阅读说明：本技术 一种辐射特性可调的低剖面天线 (Low-profile antenna with adjustable radiation characteristic ) 是由 吴玉婷 皇甫江涛 陈红胜 于 2020-12-30 设计创作，主要内容包括：本发明公开了一种辐射特性可调的低剖面天线。本发明包括辐射体金属层、周期机构、天线馈电机构和调节驱动机构；辐射体金属层、周期机构和调节驱动机构从上到下依次层叠布置,辐射体金属层和周期机构之间间隔布置,天线馈电机构布置在调节驱动机构的下方或者布置在辐射体金属层和周期机构之间,天线馈电机构与辐射体金属层相连,辐射体金属层通过天线馈电机构进行馈电。金属柱状体的高度由驱动机构单独或整体调整高度,改变金属辐射单元的谐振频率和工作的幅度相位。本发明通过调整金属柱状体的高度改变低剖面天线的工作频率和辐射方向图；机构简单且灵活性好,可以承载大功率的天线信号,可适用于5G基站等需要大功率、天线参数可调的天线设计。(The invention discloses a low-profile antenna with adjustable radiation characteristics. The antenna comprises a radiator metal layer, a periodic mechanism, an antenna feed mechanism and an adjusting drive mechanism; the antenna feeder mechanism is connected with the radiator metal layer, and the radiator metal layer is fed through the antenna feeder mechanism. The height of the metal columnar body is adjusted by the driving mechanism independently or integrally, and the resonant frequency and the working amplitude phase of the metal radiating unit are changed. The working frequency and the radiation pattern of the low-profile antenna are changed by adjusting the height of the metal columnar body; the mechanism is simple, the flexibility is good, the antenna signal with high power can be borne, and the antenna design method is suitable for antenna designs which need high power and adjustable antenna parameters, such as a 5G base station and the like.)

1. A low-profile antenna with adjustable radiation characteristics, comprising: the antenna comprises a radiator metal layer (1), a periodic mechanism (2), an antenna feed mechanism (3) and an adjusting drive mechanism (4); the antenna feeder is characterized in that a radiator metal layer (1), a periodic mechanism (2) and an adjusting driving mechanism (4) are sequentially arranged from top to bottom in a stacked mode, the radiator metal layer (1) and the periodic mechanism (2) are arranged at intervals, an antenna feeder mechanism (3) is arranged below the adjusting driving mechanism (4) or between the radiator metal layer (1) and the periodic mechanism (2), the antenna feeder mechanism (3) is connected with the radiator metal layer (1), and the radiator metal layer (1) is fed through the antenna feeder mechanism (3).

2. A low-profile antenna with adjustable radiation characteristics, as defined in claim 1, wherein: the radiator metal layer (1) comprises a metal radiation unit (5) or a metal radiation array (6) consisting of a plurality of metal radiation units (5); the metal radiation arrays (6) are arranged in a planar rectangular array mode; the metal radiation units (5) are connected with the antenna feed mechanism (3);

the periodic mechanism (2) comprises a metal flat plate (7) and at least one metal column array (22), the single metal column array (22) is mainly formed by a plurality of metal columns (8) which are distributed on the metal flat plate (7) in a planar rectangular array mode, the metal flat plate (7) at the lower end of each metal column (8) is provided with a through hole, so that the lower end of each metal column (8) penetrates through the through hole to be connected with the adjusting driving mechanism (4), and the height of each metal column (8) is adjusted through the adjusting driving mechanism (4); the metal columnar body (8) is arranged between the radiator metal layer (1) and the periodic mechanism (2); the number of the metal radiation units (5) is the same as that of the metal columnar arrays (22), the metal radiation units are in one-to-one correspondence with the upper positions and the lower positions of the metal columnar arrays (22), and the installation positions of the metal columnar arrays (22) are the same as the positions of the metal radiation units (5) or the arrangement positions of the metal radiation arrays (6), so that one metal radiation unit (5) is arranged right above each metal columnar array (22).

