length direction of the third radiation unit is parallel to a length direction of the bottom frame.

The antenna of terminal that this disclosure provided, length direction through setting up the third radiating element is on a parallel with the length direction of underframe, has improved the antenna and has produced the effect of intermediate frequency resonance.

Optionally, the frequency band of the low-frequency resonance is 700 MHz to 960 MHz;

the frequency range of the medium frequency resonance is 1710-2170 MHz.

The antenna of the terminal provided by the disclosure generates frequency ranges of low-frequency resonance and medium-frequency resonance.

Optionally, the antenna further includes:

the first parasitic unit is connected with the signal feed point, and is used for adjusting a first frequency band of high-frequency resonance, wherein the frequency range of the first frequency band is 2300-2400 MHz.

The antenna of the terminal provided by the disclosure can realize adjustment of the first frequency band of high-frequency resonance by arranging the first parasitic unit, and improves the performance of the antenna.

Optionally, the first parasitic element includes a first parasitic portion and a second parasitic portion, and the first parasitic portion and the second parasitic portion form an L-shaped structure;

one end of the first parasitic part is connected with the signal feed point, the other end of the first parasitic part is connected with the second parasitic part, and the length direction of the first parasitic part is vertical to that of the bottom frame;

the second parasitic part is positioned on one side of the first parasitic part close to the at least two first grounding points, and the length direction of the second parasitic part is vertical to that of the first parasitic part.

Compared with the antenna of the traditional terminal, the antenna of the terminal provided by the disclosure can achieve a better frequency adjusting effect and simultaneously improve the antenna performance.

Optionally, at least one second ground point disposed on the circuit board;

the at least one second grounding point is located on the other side of the signal feed point, each second grounding point is connected with one second parasitic unit, the second parasitic units are used for adjusting a second frequency band of high-frequency resonance, and the frequency range of the second frequency band is 2500-2700 MHz.

The antenna of the terminal provided by the disclosure can realize adjustment of the second frequency band of high-frequency resonance by arranging the second parasitic unit, and the performance of the antenna is improved.

Optionally, a second ground point is disposed on the circuit board;

the second parasitic unit connected with the second grounding point is of a strip structure, the second parasitic unit is positioned on one side of the second grounding point far away from the signal feed point, and the length direction of the second parasitic unit is parallel to the length direction of the bottom frame.

Optionally, two first grounding points are arranged on the circuit board;

the second radiation unit comprises a first radiation part, a second radiation part and a third radiation part, and the first radiation part, the second radiation part and the third radiation part are all of strip structures;

one end of the first radiation part is connected with the bottom frame, the other end of the first radiation part is connected with the second radiation part, and the length direction of the first radiation part is respectively vertical to the length direction of the bottom frame, the length direction of the second radiation part and the length direction of the third radiation part;

the second radiation part is positioned on one side of the first radiation part close to the signal feed point, one end of the second radiation part is connected with the first radiation part, and the other end of the second radiation part is connected with a first grounding point close to the signal feed point;

the third radiating part is positioned on one side of the first radiating part far away from the signal feed point, and the third radiating part is connected with a first grounding point far away from the signal feed point.

Optionally, the variable element includes: at least one of a resistance, an inductance, and a capacitance.

The antenna of the terminal provided by the disclosure can set the variable element to be at least one of resistance, inductance and capacitance, thereby enhancing the selectivity of the variable element.

Optionally, the variable element is controlled in a switching control manner.

According to the antenna of the terminal, the variable element is controlled in a switch control mode, and the control effect of the variable element is guaranteed.

Optionally, the antenna further includes:

and the reserved matching circuit is connected with the signal feed point and is used for finely adjusting each frequency band.

The antenna of the terminal provided by the disclosure has the advantages that each frequency band of the antenna is finely adjusted by arranging the reserved matching circuit, so that the performance of the antenna is improved.

Optionally, the first radiating element, the second radiating element, the third radiating element, the first parasitic element and the second parasitic element are all located above the circuit board element surface, and a gap exists between the first radiating element, the second radiating element, the third radiating element, the first parasitic element and the second parasitic element and the circuit board element surface.

According to the antenna of the terminal, the first radiating unit, the second radiating unit, the third radiating unit, the first parasitic unit and the second parasitic unit are arranged above the element surface of the circuit board, so that the space can be saved, and more electronic elements can be arranged on the circuit board.

