WO2015154404A1

WO2015154404A1 - Terminal device and built-in antenna with reconstructable frequency thereof

Info

Publication number: WO2015154404A1
Application number: PCT/CN2014/088304
Authority: WO
Inventors: 郝彦博; 朱强; 钟涛
Original assignee: 中兴通讯股份有限公司
Priority date: 2014-08-11
Filing date: 2014-10-10
Publication date: 2015-10-15
Also published as: CN105337051A

Abstract

A terminal device and a built-in antenna with a reconstructable frequency thereof. The antenna is an antenna of the same physical size, namely, the physical size of the antennas does no change. Whether to electrically connect coupled branches of the antenna is controlled by controlling the ON/OFF of an electronic switch, thereby enabling the resonance of the whole antenna to occur at different frequencies. The method has an obvious effect on antenna frequency reconstruction, and the structure is simple, thereby greatly saving the layout space of the antenna.

Description

Terminal device and its frequency reconfigurable built-in antenna

Technical field

The present invention relates to the field of antenna technologies in wireless communications, and in particular, to a terminal device and a frequency-reconfigurable built-in antenna.

Background technique

Mobile terminals have become an indispensable communication tool in daily life work. The development trend of mobile terminals is becoming more and more oriented towards ultra-thin, miniaturization and intelligentization. At present, the size of the mobile terminal increases with the screen. Correspondingly, the actual available area of the antenna of the mobile terminal does not increase, and the use environment is getting worse. On the other hand, the mobile terminal is developing toward ultra-thinness, which further affects the performance of the antenna. With the development of LTE (Long Term Evolution) technology in recent years, the antenna of the mobile terminal needs to support more frequency bands, which is a challenge that the 2G/3G era has not faced. LTE is a system that must support diversity. This also leads to the need to set one or more receive diversity antennas on the mobile terminal as the LTE function is added to the mobile terminal. The place where the mobile terminal can be left to the antenna is limited. If a whole machine supports the main antenna, 1 or 2 diversity antennas, and GPS (Global Positioning System) antenna, WIFI (Wireless-Fidelity, wireless fidelity) / BT (bluetooth) antenna, or even NFC (Near Field Communication) antennas and other types of antennas, too many antennas lead to insufficient layout If it can be laid down, then the antenna performance will not be discussed. Therefore, how to design a multi-band antenna in a limited antenna layout environment becomes a major difficulty in the field of terminal antenna design.

Summary of the invention

The embodiment of the invention provides a terminal device and a frequency-reconfigurable built-in antenna, which can realize the multi-band antenna function without changing the physical size of the antenna in a limited antenna deployment environment.

The technical solution adopted by the embodiment of the present invention is that the frequency reconfigurable built-in antenna is located in a terminal device, and the antenna includes: an electronic switch, and a direct connection branch and a coupling branch that do not contact each other. Section

The directly connected branch node is disposed to be connected to an antenna feeding point of the terminal device circuit board;

An electronic switch is provided to connect the coupling branch to a ground point of the terminal device circuit board to control the electronic switch to be turned on and off to operate the antenna in different frequency bands.

Optionally, the antenna further includes: an antenna bracket;

The straight branches and the coupling branches are disposed on the antenna bracket.

Optionally, the controlling the electronic switch to turn on and off to operate the antenna in different frequency bands includes:

When the control electronic switch is turned off, the antenna operates in a frequency band corresponding to the operating mode of the monopole antenna; when the control electronic switch is turned on, the antenna operates in a frequency band corresponding to the monopole antenna plus the parasitic operating mode.

Optionally, the antenna works in a frequency band corresponding to an operating mode of the monopole antenna, including:

The directly connected branches operate in a monopole antenna manner, and the coupling branches act as a suspended metal to affect the resonant frequency of the directly connected branches.

Optionally, the electronic switch connects the coupling branch to a ground point of the terminal device circuit board, and controls the electronic switch to be turned on and off to operate the antenna in different frequency bands, including:

Different points of the coupling branch are respectively connected to the grounding point of the terminal device circuit board through an electronic switch, and different on-and-off combinations are formed by controlling each electronic switch to operate the antenna in different frequency bands.

