CN218472280U - Antenna device and mobile terminal - Google Patents

Abstract

The application discloses an antenna device and a mobile terminal; the antenna device comprises an SMA connector, a spiral antenna and a choke coil; the spiral antenna is connected to one side of the SMA connector; the choke coil is connected to one side of the SMA connector close to the spiral antenna and wraps part of the spiral antenna. According to the antenna, the choke coil is introduced to the spiral antenna, so that the hollow cylindrical coupling capacitor is added to the bottom of the spiral antenna, the capacitance of the spiral antenna is increased, the inductance is reduced, and the bandwidth of the spiral antenna is increased. Due to the fact that the bandwidth of the spiral antenna is increased, the radiation performance of the spiral antenna close to a human body is improved under the corresponding application frequency band, and the anti-interference effect is achieved.

Description

Antenna device and mobile terminal

Technical Field

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

Background

The interphone is widely applied by the advantages of simplicity, rapidness, low conversation cost, no network limitation and the like, and is used for communication or command and dispatching among team members so as to improve the communication efficiency and the quick response capability of handling emergencies. In order to ensure a satisfactory conversation effect and a good conversation environment, the interphone antenna plays a vital role.

In practical application scenes of the interphone terminal, the interphone is often hung at the waist, and the performance of the external antenna is obviously reduced due to the fact that the interphone is close to a human body.

SUMMERY OF THE UTILITY MODEL

The technical problem that this application mainly solved provides an antenna device and mobile terminal to solve among the prior art intercom because of being close to the human body too closely, lead to the problem of external antenna's performance degradation.

In order to solve the technical problem, the application adopts a technical scheme that: provided is an antenna device, including: an SMA joint; the spiral antenna is connected to one side of the SMA connector; and the choke is connected to one side, close to the spiral antenna, of the SMA connector and wraps part of the spiral antenna.

The antenna device further comprises an antenna protection tube body, and the antenna protection tube body wraps the spiral antenna and the choke coil and is used for protecting the spiral antenna and the choke coil.

The antenna protection tube body, the helical antenna and the choke coil are of an integral injection molding structure.

The SMA connector comprises an outer conductor assembly, an inner conductor and an insulating layer, the outer conductor assembly is provided with a through hole, the insulating layer is arranged in the through hole of the outer conductor assembly, the insulating layer wraps part of the inner conductor and is used for separating the inner conductor from the outer conductor assembly, and the spiral antenna is connected to one side, away from the outer conductor assembly, of the inner conductor.

The outer conductor assembly comprises a first outer conductor and a second outer conductor, the diameter of the second outer conductor is larger than that of the first outer conductor, the first outer conductor is connected with one side, far away from the helical antenna, of the second outer conductor, and the second outer conductor and the first outer conductor are provided with through holes and communicated with each other.

Wherein, the insulating layer is a Teflon insulating glue layer.

Wherein, the length of choke is one fifth to one third of resonance frequency wavelength.

Wherein the length of the choke coil is one quarter of the wavelength of the resonant frequency.

The application adopts another technical scheme that: a mobile terminal is provided, which comprises a shell, a circuit board and the antenna device, wherein the circuit board is arranged in the shell, and the antenna device is connected to the circuit board.

Wherein the SMA connector of the antenna apparatus is connected to a ground terminal of the circuit board.

The beneficial effect of this application is: different from the prior art, the choke coil structure is introduced on the spiral antenna, so that the hollow cylindrical coupling capacitor is added at the bottom of the spiral antenna, the capacitance of the spiral antenna is increased, the inductance is reduced, and the bandwidth of the spiral antenna is increased. Due to the fact that the bandwidth of the spiral antenna is increased, under the corresponding application frequency band, the radiation performance of the spiral antenna close to a human body is improved, and the anti-interference effect is achieved.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed to be used in the description of the embodiments are briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present application, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without creative efforts.

Fig. 1 is a schematic structural diagram of an embodiment of an antenna apparatus provided in the present application;

fig. 2 is a schematic structural diagram of another embodiment of an antenna apparatus provided in the present application;

fig. 3 is a schematic structural diagram of an SMA contact in an antenna arrangement provided herein;

FIG. 4 is a plot of the reflection coefficients of a simulation model in one embodiment of the antenna apparatus provided herein;

fig. 5 is a radiation pattern of a phantom in one embodiment of the antenna apparatus provided herein;

fig. 6 is a diagram illustrating a result of a reflection coefficient test of an actual measurement model in a free space according to an embodiment of the antenna apparatus provided in the present application;

fig. 7 is a diagram illustrating a result of a reflection coefficient test of an actual measurement model when the actual measurement model is close to a human body according to an embodiment of the antenna apparatus provided in the present application;

fig. 8 is a schematic structural diagram of a mobile terminal provided in the present application.

