阅读说明：本技术 偶极子天线和移动终端 (Dipole antenna and mobile terminal ) 是由 桂杰 刘震 蔡隽 张健 于 2021-10-11 设计创作，主要内容包括：本申请提供了一种偶极子天线和移动终端,该偶极子天线包括介质板以及印制于介质板表面的天线单元和导流单元,该天线单元包括微带巴伦,该导流单元连接于微带巴伦,以改变微带巴伦的电流分布,从而对传统偶极子天线的方向图进行修正,在实际应用中可以减少信号发射或接收产生的误差和干扰。(The dipole antenna comprises a dielectric plate, an antenna unit and a flow guide unit, wherein the antenna unit and the flow guide unit are printed on the surface of the dielectric plate, the antenna unit comprises a microstrip balun, and the flow guide unit is connected to the microstrip balun so as to change the current distribution of the microstrip balun, so that the directional diagram of the traditional dipole antenna is corrected, and errors and interferences generated by signal transmission or signal reception can be reduced in practical application.)

1. The dipole antenna is characterized by comprising a dielectric plate, an antenna unit and a flow guide unit, wherein the antenna unit and the flow guide unit are printed on the surface of the dielectric plate, the antenna unit comprises a microstrip balun, the flow guide unit is connected to the microstrip balun, and the flow guide unit is used for changing the current distribution of the microstrip balun.

2. The dipole antenna of claim 1 wherein said microstrip balun includes a first microstrip balun and a second microstrip balun connected, said current conducting element being connected to said second microstrip balun for altering a current distribution of said microstrip balun.

3. The dipole antenna of claim 2, wherein the current guiding element comprises two metal strips respectively disposed at two ends of the second microstrip balun in a length direction thereof for changing a current distribution of the microstrip balun.

4. A dipole antenna according to claim 3, wherein said metal strips are of copper.

5. A dipole antenna according to claim 3, wherein said metal strips have a width in the range of 0.5 mm to 1.5 mm.

6. A dipole antenna according to claim 3 wherein the sum of the length of said metal strip and the length of said second microstrip balun ranges over more than one-tenth of the operating wavelength and less than one-tenth of the operating wavelength.

7. The dipole antenna of claim 2, wherein the antenna element comprises a first trace printed on the back surface of the dielectric plate and a second trace printed on the front surface of the dielectric plate, the first trace comprises a first antenna arm and the microstrip balun, the first antenna arm is connected with the first microstrip balun, the second trace comprises a second antenna arm and a microstrip transmission line which are connected, and the first antenna arm and the second antenna arm are in mirror symmetry along the microstrip transmission line.

8. A dipole antenna according to claim 7 and wherein the sum of the lengths of said first and second antenna arms is equal to one-half the operating wavelength.

9. A dipole antenna according to claim 1, wherein said dielectric sheet comprises FR-4 sheet material.

10. A mobile terminal, characterized in that it comprises a dipole antenna according to any of claims 1 to 9.

Technical Field

The application relates to the technical field of communication, in particular to a dipole antenna and a mobile terminal.

Background

Dipole antennas (dipolatenna or doublt) are the earliest type of antenna used in radio communications, the simplest structure and the most widely used.

The two sides of a dielectric plate of a traditional dipole antenna are coated with copper to form two arms of the dipole antenna, a microstrip transmission line and a microstrip balun, and an excitation signal is fed from a feed point and is transmitted to the two arms of the dipole antenna through the microstrip balun and the microstrip balun transmission line. However, simulation shows that the conventional dipole antenna has a deformation in a single direction diagram in an operating frequency band of 1.1GHz to 1.63GHz, and in practical application, an error or interference of signal transmission or reception can be generated.

Disclosure of Invention

The application provides a dipole antenna and a mobile terminal, which can correct the deformation of a single directional diagram of a traditional dipole antenna and reduce the error or interference of signal transmission or reception.

The technical scheme provided by the application is as follows:

the application provides a dipole antenna, including the dielectric-slab and print in antenna element and the water conservancy diversion unit on dielectric-slab surface, antenna element includes microstrip balun, the water conservancy diversion unit connect in microstrip balun, the water conservancy diversion unit is used for changing microstrip balun's current distribution.

In the dipole antenna of the present application, the microstrip balun includes a first microstrip balun and a second microstrip balun connected to each other, and the current guiding unit is connected to the second microstrip balun so as to change a current distribution of the microstrip balun.

In the dipole antenna of the present application, the current guiding unit includes two metal strips, and the two metal strips are respectively disposed at two ends of the second microstrip balun in the length direction so as to change the current distribution of the microstrip balun.