Optionally, when the coupling branch is more than two, the electronic switch connects the coupling branch to a ground point of the terminal device circuit board, and controls the conduction and disconnection of the electronic switch to enable the The antenna operates in different frequency bands, including:

Each coupling branch is also connected to the grounding point of the terminal device circuit board through a corresponding electronic switch, and different electrical conduction and disconnection combinations are formed by controlling each electronic switch to operate the antenna in different frequency bands.

Optionally, the directly connected branch and the coupled branch are made of flexible circuit board material, LDS (Laser-Direct-structuring, laser direct molding) material or steel sheet.

Optionally, the directly connected branches and the coupled branches are a planar structure or a three-dimensional structure.

Optionally, the antenna holder has a dielectric constant ranging from 4.3 to 4.5.

The embodiment of the invention further provides a terminal device, which comprises the above-mentioned frequency reconfigurable built-in antenna.

The terminal device and the frequency reconfigurable built-in antenna according to the embodiment of the present invention use the antenna of the same physical size to change the physical size of the antenna, and control whether the coupling portion of the antenna is electrically connected by controlling the on/off of the electronic switch. So that the entire antenna resonates at different frequencies. This method has obvious effects on antenna frequency reconstruction, and has a simple structure, which greatly saves the layout space of the antenna.

BRIEF abstract

1 is a schematic structural diagram of a frequency reconfigurable built-in antenna according to a first embodiment of the present invention;

2 is a schematic structural diagram of a frequency reconfigurable built-in antenna according to a second embodiment of the present invention;

3 is a schematic structural diagram of a frequency reconfigurable built-in antenna according to a third embodiment of the present invention;

4 is a schematic diagram of a three-dimensional structure of a frequency reconfigurable antenna according to a fifth embodiment of the present invention;

FIG. 5 is an enlarged view of an antenna pattern of a frequency reconfigurable antenna according to a fifth embodiment of the present invention.

Preferred embodiment of the invention

The preferred embodiments of the present invention are described in detail below with reference to the accompanying drawings, and the features of the embodiments and the embodiments of the present invention can be arbitrarily combined with each other without conflict.

According to a first embodiment of the present invention, a frequency reconfigurable built-in antenna is located in a terminal device. As shown in FIG. 1 , the antenna includes the following components: an electronic switch 100, and a direct connection branch 200 and a mutual contact that do not contact each other. Branch section 300;

The direct connection branch 200 is connected to the antenna feed point of the terminal device circuit board 400;

The coupling branch 300 is coupled to the ground point of the terminal device circuit board 400 by the electronic switch 100, and the antenna is operated in different frequency bands by controlling the conduction and disconnection of the electronic switch 100.

In this embodiment, the direct connection branch 200 and the coupling branch 300 can be simultaneously located in an area specially opened for the antenna pattern on one end of the terminal device circuit board 400. Specifically, the circuit board of the terminal device is directly fabricated by means of a printed circuit. 400. In addition, the direct connection branch 200 and the coupling branch 300 may also be disposed on the antenna bracket. Optionally, the antenna further includes: an antenna bracket having a dielectric constant ranging from 4.3 to 4.5, preferably 4.4. The straight branch 200 and the coupling branch 300 are made of a flexible circuit board material, an LDS material, or a steel sheet. The straight branch section 200 and the coupling branch section 300 are a planar structure or a three-dimensional structure.

Optionally, by controlling the conduction and disconnection of the electronic switch 100 to operate the antenna in different frequency bands, including:

When the control electronic switch 100 is turned off, the antenna operates in a frequency band corresponding to the operating mode of the monopole antenna; at this time, the operation mode of the monopole antenna realized by the direct connection branch 200, the coupling branch 300 is not powered The connection can only be used as a suspension metal similar to the director, which has a substantially inefficient effect on the adjacent monopole antenna, but affects the resonant frequency of the monopole antenna, making the monopole antenna The resonant frequency is low. Since the electrical length of the monopole antenna is one quarter of the wavelength corresponding to the desired resonant frequency, if the monopole resonance frequency is low, it is necessary to increase the resonant frequency of the monopole antenna to achieve the desired resonant frequency, which is To reduce the electrical length of the monopole antenna, the actual physical size can be shortened accordingly. Therefore, the introduction of the coupling branch 300 can well reduce the size of the antenna and reduce the antenna size.