3. A low-profile antenna with adjustable radiation characteristics, as defined in claim 1, wherein: the antenna feed mechanism (3) comprises a dielectric substrate (9), a feed network (10) and an SMA joint (11); the feed network (10) comprises a metal power distribution network mechanism (12) and a coaxial line (13), the metal power distribution network mechanism (12) is positioned on the dielectric substrate (9), one end of the SMA joint (11) is connected with the metal power distribution network mechanism (12) and fixed on one side surface of the dielectric substrate (9), the other end of the SMA joint (11) is connected with a signal source, and the SMA joint (11) receives a signal source transmitting signal and converts the signal source transmitting signal into total power to be transmitted to the metal power distribution network mechanism (12);

when the antenna feed mechanism (3) is arranged below the adjusting drive mechanism (4), the metal power distribution network mechanism (12) is connected with one end of the coaxial line (13), and the other end of the coaxial line (13) passes through the periodic mechanism (2) and the adjusting drive mechanism (4) and then is connected with the radiator metal layer (1);

the antenna feed mechanism (3) is arranged between the radiator metal layer (1) and the periodic mechanism (2) or arranged on the same layer as the radiator metal layer (1), and the metal radiation units (5) in the radiator metal layer (1) are directly fixed on one side surface of the dielectric substrate (9) and connected with the metal power distribution network mechanism (12).

4. A low-profile antenna with adjustable radiation characteristics, as defined in claim 1, wherein: the adjusting and driving mechanism (4) comprises a plurality of control ends, each control end is connected with the lower end of one metal cylindrical body (8), the height of the metal cylindrical body (8) is adjusted through the up-and-down movement of the control ends, and the adjusting and driving mechanism (4) is a device with the height direction adjusting capacity.

5. A low-profile antenna with adjustable radiation characteristics, as defined in claim 2, wherein: the working frequency of the low-profile antenna is adjusted through the geometric dimensions of the metal cylindrical body (8) and the metal radiating unit (5), and the specific relation is as follows:

wherein: f. of_rThe operating frequency of the low-profile antenna; v. of₀Is in vacuumElectromagnetic wave propagation velocity, specifically 3 × 10⁸m/s; w is the width of the metal radiation unit (5); l is the length of the metal radiation unit (5); h is the height difference between the metal radiation unit (5) and the metal flat plate (7); epsilon_gndIs the first equivalent dielectric constant of the periodic structure (2); epsilon_reffThe second equivalent dielectric constant of an integral module formed by the metal radiation unit (5) and the periodic mechanism (7) and the metal radiation unit (5) and the periodic mechanism (7); w is the width of the metal column (8); l is the length of the metal column (8); h is the average height of all the metal columns (8); a. the₁Is a first multiplication coefficient; a. the₂Is a second multiplication coefficient; a. the₃Is a third multiplication coefficient; a. the₄Is a fourth multiplication coefficient; b is₁Is a first summation constant; b is₂As a second summation constant, a first multiplication coefficient A₁A second multiplication coefficient A₂The third multiplication coefficient A₃Fourth multiplication coefficient A₄First summation constant B₁And a second summation constant B₂Are all arranged by the distance between the adjacent metal cylindrical bodies (8), and the value of the distance between the metal cylindrical bodies is between 0.5w and 2 w.

6. A low-profile antenna with adjustable radiation characteristics, as defined in claim 2, wherein: the radiation pattern of the low-profile antenna is set by the height of the metal cylinder (8); the height of the metal columns (8) in each metal column array is the same or different, and the height of each metal column array (22) is the same or different.

7. A low-profile antenna with adjustable radiation characteristics, as defined in claim 3, wherein: the metal power distribution network mechanism (12) equally transmits the total power sent by the SMA joint (11) to each metal radiation unit (5).

Technical Field

The invention belongs to the technical field of electronics, relates to an adjustable low-profile antenna, and particularly relates to a low-profile antenna with continuously adjustable frequency and beam direction of a communication frequency band.

Background

With the development of wireless communication, the importance of low-profile antennas and reconfigurable antennas is more significant. Patch antennas are receiving increasing attention due to their low profile, low cost and design convenience. By adding an adjustable element to the patch antenna mechanism, an adjustable antenna can be realized, which has been developed due to its characteristic of being able to realize multiple functions on one antenna.

