CN111316501B

CN111316501B - Antenna for mobile terminal and mobile terminal with same

Info

Publication number: CN111316501B
Application number: CN201780096527.0A
Authority: CN
Inventors: 章富洪; 阮勇; 胡澈; 吕伟
Original assignee: Shenzhen Transsion Manufacture Ltd
Current assignee: Shenzhen Transsion Manufacture Ltd
Priority date: 2017-11-01
Filing date: 2017-11-01
Publication date: 2022-04-29
Anticipated expiration: 2037-11-01
Also published as: WO2019084838A1; CN111316501A

Abstract

The invention provides an antenna for a mobile terminal and the mobile terminal with the antenna, wherein the antenna comprises a radiator, a feed end and a change-over switch, the change-over switch comprises a fixed end connected with the radiator and at least two free ends, and the fixed end and one of the free ends are switched to be in a connected state; at least two groups of feed circuits, wherein one end of each feed circuit is connected with one free end of the change-over switch, and the other end of each feed circuit is connected with the feed end; the change-over switch selects a feed circuit to be connected with the radiator, and the radiator generates a feed signal at the feed end through the feed circuit after receiving a wireless signal. According to the technical scheme, signals of a full frequency band are divided into a plurality of combinations or a plurality of single frequency bands to be input, and the feed circuit is good in matching flexibility; compared with the adjustable component, the loss of the signal is small; the performance of a single frequency band can be optimized, and the performance of the antenna can be improved.

Description

Antenna for mobile terminal and mobile terminal with same

Technical Field

The present invention relates to the field of antennas, and in particular, to an antenna for a mobile terminal and a mobile terminal having the same.

Background

Nowadays, with the development of communication technology, 2G, 3G, 4G, WIFI, GPS networks coexist, and in order to be compatible with different networks, the antenna of the mobile device needs to be capable of operating on multiple frequency bands. In the field of mobile terminal devices, the design environment of an antenna is very complex, space is limited, and it is necessary to consider sharing a spatial structure with other functional components. One of the limitations is that any antenna simply designed cannot cover all the required frequency bands, and in order to meet the requirement of operating in multiple frequency bands, multiple antenna units must be designed and the antenna must be tested in full frequency band. The antenna comprises a feed circuit, wherein the feed circuit comprises components such as a resistor, a capacitor and an inductor, and parameters of the feed circuit with optimal performance need to be found in the test process, namely, the parameters of a group of the resistor, the capacitor and the inductor are found to be matched with the working frequency band of the antenna. In the prior art, an adjustable device is used for matching, for example, adjustable components such as an adjustable capacitor, an adjustable resistor, an adjustable inductor, and the like, and a parameter value of the adjustable component is changed in a test process and an experimental result is observed, so that an optimal parameter value is found and used in mass-produced antennas.

The prior art realizes the parameter matching of the antenna by using an adjustable component, however, the following problems still exist:

1. all frequency bands are matched and debugged through a group of feed circuits, and due to the fact that the span of the frequency band is large, when a certain frequency band is debugged, the impedance characteristics of other frequency bands are greatly influenced, and therefore the performance of antennas of other frequency bands is influenced;

2. a group of feed circuits is used for matching and debugging of full frequency bands, and the matching flexibility is poor in order to take the influence on other frequency bands into consideration;

3. the cost of the adjustable component is high, and the parameter value is difficult to obtain.

Therefore, an antenna suitable for a mobile terminal needs to be designed, matching requirements of multiple frequency bands can be met, and component cost is reduced.

Disclosure of Invention

In order to overcome the technical defects, the invention aims to provide an antenna for a mobile terminal and the mobile terminal with the antenna.

In a first aspect of the present application, an antenna for a mobile terminal is disclosed, where the antenna includes a radiator, a feed terminal, and a switch, where the switch includes a fixed terminal connected to the radiator and at least two free terminals, and the fixed terminal and one of the free terminals are switched to be in a connected state; at least two groups of feed circuits, wherein one end of each feed circuit is connected with one free end of the change-over switch, and the other end of each feed circuit is connected with the feed end; the change-over switch selects a feed circuit to be connected with the radiator, and the radiator generates a feed signal at the feed end through the feed circuit after receiving a wireless signal.