In the dipole antenna of the present application, the material of the metal strip is copper.

In the dipole antenna of the present application, the width of the metal strip ranges from 0.5 mm to 1.5 mm.

In the dipole antenna of the present application, a sum of the length of the metal strip and the length of the second microstrip balun ranges from greater than one-tenth of an operating wavelength to less than one-tenth of the operating wavelength.

In the dipole antenna, the antenna unit comprises a first wire printed on the back of the dielectric plate and a second wire printed on the front of the dielectric plate, the first wire comprises a first antenna arm and a microstrip balun, the first antenna arm is connected with the first microstrip balun, the second wire comprises a second antenna arm and a microstrip transmission line which are connected, and the first antenna arm and the second antenna arm are in mirror symmetry along the microstrip transmission line.

In the dipole antenna of the present application, a sum of lengths of the first antenna arm and the second antenna arm is equal to one-half of an operating wavelength.

In the dipole antenna of the present application, the dielectric plate is made of an FR-4 plate material.

The application also provides a mobile terminal comprising the dipole antenna.

The beneficial effect of this application does: different from the prior art, the dipole antenna provided by the application comprises a dielectric plate, an antenna unit and a flow guide unit, wherein the antenna unit and the flow guide unit are printed on the surface of the dielectric plate, the antenna unit comprises a microstrip balun, and the flow guide unit is connected to the microstrip balun so as to change the current distribution of the microstrip balun, so that the directional diagram of the traditional dipole antenna is corrected, and errors and interferences generated by signal transmission or signal reception can be reduced in practical application.

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 front structural diagram of a conventional dipole antenna provided in an embodiment of the present application;

fig. 2 is a first simulated directional diagram of a conventional dipole antenna provided in an embodiment of the present application;

fig. 3 is a second simulated directional diagram of a conventional dipole antenna provided in an embodiment of the present application;

fig. 4 is a third simulated directional diagram of a conventional dipole antenna provided in an embodiment of the present application;

fig. 5 is a fourth simulated directional diagram of a conventional dipole antenna provided in an embodiment of the present application;

fig. 6 is a graph illustrating simulation curves of frequency-return loss of a conventional dipole antenna according to an embodiment of the present application;

fig. 7 is a schematic front view of a dipole antenna provided in an embodiment of the present application;

fig. 8 is a schematic current distribution diagram of a conventional dipole antenna provided in an embodiment of the present application;

fig. 9 is a schematic current distribution diagram of a dipole antenna provided in an embodiment of the present application;

fig. 10 is a graph illustrating frequency-return loss simulation curves of a dipole antenna provided in an embodiment of the present application;

fig. 11 is a first simulated directional diagram of a dipole antenna provided in an embodiment of the present application;

fig. 12 is a second simulated directional diagram of a dipole antenna provided in an embodiment of the present application;

fig. 13 is a third simulated directional diagram of a dipole antenna provided in an embodiment of the present application;

fig. 14 is a fourth simulated directional diagram of a dipole antenna provided in an embodiment of the present application;

fig. 15 is a schematic front view of another dipole antenna according to an embodiment of the present application.

Detailed Description

The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. It is to be understood that the embodiments described are only a few 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.

In the description of the present application, it is to be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," and the like are used in the orientations and positional relationships indicated in the drawings for convenience in describing the present application and for simplicity in description, and are not intended to indicate or imply that the referenced devices or elements must have a particular orientation, be constructed in a particular orientation, and be operated in a particular manner, and are not to be construed as limiting the present application. Furthermore, the terms "first", "second" and "first" 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, features defined as "first", "second", may explicitly or implicitly include one or more of the described features. In the description of the present application, "a plurality" means two or more unless specifically limited otherwise.

In the description of the present application, it is to be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "connected," and "connected" are to be construed broadly, e.g., as meaning either a fixed connection, a removable connection, or an integral connection; may be mechanically connected, may be electrically connected or may be in communication with each other; either directly or indirectly through intervening media, either internally or in any other relationship. The specific meaning of the above terms in the present application can be understood by those of ordinary skill in the art as appropriate.

In this application, unless expressly stated or limited otherwise, the first feature "on" or "under" the second feature may comprise direct contact of the first and second features, or may comprise contact of the first and second features not directly but through another feature in between. Also, the first feature being "on," "above" and "over" the second feature includes the first feature being directly on and obliquely above the second feature, or merely indicating that the first feature is at a higher level than the second feature. A first feature being "under," "below," and "beneath" a second feature includes the first feature being directly under and obliquely below the second feature, or simply meaning that the first feature is at a lesser elevation than the second feature.