Detailed Description

The technical solutions in the embodiments of the present application will be described clearly and completely with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are only some embodiments of the present application, and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.

The terms "first", "second" and "third" in the embodiments of the present application are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first," "second," or "third" may explicitly or implicitly include at least one of the feature. In the description of the present application, "plurality" means at least two, e.g., two, three, etc., unless explicitly specified otherwise. In the embodiment of the present application, all directional indicators (such as up, down, left, right, front, rear \8230;) are used only to explain the relative positional relationship between the components, the motion situation, etc. at a specific posture (as shown in the drawing), and if the specific posture is changed, the directional indicator is changed accordingly. The terms "comprising" and "having," as well as any variations thereof, in the embodiments of the present application are intended to cover non-exclusive inclusions. For example, a process, method, system, article, or apparatus that comprises a list of steps or elements is not limited to only those steps or elements listed, but may alternatively include other steps or elements not listed, or may alternatively include other steps or elements inherent to such process, method, article, or apparatus.

Reference herein to "an embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment can be included in at least one embodiment of the application. The appearances of the phrase in various places in the specification are not necessarily all referring to the same embodiment, nor are separate or alternative embodiments mutually exclusive of other embodiments. It is explicitly and implicitly understood by one skilled in the art that the embodiments described herein can be combined with other embodiments.

Referring to fig. 1 and 8, fig. 1 is a schematic structural diagram of an embodiment of an antenna device provided in the present application; fig. 8 is a schematic structural diagram of a mobile terminal provided in the present application. The antenna device 20 includes, but is not limited to, an SMA (miniature version inductor) connector 100, a helical antenna 300, and a choke coil 200. In this embodiment, the helical antenna 300 is connected to one side of the SMA connector 100, and the choke coil 200 is connected to one side of the SMA connector 100 close to the helical antenna 300 and wraps a part of the helical antenna 300. The helical antenna 300 generates frequency components.

In the actual use process, the radio frequency signal output by the circuit board 40 at the transmitting end is transmitted to the helical antenna 300 through the feeder (cable), and then radiated out by the helical antenna 300 in the form of electromagnetic wave. When the electromagnetic wave reaches the receiving end, it is received by the helical antenna 300 (only a small portion of the power is received) and transmitted to the circuit board 40 through the feeder. The present application couples the choke coil 200 to the helical antenna 300, increasing the capacitance of the helical antenna 300 and increasing the impedance bandwidth. Therefore, after the helical antenna 300 is close to the human body, even if the frequency band shifts forward, the required application frequency band can still be covered, and the helical antenna has good radiation performance, so that the anti-interference effect is achieved.

Optionally, the operating frequency band of the helical antenna 300 is U-segment. The U-section helical antenna 300 is an electrically small antenna and is inductive, thus limiting the impedance bandwidth, and the bandwidth can be extended by adding a capacitive method. The introduction of the choke coil 200 at one side of the helical antenna 300 can increase the capacitance of the helical antenna 300. When the external helical antenna 300 is close to a human body, the standing wave of the helical antenna 300 shifts forward, but the impedance bandwidth is wide, so that the required communication frequency band can be still covered, the radiation performance requirement is met, and the interference close to the human body is resisted. Optionally, the helical antenna 300 is a single-frequency antenna or a multi-frequency antenna.

Optionally, in a specific embodiment, the length of choke 200 is one fifth to one third of the wavelength of the resonant frequency. Preferably, the length of the choke 200 is one quarter of the wavelength of the resonant frequency, and the choke 200 is coupled to the helical antenna 300, so that the helical antenna 300 has a stronger anti-interference performance.

Referring to fig. 2, fig. 2 is a schematic structural diagram of another embodiment of an antenna device according to the present application. The antenna device 20 further includes an antenna protection tube body 400. In this embodiment, the antenna protection pipe body 400 wraps the helical antenna 300 and the choke coil 200 for protecting the helical antenna 300 and the choke coil 200. In an embodiment, the antenna protection tube 400 is made of rubber, and the antenna protection tube 400, the helical antenna 300 and the choke coil 200 are integrally injection-molded. This not only protects the helical antenna 300 and the choke coil 200 but also separates the helical antenna 300 and the choke coil 200.

