WO2019114622A1

WO2019114622A1 - Antenna tuning circuit, antena apparatus and mobile terminal

Info

Publication number: WO2019114622A1
Application number: PCT/CN2018/119757
Authority: WO
Inventors: 杨怀
Original assignee: Oppo广东移动通信有限公司
Priority date: 2017-12-14
Filing date: 2018-12-07
Publication date: 2019-06-20
Also published as: CN108110423B; CN108110423A

Abstract

Disclosed are an antenna tuning circuit and a mobile terminal. The antenna tuning circuit comprises: an antenna, a first matching circuit, a second matching circuit, a first switch, a second switch and a radio frequency signal transceiver. The antenna comprises a first feed point, a second feed point and a third feed point that are sequentially arranged. The first matching circuit and the first switch are serially connected between the first feed point and the ground, and the second matching circuit and the second switch are serially connected between the second feed point and the ground. When a working frequency band is at a low frequency, a radio frequency signal emitted by the radio frequency signal transceiver is transmitted to an antenna radiating body via the third feed point, the first switch and the second switch are both turned on, and a frequency band within a third frequency band range is smaller than a frequency band within a second frequency band range. By means of the embodiments of the present application, stray radiation can be suppressed.

Description

Antenna tuning circuit, antenna device and mobile terminal

Technical field

The present application relates to the field of electronic technologies, and in particular, to an antenna tuning circuit, an antenna device, and a mobile terminal.

Background technique

As a mandatory certification indicator for current electronic devices (such as smart phones), radiated spurs are the most complicated and difficult problem among all certifications. Especially in the Global System for Mobile Communication (GSM) frequency band, because of the high power of GSM itself, it is easy to excite strong energy in an instant, resulting in excessive harmonics of radiated spurs. In the actual project, it is mainly the third harmonic of GSM900, the second harmonic of GSM1800 or the third harmonic of GSM1800.

Summary of the invention

The embodiment of the present application provides an antenna tuning circuit and a mobile terminal, which are used to eliminate the situation that the high voltage of the feeding point causes the tuning switch to be saturated when the low frequency is working, thereby suppressing the radiation spur.

In a first aspect, an embodiment of the present application provides an antenna tuning circuit, including an antenna, a first matching circuit, a second matching circuit, a first switch, a second switch, and a radio frequency signal transceiver;

The antenna includes a first feed point, a second feed point, and a third feed point arranged in sequence; the first matching circuit is connected in series with the first switch between the first feed point and ground The second matching circuit is connected in series with the second switch between the second feeding point and the ground;

When the working frequency band is in the first frequency band, the radio frequency signal transmitted by the radio frequency signal transceiver is transmitted to the antenna radiator through the first feeding point, the second switch is turned on, and the first switch is off. Open or conduct;

When the working frequency band is in the second frequency band, the radio frequency signal transmitted by the radio frequency signal transceiver is transmitted to the antenna radiator through the first feeding point, the first switch is turned on, and the second switch is turned off. Open, the frequency band in the second frequency band is smaller than the frequency band in the first frequency band;

When the working frequency band is in the third frequency band, the radio frequency signal transmitted by the radio frequency signal transceiver is transmitted to the antenna radiator through the third feeding point, and the first switch and the second switch are both turned on. The frequency band in the third frequency band is smaller than the frequency band in the second frequency band.

In a second aspect, an embodiment of the present disclosure provides an antenna apparatus, including a power amplifier, and an antenna tuning circuit provided by the first aspect, where the power amplifier is used to amplify a radio frequency signal sent by the radio frequency signal transceiver and output the antenna.

In a third aspect, an embodiment of the present application provides a mobile terminal, including a terminal body and an antenna device provided by the first aspect.

DRAWINGS

In order to more clearly illustrate the technical solutions in the embodiments of the present application or the background art, the drawings to be used in the embodiments of the present application or the background art will be described below.

1 is a schematic diagram of a tuning circuit of a slot antenna according to an embodiment of the present application;

2 is a schematic diagram of an antenna tuning circuit provided by an embodiment of the present application;

3 is a partial schematic diagram of an antenna tuning circuit according to an embodiment of the present application;

4 is a partial schematic diagram of another antenna tuning circuit according to an embodiment of the present application;

FIG. 5 is a partial schematic diagram of another antenna tuning circuit according to an embodiment of the present application; FIG.

