Antenna device and mobile terminal
By using metal radiators and feeders to generate polarized orthogonal circular polarization current in the mobile terminal, the problem of insufficient isolation in the dense antenna design is solved, and the stability and efficiency improvement of wireless communication is achieved.
Patent Information
- Application Number
- CN202310745754.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2023-06-21
- Publication Date
- 2024-12-24
AI Technical Summary
In mobile terminals, the isolation between antennas is difficult to improve without increasing the antenna distance, resulting in poor isolation effect in dense antenna design and affecting the stability of wireless communication.
Using an antenna device design including a first antenna, a second antenna and a metal radiator, the metal radiator is excited by the first feed source to generate a first circular polarization current, and the second feed source to generate a second circular polarization current , so that the two are polarized orthogonal, thereby increasing the isolation between the antennas without increasing the antenna distance.
It realizes that the degree of isolation is maintained without increasing the antenna distance, ensures the stability and efficiency of wireless communication functions, and is suitable for mobile terminals such as mobile phones and tablets.
Smart Images
Figure CN119181957A_ABST
Abstract
Description
Technical Field
[0001] The present application relates to the field of communications, and in particular to an antenna device and a mobile terminal. Background Art
[0002] With the development of communication technology, on the one hand, mobile terminals need to use multiple antennas to realize functions such as GPS navigation, Wi-Fi, and Bluetooth. On the other hand, mobile terminals such as mobile phones tend to be thin and light, making the antenna distribution in mobile terminals more and more dense. The isolation between antennas is closely related to the distance between antennas. When other conditions remain unchanged, the larger the distance between antennas, the better the isolation. Therefore, how to improve the isolation between antennas without increasing the distance between antennas has become an urgent problem to be solved. Summary of the invention
[0003] In view of this, the present invention aims to solve one of the problems in the related art at least to a certain extent. To this end, an object of the present invention is to provide an antenna device and a mobile terminal.
[0004] The antenna device provided by the implementation method of the present application is used in a mobile terminal, and the antenna device includes a first antenna, a second antenna and a metal radiator;
[0005] The first antenna comprises a first radiator and a first feed source, the first radiator has a first ground end and a first free end, and the first feed source is connected to the first radiator;
[0006] The second antenna comprises a second radiator and a second feed source, the second radiator has a second ground end and a second free end, the second radiator is arranged at a side away from the first ground end, and the second free end is arranged opposite to the first free end;
[0007] The metal radiator is spaced apart from the first free end and the second free end, so that the first feed source excites the metal radiator to generate a first circularly polarized current, and the second feed source excites the metal radiator to generate a second circularly polarized current, and the first circularly polarized current is orthogonal to the second circularly polarized current.
[0008] The present application also provides a mobile terminal, which includes an antenna device, which includes a first antenna, a second antenna and a metal radiator; the first antenna includes a first radiator and a first feed source, the first radiator has a first ground end and a first free end, and the first feed source is connected to the first radiator; the second antenna includes a second radiator and a second feed source, the second radiator has a second ground end and a second free end, the second radiator is arranged on a side away from the first ground end, and the second free end is arranged opposite to the first free end; the metal radiator is spaced apart from the first free end and the second free end, so that the first feed source excites the metal radiator to generate a first circularly polarized current, and the second feed source excites the metal radiator to generate a second circularly polarized current, and the first circularly polarized current and the second circularly polarized current are polarized orthogonally.
[0009] In the antenna device and mobile terminal of the present application, the first feed source excites the metal radiator to generate a first circularly polarized current, and the second feed source excites the metal radiator to generate a second circularly polarized current. The polarizations of the first circularly polarized current and the second circularly polarized current are orthogonal. In this way, the first antenna and the second antenna can maintain good isolation during working excitation.