Preferably, the feeding circuit comprises three groups: the first feed circuit has a working frequency range of 600MHz to 960 MHz; the working frequency band of the second feed circuit is 1700MHz to 2200 MHz; and the working frequency band of the third feed circuit is 2300MHz to 2700 MHz.

Preferably, the first feeding circuit, the second feeding circuit and the third feeding circuit each comprise at least two groups of sub-feeding circuits connected in parallel; each sub-feeder circuit operates in a different frequency band range.

Preferably, at least one of the following is included: the first feed circuit comprises a first switching sub-switch, a fixed end of the first switching sub-switch is connected with a free end of the switching sub-switch, and the free end of the first switching sub-switch is respectively connected with at least two groups of sub-feed circuits; the second feed circuit comprises a second switching sub-switch, a fixed end of the second switching sub-switch is connected with a free end of the switching sub-switch, and the free end of the second switching sub-switch is respectively connected with at least two groups of sub-feed circuits; the third feed circuit comprises a third switching sub-switch, a fixed end of the third switching sub-switch is connected with a free end of the switching sub-switch, and the free end of the third switching sub-switch is respectively connected with at least two groups of sub-feed circuits.

Preferably, the feeding circuit includes any one of a pi circuit, an L circuit, or a pi + L circuit.

Preferably, the feed circuit and the switch, and the feed circuit and the feed end are connected by impedance cables having a resistance value of 50 ohms, respectively.

Preferably, the antenna is any one of a slot type, a monopole type, or an inverted F type.

Preferably, the switch selects a preset free end to be connected with the fixed end according to the frequency band of the wireless signal received by the radiator.

In a second aspect of the present application, a mobile terminal is disclosed, which comprises the above antenna.

After the technical scheme is adopted, compared with the prior art, the method has the following beneficial effects:

1. signals of the full frequency band are divided into a plurality of combinations or a plurality of single frequency bands to be input, and the matching flexibility of the feed circuit is good;

2. compared with the adjustable component, the loss of the signal is small;

3. the performance of a single frequency band can be optimized, and the performance of the antenna can be improved.

Drawings

Fig. 1 is a schematic diagram of an antenna for a mobile terminal according to a preferred embodiment of the present invention;

fig. 2 is a schematic structural view of an antenna for a mobile terminal according to another preferred embodiment of the present invention;

fig. 3 is a schematic structural diagram of an antenna for a mobile terminal according to still another preferred embodiment of the present invention;

FIG. 4 is a schematic diagram of the structure of a feed circuit according to a preferred embodiment of the present invention;

fig. 5 is a schematic structural diagram of a mobile terminal according to a preferred embodiment of the present invention.

Reference numerals:

the radio frequency antenna comprises a radiator 1, a feed end 2, a change-over switch 3, a fixed end 31, a free end 32, a first feed circuit 4, a second feed circuit 5, a third feed circuit 6, a first change-over sub-switch 41, a second change-over sub-switch 51, a third change-over sub-switch 61 and a radio frequency chip 7.

Detailed Description

The advantages of the invention are further illustrated in the following description of specific embodiments in conjunction with the accompanying drawings.

Reference will now be made in detail to the exemplary embodiments, examples of which are illustrated in the accompanying drawings. When the following description refers to the accompanying drawings, like numbers in different drawings represent the same or similar elements unless otherwise indicated. The implementations described in the exemplary embodiments below are not intended to represent all implementations consistent with the present disclosure. Rather, they are merely examples of apparatus and methods consistent with certain aspects of the present disclosure, as detailed in the appended claims.