6 is a partial schematic diagram of another antenna tuning circuit according to an embodiment of the present application;

7 is a partial schematic diagram of another antenna tuning circuit provided by an embodiment of the present application;

FIG. 8 is a schematic structural diagram of an antenna device according to an embodiment of the present disclosure;

FIG. 9 is a schematic structural diagram of a mobile terminal according to an embodiment of the present application.

Detailed ways

The technical solutions in the embodiments of the present invention are clearly and completely described in the following with reference to the accompanying drawings in the embodiments of the present invention. It is a partial embodiment of the invention, and not all of the embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative efforts are within the scope of the present invention.

The terms "first", "second" and the like in the specification and claims of the present invention and the above drawings are used to distinguish different objects, and are not intended to describe a specific order. Furthermore, the terms "comprising" and "having" and "the" are intended For example, a process, system, product, or device that comprises a series of steps or units is not limited to the listed steps or units, but optionally also includes steps or units not listed, or alternatively also includes Other steps or units inherent to the process, product, or equipment.

References to "an embodiment" herein mean that a particular feature, structure, or characteristic described in connection with the embodiments can be included in at least one embodiment of the invention. The appearances of the phrases in various places in the specification are not necessarily referring to the same embodiments, and are not exclusive or alternative embodiments that are mutually exclusive. Those skilled in the art will understand and implicitly understand that the embodiments described herein can be combined with other embodiments.

The mobile terminal involved in the embodiments of the present invention may include various handheld devices having wireless communication functions, in-vehicle devices, wearable devices, computing devices, or other processing devices connected to the wireless modem, and various forms of user equipment (User Equipment, UE), mobile station (MS), terminal device, and the like. For convenience of description, the devices mentioned above are collectively referred to as mobile terminals.

1 is a schematic diagram of a tuning circuit of a slot antenna according to an embodiment of the present application. Referring to FIG. 1, the antenna tuning circuit includes an antenna, a ground feed point, a main feed point, two tuning switches, and two matching circuits. The two tuning switches connected to the ground feed point and the main feed point are mainly used to adjust the medium and high frequency. The working principle of the tuned circuit of the slot antenna is mainly to realize switching of different frequency bands by two tuning switches and two matching circuits.

As shown in Figure 1, the main feed point is grounded through the tuning switch. The high frequency (if the size of the antenna itself is GSM 900 MHz, the medium and high frequency refers to the frequency band greater than GSM 900 MHz, such as medium and high frequency. GSM1800 megahertz, GSM1900 megahertz, etc. If the frequency band supported by the antenna itself is GSM 1800 MHz, then the medium and high frequency refers to the frequency band larger than GSM 1800 MHz, such as GSM 1900 MHz, etc. The matching circuit and the tuning switch are switched to match the middle and high frequencies, so that the antenna operates at a medium and high frequency, thereby radiating the medium and high frequency energy. When the frequency is low (if the size of the antenna itself is GSM 900 MHz, then the low frequency refers to the frequency band less than or equal to GSM 900 MHz, and if the frequency band supported by the antenna itself is GSM1800, then the low frequency means less than or equal to In the GSM 1800 MHz band, the antenna itself is designed in the low frequency band, so there is no need to use the tuning switch at the main feed point. The low frequency energy is conducted directly from the main feed point and then radiated. For slot antennas, when operating at low frequencies, the main feed point radiates low-frequency energy in an intense electric field, so that there is a very strong voltage signal at the main feed point, and high voltage will cause the main feed point. The tuning switch is saturated, which causes the radiation spurs to exceed the standard.

For the above problem, referring to FIG. 2, an embodiment of the present application provides a schematic diagram of an antenna tuning circuit, where the antenna tuning circuit includes: an antenna 10, a first matching circuit 20, a second matching circuit 30, a first switch 40, and a second Switch 50 and RF signal transceiver 60;

The antenna 10 includes a first feeding point 11, a second feeding point 12 and a third feeding point 13 arranged in sequence; the first matching circuit 20 is connected in series with the first switch 40 between the first feeding point 11 and the ground, The second matching circuit 30 is connected in series with the second switch 50 between the second feeding point 12 and the ground;

When the working frequency band is in the first frequency range, the radio frequency signal transmitted by the radio frequency signal transceiver 60 is transmitted to the antenna 10 through the first feeding point 11, the second switch 50 is turned on, and the first switch 40 is turned off or turned on;

When the working frequency band is in the second frequency band range, the radio frequency signal transmitted by the radio frequency signal transceiver 60 is transmitted to the antenna 10 through the first feeding point 11, the first switch 40 is turned on, and the second switch 50 is turned off, and the second frequency band is in the range of the second frequency band. The frequency band is smaller than the frequency band within the first frequency band;

When the working frequency band is in the third frequency range, the radio frequency signal transmitted by the RF signal transceiver 60 is transmitted to the antenna 10 through the third feeding point 13, and the first switch 40 and the second switch 50 are both turned on, and the third frequency range is The frequency band within the frequency band is smaller than the frequency band within the second frequency band.