The technical scheme provided by the embodiment of the disclosure can have the following beneficial effects:

the present disclosure provides an antenna of a terminal, the antenna includes a circuit board on which a signal feed point is disposed, the signal feed point is connected to the bottom frame through a first radiation unit; the circuit board is also provided with at least two first grounding points which are positioned on one side of the signal feed point and are connected with the bottom frame through a second radiation unit to form first gap coupling so as to generate low-frequency resonance. When the low-frequency resonance is adjusted by adjusting at least one variable element in the antenna, compared with the antenna of the traditional terminal, the antenna has the advantages that a better adjusting effect can be achieved, and meanwhile, the antenna performance is improved.

It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the disclosure.

Drawings

In order to more clearly illustrate the embodiments of the present disclosure, the drawings that are needed to be used in the description of the embodiments will be briefly described below, and it is apparent that the drawings in the following description are only some embodiments of the present disclosure, and that other drawings can be obtained by those skilled in the art without inventive effort.

Fig. 1 is a schematic diagram illustrating a structure of an antenna of a terminal according to an exemplary embodiment;

FIG. 2 is a schematic diagram illustrating the structure of a variable element in accordance with an exemplary embodiment;

FIG. 3 is a schematic diagram illustrating the structure of another variable element in accordance with an exemplary embodiment;

fig. 4 is a schematic diagram illustrating a structure of an antenna of another terminal according to an exemplary embodiment;

FIG. 5 is a schematic diagram illustrating a reservation matching circuit in accordance with an exemplary embodiment;

fig. 6 is a schematic diagram illustrating a structure of an antenna of still another terminal according to an exemplary embodiment.

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present disclosure and together with the description, serve to explain the principles of the disclosure.

Detailed Description

To make the objects, technical solutions and advantages of the present disclosure more clear, the present disclosure will be described in further detail with reference to the accompanying drawings, and it is apparent that the described embodiments are only a part of the embodiments of the present disclosure, not all of the embodiments. All other embodiments, which can be derived by one of ordinary skill in the art from the embodiments disclosed herein without making any creative effort, shall fall within the scope of protection of the present disclosure.

Fig. 1 is a schematic structural diagram illustrating an antenna of a terminal according to an exemplary embodiment, where the antenna includes:

the antenna comprises a metal frame 10 of a terminal, a circuit board 20 positioned in the metal frame 10, at least two radiation units 30 arranged on the circuit board 20, and at least one variable element, wherein the at least two radiation units 30 comprise a first radiation unit 301 and a second radiation unit 302.

The metal frame 10 has two slits on one side with a shorter length, and the two slits divide the metal frame 10 into a bottom frame 101 and a side frame 102.

The circuit board 20 is provided with a signal feed point 40, and the signal feed point 40 is connected with the bottom frame 101 through the first radiation unit 301.

The circuit board 20 is further provided with at least two first grounding points 50, the at least two first grounding points 50 are located on the same side of the signal feed point 40 and connected to the bottom frame 101 through a second radiating unit 302, the second radiating unit 302 and the bottom frame 101 form a first gap coupling, and a low frequency resonance is generated through the first gap coupling. The frequency band of the low frequency resonance may be 700 mhz to 960 mhz.

There is at least one of the at least two first grounding points 50 with a variable element (not shown in fig. 1) connected in series between the second radiating element 302. That is, the variable element may be connected in series only between the first grounding point 501 close to the signal feeding point 40 and the second radiating element 302, or may be connected in series only between the first grounding point 502 far from the signal feeding point 40 and the second radiating element 302, or may be connected in series between the first grounding point 501 close to the signal feeding point 40 and the second radiating element 302, and the variable element may be connected in series between the first grounding point 502 far from the signal feeding point 40 and the second radiating element 302. In practical applications, the specific arrangement manner of the variable element may be selected according to practical situations, and the embodiment of the present disclosure does not limit this.

In summary, the present disclosure provides an antenna of a terminal, where a circuit board of the antenna includes a signal feed point, and the signal feed point is connected to the bottom frame through a first radiation unit; the circuit board is also provided with at least two first grounding points which are positioned on one side of the signal feed point and are connected with the bottom frame through a second radiation unit to form first gap coupling so as to generate low-frequency resonance. When the low-frequency resonance is adjusted by adjusting at least one variable element in the antenna, compared with the antenna of the traditional terminal, the antenna has the advantages that a better adjusting effect can be achieved, and meanwhile, the antenna performance is improved.

Further, the at least one variable element may include: at least one of a resistance, an inductance, and a capacitance.