The following disclosure provides many different embodiments or examples for implementing different features of the application. In order to simplify the disclosure of the present application, specific example components and arrangements are described below. Of course, they are merely examples and are not intended to limit the present application. Moreover, the present application may repeat reference numerals and/or letters in the various examples, such repetition is for the purpose of simplicity and clarity and does not in itself dictate a relationship between the various embodiments and/or configurations discussed. In addition, examples of various specific processes and materials are provided herein, but one of ordinary skill in the art may recognize applications of other processes and/or use of other materials.

It should be noted that the thicknesses and shapes in the drawings of the present application do not reflect actual proportions, but are merely intended to schematically illustrate the contents of the embodiments of the present application.

For ease of understanding, the conventional dipole antenna will be explained first:

referring to fig. 1, a dielectric plate 100 is used to coat copper on both sides of a conventional dipole antenna 1000 to form two arms of the dipole antenna, a microstrip transmission line 112 and a microstrip balun 122, wherein the antenna arm 111 and the microstrip transmission line 112 are integrally formed on the front side, and the antenna arm 121 and the microstrip balun 122 are integrally formed on the back side. Specifically, on the front side, the current flows from the feeding point 130 to the microstrip transmission line 112 and then to the antenna arm 111, and on the back side, the current flows from the antenna arm 121 to the microstrip balun 122, and the microstrip transmission line 112 and the microstrip balun 122 have the opposite current direction, and therefore, no electromagnetic wave is radiated, and on both antenna arms, the current direction is the same, and therefore, an electromagnetic wave is radiated. However, simulation shows that, for the conventional dipole antenna 1000, when the operating frequency band is 1.1GHz-1.63GHz, the FR-4 plate is used as the dielectric plate, the thickness is 1 mm, and the size is 50 mm × 120 mm, the simulated pattern of the dielectric plate is deformed. Specifically, ideally, the simulation diagram should be a three-dimensional ring structure in the operating frequency band of 1.1GHz to 1.63GHz, however, as shown in fig. 2 to 5, the directional diagram of the conventional dipole antenna has a convex portion a in the horizontal 240-degree direction, and in practical application, errors and interferences of signal transmission or reception may be generated. Fig. 2 to 5 are simulated directional diagrams corresponding to different view directions of a conventional dipole antenna.

In order to modify the directional diagram of the conventional dipole antenna, so as to reduce errors and interferences generated by signal transmission or signal reception in practical applications, embodiments of the present application provide a dipole antenna.

Referring to fig. 7, fig. 7 is a schematic structural diagram of a dipole antenna according to an embodiment of the present application. As shown in fig. 1, the dipole antenna 2000 includes a dielectric plate 200, and an antenna element 210 and a current guiding element 220 printed on a surface of the dielectric plate 200, where the antenna element 210 includes a microstrip balun 2112, the current guiding element 220 is connected to the microstrip balun 2112, and the current guiding element 220 is configured to change a current distribution of the microstrip balun 2112.

Specifically, by arranging the current guiding unit 220 to be connected to the microstrip balun 2112, the current transmission path can be extended, so as to change the current distribution of the microstrip balun 2112, thereby changing the radiation range of the dipole antenna 2000.

In this embodiment, the antenna unit 210 includes a first trace 211 printed on the back surface of the dielectric board 200, where the first trace 211 includes a first antenna arm 2111 and a microstrip balun 2112, the microstrip balun 2112 includes a first microstrip balun 2112-1 and a second microstrip balun 2112-2 connected together, the first microstrip balun 2112-1 is connected to the first antenna arm 2111, and the current guiding unit 220 is connected to the second microstrip balun 2112-2 to change the current distribution of the microstrip balun 2112.

In some embodiments, the current guiding unit 220 includes two metal strips respectively disposed at two ends of the second microstrip balun 2112-2 in the length direction to change the current distribution of the microstrip balun 2112.

It is easy to understand that besides the metal strip, the resistor, the capacitor and other elements can also conduct electricity, however, the resistor, the capacitor and other elements can cause antenna loss, reduce the radiation efficiency of the antenna, and the influence of pure metal on the antenna is minimal. The dipole antenna 2000 has a symmetrical structure, and the feeding currents on the transmission lines are symmetrically distributed, so that the current guiding unit 220 includes two metal strips symmetrically disposed at two ends of the second microstrip balun 2112-2 in the length direction, so as to ensure that the feeding currents of the transmission lines of the dipole antenna 2000 are symmetrically distributed.