When the control electronic switch is turned on, the antenna operates in a frequency band corresponding to the operation mode of the monopole antenna plus the parasitic operation mode; at this time, the operation mode of the monopole antenna realized by the direct connection branch 200 is also performed by the coupling branch 300 An electrical connection is provided which acts as a coupling feed to the monopole antenna.

Therefore, the present embodiment is actually directed to the case where there is only one electronic switch 100 corresponding to a coupling branch 300 connected to the ground point of the terminal device circuit board.

The second embodiment of the present invention is a frequency reconfigurable internal antenna, which is located in the terminal device. The antenna of the embodiment is substantially the same as the antenna structure of the first embodiment, except that the coupling branch 300 is not only There is one node connected to the ground point of the terminal device board, but multiple.

As shown in FIG. 2, in the present embodiment, the coupling branch 300 is connected to the grounding point of the terminal device circuit board by the electronic switch 100, and the electronic switch 100 is controlled to be turned on and off to make the antenna Working in different frequency bands, including:

Different points of the coupling branch 300 are respectively connected to the grounding point of the terminal device circuit board through the electronic switch 100, and different electrical conduction and disconnection combinations are formed by controlling the electronic switches 100 to operate the antennas in different frequency bands. .

Since the coupling branch 300 and the straight branch 200 are used as antenna patterns, the relative positional relationship between the coupling branch 300 and the straight branch 200 is not limited, as long as the following conditions are met: when controlling When all the electronic switches 100 are disconnected, the antenna can be operated based on the direct connection branch 200 in a frequency band corresponding to the operating mode of the monopole antenna, and the coupling branch acts as a suspension metal to affect the resonant frequency of the directly connected branch; Controlling each electronic switch 100 to form different combinations of conduction and disconnection, at which time at least one electronic switch 100 is turned on, and the antenna can be based on the operation mode of the monopole antenna plus parasitic operation based on the direct connection branch 200 and the coupling branch 300 The band works. In fact, all electronic switch 100 disconnection is also one of the different combinations of conduction and disconnection. At this time, the operating frequency of the antenna is also different from the operating frequency corresponding to other combinations of conduction and disconnection.

A third embodiment of the present invention is a frequency reconfigurable internal antenna, which is located in a terminal device. The antenna of the embodiment is substantially the same as the antenna structure of the first embodiment, except that there is not only one coupling branch 300. Connected to the ground point of the terminal device circuit board 400, but a plurality of coupling branches.

Specifically, as shown in FIG. 3, in the embodiment, when the coupling branch 300 is two or more, the coupling branch 300 is connected to the grounding point of the terminal device circuit board 400 by the electronic switch 100, and the electronic switch 100 is controlled. Turning on and off to operate the antenna in different frequency bands, including:

Each of the coupling branches 300 is also connected to the grounding point of the terminal device circuit board 400 through the corresponding electronic switch 100, and different combinations of conduction and disconnection are formed by controlling the electronic switches 100 to operate the antennas in different frequency bands. .

Since the direct connection branch 200 and all the coupling branches 300 are used as antenna patterns, they are various. The relative positional relationship between the coupling branch 300 and each of the straight branches 200 is not limited in this embodiment, as long as the following conditions are met: when all the electronic switches 100 are controlled to be disconnected, the antenna can be based on the directly connected branches 200 The operating mode of the monopole antenna operates in a frequency band corresponding to the suspension metal as a suspension metal affecting the resonant frequency of the directly connected branch; when the electronic switches 100 are controlled to form different combinations of conduction and disconnection, the antenna It is possible to operate in a frequency band corresponding to a monopole antenna plus a parasitic operating mode based on the directly connected branch section 200 and all of the coupled stub sections 300. In fact, all electronic switch 100 disconnection is also one of the different combinations of conduction and disconnection. At this time, the operating frequency of the antenna is also different from the operating frequency corresponding to other combinations of conduction and disconnection.