It is assumed that the frequency band supported by the antenna 10 itself is GSM 850 MHz, then the frequency band in the third frequency band is less than or equal to GSM 850 MHz, and the frequency band supported by the antenna 10 itself is GSM 900 MHz, then the third frequency range The frequency band is less than or equal to GSM 900 MHz. It is assumed that the frequency band supported by the antenna 10 itself is GSM 1800 MHz, and the frequency band in the third frequency band is less than or equal to GSM 1800 MHz, etc., and is not limited herein.

It is assumed that the frequency band supported by the antenna 10 itself is GSM 850 MHz, then the frequency band in the second frequency band is around 850 megahertz and greater than GSM 850 MHz, assuming that the frequency band supported by the antenna 10 itself is GSM 900 MHz. Then, the frequency band in the second frequency band is around GSM 900 MHz and larger than GSM 900 MHz. Assuming that the frequency band supported by the antenna 10 itself is GSM 1800 MHz, the frequency band in the second frequency band is around GSM 1800 MHz. It is greater than GSM 1800 MHz and so on, and is not limited herein.

It is assumed that the frequency band supported by the antenna 10 itself is GSM 850 MHz, and the frequency band in the first frequency band is around GSM 1700 MHz and larger than GSM 1700 MHz. It is assumed that the frequency band supported by the antenna 10 itself is GSM 900 MHz. Then, the frequency band in the first frequency band is around GSM1800 MHz, and is greater than GSM 1800 MHz, etc., and is not limited herein.

The radio frequency signal transceiver 60 is used as an original signal source, and the frequency band of the normally transmitted radio frequency signal has one or more of 850 megahertz, 900 megahertz, 1800 megahertz, and 1900 megahertz. The mobile terminal can automatically switch the frequency according to the network coverage within these frequency bands to ensure the best use effect.

Among them, the antenna 10 is a converter that converts a guided wave propagating on a transmission line into an electromagnetic wave propagating in an unbounded medium (usually free space), or vice versa. An antenna is a component for transmitting or receiving electromagnetic waves in a mobile terminal. Radio communication, broadcasting, television, radar, navigation, electronic countermeasures, remote sensing, radio astronomy and other engineering systems, all using electromagnetic waves to transmit information, rely on antennas to work. In addition, non-signal energy radiation also requires an antenna in terms of transmitting energy using electromagnetic waves. Generally, the antennas are reversible, that is, the same antenna can be used as both a transmitting antenna and a receiving antenna. The same characteristic parameters of the same antenna as transmitting or receiving are the same. The antenna 10 is a slot antenna.

The first switch 40 and the second switch 50 are tuning switches.

In an embodiment of the present application, the first feeding point 11 is a main feeding point, the second feeding point 12 is a ground feeding point, and the third feeding point 13 is a low frequency feeding point.

Where the antenna is connected to the antenna feed line is called the feed point. An antenna feeder is a transmission line that connects an antenna to a receiver and a transmitter to transmit RF energy. Both the primary feed point and the low frequency feed point are used to transmit the RF signal transmitted by the RF transceiver to the antenna for radiation. The ground feed point is used for combining the matching circuit connected with the ground feed point, the main feed point and the matching circuit connected with the main feed point to realize switching of different frequency bands.

In an embodiment of the present application, as shown in FIG. 2, the first feeding point 11 is placed at the first end point of the antenna radiator, and the third feeding point 13 is placed at the second end point and second of the antenna radiator 11. The feed point 12 is placed between the first feed point 11 and the third feed point 13.

Specifically, since the voltage is gradually reduced from the third feed point 13 to the other end of the antenna 10 (ie, the first feed point) under low frequency operation, the tuning switch (ie, the first tuning switch and the second tuning) The switch) is kept away from high voltages, further avoiding radiated spurs due to saturation of the tuning switch.