The terminology used in the present disclosure is for the purpose of describing particular embodiments only and is not intended to be limiting of the disclosure. As used in this disclosure and the appended claims, the singular forms "a," "an," and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It should also be understood that the term "and/or" as used herein refers to and encompasses any and all possible combinations of one or more of the associated listed items.

It is to be understood that although the terms first, second, third, etc. may be used herein to describe various information, such information should not be limited to these terms. These terms are only used to distinguish one type of information from another. For example, first information may also be referred to as second information, and similarly, second information may also be referred to as first information, without departing from the scope of the present disclosure. The word "if" as used herein may be interpreted as "at … …" or "when … …" or "in response to a determination", depending on the context.

In the description of the present invention, it is to be understood that the terms "longitudinal", "lateral", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", and the like, indicate orientations or positional relationships based on those shown in the drawings, and are used merely for convenience of description and for simplicity of description, and do not indicate or imply that the referenced devices or elements must have a particular orientation, be constructed in a particular orientation, and be operated, and thus, are not to be construed as limiting the present invention.

In the description of the present invention, unless otherwise specified and limited, it is to be noted that the terms "mounted," "connected," and "connected" are to be interpreted broadly, and may be, for example, a mechanical connection or an electrical connection, a communication between two elements, a direct connection, or an indirect connection via an intermediate medium, and specific meanings of the terms may be understood by those skilled in the art according to specific situations.

In the following description, suffixes such as "module", "component", or "unit" used to denote elements are used only for facilitating the explanation of the present invention, and have no specific meaning in themselves. Thus, "module" and "component" may be used in a mixture.

Referring to fig. 1, a schematic structural diagram of an antenna for a mobile terminal according to a preferred embodiment of the present invention is shown, where the antenna includes:

a radiator 1

The radiator 1 is used for transmitting or receiving radio signals and supports the antenna to work on a plurality of frequency bands. The radiator 1 is an antenna in the narrow sense, and is a converter that converts a signal propagating on a wired medium into an electromagnetic wave propagating in an unbounded medium (usually free space), or vice versa; is a component used in a radio device to transmit or receive electromagnetic waves. Engineering systems such as radio communication, broadcasting, television, radar, navigation, electronic countermeasure, remote sensing, radio astronomy and the like all use electromagnetic waves to transmit information and work by depending on antennas. The antennas are usually reversible, i.e. the same pair of antennas can be used as both transmitting and receiving antennas; the same antenna is the same as the basic characteristic parameter for transmission or reception; i.e. the reciprocity theorem of the antenna. In this embodiment, the antenna has a richer meaning than a narrow antenna, and further includes a feed circuit and a feed terminal 2 that cooperate with the radiator 1. The antenna works in a frequency band of a mobile communication network, comprises various network modes such as 2G, 3G, 4G and the like, and supports the mobile terminal to carry out information interaction with the outside. According to different working frequency bands and application occasions, the radiator 1 is designed to have different structures, for example, the radiator 1 in the mobile terminal needs to be correspondingly designed according to the structural characteristics of the mobile terminal, for example, electromagnetic oscillation is realized by utilizing a metal shell of the mobile terminal and a gap on the shell, and the miniaturization of the radiator 1 is realized. For another example, the radiator 1 may also be used in an antenna for laboratory tests, and the antenna is designed according to a laboratory environment, so that various frequency bands required by experiments can be covered, and the size is less limited.

-a feeding terminal 2

The feed end 2 is connected with a feed line to form a signal input end or an output end of the antenna, and when the antenna transmits signals, the feed end 2 receives electric signals transmitted by a signal source and forms radio signals through the feed circuit and the radiator 1 to be transmitted; when the antenna receives signals, the wireless signals received by the radiator 1 are converted into electric signals through the feed circuit, and then the electric signals are transmitted to other parts for processing through the feed end 2. The feed end 2 is usually connected with a radio frequency chip or a baseband chip, and processes a received radio frequency signal and converts the radio frequency signal into a digital signal.