In addition to the design of the radiator mechanism, some designs for improving the performance of the antenna through the ground plane mechanism are also gradually developed, and many periodic mechanisms are used for designing the ground plane of the antenna to improve the performance of the antenna in the aspects of volume, gain, directivity, impedance matching and the like. The current major design methods for ground planes with periodic mechanisms mainly focus on adding periodic patch or slot mechanisms, such as frequency selective surfaces, photonic band gaps, and super-surfaces, on the antenna ground plane.

However, the design of these antenna ground planes is based on metal structures printed on a dielectric substrate, and it is difficult to change once they are formed. Therefore, it is desirable to design a low-profile antenna with adjustable radiation characteristics to meet the requirements of various operating conditions and scenes.

Disclosure of Invention

To address the problems and needs in the art, a low profile antenna with adjustable radiation characteristics is provided.

The technical scheme of the invention is as follows:

the antenna comprises a radiator metal layer, a periodic mechanism, an antenna feed mechanism and an adjusting drive mechanism; the antenna feeder mechanism is connected with the radiator metal layer, and the radiator metal layer is fed through the antenna feeder mechanism.

The radiator metal layer comprises a metal radiation unit or a metal radiation array consisting of a plurality of metal radiation units; the metal radiation arrays are arranged in a planar rectangular array mode; the metal radiating units are connected with the antenna feed mechanism;

the periodic mechanism comprises a metal flat plate and at least one metal column array, wherein the single metal column array is mainly formed by arranging a plurality of metal columns on the metal flat plate in a planar rectangular array mode, the metal flat plate at the lower end of each metal column is provided with a through hole, so that the lower end of each metal column penetrates through the through hole to be connected with the adjusting and driving mechanism, and the height of each metal column is adjusted through the adjusting and driving mechanism; the metal columnar body is arranged between the radiator metal layer and the periodic mechanism; the number of the metal radiation units is the same as that of the metal columnar arrays, the metal radiation units are in one-to-one correspondence with the upper positions and the lower positions, and the installation positions of the metal columnar arrays are the same as the positions of the metal radiation units or the arrangement positions of the metal radiation arrays, so that one metal radiation unit is arranged right above each metal columnar array.

The antenna feed mechanism comprises a dielectric substrate, a feed network and an SMA joint; the feed network comprises a metal power distribution network mechanism and a coaxial line, the metal power distribution network mechanism is positioned on the medium substrate, one end of the SMA joint is connected with the metal power distribution network mechanism and is fixed on one side surface of the medium substrate, the other end of the SMA joint is connected with the signal source, and the SMA joint receives the signal transmitted by the signal source and converts the signal transmitted by the signal source into total power to be transmitted to the metal power distribution network mechanism;

when the antenna feed mechanism is arranged below the adjusting driving mechanism, the metal power distribution network mechanism is connected with one end of the coaxial line, and the other end of the coaxial line passes through the periodic mechanism and the adjusting driving mechanism and then is connected with the metal layer of the radiator;

the antenna feed mechanism is arranged between the radiator metal layer and the period mechanism or on the same layer with the radiator metal layer, and the metal radiation unit in the radiator metal layer is directly fixed on one side surface of the dielectric substrate and connected with the metal power distribution network mechanism.

The adjusting and driving mechanism comprises a plurality of control ends, each control end is connected with the lower end of one metal column, the height of each metal column is adjusted through the up-and-down movement of the control end, and the adjusting and driving mechanism is a device with height direction adjusting capability.