In this embodiment, by adding a metal strip, the current distribution of the microstrip balun 2112 can be changed, an additional directional diagram is generated, and the original directional diagram can be corrected. Specifically, referring to fig. 8 and 9, it can be seen from fig. 8 that the current distribution on the microstrip balun of the conventional dipole antenna is not uniform, and is corrected by the metal strip, as shown in fig. 9, the current distribution on the microstrip balun 2112 is uniform.

In some embodiments, the metal strip is made of copper.

It is readily understood that copper is second only to silver in its conductive properties and is far less expensive than silver, and therefore copper is typically used in factories for processing.

In some embodiments, the width of the metal strip ranges from 0.5 mm to 1.5 mm, and the sum of the length of the metal strip and the length of the second microstrip balun 2112-2 ranges from greater than one-tenth of the operating wavelength to less than one-tenth of the operating wavelength.

In particular, the width of the metal strip mainly affects the port impedance, and the length of the metal strip mainly affects the resonant frequency of the antenna. The length, the width and the position of the metal strip are mainly determined through simulation and optimization, so that the metal strip cannot generate large influence on input impedance, and the dipole antenna can be matched in a specific working frequency.

It is easily understood that the position, size, etc. of the metal strip provided in the embodiments of the present application do not limit the present application, and the adjustment of the position and size of the metal strip according to the operating frequency of the dipole antenna and the shape and size of the microstrip balun falls within the protection scope of the present application.

In some embodiments, the dielectric sheet 200 comprises FR-4 sheet material.

The FR-4 board is a double-sided copper-clad PCB board formed by laminating epoxy resin and glass cloth, and the dielectric constant of the common FR-4 copper-clad board relative to air is 4.2-4.7. This dielectric constant varies with temperature, and can vary up to 20% at a maximum over a temperature range of 0-70 degrees. The change in dielectric constant results in a 10% change in line delay, with the delay increasing with higher temperatures. The dielectric constant also varies with the frequency of the signal, with higher frequencies having smaller dielectric constants, typically designed to be a classical value of 4.4.

In the present embodiment, the dielectric plate 200 has a thickness of one millimeter, a width of 50 millimeters, and a length of 120 millimeters.

In this embodiment, the dipole antenna 2000 further includes a second trace 212 printed on the front surface of the dielectric board 200, where the second trace 212 includes a second antenna arm 2121 and a microstrip transmission line 2122 connected to each other, and the first antenna arm 2111 and the second antenna arm 2121 are mirror-symmetric along the microstrip transmission line 2122.

Specifically, the central axes of the microstrip transmission line 2122 and the microstrip balun 2112 may coincide, and the first antenna arm 2111 and the second antenna arm 2121 are mirror-symmetric along the central axes of the microstrip transmission line 2122 and the microstrip balun 2112.

It is easy to understand that the antenna unit 210 is printed on the surface of the dielectric plate 200, and the dielectric plate 200 may affect the transmission of the electromagnetic wave, so the waveguide wavelength on the dielectric plate 200 is used as the operating wavelength of the antenna unit 210. First, the operating wavelength is determined according to the formula:wherein the content of the first and second substances,λ_gis the waveguide wavelength of the electromagnetic wave propagating on the dielectric plate 200, ω is the antenna width, and h is the dielectric plate 200 thickness. Epsilon_reIs the effective dielectric constant, ε, of the dielectric plate 200_rIs the dielectric constant, λ, of the dielectric plate 200₀Is the free space wavelength of an electromagnetic wave.

In this embodiment, the sum of the lengths of the first antenna arm 2111 and the second antenna arm 2121 is equal to one-half of the operating wavelength.

It is easily understood that when the operating frequency of the dipole antenna is high, the coaxial feeding is generally adopted in consideration of the existence of radiation loss and the like. However, the coaxial feeding causes the current distribution of the two antenna arms to be asymmetric, i.e. unbalanced feeding, which affects the input impedance thereof, and therefore, microstrip balun is used for impedance conversion.

Specifically, when coaxial feeding is used, the input impedance of the coaxial feeding is generally 50 ohms, and when the angle between the first antenna arm 2111 and the second antenna arm 2121 is 180 degrees, the output impedance of the dipole antenna 2000 is generally 73.2, so that impedance matching can be performed by using the microstrip balun 2112, which is equivalent to a quarter-wave impedance converter, and the input impedance of the feeding port can be changed by adjusting the size of the microstrip balun 2112. Moreover, the microstrip balun 2112 may also convert the unbalanced electromagnetic wave into a balanced electromagnetic wave, which is beneficial to energy transmission and dipole antenna radiation of the first antenna arm 2111 and the second antenna arm 2121.