Specifically, the SMA contact 100 includes, but is not limited to, an outer conductor assembly 110, an inner conductor 120, and an insulation layer 130. In this embodiment, the outer conductor assembly 110 is formed with a through hole, the insulating layer 130 is disposed in the through hole of the outer conductor assembly 110, and the insulating layer 130 wraps a portion of the inner conductor 120 to block the inner conductor 120 and the outer conductor assembly 110. Optionally, the insulating layer 130 is a teflon insulating glue layer.

Referring to fig. 2 and 3, fig. 3 is a schematic structural diagram of an SMA contact in the antenna apparatus provided in the present application. The outer conductor assembly 110 includes, but is not limited to, a first outer conductor 111 and a second outer conductor 112. In the present embodiment, the diameter of the second outer conductor 112 is larger than that of the first outer conductor 111, and the first outer conductor 111 connects the side of the second outer conductor 112 away from the helical antenna 300. Specifically, the second outer conductor 112 and the first outer conductor 111 are both provided with through holes and are communicated with each other. A portion of the insulating layer 130 is disposed in the through hole formed in the first outer conductor 111, and another portion of the insulating layer 130 is disposed in the through hole formed in the second outer conductor 112.

Optionally, a portion of the antenna protective tube body 400 is positioned within the through hole of the second outer conductor 112, adjacent to the insulating layer 130, and wraps around a portion of the inner conductor 120, separating the inner conductor 120 from the second outer conductor 112.

Optionally, the helical antenna 300 is connected to a side of the inner conductor 120 remote from the outer conductor assembly 110.

Alternatively, the side of the helical antenna 300 remote from the SMA connector 100 is connected to the feed point of the circuit board 40, and the outer conductor assembly 110 of the SMA connector 100 is connected to the ground of the circuit board 40.

Referring to fig. 4, fig. 4 is a reflection coefficient diagram of a simulation model in an embodiment of an antenna apparatus provided in the present application. In the present embodiment, the abscissa represents the Frequency (Frequency) of the helical antenna 300, and the ordinate represents the reflection coefficient (S-parameters) of the helical antenna 300. In a free space state, when the spiral antenna 300 is not close to a human body, the frequency of the spiral antenna 300 is detected to be 400-470MHz, and the reflection coefficients corresponding to the spiral antenna 300 are all smaller than or equal to-4 dB, so that the mobile communication requirement is met.

Referring to fig. 5, fig. 5 is a radiation pattern of a simulation model in an embodiment of the antenna apparatus provided in the present application. In the present embodiment, the frequency of the helical antenna 300 is set to 435MHz. As shown in fig. 5, when the helical antenna 300 is not close to the human body in the free space state, the radiation pattern of the helical antenna 300 in the xoy plane is close to a circle, and at this time, it indicates that the helical antenna 300 corresponding to the frequency is omnidirectional radiation, so as to meet the mobile communication requirement.

Referring to fig. 6, fig. 6 is a diagram illustrating a reflection coefficient test result of an actual measurement model in a free space according to an embodiment of the present invention. In the present embodiment, the abscissa represents the frequency of the spiral antenna 300, and the ordinate represents the reflection coefficient corresponding to the spiral antenna 300. In the free space state, when the helical antenna 300 is not close to the human body, the reflection coefficient at 400-470MHz satisfies the mobile communication requirement. Specifically, the reflection coefficient at 400MHz was at most-8.07 dB, and the reflection coefficient at 470MHz was-9.72 dB. Therefore, when the frequency of the helical antenna 300 is 400-470MHz, the reflection coefficients corresponding to the helical antenna 300 are all less than or equal to-4 dB, and the mobile communication requirement is met.

Referring to fig. 7, fig. 7 is a diagram illustrating a reflection coefficient test result when an actual measurement model of an antenna apparatus according to an embodiment of the present disclosure is close to a human body. In the present embodiment, the abscissa represents the frequency of the helical antenna 300, and the ordinate represents the reflection coefficient corresponding to the helical antenna 300. In a state close to a human body, the reflection coefficient of the helical antenna 300 is better in an application frequency band than that in a free space state, and the mobile communication requirement is also met. Specifically, the reflection coefficient at 400MHz was at least-7.72 dB and the reflection coefficient at 470MHz was at most-6.69 dB. Therefore, when the frequency of the helical antenna 300 is 400-470MHz, the reflection coefficients corresponding to the helical antenna 300 are all less than or equal to-4 dB, and the mobile communication requirement is met.