It can be seen that, in the embodiment of the present application, a low frequency feed point (ie, a third feed point) is added. Under low frequency operation, the radio frequency signal transmitted by the radio frequency signal transceiver directly passes the low frequency through the low frequency feed point and the antenna. The energy is radiated to eliminate the high voltage at the feed point causing the tuning switch to saturate when operating at low frequencies, thereby suppressing radiated spurs.

In an embodiment of the present application, the first matching circuit 20 is connected to the first switch 40, and the first matching circuit 20 is connected to the antenna 10 through the first feeding point 11; the second matching circuit 30 and the second switch 50 The connection and the second matching circuit 30 are connected to the antenna 10 via the second feed point 12. Specifically as shown in Figure 2.

In an embodiment of the present application, the first matching circuit 20 is connected to the first switch 40, and the first switch 40 is connected to the antenna 10 through the first feeding point 11; the second matching circuit 30 is connected to the second switch 50, and The second switch 50 is connected to the antenna 10 via a second feed point 12. Specifically shown in Figure 3.

In an embodiment of the present application, the first matching circuit 20 includes M matching sub-circuits, and the second matching circuit 30 includes N matching sub-circuits, and both M and N are positive integers.

In an embodiment of the present application, at least one of the N matching sub-circuits is turned on when the operating frequency band is in the first frequency band range; or at least one of the N matching sub-circuits is turned on and At least one of the M matching sub-circuits is turned on.

In an embodiment of the present application, at least one of the M matching sub-circuits is turned on when the operating frequency band is in the second frequency band range.

In an embodiment of the present application, when the operating frequency band is in the third frequency band range, at least one of the matching sub-circuits of the N matching sub-circuits is turned on and at least one of the matching sub-circuits of the M matching sub-circuits is turned on.

It should be noted that, when at least one matching sub-circuit is turned on, the at least one matching sub-circuit is connected to the antenna to adjust the impedance of the antenna, so that the impedance of the antenna matches the impedance of the feeding line of the feeding point, thereby enabling the antenna tuning circuit to work. In the impedance matching state. The matching sub-circuit can not only adjust the operating frequency of the antenna at high frequencies, but also adjust the antenna tuning circuit to be in an impedance matching state.

In addition, the matching sub-circuit may be a single original, such as an inductor or a capacitor, or may be composed of an inductor and two capacitors, a π-type matching circuit, or a complex structure, such as a frequency gating circuit, or other similar functions. Circuits are not listed one by one. Among them, the frequency gating circuit can be equivalent to a short circuit in a low frequency band and equivalent to an inductor or a capacitor in a high frequency band. In addition, the impedances of the different matching sub-circuits are different. Specifically, the structure of the matching sub-circuit can be seen in FIG. 4. FIG. 4 is a partial schematic diagram of an antenna tuning circuit according to an embodiment of the present application.

In an embodiment of the present application, the matching sub-circuit of the first matching circuit 20 is a GSM 850 MHz or 900 MHz band matching sub-circuit, and the matching sub-circuit of the second matching circuit 30 is a GSM 1800 MHz band matching sub-circuit.

In an embodiment of the present application, the third feeding point 13 is placed at one end of the antenna 10, and the distance between the third feeding point 13 and the first feeding point 11 and the second feeding point 12 is greater than or equal to the set distance. .

Specifically, since the third feeding point 13 radiates the low frequency energy in an intense manner by the electric field when operating at a low frequency, the third feeding point 13 has a strong voltage signal, so in order to avoid the high voltage In the case where the first switch 40 and the second switch 50 are saturated, the first feed point 11 and the second feed point 12 need to be kept at a certain distance from the third feed point 13.

Wherein, the set distance is obtained by the R&D personnel when the distance between the third feed point 13 and the first feed point 11 and the second feed point 12 is greater than or equal to the value, the first switch 40 and the first The second switch 50 does not appear to be saturated. This set distance is smaller than the length of the antenna 10.

In an embodiment of the present application, the antenna tuning circuit further includes a first filter 80 and/or a second filter 90. The first filter 80 is connected in series between the matching sub-circuit of the first matching circuit 20 and the first switch 40. A second filter 90 is connected in series between the matching sub-circuit of the two matching circuit 30 and the second switch 50. The filter is used to retain the main frequency signal of the corresponding frequency band and filter the harmonics generated by the tuning switch.

Further, in a case where the distance between the third feed point 13 and the first feed point 11 and the second feed point 12 is less than a set distance, the antenna tuning circuit further includes a first filter 80 and a second filter. 90.