The working frequency of the low-profile antenna is adjusted through the geometric dimensions of the metal cylindrical body and the metal radiating unit, and the specific relation is as follows:

wherein: f. of_rThe operating frequency of the low-profile antenna; v. of₀Is the propagation speed of electromagnetic wave in vacuum, specifically 3 × 10⁸m/s; w is the width of the metal radiation unit; l is the length of the metal radiation unit; h is the height difference between the metal radiation unit and the metal flat plate; epsilon_gndIs the first equivalent dielectric constant of the periodic mechanism; epsilon_reffThe second equivalent dielectric constant of the integral module formed by the metal radiation unit and the periodic mechanism and the metal radiation unit and the periodic mechanism; w is the width of the metal cylinder; l is the length of the metal column; h is the average height of all metal columns; a. the₁Is a first multiplication coefficient; a. the₂Is a second multiplication coefficient; a. the₃Is a third multiplication coefficient; a. the₄Is a fourth multiplication coefficient; b is₁Is a first summation constant; b is₂As a second summation constant, a first multiplication coefficient A₁A second multiplication coefficient A₂The third multiplication coefficient A₃Fourth multiplication coefficient A₄First summation constant B₁And the second solutionAnd constant B₂The metal columns are arranged by the distance between the adjacent metal columns, and the distance between the metal columns is 0.5w to 2 w.

The radiation pattern of the low-profile antenna is set through the height of the metal columnar body; the height of the metal columns in each metal column array is the same or different, and the height of each metal column array is the same or different.

The metal power distribution network mechanism equally transmits the total power sent by the SMA joint to each metal radiation unit.

The low-profile antenna comprises a radiator metal layer, a periodic mechanism, an antenna feed mechanism and an adjusting drive mechanism, and realizes the low-profile antenna with adjustable radiation characteristics. The invention utilizes the adjusting driving mechanism to adjust the height of the metal column on the periodic mechanism, changes the resonance state between the radiator metal layer and the periodic mechanism, further plays a role in changing the working frequency and the radiation characteristic of the antenna, and has good application prospect.

Compared with the prior art, the invention can obtain the following beneficial effects:

the invention adjusts the height of the metal column on the periodic mechanism by adjusting the driving mechanism, changes the resonance state between the radiator metal layer and the periodic mechanism, and further changes the working frequency and the radiation characteristic of the antenna. The antenna design mechanism is simple, has good adjustment flexibility, can bear high-power antenna signals, and is suitable for application scenes such as 5G base stations and the like which need high power and adjustable antenna parameters.

Drawings

FIG. 1 is an overall schematic view of the present invention;

FIG. 2 is a schematic view of the cycle mechanism of the present invention;

fig. 3 is a schematic connection diagram of the metal radiating element and the antenna feeding mechanism in fig. 1;

fig. 4 is another schematic connection diagram of the metal radiating element and the antenna feeding mechanism in the present invention;

FIG. 4(A) is a side feed;

FIG. 4(B) is bottom feed;

FIG. 5 is a diagram illustrating the trend of the effect of the height of the metal pillar on the operating frequency of the antenna;

FIG. 6 is a diagram showing the trend of the influence of the height of the metal pillar on the far-field radiation of the antenna (metal radiating element);

fig. 7 is a graph showing the trend of the influence of the height of the metal pillar on the far-field radiation of the antenna (metal radiation array).

In the figure: the antenna comprises a radiator metal layer 1, a periodic mechanism 2, an antenna feed mechanism 3, an adjusting drive mechanism 4, a metal radiation unit 5, a metal radiation array 6, a metal flat plate 7, a metal columnar body 8, a dielectric substrate 9, a feed network 10, an SMA joint 11, a metal power distribution network mechanism 12, a coaxial line 13, a first metal radiation unit 14, a second metal radiation unit 15, a third metal radiation unit 16, a fourth metal radiation unit 17, a first microstrip line 18, a second microstrip line 19, a third microstrip line 20, a fourth microstrip line 21, a metal column array 22, a first metal column array 23, a second metal column array 24, a third metal column array 25 and a fourth metal column array 26.

Detailed Description

In order to make the invention more comprehensible, preferred embodiments are described in detail below with reference to the accompanying drawings.

As shown in fig. 1 and 4, the present invention includes a radiator metal layer 1, a period mechanism 2, an antenna feed mechanism 3, and an adjustment drive mechanism 4; the antenna feeder mechanism 3 is connected with the radiator metal layer 1, and the radiator metal layer 1 feeds power through the antenna feeder mechanism 3. The low profile antenna has a height of 2.5cm or 2.1 cm.