[0010] Additional aspects and advantages of the present application will be given in part in the description below, and in part will become apparent from the description below, or will be learned through the practice of the present application. BRIEF DESCRIPTION OF THE DRAWINGS
[0011] The above and / or additional aspects and advantages of the present application will become apparent and easily understood from the following description of the embodiments in conjunction with the accompanying drawings, in which:
[0012] Figure 1 is a schematic diagram of the structure of an antenna device in some embodiments of the present application;
[0013] Figure 2 is a schematic structural diagram of an antenna device according to some embodiments of the present application;
[0014] Figure 3 is a schematic structural diagram of an antenna device according to some embodiments of the present application;
[0015] Figure 4 yes Figure 3 Schematic diagram of the cross-sectional structure at IV-IV in the middle;
[0016] Figure 5 It is a simulation schematic diagram of the antenna device of some embodiments of the present application.
[0017] Description of main component symbols:
[0018] Mobile terminal 100, antenna device 10, first antenna 11, first radiator 111, first ground terminal 1111, first free end 1112, first feed source 112, first ground terminal 1111, first free end 1112, second antenna 12, second ground terminal 1221, second radiator 122, second ground terminal 1221, second free end 1222, metal radiator 13, shell 20, frame 21, mainboard 30, camera module 40, back cover 50. DETAILED DESCRIPTION
[0019] The embodiments of the present application are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present application, and cannot be understood as limiting the present application.
[0020] In the description of the present application, it should be understood that the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of the present application, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.
[0021] In the description of this application, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection, an electrical connection, or can communicate with each other; it can be a direct connection, or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.
[0022] The disclosure below provides many different embodiments or examples to realize the different structures of the present application. In order to simplify the disclosure of the present application, the parts and settings of specific examples are described below. Of course, they are only examples, and the purpose is not to limit the present application. In addition, the present application can repeat reference numbers and / or reference letters in different examples, and this repetition is for the purpose of simplification and clarity, which itself does not indicate the relationship between the various embodiments and / or settings discussed.
[0023] The embodiments of the present application are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present application, and cannot be understood as limiting the present application.
[0024] Please combine Figure 1 The present application provides an antenna device 10 , which includes a first antenna 11 , a second antenna 12 and a metal radiator 13 .
[0025] The first antenna 11 includes a first radiator 111 and a first feed source 112 . The first radiator 111 has a first ground end 1111 and a first free end 1112 . The first feed source 112 is connected to the first radiator 111 .
[0026] The second antenna 12 includes a second radiator 121 and a second feed source 122 . The second radiator 121 has a second ground end 1211 and a second free end 1222 . The second radiator 121 is disposed at a side away from the first ground end 111 . The second free end 1222 is disposed opposite to the first free end 1112 .
[0027] The metal radiator 13 is spaced apart from the first free end 1112 and the second free end 1222, so that the first feed source 112 excites the metal radiator 13 to generate a first circularly polarized current, and the second feed source 122 excites the metal radiator 13 to generate a second circularly polarized current, and the first circularly polarized current and the second circularly polarized current are polarized orthogonally.
[0028] In the antenna device 10 provided by the present invention, the metal radiator 13 is spaced apart from the first free end 1112 of the first antenna 11 and the second free end 1222 of the second antenna 12, so that the first feed source 112 of the first antenna 11 can excite the metal radiator 13 to generate a first circularly polarized current, and the second feed source 122 of the second antenna 12 can excite the metal radiator 13 to generate a second circularly polarized current, and the polarizations of the first circularly polarized current and the second circularly polarized current are orthogonal, so that the first antenna 11 and the second antenna 12 can maintain good isolation when they are working and excited at the same time.
[0029] Specifically, the antenna device 10 can be applied to mobile terminals such as mobile phones and tablets to realize wireless communication of the mobile terminals. For example, in this embodiment, the antenna device 10 is applied to a mobile phone, and the antenna device 10 can realize the wireless communication functions of the mobile phone such as Bluetooth and Wi-Fi.
[0030] The first antenna 11 and the second antenna 12 may be of a port-to-port dual-feed design, that is, the first free end 1112 of the first antenna 11 and the second free end 1222 of the second antenna 12 are arranged opposite to each other.