Further, the distance between the third feeding point 13 and the first feeding point 11 is less than the set distance, and the distance between the third feeding point 13 and the second feeding point 12 is greater than or equal to the set distance In the case of the antenna tuning circuit, the first filter 80 is further included.

Further, the distance between the third feeding point 13 and the second feeding point 12 is less than the set distance, and the distance between the third feeding point 13 and the first feeding point 12 is greater than or equal to the set distance In the case of the antenna tuning circuit, the second filter 90 is further included.

The first filter 80 and the second filter 90 are low pass filters.

Specifically, please refer to FIG. 5. FIG. 5 is a schematic diagram of an antenna tuning circuit according to an embodiment of the present application. Since the third feed point 13 radiates low frequency energy in a manner that is intense in electric field when operating at low frequencies, there is a strong voltage signal at the third feed point 13. In the case where the distance between the third feed point 13 and the first feed point 11 and the second feed point 12 is less than the set distance, there may be a strong voltage signal generated by the third feed point 13 reaching the second The feed point 12 and the first feed point 11 still have a strong voltage signal, which may cause the first switch 40 and the second switch 50 to saturate to generate radiation spurs, so in order to avoid this situation, The matching sub-circuit of the first matching circuit 20 and the matching sub-circuit of the second matching circuit 30 are respectively connected in series with a low-pass filter, so that the filter can be filtered out even if harmonics are generated at the tuning switch, which further solves The problem of radiated spurs.

Please refer to FIG. 6. FIG. 6 is a schematic diagram of an antenna tuning circuit according to an embodiment of the present application. Since the third feed point 13 radiates low frequency energy in a manner that is intense in electric field when operating at low frequencies, there is a strong voltage signal at the third feed point 13. If the distance between the third feeding point 13 and the first feeding point 11 is less than the set distance, and the distance between the third feeding point 13 and the second feeding point 12 is greater than or equal to the set distance, there may be The strong voltage signal generated by the third feed point 13 still has a strong voltage signal when it reaches the first feed point 11, which may cause the first switch 40 to saturate and generate radiation spurs, so in order to avoid this situation It appears that a matching low-pass filter is connected in series with the matching sub-circuit of the first matching circuit 20, so that the filter can be filtered out even if harmonics are generated at the tuning switch, further solving the problem of radiated spurs.

Please refer to FIG. 7. FIG. 7 is a schematic diagram of an antenna tuning circuit according to an embodiment of the present application. Since the third feed point 13 radiates low frequency energy in a manner that is intense in electric field when operating at low frequencies, there is a strong voltage signal at the third feed point 13. If the distance between the third feeding point 13 and the second feeding point 12 is less than the set distance, and the distance between the third feeding point 13 and the first feeding point 11 is greater than or equal to the set distance, there may be The strong voltage signal generated by the third feed point 13 still has a strong voltage signal when it reaches the second feed point 12, which may cause the second switch 50 to saturate and generate radiation spurs, so in order to avoid this situation It appears that a matching low-pass filter is connected in series with the matching sub-circuit of the second matching circuit 30, so that the filter can be filtered out even if harmonics are generated at the tuning switch, further solving the problem of radiated spurs.

In an embodiment of the present application, the tuning switch is any one of a single pole double throw, a single pole triple throw, and a single pole four throw.

In an embodiment of the present application, the antenna tuning circuit further includes a control module 70. The first tuning switch 40 and the second tuning switch 50 are connected to the control module 70. The first tuning switch 40 and the second tuning switch 50 are used in In the event that a switch logic control signal from control module 70 is received, a corresponding match sub-circuit is selected based on the switch logic control signal.

Referring to FIG. 8, FIG. 8 is an antenna apparatus according to an embodiment of the present application. The antenna apparatus includes a power amplifier and an antenna tuning circuit according to the foregoing embodiments, where the power amplifier is used to transmit a radio frequency signal to a radio frequency signal transceiver. After amplification, output to the antenna.

As shown in FIG. 8 , the antenna device provided by the embodiment of the present application includes the antenna tuning circuit described in the foregoing embodiments, and thus the antenna device also has the same beneficial effects as the antenna tuning circuit.

The above product can perform the antenna tuning circuit provided by any embodiment of the present application, and has the corresponding functional modules and beneficial effects of the execution method. For details of the techniques not described in detail in this embodiment, reference may be made to the antenna tuning circuit provided by any embodiment of the present application.