For example, the at least one variable element may be one or more variable elements, and the at least one variable element may be the same variable element or different variable elements, for example, the at least one variable element is three variable elements, the three variable elements may all be resistors, the three variable elements may all be inductors, and the three variable elements may all be capacitors; correspondingly, the three variable elements may be a resistor and two capacitors, a capacitor and two inductors, or a resistor, an inductor and a capacitor. Fig. 2 is a schematic structural diagram of a variable element according to an exemplary embodiment, and fig. 2 is schematically illustrated by taking an example that three variable elements are connected in series between the second radiating unit 302 and the first grounding point 501, and as shown in fig. 2, the three variable elements are a resistor a, a resistor B, and a resistor C, respectively, wherein resistance values of the resistor a, the resistor B, and the resistor C are different. Fig. 3 is a schematic structural diagram of another variable element according to an exemplary embodiment, and fig. 3 is schematically illustrated by taking an example that three variable elements are connected in series between the second radiating unit 302 and the first grounding point 501 and three variable elements are also connected in series between the second radiating unit 302 and the first grounding point 502, as shown in fig. 3, the three variable elements connected in series between the second radiating unit 302 and the first grounding point 501 are a resistor a, a resistor B and a resistor C, respectively, wherein resistance values of the resistor a, the resistor B and the resistor C are different; the three variable elements connected in series between the second radiating unit 302 and the first ground 502 are respectively a capacitor D, a capacitor E and a capacitor F, wherein the capacitance values of the capacitor D, the capacitor E and the capacitor F are different. In practical applications, the number, the type, and the size of the parameter values of the specific variable elements may be selected according to actual situations, which is not limited in the embodiments of the present disclosure.

Further, the variable element may be controlled by a switch control, which is a commonly used judgment selection control method. For example, the variable element to be communicated may be selected by performing switch control through a control chip disposed in the terminal, and the variable element currently communicated with the second radiation unit is switched to the variable element to be communicated, so as to adjust the attribute parameter of the variable element, and further adjust the resonant frequency band of the antenna. The property parameter of the tuning variable element may be a parameter of the tuning variable element, and may be, for example, a resistance value of the tuning resistor, for example, a resistor with a larger resistance value, which is communicated with the second radiation unit, may be switched to a resistor with a smaller resistance value; for example, the inductance value of the inductor may be adjusted, for example, an inductor with a larger inductance value, which is communicated with the second radiating unit, may be switched to an inductor with a smaller inductance value; for example, the capacitance value of the capacitor may be adjusted, for example, a capacitor with a larger capacitance value, which is communicated with the second radiating unit, may be switched to a capacitor with a smaller capacitance value; the attribute parameter of the tuning variable element may also be an attribute of the tuning variable element, that is, a type of the tuning variable element communicated with the second radiation unit is changed, for example, a resistor communicated with the second radiation unit may be switched to a capacitor, or a capacitor communicated with the second radiation unit may be switched to an inductor, which is not described in detail in this embodiment of the disclosure.

By adjusting the attribute parameters of the variable element, after the attribute parameters of the variable element are changed, the current between the bottom frame and the first grounding point is changed, namely the equivalent electrical length between the bottom frame and the first grounding point is changed, and the frequency band of low-frequency resonance generated by the gap coupling between the second radiation unit and the bottom frame can be adjusted. The electrical length is a ratio of a physical length of the antenna to a propagation speed of an electromagnetic signal in a free space and the antenna, and generally, a resonant frequency is inversely related to the electrical length, that is, the longer the electrical length is, the lower the resonant frequency is.

Fig. 4 is a schematic structural diagram illustrating an antenna of another terminal according to an exemplary embodiment, where as shown in fig. 4, the antenna may further include:

a third radiation unit 60, the third radiation unit 60 is connected to the first radiation unit 301, a length direction of the third radiation unit 60 is parallel to a length direction of the bottom frame 101, the third radiation unit 60 and the bottom frame 101 form a second gap coupling, and a mid-frequency resonance is generated through the second gap coupling, wherein a frequency range of the mid-frequency resonance may be 1710-2170 mhz.

Further, referring to fig. 4, the antenna may further include:

a first parasitic element 70, the first parasitic element 70 may be connected to the signal feed point 40, the first parasitic element 70 is used for adjusting a first frequency band of the high frequency resonance, and the frequency range of the first frequency band may be 2300 and 2400 MHz.