[0031] The first antenna 11 and the second antenna 12 adopt an inverted-F antenna (IFA) structure, and may be a flexible printed circuit antenna (FPC) or a frame antenna.
[0032] Those skilled in the art can understand that the inverted F antenna is a deformed structure of the monopole antenna, and its evolution and development process can be seen as a process from a 1 / 4 wavelength monopole antenna to an inverted L antenna and then to an inverted F antenna. The structure of the inverted F antenna is formed by a terminal open-circuit transmission line with a length of L and a terminal short-circuit transmission line with a length of S in parallel. Among them, the open-circuit end to the feeding point can be equivalent to a parallel connection of a resistor and a capacitor (equivalent to a load, open circuit when resonant), and the short-circuit end to the feeding point can be equivalent to a series connection of a resistor and an inductor (short circuit when resonant). When the antenna resonates, the current is mainly distributed in the horizontal part of the antenna and the short-circuit part to the ground, and there is basically no current distribution in the feeding branch.
[0033] The metal radiator 13 is located on one side of the line connecting the first free end 1112 and the second free end 1222 and is spaced apart from the first free end 1112 and the second free end 1222, so that the first feed source 112 excites the metal radiator 13 to generate a first circularly polarized current, and the second feed source 122 excites the metal radiator 13 to generate a second circularly polarized current, and the polarizations of the first circularly polarized current and the second circularly polarized current are orthogonal.
[0034] The metal radiator 13 may be circular, rectangular, or other regular or irregular shapes. Figure 1 In some examples, the metal radiator 13 may be rectangular. For example, please combine Figure 3 In some examples, the metal radiator 13 may be circular. For example, Figure 2 The metal radiator 13 is an irregular shape. The metal radiator 13 can be made of metal materials such as copper, iron, aluminum, magnesium-aluminum alloy, etc., and the specific material is not limited.
[0035] The current paths of the first circularly polarized current and the second circularly polarized current are opposite in direction. For example, the first circularly polarized current may be a left-handed circularly polarized current (the current is in a clockwise direction), and the second circularly polarized current may be a right-handed circularly polarized current (the current is in a counterclockwise direction), or the first circularly polarized current may be a right-handed circularly polarized current, and the second circularly polarized current may be a left-handed circularly polarized current. It can be understood that there is a natural polarization orthogonality between the left-handed circularly polarized current and the right-handed circularly polarized current, and a good isolation can be maintained when the first antenna and the second antenna are excited at the same time.
[0036] Please combine Figure 1-3In some embodiments, the first antenna 11 and the second antenna 12 are substantially symmetrical about the perpendicular bisector of the line connecting the first free end 1112 and the second free end 1112, and the metal radiator 13 is symmetrical about the midline, and the midline substantially coincides with the perpendicular bisector of the line connecting the first free end 1112 of the first antenna 11 and the second free end 1222 of the second antenna 12.
[0037] It should be noted that the first antenna 11 and the second antenna 12 are substantially symmetrical about the perpendicular midline of the line connecting the first free end 1112 and the first free end 1112, which means that the first antenna 11 and the second antenna 12 are substantially or generally symmetrical about the perpendicular midline of the line connecting the first free end 1112 and the second free end 1222, and the center line substantially coincides with the perpendicular midline of the line connecting the first free end 1112 and the second free end 1222, which means that the center line substantially or generally coincides with the perpendicular midline of the line connecting the first free end 1112 and the second free end 1222. Specifically, the adjustment and setting can be made according to actual needs so that the orthogonal polarization effect of the first circularly polarized current and the second circularly polarized current is optimal.