Referring to FIG. 9, FIG. 9 is a mobile terminal, where the mobile terminal includes a main board and the antenna device, and the antenna device is connected to the main board.

As shown in FIG. 9, the mobile terminal provided by the embodiment of the present application includes the antenna device, and the antenna device includes the antenna tuning circuit described in the foregoing embodiments. Therefore, the mobile terminal also has the same beneficial effects as the antenna tuning circuit. It should be noted that the mobile terminal further includes other components that support the normal operation of the mobile terminal, such as a touch display screen, a processor, a memory, a camera, a microphone, a speaker, various sensors, function buttons, and the like.

It should be noted that the above is merely a preferred embodiment of the present application and the technical principles applied thereto. A person skilled in the art will understand that the present application is not limited to the specific embodiments described herein, and that various changes, modifications and substitutions can be made by those skilled in the art without departing from the scope of the invention. Therefore, although the present application has been described in detail by the above embodiments, the present application is not limited to the above embodiments, and other equivalent embodiments may be included without departing from the concept of the present application. The scope is determined by the scope of the appended claims.

Claims

An antenna tuning circuit, comprising: an antenna, a first matching circuit, a second matching circuit, a first switch, a second switch, and a radio frequency signal transceiver;

The antenna includes a first feed point, a second feed point, and a third feed point arranged in sequence; the first matching circuit is connected in series with the first switch between the first feed point and ground The second matching circuit is connected in series with the second switch between the second feeding point and the ground;

When the working frequency band is in the first frequency range, the radio frequency signal transmitted by the radio frequency signal transceiver is transmitted to the antenna through the first feeding point, the second switch is turned on, and the first switch is turned off or Conduction

When the working frequency band is in the second frequency band, the radio frequency signal transmitted by the radio frequency signal transceiver is transmitted to the antenna through the first feeding point, the first switch is turned on, and the second switch is turned off. The frequency band in the second frequency band is smaller than the frequency band in the first frequency band;

When the working frequency band is in the third frequency range, the radio frequency signal transmitted by the radio frequency signal transceiver is transmitted to the antenna through the third feeding point, and the first switch and the second switch are both turned on. The frequency band in the third frequency band is smaller than the frequency band in the second frequency band.
The antenna tuning circuit according to claim 1, wherein said first matching circuit is coupled to said first switch, and said first matching circuit is coupled to said antenna through said first feed point; The second matching circuit is coupled to the second switch, and the second matching circuit is coupled to the antenna through the second feed point.
The antenna tuning circuit according to claim 1, wherein said first matching circuit is coupled to said first switch, and said first switch is coupled to said antenna through said first feed point; The second matching circuit is connected to the second switch, and the second switch is connected to the antenna through the second feeding point.
The antenna tuning circuit according to any one of claims 1 to 3, wherein said first matching circuit comprises M matching sub-circuits, said second matching circuit comprises N matching sub-circuits, said M and The N is a positive integer.
The antenna tuning circuit according to claim 4, wherein at least one of the N matching sub-circuits is turned on when the operating frequency band is in the first frequency band range; or, the N At least one of the matching sub-circuits is turned on and at least one of the M matching sub-circuits is turned on.
The antenna tuning circuit according to claim 4 or 5, wherein at least one of the M matching sub-circuits is turned on when the operating frequency band is in the second frequency band range.
The antenna tuning circuit according to any one of claims 4-6, wherein at least one of the N matching sub-circuits is turned on and on when the operating frequency band is in the third frequency band range At least one of the M matching sub-circuits is turned on.
The antenna tuning circuit according to any one of claims 1 to 7, wherein the first feed point is placed at a first end of the antenna, and the third feed point is placed at the antenna The second endpoint.
The antenna tuning circuit according to any one of claims 1 to 7, wherein said third feed point is placed at an end of said antenna, said third feed point and said first feed The distance between the point and the second feed point is greater than or equal to the set distance.
The antenna tuning circuit according to any one of claims 1 to 7, wherein the antenna tuning circuit further comprises a first filter and/or a second filter, and the matching sub-circuit of the first matching circuit The first filter is connected in series between the first switch, the second filter is connected in series between the matching sub-circuit of the second matching circuit and the second switch, and the filter is used to reserve the corresponding The primary frequency signal of the frequency band and the harmonics generated by the tuning switch.
The antenna tuning circuit according to claim 10, wherein a distance between the third feed point and the first feed point and the second feed point is less than the set distance, The antenna tuning circuit further includes a first filter and a second filter.
The antenna tuning circuit according to claim 10, wherein the distance between the third feed point and the first feed point is less than the set distance, and the antenna tuning circuit further comprises a first filter Device.
The antenna tuning circuit according to claim 10, wherein the distance between the third feed point and the second feed point is less than the set distance, and the antenna tuning circuit further comprises a second filter Device.
The antenna tuning circuit according to any one of claims 1 to 13, wherein the antenna tuning circuit further comprises a control module, the tuning switch is connected to the control module, and the tuning switch is used to receive In the case of a switch logic control signal from the control module, a corresponding matching sub-circuit is selected based on the switch logic control signal.
An antenna device, comprising: a power amplifier and an antenna tuning circuit, the antenna tuning circuit comprising an antenna, a first matching circuit, a second matching circuit, a first switch, a second switch, and a radio frequency signal transceiver;