The radiator metal layer 1 comprises a metal radiating unit 5 or a metal radiating array 6 consisting of a plurality of metal radiating units 5; each metal radiation unit 5 is the same, and the metal radiation arrays 6 are arranged in a planar rectangular array mode; the metal radiation units 5 are connected with the antenna feed mechanism 3; when the antenna feeding mechanism 3 is disposed below the adjusting driving mechanism 4, in a specific implementation, the foam board or FR4 dielectric board is provided with through slots having the same number as the metal radiating elements 5, the foam board or FR4 dielectric board is used to support the metal radiating elements 5, and the metal radiating elements 5 are installed in the through slots and connected to the coaxial lines 13 in the antenna feeding mechanism 3. The characteristic impedance of the coaxial line 13 is 50 ohms. As shown in fig. 2, the metal radiating elements 5 have a rectangular shape, the length and width of the metal radiating elements 5 are 51mm and 35mm, respectively, and the interval between adjacent metal radiating elements 5 is 51mm and 35mm in the length and width directions, respectively. The area of the metal radiating unit (5) and the area of the metal pillar array (22) are not particularly limited, and in specific implementation, the area of the metal radiating unit (5) is the same as the area of the metal pillar array (22).

The antenna feed mechanism 3 comprises a dielectric substrate 9, a feed network 10 and an SMA joint 11; the feed network 10 comprises a metal power distribution network mechanism 12 and a coaxial line 13, the metal power distribution network mechanism 12 is positioned on the dielectric substrate 9, one end of an SMA joint 11 is connected with the metal power distribution network mechanism 12 and fixed on one side surface of the dielectric substrate 9, the other end of the SMA joint 11 is connected with a signal source, the SMA joint 11 receives a signal transmitted by the signal source and converts the signal transmitted by the signal source into total power to be transmitted to the metal power distribution network mechanism 12;

the metal power distribution network mechanism 12 equally transmits the total power sent by the SMA joint 11 to each metal radiation unit 5. Typically, when four metal radiating elements 5 are arranged in a 2 × 2 arrangement, the metal power distribution network mechanism 12 divides the total power evenly into four equal powers and transmits each power to a corresponding one of the metal radiating elements 5.

When the antenna feed mechanism 3 is arranged below the adjusting drive mechanism 4, the metal power distribution network mechanism 12 is connected with one end of the coaxial line 13, the other end of the coaxial line 13 passes through the periodic mechanism 2 and the adjusting drive mechanism 4 and then is connected with the metal radiation unit 5 of the radiator metal layer 1, and the number of the coaxial lines 13 is the same as that of the metal radiation units 5; the antenna feed mode of the connection structure is bottom feed;

the antenna feed mechanism 3 is arranged between the radiator metal layer 1 and the periodic mechanism 2 or on the same layer as the radiator metal layer 1, and the metal radiation unit 5 in the radiator metal layer 1 is directly fixed on one side surface of the dielectric substrate 9 and connected with the metal power distribution network mechanism 12; the antenna feeding mode of the connecting structure is side feeding and bottom feeding.