A change-over switch 3

The change-over switch 3 comprises a fixed end 31 and at least two free ends 32. The fixed end 32 is connected to the radiator 1. The change-over switch 3 can control the fixed end 31 to be connected with one of the free ends 32 respectively, so as to realize the communication of circuits on two sides, and the free end 32 which is not connected is in a suspended state. The change-over switch 3 may be an on-off device having a switching function, such as a single-pole double-throw switch or a single-pole triple-throw switch.

-a feed circuit

And at least two groups of feed circuits are arranged, one end of each feed circuit is connected with one free end of the selector switch 3, and the other end of each feed circuit is connected with the feed end 2. I.e. the different feed circuits are in a parallel relationship, and only one feed circuit is connected to the radiator 1 through the diverter switch 3 at a time. The feed circuit is composed of components such as a resistor, a capacitor and an inductor, can vibrate with the radiator 1 and transmit the vibration in the form of electromagnetic waves through the radiator 1, and can also convert a wireless signal received by the radiator 1 into an electric signal. The function of the feed circuit in the antenna is crucial, and without the feed circuit, the antenna cannot generate oscillation, and thus cannot transmit or receive electromagnetic wave signals. The structure and the electrical parameters of the feed circuit are different, which can affect the working frequency band and the performance of the antenna, so that the performance of the antenna can be optimized and adjusted by changing the parameters of the components of the feed circuit. In this embodiment, each of the feeding circuits adopts different parameters and operates in different frequency bands.

When the antenna works, the change-over switch 3 selects one of the feed circuits to be connected with the radiator 1, and the radiator 1 generates a feed signal at the feed end 2 through the feed circuit after receiving a wireless signal. In an experimental test, a detection instrument can be used for detecting a feed signal on the feed end 2, so that the performance of the antenna when the feed circuit works is shown. The parameters of the components in the feed circuit can be continuously adjusted to find the best matching parameters. In this embodiment, when the antenna works, only one feed circuit is in a working state, and is not interfered by other feed circuits, and a parameter corresponding to the optimal antenna performance can be found out in a working frequency band corresponding to the feed circuit, so as to provide a technical support for parameter selection for mass production of the antenna.

As a further improvement of the above antenna, the feed circuits are three groups, which are respectively:

a first feeding circuit 4

The operating frequency band of the first feeding circuit 4 is 600MHz to 960MHz, which is a low frequency band in mobile communication.

A second feeding circuit 5

The operating frequency band of the second feeding circuit 5 is 1700MHz to 2200MHz, which is the middle frequency band in mobile communication.

-a third feeding circuit 6

The working frequency band of the third feeding circuit 6 is 2300MHz to 2700MHz, which is a high frequency band in mobile communication.

Correspondingly, in this embodiment, three free ends 32 of the switch 3 are connected to the first feeding circuit 4, the second feeding circuit 5 and the third feeding circuit 6, respectively. When the selector switch 3 selects the above feed circuits respectively, the antennas respectively work in a low frequency band, a middle frequency band and a high frequency band, the performance of the antennas in three frequency bands can be tested respectively in experimental tests, and the optimal feed circuit parameters are found out for matching.

As a further improvement of the antenna, the feed circuit and the switch 3, and the feed circuit and the feed terminal 2 are connected by impedance cables having a resistance value of 50 ohms, respectively. The improvement further limits the connection mode among all components in the antenna, the impedance of a signal line plays a crucial role in signal transmission and interference resistance, and in the embodiment, a 50-ohm impedance cable is selected to connect the feed circuit and the change-over switch 3 and connect the feed circuit and the feed end 2, so that signal crosstalk on a transmission line can be reduced, and the distortion of signals is reduced.