It is easily understood that the angle between the first antenna arm 2111 and the second antenna arm 2121 may be different from 180 degrees, and as the angle between the first antenna arm 2111 and the second antenna arm 2121 decreases, the output impedance thereof also decreases, and at this time, the size of the microstrip balun may be adjusted for impedance matching.

In this embodiment, the angle between the first antenna arm 2111 and the second antenna arm 2121 is 180 degrees, and in this case, the size of the dipole antenna 2000 may be: width w of second antenna arm 2121₁And a width w of the first antenna arm 2111₅Each 3 mm, the length l of the second antenna arm 2121₁Has a length of 49 mm, and the length l of the first antenna arm 2111₆48 mm, length l of microstrip transmission line 212₂Is 23 mm, and has a width w₃1 mm, l of microstrip balun 2112₃The segment length is 11 mm, the width w₄Is 2 mm,. l₄The segment is 20 mm, the length l of the second microstrip balun 2112-2₅Is 8 mm, width w₂Is 2 mm.

Further, please refer to fig. 6 and fig. 10 to 14, wherein an ordinate S (1,1) of fig. 6 represents the return loss of the conventional dipole antenna 1000, an abscissa of fig. 6 represents the operating frequency of the conventional dipole antenna 1000, an ordinate S (1,1) of fig. 10 represents the return loss of the dipole antenna 2000, and an abscissa represents the operating frequency of the dipole antenna 2000. Fig. 6 and 10 represent the matching of the dipole antenna 2000 in the whole operating frequency band. If the return loss is small, the antenna is well matched, otherwise, the energy of the feed port is reflected back by the antenna, which causes performance degradation, and it can be seen that the matching of the dipole antenna 2000 is better in the working frequency band of 1.1GHz to 1.63 GHz. As can be seen from fig. 11 to 14, the entire artificial pattern of the dipole antenna 2000 is distributed in an omnidirectional manner, and the distortion in the horizontal 240-degree direction is corrected.

Specifically, the current distribution on the microstrip balun 2112 is changed by adding the flow guide unit 220, the traditional antenna design is not required to be changed, the antenna processing complexity is not increased, the integrated design is facilitated, and the microstrip balun is simple and practical.

In this embodiment, the dipole antenna 2000 may be an LDS antenna or an FPC antenna.

Among them, an FPC (flexible printed circuit) antenna is suitable for almost all small electronic products, can be a complicated antenna of ten or more frequency bands such as 4G, and has good performance and low cost. The LDS antenna technology is a Laser-Direct-structuring technology (Laser-Direct-structuring), which uses a computer to control the movement of Laser according to the trace of a conductive pattern, so as to project the Laser onto a molded three-dimensional plastic device, and activate a circuit pattern within a few seconds. For the design and production of the mobile phone antenna, the metal antenna pattern is directly formed on the formed plastic support by chemical plating by using a laser technology, so that the antenna can be directly laser on the mobile phone shell, the antenna has the advantages of being more stable, avoiding the interference of internal components, saving more design space and enabling the mobile phone to be thinner.

Specifically, the dipole antenna 2000 may be installed in a mobile terminal such as a mobile phone or a computer, and the overall size of the dipole antenna 2000, the distance of internal routing, and the like may be adjusted according to actual conditions.

Different from the prior art, the dipole antenna 2000 provided by the present application includes a dielectric plate 200, and an antenna unit 210 and a current guiding unit 220 printed on a surface of the dielectric plate 200, where the antenna unit 210 includes a microstrip balun 2112, and the current guiding unit 220 is connected to the microstrip balun 2112 to change a current distribution of the microstrip balun 2112, so as to modify a directional diagram of the conventional dipole antenna, and reduce errors and interferences generated by signal transmission or reception in practical applications.

The application also provides a mobile terminal which comprises the dipole antenna of the embodiment.

In addition to the above embodiments, other embodiments are also possible. All technical solutions formed by using equivalents or equivalent substitutions fall within the protection scope of the claims of the present application.

In summary, although the present application has been described with reference to the preferred embodiments, the above-described preferred embodiments are not intended to limit the present application, and those skilled in the art can make various changes and modifications without departing from the spirit and scope of the present application, so that the scope of the present application shall be determined by the appended claims.