Further, referring to fig. 4, the antenna further includes:

at least one second ground point 80 disposed on the circuit board 20.

At least one second grounding point 80 is located at the other side of the signal feeding point 40, and each second grounding point 80 is connected to one second parasitic unit 90, and the second parasitic unit 90 is used for adjusting a second frequency band of the high frequency resonance, and the frequency range of the second frequency band is 2500-.

It should be noted that, in another alternative embodiment, two second grounding points 80 may be further disposed on the circuit board 20, and the two second grounding points 80 may be connected to the second parasitic element 90.

Further, the antenna may further include: and the reserved matching circuit is arranged for matching the impedance of the antenna circuit, and each frequency band of the antenna can be finely adjusted through the reserved matching circuit. The reserved matching circuit can be connected to the signal feed point 40, for example, fig. 5 is a schematic diagram of a reserved matching circuit according to an exemplary embodiment, as shown in fig. 5, a capacitor C1 and a capacitor C2 are connected in series with the signal feed point 40, and the end of a capacitor C2 is connected to a test socket T, wherein the test socket T is a standard test device and can be used for testing the electrical performance and electrical connection of a device to check for defects and defects; the inductor L1 and the inductor L2 are connected in parallel with the signal feed point, one end of the inductor L1 and the inductor L2 is connected with the signal feed point, and the other end is connected with the ground.

It should be noted that the first radiating unit, the second radiating unit, the third radiating unit, the first parasitic unit and the second parasitic unit are all located above the circuit board element surface, and have a gap with the circuit board element surface. In practical application, the first radiating unit, the second radiating unit, the third radiating unit, the first parasitic unit and the second parasitic unit can be printed on the antenna bracket, and the plurality of metal elastic pieces are connected with the signal feed point, the grounding point, the bottom frame and the side frame on the circuit board.

The antenna support is used for suspending the radiating unit and the parasitic unit of the antenna on the circuit board, so that more electronic elements such as a motor, a loudspeaker and a Universal Serial Bus (USB) interface can be arranged on the circuit board. For example, as shown in fig. 4, the motor 21 may be disposed on a side of the second parasitic unit 90 where the orthographic projection is away from the bottom frame 101, the speaker 22 may be disposed on a side of the second radiating unit 302 where the orthographic projection is away from the bottom frame 101, and for the USB interface 23, the USB interface 23 may be disposed between the second radiating unit 302 and the bottom frame 101, and a side of the USB interface 23 perpendicular to the bottom frame 101 is connected to the first ground point 501 close to the signal feed point 40, and another side perpendicular to the bottom frame 101 is connected to the first ground point 502 far from the signal feed point 40. In practical applications, when the two sides of the USB interface 23 are connected to the first ground point, a metal elastic sheet may be used for the connection. Therefore, the two sides of the USB interface 23 are respectively connected to the two first grounding points, so that the influence of the USB interface 23 on the antenna signal is smaller, for example, when the terminal is charged through the USB interface, the influence of the USB interface on the antenna signal when the terminal is charged through the USB interface can be reduced due to the grounding of the two sides of the USB interface.

In practical applications, when a user holds the side frame of the terminal or places the terminal beside the ear (the two states are also referred to as a head-hand state), the human body may cause certain interference to the antenna signal, which results in the radiation performance of the antenna being reduced. As can be seen from fig. 4, in the embodiment of the present disclosure, both sides of the terminal side frame are not connected to the radiation unit of the antenna, so that the influence of a human body on the radiation performance of the antenna in a head-hand state can be reduced, thereby ensuring the stability of the radiation performance of the antenna and improving the user experience.

Fig. 6 is a schematic structural diagram of an antenna of another terminal according to an embodiment of the present disclosure, and as shown in fig. 6, two first grounding points 501 and 502 may be disposed on the circuit board 20. The second radiation unit 302 may include a first radiation portion 3021, a second radiation portion 3022, and a third radiation portion 3023, and the first to third radiation portions may be all in a stripe structure.

One end of the first radiation portion 3021 is connected to the bottom frame 101, the other end is connected to the second radiation portion 3022, and the longitudinal direction of the first radiation portion 3021 is perpendicular to the longitudinal direction of the bottom frame 101, the longitudinal direction of the second radiation portion 3022, and the longitudinal direction of the third radiation portion 3023, respectively.

The second radiating portion 3022 is located on a side of the first radiating portion 3021 close to the signal feed point 40, one end of the second radiating portion 3022 is connected to the first radiating portion 3021, and the other end is connected to the first ground point 501 close to the signal feed point 40.