According to a fourth embodiment of the present invention, a terminal device includes the frequency reconfigurable built-in antenna of the first embodiment, the second embodiment, or the third embodiment described above.

Due to the reduction of the size of the reconfigurable built-in antenna, the terminal device can support the operation of the short-wave band, and further expand the application scenario of the terminal device.

The fifth embodiment of the present invention is based on the above embodiment, and an example of application of the present invention is described with reference to FIGS. 4-5.

This application example introduces a frequency reconfigurable antenna built in a mobile terminal, and adjusts the working of the antenna through a connection switch (ie, an electronic switch of the foregoing embodiment) connected between a short-circuit point of the antenna and the mobile terminal circuit board, that is, an electronic switch of the foregoing embodiment. In the case of multi-frequency operation, the antenna space is saved because only the same antenna is used, that is, the physical size of the antenna is not changed. When the connection switch connected between the antenna and the short-circuit point is disconnected, the antenna operates in the direct-feed monopole antenna mode, and a resonance frequency is generated; when the connection switch is closed, the antenna operates in the coupling feed. In the parasitic mode of electricity, a different resonant frequency is generated, thereby realizing that one antenna operates at a plurality of different frequencies, that is, the antenna frequency can be reconstructed.

4 and FIG. 5 are respectively a three-dimensional structure diagram of the frequency reconfigurable antenna and an enlarged view of the antenna pattern. It can be seen that the antenna is composed of the following parts: the first connection switch 11 is responsible for connecting the circuit board feed. The point and the antenna pattern are connected directly to each other and remain conductive; the second connection switch 12 is responsible for connecting the short circuit point of the circuit board and the coupling branch in the antenna pattern, that is, the main control The switch; the direct connection of the antenna pattern 13 in the antenna pattern is directly connected to the branch because it is directly connected to the feed point; hence the coupling branch 14 in the antenna pattern, because the branch and the feed point are not directly conductive, Radiation is only performed by means of coupled feeding or parasitic; the circuit board 15 is equivalent to a PCB (Printed Circuit Board) in the whole machine; the antenna holder 16 is used for fixing the antenna, for example, the mobile terminal can be The outer casing acts as an antenna mount. In this application example, the antenna holder may not be provided, and the antenna pattern of the antenna may be directly disposed on the circuit board of the mobile terminal.

1. The antenna works in mode 1:

The connection switch 11 is responsible for communicating the feed point on the circuit board, so it is always closed. When the second connection switch 12 is disconnected, it can be seen from FIG. 5 that the antenna structure is equivalent to a normal monopole antenna, and a suspension metal like a director is added next to it. After simulation analysis and actual experiment, it is found that The suspended metal has substantially no effect on the antenna of the monopole form, but the resonance frequency of the monopole antenna is low, that is, the dummy metal can well serve to miniaturize the antenna and reduce Antenna size. According to the antenna theory, the resonant frequency of the monopole antenna is the frequency corresponding to the quarter-wavelength of the electrical length, which is also an important reason why the monopole antenna is widely used in the terminal field, and is easy to debug; The metal piece can serve the purpose of miniaturizing the antenna, so its actual physical size will be shorter than the electrical length. The antenna operates at a frequency of around 1575 MHz and can be used as a GPS antenna.

2. When the antenna works in mode 2:

When the second connection switch 12 is changed from off to closed, the antenna pattern is equivalent to the monopole plus parasitic mode. From the antenna theory, the coupling feed is one of the commonly used methods for improving the efficiency and bandwidth of the device. With this coupling feed, the coupling branches 14 in the antenna pattern can radiate outwardly, creating resonance at another different frequency. The antenna operates at a frequency of around 2.4 GHz and can be used as a WIFI or BT antenna.