[0038] It can be understood that the better the polarization orthogonality effect of the first circularly polarized current and the second circularly polarized current is, the higher the isolation between the first antenna 11 and the second antenna 12 is, and the antenna length determines its own operating frequency. If the operating frequencies of the first antenna 11 and the second antenna 12 are inconsistent, the lengths of the first antenna 11 and the second antenna 12 are inconsistent, resulting in the first antenna 11 and the second antenna 12 being unable to be completely symmetrical about the perpendicular bisector of the line connecting the first free end 1112 and the second free end 1222. If the lengths of the first antenna 11 and the second antenna 12 are inconsistent, in order to optimize the polarization orthogonality effect of the first circularly polarized current and the second circularly polarized current, the midline and the perpendicular bisector of the line connecting the first free end 1112 and the second free end 1222 may not be completely symmetrical.
[0039] In this way, the first antenna 11 and the second antenna 12 are basically symmetrical about the perpendicular bisector of the line connecting the first free end 1112 and the first free end 1112, and the midline of the metal radiator 13 is basically coincident with the perpendicular bisector of the line connecting the first free end 1112 of the first antenna 11 and the second free end 1222 of the second antenna 12, so that the polarization orthogonality effect of the first circularly polarized current generated by the first antenna 11 coupling the metal radiator 13 and the second circularly polarized current generated by the second antenna 12 coupling the metal radiator 13 is optimal, thereby achieving the best isolation between the first antenna 11 and the second antenna 12.
[0040] In some embodiments, the first antenna 11 supports a first operating frequency band, the second antenna 12 supports a second operating frequency band, and the first operating frequency band and the second operating frequency band at least partially overlap. For example, in this embodiment, the first operating frequency band of the first antenna 11 and the second operating frequency band of the second antenna 12 are the same, both operating at 2.4 GHz, wherein the first operating frequency band of the first antenna 11 may be 2.4 GHz WI-FI, and the second operating frequency band of the second antenna 12 may be 2.4 GHz Bluetooth.
[0041] Please combine Figure 2 In some embodiments, the distance between the metal radiator 13 and the first antenna 11 or the second antenna 12 is no greater than 0.1 times the wavelength of the first working frequency band of the first antenna 11 .
[0042] It can be understood that the greater the distance between the metal radiator 13 and the first antenna 11 or the second antenna 12, the worse the coupling effect. If the distance between the metal radiator 13 and the first antenna 11 or the second antenna 12 is too large, the first antenna 11 and the second antenna 12 cannot be coupled with the metal radiator 13, and circularly polarized current cannot be generated.
[0043] When the distance between the metal radiator 13 and the first antenna 11 or the second antenna 12 is greater than 0.1 times the wavelength of the first working frequency band of the first antenna 11, the coupling effect of the first antenna 11 or the second antenna 12 on the metal radiator 13 is very poor, and it is difficult to couple the metal radiator 13 to generate current, and the polarization orthogonal effect cannot be achieved. That is, it is through the setting that the distance between the metal radiator 13 and the first antenna 11 or the second antenna 12 is not greater than 0.1 times the wavelength of the first working frequency band of the first antenna 11 that the first antenna 11 and the second antenna 12 can be coupled to the metal radiator 13 to generate circular polar currents with opposite current paths during feeding excitation, thereby achieving the polarization orthogonal effect and ensuring the isolation between the first antenna 11 and the second antenna 12.
[0044] In some examples, the first operating frequency band is 2.4 GHz, the wavelength of the first antenna 11 at the first operating frequency is 125 mm, and the distance between the metal radiator 13 and the first antenna 11 / the second antenna 12 is not greater than 12.5 mm. The distance between the metal radiator 13 and the first antenna 11 / the second antenna 12 can be 2 mm, 3 mm, 5 mm, 7 mm, 8 mm, 9 mm or 10 mm, etc. The distance between the metal radiator 13 and the first antenna 11 / the second antenna 12 is not limited and can be set according to actual needs.
[0045] Please further combine Figure 2In some embodiments, the length of the metal radiator 13 in the first direction is in the range of 0.35-0.65 times the wavelength of the first working frequency band, and the first direction is substantially parallel to the direction in which the first free end 1112 of the first antenna 11 and the second free end 1222 of the second antenna 12 are connected.