As a further improvement of the antenna, the antenna is any one of a slot type, a monopole type, or an inverted F type. The present preferred embodiment makes the preference for the type of antenna. The slot type antenna is a common antenna used for a mobile terminal, a slot needs to be formed on the mobile terminal, the slot is insulated, metal areas are arranged on two sides of the slot, a feed circuit is bridged on the slot, a radiating body 1 is arranged on one side of the slot, and a feed end 2 is arranged on the other side of the slot. The monopole antenna is characterized in that a radiator 1 of the antenna extends in a monopole mode, a physical structure extending left and right is omitted, and the working frequency band of the monopole antenna is concentrated. The radiator 1 of the inverted-F antenna is integrally in a lying F shape, two transverse extending ends of the F are respectively connected with the feed circuit, the inverted-F antenna can adapt to various frequency range, and if the inverted-F antenna is matched with the change-over switch 3, the switching of various frequency ranges can be realized.

As a further improvement of the antenna, the change-over switch 3 is a single-pole multi-throw switch of a micro electro mechanical technology. The Micro Electro Mechanical process is a popular manufacturing technology in recent years, and the manufactured devices or components are also called Micro Electro Mechanical Systems (MEMS) for short, and Micro-Electro-Mechanical systems for full name. The micro electro mechanical system is also called a micro electro mechanical system, a micro machine and the like, and refers to a high-tech device with the size of several millimeters or even smaller, and the internal structure of the micro electro mechanical system is generally in the micrometer or even nanometer level, so that the micro electro mechanical system is an independent intelligent system. The micro electro mechanical system is developed on the basis of microelectronic technology (semiconductor manufacturing technology), and integrates high-tech electronic mechanical devices manufactured by technologies such as photoetching, corrosion, thin film, LIGA, silicon micromachining, non-silicon micromachining, precision machining and the like. Due to the shortage of available space resources in the mobile terminal, components produced by micro-electromechanical technology have the advantage of small size, and the diverter switch 3 is also called a MEMS switch. The concept of MEMS switches was proposed in the late 80 s and early 90 s of the 20 th century, with great appeal to radio frequency engineers, with their potential including reduction in overall chip area, power consumption and device cost. Common MEMS switches are single-pole four-throw (SP4T) MEMS switches with the type ADGM1304 and also have the characteristic of electrostatic protection, and compared with radio frequency relays, the volume of the MEMS switches is reduced by 95%, the reliability is improved by 10 times, the speed is improved by 30 times, and the power consumption is reduced by 10 times. The change-over switch 3 is a single-pole multi-throw switch, wherein a single pole is connected with the fixed end 31, different free ends 32 can be selected for throwing connection, finally, a one-to-many selection mode is realized, and the change-over switches 3 with the corresponding number of the free ends 32 can be selected according to the number of the feed circuits.

As a further improvement of the antenna, the control logic is embedded in the switch 3, and a preset free end 32 is selected to be connected with the fixed end 31 according to the frequency band of the wireless signal received by the radiator 1. The switch 3 is a programmable logic control device and has the capability of identifying the frequency band of the signal received by the fixed end 31. When the switch 3 is used, control logic may be written into the switch 3 in advance, for example, when the frequency band of the received signal is a low frequency band, the free end 32 corresponding to the first feeding circuit 4 is selected to be connected to the fixed end 31; when the frequency band of the received signal is the middle frequency band, selecting the free end 32 corresponding to the second feeding circuit 5 to be connected with the fixed end 31; by analogy, the selection of the feed circuits corresponding to different frequency bands is realized, and the optimal matching of the antenna performance on the frequency band is realized.

Referring to fig. 2, which is a schematic structural diagram of an antenna for a mobile terminal according to another preferred embodiment of the present invention, each of the first feeding circuit 4, the second feeding circuit 5 and the third feeding circuit 6 includes at least two sets of sub-feeding circuits connected in parallel; each sub-feeder circuit operates in a different frequency band range. The improved embodiment further subdivides the working frequency band of the feed circuit on the basis of fig. 1, and allows the antenna to be further subjected to performance test in a small frequency band range. For example, the first feeding circuit 4 may be divided into sub-feeding circuits with working frequency bands of 600MHz to 700MHz, 700MHz to 860MHz, and 860MHz to 960 MHz; the second feeding circuit 5 can be divided into sub-feeding circuits with working frequency ranges of 1700MHz to 1850MHz, 1850MHz to 1900MHz and 1900MHz to 2200 MHz; the third feeding circuit 6 can be divided into sub-feeding circuits with working frequency ranges of 2300MHz to 2400MHz, 2400MHz to 2500MHz and 2500MHz to 2700 MHz. Correspondingly, the number of the free ends 32 of the change-over switch 3 is selected to meet the number of the sub-feeder circuits, or a plurality of the change-over switches 3 are selected to operate in parallel; one end of each sub-feeder circuit is connected to the free end 32, and the other end is connected to the feeding terminal 2.