The antenna includes a first feed point, a second feed point, and a third feed point arranged in sequence; the first matching circuit is connected in series with the first switch between the first feed point and ground The second matching circuit is connected in series with the second switch between the second feeding point and the ground;

When the working frequency band is in the first frequency range, the radio frequency signal transmitted by the radio frequency signal transceiver is transmitted to the antenna through the first feeding point, the second switch is turned on, and the first switch is turned off or Conduction

When the working frequency band is in the second frequency band, the radio frequency signal transmitted by the radio frequency signal transceiver is transmitted to the antenna through the first feeding point, the first switch is turned on, and the second switch is turned off. The frequency band in the second frequency band is smaller than the frequency band in the first frequency band;

When the working frequency band is in the third frequency range, the radio frequency signal transmitted by the radio frequency signal transceiver is transmitted to the antenna through the third feeding point, and the first switch and the second switch are both turned on. The frequency band in the third frequency band is smaller than the frequency band in the second frequency band;

The power amplifier is configured to amplify a radio frequency signal sent by the radio frequency signal transceiver and output the signal to the antenna.
The antenna device according to claim 15, wherein said first matching circuit is connected to said first switch, and said first matching circuit is connected to said antenna through said first feeding point; The second matching circuit is coupled to the second switch, and the second matching circuit is coupled to the antenna through the second feed point.
The antenna device according to claim 15, wherein said first matching circuit is connected to said first switch, and said first switch is connected to said antenna through said first feeding point; The second matching circuit is connected to the second switch, and the second switch is connected to the antenna through the second feeding point.
A mobile terminal, characterized in that the mobile terminal comprises a main board ground and an antenna device, the antenna device is connected to the main board, the antenna device comprises a power amplifier and an antenna tuning circuit, and the antenna tuning circuit comprises an antenna a first matching circuit, a second matching circuit, a first switch, a second switch, and a radio frequency signal transceiver;

The antenna includes a first feed point, a second feed point, and a third feed point arranged in sequence; the first matching circuit is connected in series with the first switch between the first feed point and ground The second matching circuit is connected in series with the second switch between the second feeding point and the ground;

When the working frequency band is in the first frequency range, the radio frequency signal transmitted by the radio frequency signal transceiver is transmitted to the antenna through the first feeding point, the second switch is turned on, and the first switch is turned off or Conduction

When the working frequency band is in the second frequency band, the radio frequency signal transmitted by the radio frequency signal transceiver is transmitted to the antenna through the first feeding point, the first switch is turned on, and the second switch is turned off. The frequency band in the second frequency band is smaller than the frequency band in the first frequency band;

When the working frequency band is in the third frequency range, the radio frequency signal transmitted by the radio frequency signal transceiver is transmitted to the antenna through the third feeding point, and the first switch and the second switch are both turned on. The frequency band in the third frequency band is smaller than the frequency band in the second frequency band;

The power amplifier is configured to amplify a radio frequency signal sent by the radio frequency signal transceiver and output the signal to the antenna.
The mobile terminal according to claim 18, wherein said first matching circuit is connected to said first switch, and said first matching circuit is connected to said antenna through said first feed point; The second matching circuit is coupled to the second switch, and the second matching circuit is coupled to the antenna through the second feed point.
The mobile terminal according to claim 18, wherein the first matching circuit is connected to the first switch, and the first switch is connected to the antenna through the first feeding point; The second matching circuit is connected to the second switch, and the second switch is connected to the antenna through the second feeding point.