[0046] For example, the length of the metal radiator 13 in the first direction may be 0.35, 0.4, 0.45, 0.5, 0.6 or 0.65 times the wavelength of the first working frequency band. In this embodiment, the length of the metal radiator 13 in the first direction may be 0.5 times the wavelength of the first antenna 11.
[0047] It can be understood that the more the radiation area of the first antenna 11 or the second antenna 12 is arranged opposite to the metal radiator 13, the better the coupling effect with the metal radiator 13, and the stronger the circularly polarized current generated by the metal radiator 13, and the length of the antenna is 1 / 4 of the wavelength of its own operating frequency, and the length of the first antenna 11 and the second antenna 12 is equal to 1 / 2 of the wavelength. If the length of the metal radiator 13 in the first direction is very short (less than 0.35-0.65 times the wavelength of the operating frequency band of the first antenna 11), the first antenna 11 and the second antenna 12 can only be partially coupled with the metal radiator 13, and the remaining part will still affect the antenna, and affect the isolation between the first antenna 11 and the second antenna 12, and if the length of the metal radiator 13 in the first direction is too long, the metal radiator 13 partially exceeds the radiation area of the first antenna 11 and the second antenna 12, so that the polarization orthogonality of the first circularly polarized current and the second circularly polarized current is not good.
[0048] In this way, by setting the length of the metal radiator 13 in the first direction to be in the range of 0.35-0.65 of the wavelength of the first working frequency band, the polarization orthogonal effect of the antenna device 10 can be ensured.
[0049] See also Figure 1 The present application also provides a mobile terminal 100 , and the antenna device 10 of the present application is applied to the mobile terminal 100 , or in other words, the mobile terminal 100 includes the above-mentioned antenna device 10 .
[0050] In the mobile terminal 100 of the present application, the metal radiator 13 is spaced apart from the first free end 1112 of the first antenna 11 and the second free end 1222 of the second antenna 12, so that the first feed source 112 of the first antenna 11 can excite the metal radiator 13 to generate a first circularly polarized current, and the second feed source 122 of the second antenna 12 can excite the metal radiator 13 to generate a second circularly polarized current, and the polarizations of the first circularly polarized current and the second circularly polarized current are orthogonal, so that the first antenna 11 and the second antenna 12 can maintain good isolation when working and being excited at the same time, thereby ensuring stable wireless communication.
[0051] Specifically, the mobile terminal 100 may be, but is not limited to, a mobile phone, a tablet computer, a smart wearable device (smart watch, smart bracelet, smart helmet, smart glasses, etc.), a virtual reality device or a head-mounted display device, etc. For example, the mobile terminal 100 may be a mobile phone, that is, the antenna device 10 is applied to the mobile phone, and the mobile phone may realize communication functions such as Bluetooth, Wi-Fi, etc. through the antenna device 10.
[0052] Please combine Figure 3 In some embodiments, the mobile terminal 100 includes a housing 20, the housing 20 includes four borders 21, and the first antenna 11 and the second antenna 12 are spaced apart on the same border 21 so that the first free end 1112 of the first antenna 11 and the second free end 1222 of the second antenna 12 are arranged opposite to each other.
[0053] Specifically, the frame 21 is a metal frame, the first antenna 11 and the second antenna 12 are IFA antennas with the metal frame as a radiator, and the first antenna 11 and the second antenna 12 can be a mouth-to-mouth dual-feed design, located on the same frame 21, that is, the first antenna 11 and the second antenna 12 are arranged on the same metal frame 21, and the first free end 1112 of the first antenna 11 and the second free end 1222 of the second antenna 12 are arranged relative to each other. For example, please combine Figure 1 The mobile terminal 100 includes two long frames and two short frames that are arranged opposite to each other, and the first antenna 11 and the second antenna 12 can be arranged on one of the long frames.