Referring to fig. 3, which is a schematic structural diagram of an antenna for a mobile terminal according to still another preferred embodiment of the present invention, the first feeding circuit 4 includes:

first switching sub-switch 41

The fixed end of the first switch sub-switch 41 is connected with the free end 32 of the switch 3, and the free end of the first switch sub-switch 41 is respectively connected with at least two groups of sub-feeding circuits. The first switch sub-switch 41 selectively switches on only the sub-feeding circuits within the first feeding circuit 4.

Second switch sub-switch 51

The fixed end of the second switch sub-switch 51 is connected with the free end 32 of the switch 3, and the free end of the first switch sub-switch 51 is connected with at least two groups of sub-feeding circuits respectively. The second switch sub-switch 51 selectively switches on only the sub-feeding circuits within the second feeding circuit 5.

-a third switch sub-switch 61

The fixed end of the third switch sub-switch 61 is connected to the free end 32 of the switch 3, and the free end of the third switch sub-switch 61 is connected to at least two groups of sub-feeding circuits. The third switch sub-switch 61 only selectively switches on the sub-feeding circuit within the third feeding circuit 6.

In the embodiment, a two-stage switch mode is adopted, the first stage is still the switch 3, and each feed circuit is selected; the second stage selects the sub-feeding circuits to connect through the first switch sub-switch 41, the second switch sub-switch 51 and the third switch sub-switch 61.

Referring to fig. 4, a schematic diagram of a structure of a feeding circuit according to a preferred embodiment of the present invention, the feeding circuit includes any one of a pi circuit, an L circuit, or a pi + L circuit. The pi-shaped circuit is the circuit type of the first feed circuit 4 in fig. 3, and includes 3 components, wherein one end of two components is grounded, the other end is connected with two ends of a third component, two ends of the third component are connected with the free end 32 and the feed end 2, and the 3 components form a "pi shape". The L-shaped circuit is a circuit type of the second feeding circuit 5 in fig. 3, and is composed of 2 components, a first component is connected in series between the free end 32 and the feeding end 2, and a second component is connected with the feeding end 2 and the ground respectively. The pi + L-shaped circuit is formed by connecting the pi circuit and the L-shaped circuit in series for combination. The components in the feed circuit can be a combination of resistors, capacitors and inductors, different resistance values, capacitance values and inductance values can be selected to influence the working frequency band of the feed circuit, and the resistors, capacitors and inductors are selected from components with fixed parameter values, so that the energy loss can be reduced relative to adjustable components. The feed circuits of the antenna can adopt the same circuit structure or different circuit structures, and the type selection arrangement is carried out according to the working frequency band and the working space in the mobile terminal.

Referring to fig. 4, which is a schematic structural diagram of a mobile terminal according to a preferred embodiment of the present invention, the mobile terminal includes the antenna. The mobile terminal further includes:

radio frequency chip 7

The radio frequency chip 7 is responsible for radio frequency transceiving, frequency synthesis and power amplification. The radio frequency chip is simply a part for receiving and sending signals, and is a part for mainly communicating with the base station when the mobile terminal makes a call and receives a short message. The radio frequency chip 7 is provided with a radio frequency signal interface and is connected with the feed end 2. With the development of integrated circuit technology, many manufacturers will integrate the rf chip 7 into a communication baseband chip, and integrate the transceiving and processing of signals together.