In the antenna of the application example, the straight connecting branch 13 has a length of 35 mm and a width of 1.5 mm, the coupling branch 14 has a length of 28 mm and a width of 1.5 mm; the antenna bracket has a height of 6 mm, and the antenna size has been the antenna bracket. Highly counted. The board size is 100mm long and 50mm wide.

Experiments were carried out in the laboratory using passive jigs. In modes 1 and 2, the antenna efficiency is above 40% in the required frequency band and can be used normally.

The above description is only a specific preferred example of the experiment, and all the equivalent changes made within the scope of the claims of the present patent are covered by the patent claims.

The technical means and functions of the present invention for achieving the intended purpose can be more deeply and specifically understood by the description of the specific embodiments. However, the accompanying drawings are only for the purpose of illustration and description, and are not intended to limit.

Industrial applicability

The terminal device and the frequency reconfigurable built-in antenna of the embodiment of the present invention use the same physical size antenna, that is, do not change the physical size of the antenna, and control whether the antenna coupling portion is electrically connected by controlling the on/off of the electronic switch. Thus, the entire antenna resonates at different frequencies, which can meet the requirements of switching between a plurality of different frequencies. This method has obvious effects on antenna frequency reconstruction, and has a simple structure, which greatly saves the layout space of the antenna.

Claims

A frequency reconfigurable built-in antenna is located in a terminal device, the antenna comprising: an electronic switch, and a direct connecting branch and a coupling branch that do not contact each other;

The directly connected branch node is disposed to be connected to an antenna feeding point of the terminal device circuit board;

The electronic switch is configured to connect the coupling branch to a ground point of the terminal device circuit board to control the electronic switch to be turned on and off to operate the antenna in different frequency bands.
The frequency reconfigurable built-in antenna according to claim 1, further comprising: an antenna bracket;

The straight branches and the coupling branches are disposed on the antenna bracket.
The frequency reconfigurable built-in antenna according to claim 1, wherein said controlling said electronic switches to be turned on and off to operate said antennas in different frequency bands comprises:

When the control electronic switch is turned off, the antenna operates in a frequency band corresponding to the operating mode of the monopole antenna; when the control electronic switch is turned on, the antenna operates in a frequency band corresponding to the monopole antenna plus the parasitic operating mode.
The frequency reconfigurable built-in antenna according to claim 3, wherein the antenna operates in a frequency band corresponding to an operation mode of the monopole antenna, including:

The directly connected branches operate in a monopole antenna manner, and the coupling branches act as a suspended metal to affect the resonant frequency of the directly connected branches.
The frequency reconfigurable built-in antenna according to claim 1, wherein the electronic switch is configured to connect the coupling branch to a ground point of a terminal device circuit board by controlling conduction and disconnection of the electronic switch The antennas are operated in different frequency bands, including:

Connecting different points of the coupling branch to the grounding point of the circuit board of the terminal device through an electronic switch, respectively, forming different combinations of conduction and disconnection by controlling each electronic switch, so that the antenna is in different frequency bands jobs.
The frequency reconfigurable built-in antenna according to claim 1, wherein when the coupling branch is two or more, the coupling branch is connected to a ground point of the terminal device circuit board by an electronic switch, Controlling the turning on and off of the electronic switch to cause the antenna to be in different frequency bands Work, including:

Each of the coupling branches is connected to the grounding point of the terminal device circuit board through a corresponding electronic switch, and different combinations of conduction and disconnection are formed by controlling the electronic switches to operate the antennas in different frequency bands.
The frequency reconfigurable built-in antenna according to claim 1, wherein the straight branches and coupling branches are made of a flexible circuit board material, a laser direct formed LDS material, or a steel sheet.
The frequency reconfigurable built-in antenna according to claim 1, wherein the straight branching section and the coupling branch section are a planar structure or a three-dimensional structure.
The frequency reconfigurable built-in antenna according to claim 2, wherein the antenna holder has a dielectric constant ranging from 4.3 to 4.5.
A terminal device comprising: the frequency reconfigurable built-in antenna according to any one of claims 1 to 9.