[0054] In this way, the antenna aperture utilization of the antenna device 10 is improved without changing the number of antennas, which effectively saves the internal space of the mobile terminal 100 and facilitates better stacking of the entire device.
[0055] Please participate Figure 3 and Figure 4 In some embodiments, the mobile terminal 100 includes a mainboard 30 , the metal radiator 13 is configured to be substantially parallel to the mainboard 30 , and the spacing between the metal radiator 13 and the mainboard 30 is not less than 0.01 times the wavelength of the first antenna 11 .
[0056] For example, in some examples, the spacing between the metal radiator 13 and the mainboard 30 may be 0.05 times the wavelength of the first antenna 11. It can be understood that the mainboard 30 of the mobile terminal 100 is grounded, and the spacing between the metal radiator 13 and the mainboard 30 can prevent the metal radiator 13 from being grounded, ensuring that the first antenna 11 or the second antenna 12 can be coupled to the metal radiator 13 to generate the first circularly polarized current or the second circularly polarized current when feeding, so that the first antenna 11 and the second antenna 12 maintain good isolation.
[0057] In some embodiments, the mobile terminal 100 includes a back cover 50 , and the metal radiator 13 is placed on the back cover 50 in a printed manner.
[0058] Specifically, the metal radiator 13 can be set on the front or back of the back cover 50 in a printed manner, with the front and back being set opposite to each other, and the back of the back cover 50 is the side of the back cover that is attached to the mobile phone battery. For example, the metal radiator 13 can be set on the back of the back cover 50.
[0059] In this way, the back cover 50 can be set in a printed manner through the metal radiator 13. Since the ground of the mobile terminal 100 is located on the mainboard 30, the metal radiator 13 can be spaced from the ground of the mobile terminal 100, ensuring that the first feed source 112 excites the metal radiator 13 to generate a first circularly polarized current, and the second feed source 122 excites the metal radiator 13 to generate a second circularly polarized current, so that the first antenna 11 and the second antenna 12 can have good isolation due to the orthogonal polarization of the first circularly polarized current and the second circularly polarized current. In addition, the existing internal structure of the mobile terminal 100 can be unchanged, so that the manufacturing process of the antenna device 10 is simple, the process cost of the antenna device 10 is simplified, and at the same time, it can also facilitate the improvement of existing products with poor coupling in the later stage.
[0060] Please further combine Figure 3 and 4 In some embodiments, the mobile terminal 100 includes a camera module 40 , and the metal radiator 13 is disposed on the camera module 40 .
[0061] Specifically, the camera module 40 can be a rear camera module, and the number of cameras of the camera module 40 can be one or more, and there is no specific limit on the number. In this embodiment, the metal radiator 13 can be integrated on the rear camera module 40, or in other words, the metal radiator 13 can be a part of the rear camera module 40.
[0062] For example, the camera module 40 includes a rear camera and a metal decorative part. The metal decorative part can be detachably mounted on the rear cover 50 after electroplating, or can form an integrated structure with the rear cover 50. The lens of the rear camera is embedded in the metal decorative part of the camera. The metal decorative part is used to protect the lens of the rear camera. The metal radiator 13 is the metal decorative part of the rear camera. The metal decorative part is symmetrical about the midline. The first antenna 11 and the second antenna 12 are frame antennas. The midpoint of the connection line of the first antenna 11 and the second antenna 12 is substantially coincident with the midline. In this way, the antenna device 10 can avoid adding additional components and reduce the volume of the mobile terminal 100 by using the existing metal decorative part of the mobile terminal 100 as the metal radiator 13.
[0063] In addition, in some embodiments, if the back cover 50 of the mobile terminal 100 includes part of metal, the metal portion of the back cover 50 can also be used as the metal radiator 13. In this way, the additional metal radiator 13 can be omitted, which reduces the cost and space of the mobile terminal 100 and is conducive to the thinness of the mobile terminal 100.