The third radiating portion 3023 is located on a side of the first radiating portion 3021 away from the signal feed point 40, and the third radiating portion 3023 is connected to the first ground point 502 away from the signal feed point 40.

It should be noted that, in another alternative embodiment, three first grounding points 50 may be further disposed on the circuit board 20, and the three first grounding points 50 may be connected to the bottom frame 101 through the second radiation unit 302.

Further, as shown in fig. 6, the first parasitic element 70 may include a first parasitic part 701 and a second parasitic part 702, and the first parasitic part 701 and the second parasitic part 702 constitute an L-shaped structure.

One end of the first parasitic portion 701 is connected to the signal feed point 40, the other end is connected to the second parasitic portion 702, and the length direction of the first parasitic portion 701 is perpendicular to the length direction of the bottom frame 101.

The second parasitic portion 702 is located on a side of the first parasitic portion 701 close to the at least two first grounding points 50, and a length direction of the second parasitic portion 702 is perpendicular to a length direction of the first parasitic portion 701.

Further, as shown in fig. 6, a second ground point 80 may be provided on the circuit board 20. The second parasitic unit 90 connected to the second ground point 80 may have a strip structure, the second parasitic unit 90 is located on a side of the second ground point 80 away from the signal feed point 40, and a length direction of the second parasitic unit 90 is parallel to a length direction of the bottom frame 101.

It should be further noted that, in the embodiment of the present disclosure, a frequency band to be applied by the terminal antenna may be determined according to an application environment of the terminal, and then the length, the thickness, and the interval of each radiating element and each parasitic element in the antenna may be adjusted, so that the performance of the antenna on the frequency band to be applied is the best, and the flexibility in antenna design is further improved.

Other embodiments of the disclosure will be apparent to those skilled in the art from consideration of the specification and practice of the disclosure disclosed herein. This application is intended to cover any variations, uses, or adaptations of the disclosure following, in general, the principles of the disclosure and including such departures from the present disclosure as come within known or customary practice within the art to which the disclosure pertains. It is intended that the specification and examples be considered as exemplary only, with a true scope and spirit of the disclosure being indicated by the following claims.

It will be understood that the present disclosure is not limited to the precise arrangements described above and shown in the drawings and that various modifications and changes may be made without departing from the scope thereof. The scope of the present disclosure is limited only by the appended claims.

Claims

1. An antenna for a terminal, the antenna comprising:

the antenna comprises a metal frame of a terminal, a circuit board positioned in the metal frame, at least two radiation units arranged on the circuit board and at least one variable element, wherein the at least two radiation units comprise a first radiation unit, a second radiation unit and a third radiation unit;

a variable element is connected in series between the at least two first grounding points and the second radiating unit, and the variable element needing to be communicated is selected in a switch control mode to adjust the frequency band of the low-frequency resonance;

the third radiation unit is connected with the first radiation unit, the third radiation unit and the bottom frame form second gap coupling, and medium-frequency resonance is generated through the second gap coupling;

the circuit board is also provided with a Universal Serial Bus (USB), and two sides of the USB are respectively connected with two first grounding points of the at least two first grounding points;

the first radiating unit, the second radiating unit and the third radiating unit are printed on an antenna support, are overhead above the circuit board element surface through the antenna support, and have a gap with the circuit board element surface.

2. The antenna of claim 1, wherein a length direction of the third radiating element is parallel to a length direction of the bottom frame.

3. The antenna of claim 1,

the frequency band of the low-frequency resonance is 700 MHz to 960 MHz;

the frequency range of the medium frequency resonance is 1710-2170 MHz.

4. The antenna of claim 1, further comprising:

5. The antenna of claim 4,

the first parasitic unit comprises a first parasitic part and a second parasitic part, and the first parasitic part and the second parasitic part form an L-shaped structure;

6. The antenna of claim 4 or 5, further comprising:

at least one second ground point disposed on the circuit board;

7. The antenna of claim 6,

a second grounding point is arranged on the circuit board;

8. The antenna of claim 1,

two first grounding points are arranged on the circuit board;

9. The antenna of claim 1, wherein the variable element comprises: at least one of a resistance, an inductance, and a capacitance.

10. The antenna of claim 1, further comprising:

11. The antenna of claim 6,

the first parasitic unit and the second parasitic unit are both positioned above the circuit board element surface, and a gap is formed between the first parasitic unit and the circuit board element surface.