Referring to fig. 8 again, the mobile terminal 10 provided by the present application includes, but is not limited to, a housing 30, a circuit board 40, and the antenna device 20. In the present embodiment, the circuit board 40 is disposed in the housing 30, and the antenna device 20 is connected to the circuit board 40. In actual use, the radio frequency signal output from the circuit board 40 at the transmitting end is transmitted to the helical antenna 300 through the feeder (cable), and is radiated by the helical antenna 300 in the form of electromagnetic wave. When the electromagnetic wave reaches the receiving end, it is received by the helical antenna 300 (only a small portion of the power is received) and transmitted to the circuit board 40 through the feeder.

Optionally, the SMA connector 100 of the antenna arrangement 20 is connected to the ground of the circuit board 40. In the mobile terminal 10 of the present application, when a human body approaches to the external helical antenna 300 in the U-band communication, the standing wave of the helical antenna 300 may shift, which may cause the radiation performance of the mobile terminal 10 to decrease. Therefore, with the helical antenna 300 proposed in the present application, even if the entire frequency band of the helical antenna 300 shifts forward when approaching a human body, coverage to a desired communication frequency band can be ensured, and radiation performance requirements can be satisfied, thereby achieving resistance to interference approaching a human body.

Alternatively, the mobile terminal 10 may be a walkie-talkie, law enforcement recorder, or other terminal device requiring an external antenna.

By introducing the choke coil 200 to the helical antenna 300, the present application adds a hollow cylindrical coupling capacitor to the bottom of the helical antenna 300, which increases the capacitance of the helical antenna 300, reduces the inductance, and thus increases the bandwidth of the helical antenna 300. Due to the fact that the bandwidth of the spiral antenna 300 is increased, the radiation performance of the spiral antenna 300 close to a human body is improved under the corresponding application frequency band, and the anti-interference effect is achieved.

The above description is only a part of the embodiments of the present application, and not intended to limit the scope of the present application, and all equivalent devices or equivalent processes performed by the content of the present application and the attached drawings, or directly or indirectly applied to other related technical fields, are also included in the scope of the present application.

Claims (10)

1. An antenna device, comprising:

an SMA joint;

the spiral antenna is connected to one side of the SMA connector;

and the choke is connected to one side, close to the spiral antenna, of the SMA connector and wraps part of the spiral antenna.

2. The antenna device according to claim 1, wherein the antenna device further comprises an antenna protection tube body that wraps the helical antenna and the choke coil for protecting the helical antenna and the choke coil.

3. The antenna device according to claim 2, wherein the antenna protection tube body is of an integral injection molding structure with the helical antenna and the choke coil.

4. The antenna assembly of claim 2, wherein the SMA contact comprises an outer conductor assembly, an inner conductor, and an insulating layer, wherein the outer conductor assembly defines a through hole, the insulating layer is disposed in the through hole of the outer conductor assembly, the insulating layer wraps a portion of the inner conductor to block the inner conductor from the outer conductor assembly, and the helical antenna is connected to a side of the inner conductor away from the outer conductor assembly.

5. The antenna device of claim 4, wherein the outer conductor assembly comprises a first outer conductor and a second outer conductor, the diameter of the second outer conductor is larger than that of the first outer conductor, the first outer conductor is connected with one side of the second outer conductor, which is far away from the helical antenna, and the second outer conductor and the first outer conductor are both provided with through holes and are communicated with each other.

6. The antenna device of claim 4, wherein the insulating layer is a Teflon insulating glue layer.

7. An antenna device according to any of claims 1-6, characterized in that the length of the choke is one fifth to one third of the wavelength of the resonance frequency.

8. The antenna device according to claim 7, wherein the length of the choke is one quarter of the wavelength of the resonance frequency.

9. A mobile terminal, comprising: a housing, a circuit board disposed within the housing, and an antenna device as claimed in any one of claims 1-8, the antenna device being connected to the circuit board.

10. A mobile terminal as claimed in claim 9, characterised in that the SMA connector of the antenna arrangement is connected to a ground terminal of the circuit board.

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