[0064] See also Figure 5 For example, in some examples, the first antenna 11 and the second antenna 12 are IFA antennas with the metal frame 21 of the mobile terminal as the radiator, and the metal radiator 13 is a metal decorative part of the camera module 40. The curve in the corresponding isolation diagram is the S parameter diagram of the first antenna 12 and the second antenna 12 obtained during the simulation process. It can be seen from the simulation curve diagram that the isolation between the first antenna 11 and the second antenna 12 at 2.4 GHz exceeds 25 dB.
[0065] The above embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the present application. It should be pointed out that, for a person of ordinary skill in the art, several modifications and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the present application shall be subject to the attached claims.
Claims
1. An antenna device, characterized in that: The antenna device comprises a first antenna, a second antenna and a metal radiator; The first antenna comprises a first radiator and a first feed source, the first radiator has a first ground end and a first free end, and the first feed source is connected to the first radiator; The second antenna comprises a second radiator and a second feed source, the second radiator has a second ground end and a second free end, the second radiator is arranged at a side away from the first ground end, and the second free end is arranged opposite to the first free end; The metal radiator is spaced apart from the first free end and the second free end, so that the first feed source excites the metal radiator to generate a first circularly polarized current, and the second feed source excites the metal radiator to generate a second circularly polarized current, and the first circularly polarized current is orthogonal to the second circularly polarized current.
2. The antenna device according to claim 1, characterized in that The current paths of the first circularly polarized current and the second circularly polarized current are in opposite directions.
3. The antenna device according to claim 2, characterized in that The first circularly polarized current is a left-handed circularly polarized current, and the second circularly polarized current is a right-handed circularly polarized current; or, the first circularly polarized current is a right-handed circularly polarized current, and the second circularly polarized current is a left-handed circularly polarized current.
4. The antenna device according to claim 1, characterized in that: The first antenna and the second antenna are substantially symmetrical about a perpendicular midline connecting the first free end and the first free end, the metal radiator is symmetrical about a midline, and the midline substantially coincides with the perpendicular midline.
5. The antenna device according to claim 1, characterized in that: The first antenna supports a first operating frequency band, the second antenna supports a second operating frequency band, and the first operating frequency band at least partially overlaps with the second operating frequency band.
6. The antenna device according to claim 5, characterized in that The distance between the metal radiator and the first antenna or the second antenna is no greater than 0.1 times the wavelength of the first working frequency band.
7. The antenna device according to claim 5, characterized in that: The length of the metal radiator in the first direction is in the range of 0.35-0.65 times of the wavelength of the first working frequency band, and the first direction is substantially parallel to the direction of the line connecting the first free end and the second free end.
8. The antenna device according to claim 1, characterized in that The first antenna and the second antenna are inverted-F antenna structures.
9. A mobile terminal, characterized in that: The invention comprises the antenna device as claimed in any one of claims 1 to 8.
10. The mobile terminal according to claim 9, characterized in that: The mobile terminal includes a housing, the housing includes four frames, and the first antenna and the second antenna are used to be arranged at intervals on the same frame so that the second free end is arranged opposite to the first free end.
11. The mobile terminal according to claim 9, characterized in that: The mobile terminal includes a mainboard, and the metal radiator is configured to be substantially parallel to the mainboard, and a distance between the metal radiator and the mainboard is not less than 0.01 times of a wavelength of the first antenna in a first working frequency band.
12. The mobile terminal according to claim 11, characterized in that: The mobile terminal comprises a back cover, and the metal radiator is used to be placed on the back cover in a printed manner.
13. The mobile terminal according to claim 11, characterized in that: The mobile terminal includes a rear camera, and the metal radiator is a metal decorative piece arranged on the rear camera.
14. The mobile terminal according to claim 13, characterized in that: The metal decorative part is symmetrical about the midline, the first antenna and the second antenna are frame antennas, and the perpendicular bisector of the line connecting the first antenna and the second antenna substantially coincides with the midline.