The mobile terminal may be implemented in various forms. For example, the terminal described in the present invention may include a mobile terminal such as a mobile phone, a smart phone, a notebook computer, a PDA (personal digital assistant), a PAD (tablet computer), a PMP (portable multimedia player), a navigation device, and the like, and a fixed terminal such as a digital TV, a desktop computer, and the like. In the following, it is assumed that the terminal is a mobile terminal. However, it will be understood by those skilled in the art that the configuration according to the embodiment of the present invention can be applied to a fixed type terminal in addition to elements particularly used for moving purposes.

It should be noted that the embodiments of the present invention have been described in terms of preferred embodiments, and not by way of limitation, and that those skilled in the art can make modifications and variations of the embodiments described above without departing from the spirit of the invention.

Claims

1. An antenna for a mobile terminal, the antenna comprising a radiator and a feed end, the antenna further comprising:

the change-over switch comprises a fixed end and three free ends, wherein the fixed end is connected with the radiating body, and the fixed end and one of the free ends are switched to be in a connected state;

the feed circuit comprises a first feed circuit, a second feed circuit and a third feed circuit, wherein three free ends of the switch are respectively connected with one ends of the first feed circuit, the second feed circuit and the third feed circuit, the other ends of the first feed circuit, the second feed circuit and the third feed circuit are respectively connected with the feed ends, the working frequency range of the first feed circuit is 600MHz to 960MHz and is a low frequency range in mobile communication, the working frequency range of the second feed circuit is 1700MHz to 2200MHz and is a medium frequency range in mobile communication, and the working frequency range of the third feed circuit is 2300MHz to 2700MHz and is a high frequency range in mobile communication;

the antenna comprises a feed end, a feed circuit, a programmable logic control device, a selector switch, a fixed end and a feed circuit, wherein the feed circuit is connected with the radiator through the feed circuit after the selector switch selects the feed circuit, the feed circuit generates a feed signal at the feed end after receiving a wireless signal, the feed circuit vibrates with the radiator and sends the signal in the form of electromagnetic waves through the radiator when the antenna transmits the signal, the selector switch selects a free end to be connected with the fixed end according to the frequency band of the wireless signal received by the radiator to select the feed circuit of the corresponding frequency band when the antenna receives the signal, the wireless signal received by the radiator is converted into an electric signal through the selected feed circuit, and then the electric signal is transmitted to a radio frequency chip or a baseband chip through the feed end to be processed.

2. The antenna of claim 1,

the first feed circuit, the second feed circuit and the third feed circuit each comprise at least two groups of connected sub-feed circuits.

3. The antenna of claim 2, comprising at least one of:

the first feed circuit comprises a first switching sub-switch, a fixed end of the first switching sub-switch is connected with a free end of the switching sub-switch, and the free end of the first switching sub-switch is respectively connected with at least two groups of sub-feed circuits;

the second feed circuit comprises a second switching sub-switch, a fixed end of the second switching sub-switch is connected with a free end of the switching sub-switch, and the free end of the second switching sub-switch is respectively connected with at least two groups of sub-feed circuits;

the third feed circuit comprises a third switching sub-switch, a fixed end of the third switching sub-switch is connected with a free end of the switching sub-switch, and the free end of the third switching sub-switch is respectively connected with at least two groups of sub-feed circuits.

4. The antenna according to any of claims 1 to 3,

the feed circuit includes any one of a pi circuit, an L circuit, or a pi + L circuit.

5. The antenna according to any of claims 1 to 3,

the feed circuit is connected with the switch and the feed end through impedance cables.

6. The antenna according to any of claims 1 to 3,

the antenna is any one of a slot type, a monopole type or an inverted F type.

7. The antenna according to any of claims 1 to 3,

the change-over switch is a single-pole multi-throw switch.

8. A mobile terminal, characterized in that it comprises an antenna according to any of claims 1 to 7.