As shown in fig. 3, the structure of the metal power distribution network mechanism 12 depends on the structure of the metal radiating array 6, and the metal radiating array 6 is a 2 × 2 array as an example. The metal radiation array 6 is composed of a first metal radiation unit 14, a second metal radiation unit 15, a third metal radiation unit 16 and a fourth metal radiation unit 17, wherein the metal power distribution network mechanism 12 is a four-in-one metal power distribution network mechanism 12 and is printed on a dielectric substrate 9 with the length, width and thickness of 174mm, 141mm and 1.5mm respectively, the dielectric substrate 9 is made of Rogers RO4003C, and the relative dielectric constant is 3.38 +/-0.05. The antenna emission signal is fed in by the SMA joint 11, the SMA joint 11 converts the signal source emission signal into the total power and transmits to the metal power distribution network mechanism 12, the total power is equally divided into four equal powers by the metal power distribution network mechanism 12 and then fed into the metal radiation array 6 through the coaxial line 13, and the resonance is generated between the metal radiation array 6 and the periodic mechanism 2 to form the radiation. The metal power distribution network mechanism 12 is composed of a first microstrip line 18, a second microstrip line 19, a third microstrip line 20 and a fourth microstrip line 21, the first microstrip line 18 and the second microstrip line 19 are arranged in parallel, two ends of the third microstrip line 20 are respectively connected with the middle parts of the first microstrip line 18 and the second microstrip line 19, one end of the fourth microstrip line 21 is connected with the middle part of the third microstrip line 20, the other end of the fourth microstrip line 21 is connected with the SMA connector 11, the first microstrip line 18, the second microstrip line 19 and the fourth microstrip line 21 are arranged in parallel on the same plane, two ends of the first microstrip line 18 and the second microstrip line 19 are connected with a metal radiation unit 5 through a coaxial line 13, and the coaxial line 13 penetrates through the periodic mechanism 2 and the adjustment driving mechanism 4. The first microstrip line 18 has a length of 74.15mm and a width of 2.89 mm. The second microstrip line 19 has a length of 74.15mm and a width of 2.89 mm. The third microstrip line 20 has a length of 72.05mm and a width of 7.79 mm. The length of the fourth microstrip line 21 is 27.33mm, and the width is 18.06 mm.

As shown in fig. 2, the length and width of the flat metal plate 7 are 174mm and 141mm, respectively, the thickness is 2mm, and the distance from the upper surface of the flat metal plate 7 to the lower surface of the radiator metal layer 1 is 8 mm. The metal column 8 is typically shaped as a rectangular parallelepiped or a cylinder, here, the rectangular parallelepiped is taken as an example, the length and the width of the metal column 8 are both 5mm, the height can be adjusted by the adjusting and driving mechanism 4, and the adjusting range is 0 to 7.5 mm. The adjusting and driving mechanism 4 comprises a plurality of control ends, each control end is connected with the lower end of one metal column body 8, the lower end of each metal column body 8 is connected with one control end, the height of each metal column body 8 is adjusted through the up-and-down movement of the control end, and the adjusting and driving mechanism 4 is a device with height direction adjusting capability. In a specific implementation, the adjusting and driving mechanism 4 is a device with height direction adjusting capability and a stepping motor or an electromagnet. The metal columnar bodies 8 form a 6 × 6 metal column array 22, which is uniformly distributed along the length and width directions, and the outer edge of the metal column array 22 coincides with the outer edge of the metal radiation unit 5. As shown in fig. 1, when the metal radiating array 6 is the above-mentioned 2 × 2 array, the first metal radiating element 14, the second metal radiating element 15, the third metal radiating element 16, and the fourth metal radiating element 17 correspond to the first metal pillar array 23, the second metal pillar array 24, the third metal pillar array 25, and the fourth metal pillar array 26, respectively. The dielectric substrate 9 is rectangular in shape. The preferred shape of the metal cylindrical body 8 is a cuboid or a cylinder; the flat metal plate 7 is rectangular in shape.

Fig. 5 shows a trend chart of the effect of the height of the metal cylinder on the operating frequency of the antenna. The low-profile antenna adopts the sequential arrangement of a radiator metal layer 1, a periodic mechanism 2, an adjusting and driving mechanism 4 and an antenna feed mechanism 3. The characteristic impedance of the coaxial line is 50 ohms, the height of the metal cylinder 8 is adjusted to be changed between 5 and 7.5mm, and it can be seen that the operating frequency of the low-profile antenna is changed from 3.35GHz to 2.2GHz along with the increase of the height of the metal cylinder 8. The working frequency of the low-profile antenna is adjusted by the geometric dimensions of the metal cylindrical body 8 and the metal radiating unit 5, and the specific relationship is as follows:

wherein: f. of_rIs the operating frequency of the antenna; v. of₀The propagation speed of electromagnetic wave in vacuum is 3 × 10⁸m/s; w is the width of the metal radiation unit 5 and is 35 mm; l is the length of the metal radiation unit 5 and is 51 mm; h is the height difference between the metal radiation unit 5 and the metal flat plate 7 and is 8 mm; epsilon_gndIs a first equivalent dielectric constant; epsilon_reffA second equivalent dielectric constant; w is the width of the metal column 8 and is 5 mm; l is the length of the metal column body 8 and is 5 mm; h is the average height of all the metal columns 8, and the adjustment range is 5-7.5 mm; a. the₁Is the first multiplication coefficient, which is 1.2 × 10 in this embodiment¹⁹；A₂Is a second multiplication coefficient, which is 5 × 10 in this embodiment^-9；A₃Is the third multiplication coefficient, which is 1.375 × 10 in this embodiment^-16；A₄Is a fourth multiplication coefficient, whose value is 2 × 10 in this embodiment⁷；B₁Is a first summation constant, which in this embodiment is 3.5 × 10^-10；B₂A second summation constant, in this example 27, a first multiplication factor A₁A second multiplication coefficient A₂The third multiplication coefficient A₃Fourth multiplication coefficient A₄First summation constant B₁And a second summation constant B₂Are all arranged by the distance between adjacent metal cylindrical bodies (8)The spacing value is between 0.5w and 2w, and the spacing of the metal columnar bodies along the length direction is 9.2mm, and the spacing of the metal columnar bodies along the width direction is 6 mm.

The radiation pattern of the low-profile antenna is set by the height of the metal cylinder 8; the height of the metal columns 8 in each metal column array is the same or different, and the height of each metal column array is the same or different. When the height of the metal cylinder 8 is changed, the null distribution and the beam angle in the radiation pattern are changed accordingly.

When the metal radiating element 5 and the metal pillar array 22 in the low-profile antenna are one, the heights of the metal pillars 8 at different positions in the metal pillar array 22 are respectively adjusted, and fig. 6 shows a trend chart of the influence of the heights of the metal pillars on the far-field radiation of the antenna (metal radiating element). In the metal column array 22, six metal columns distributed on the same straight line along the width direction of the metal radiating unit 5 are in a row, and a first row of metal columns, a second row of metal columns, a third row of metal columns, a fourth row of metal columns, a fifth row of metal columns and a sixth row of metal columns are respectively arranged inwards from a position close to any width direction edge of the metal radiating unit. In the metal column array 22, the metal columns are divided into inner layer metal columns, middle layer metal columns and outer layer metal columns according to the distance from the metal columns to the center of the metal column array 22, the inner layer metal columns include 4 metal columns closest to the center of the metal column array 22, the outer layer metal columns include 20 metal columns closest to the outer edge of the metal column array 22, and the remaining 12 metal columns are middle layer metal columns.

In fig. 6, the first height distribution is specifically: the heights of the metal cylindrical bodies 8 in the metal cylindrical array 22 are all 7.2 mm; the second height distribution is specifically: the height of the first row of metal columnar bodies is 7.5mm, the height of the second row of metal columnar bodies is 6.5mm, the height of the third row of metal columnar bodies is 5.5mm, the height of the fourth row of metal columnar bodies is 5.5mm, the height of the fifth row of metal columnar bodies is 6.5mm, and the height of the sixth row of metal columnar bodies is 7.5 mm; the third height distribution is specifically: the height of the inner layer metal column is 7.5mm, the height of the middle layer metal column is 6.5mm, and the height of the outer layer metal column is 5.5 mm. Fig. 6 shows that the far-field radiation of the antenna is affected by the height of the metal pillar, and the far-field radiation characteristic of the antenna is changed by adjusting the height of the metal pillar 8 by adjusting the driving mechanism 4.

When the number of the metal radiating elements 5 and the metal pillar arrays 22 in the low-profile antenna is four, fig. 7 shows the trend of the influence of the height of the metal pillar on the far-field radiation of the antenna. Fig. 7 shows that by setting the heights of the first metal pillar array 23, the second metal pillar array 24, the third metal pillar array 25, and the fourth metal pillar array 26, the beam angle radiated by the antenna can be adjusted, and the adjustment range can reach ± 25 ° at most.

In the above, the invention realizes a low-profile antenna with adjustable radiation characteristics. The radiation characteristic of the antenna can be adjusted by adjusting the height of the metal pillar.

Although the present invention has been described with reference to specific embodiments, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention.