Ultra-wideband dual-polarized all-metal array antenna based on heterogeneous conical units

Abstract

The application discloses a kind of ultra-wideband dual-polarized full-metal array antennas based on isomerism conical unit, antenna array arrangement mode is square grid form, to reduce the influence of edge truncation effect on array, array edge unit and middle unit adopt two structures;Edge unit is basic conical metal Vivaldi antenna;Middle unit is cut in four corners on basic type unit to optimize impedance matching, meanwhile, add orthogonal metal partition in bottom to improve port isolation;Electromagnetic energy is radiated outward at the exponential gradient groove formed by adjacent unit;Antenna array structure includes bottom plate, two kinds of radiating units, commercial standard radio frequency connector.The antenna array of the application has active S parameters below-10dB at each port in the design frequency band, meeting the electrical performance requirements of wideband dual-polarization.The antenna as a whole is made of metal, has high mechanical strength, is convenient to repair and replace, and has wide bandwidth.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of antennas, and particularly relates to a super-wideband dual-polarized full-metal array antenna based on heterogeneous conical units. BACKGROUND

[0002] A Vivaldi antenna is an exponential tapered slot line traveling wave antenna proposed in 1979. The Vivaldi antenna satisfies the similarity principle and the scaling transformation principle, the starting width and the opening width of the slot line correspond to different resonant frequencies, and a very wide impedance bandwidth can be achieved by adjusting the distance between the starting end and the opening end.

[0003] A common dielectric substrate type Vivaldi antenna uses printed circuit technology for the feed structure, which has low mechanical strength and cannot adapt to work in some special environments. The full-metal type Vivaldi antenna has good structural stability and can be directly fed by a coaxial radio frequency connector, and the structure is firm and simple. However, the conventional thin sheet Vivaldi antenna has a complex structure and is difficult to assemble when forming a dual-polarized array. The conical Vivaldi antenna, which is improved from the thin sheet Vivaldi antenna, combines two originally orthogonal sheet units into one conical unit, greatly simplifying the overall structure of the array antenna and reducing the assembly difficulty.

[0004] When the antenna units are arrayed, the performance of the edge units will be greatly deteriorated compared with the infinite array units due to the edge truncation effect, especially in the case of a small array size. The common methods to deal with the edge truncation effect of the finite array antenna are: (1) loading dummy elements at the edges of the array; (2) loading metal plates at the edges of the units; (3) extending the metal arms outside the edge units and loading corrugated structures. However, these methods will increase the size of the array to some extent, for example, in a 5*5 array, only 36% of the units participate in radiation when a circle of dummy elements is loaded at the edges of the array. This causes a great waste of resources when the installation space of the array is limited. SUMMARY

[0005] The application aims to provide a super-wideband dual-polarized full-metal array antenna based on heterogeneous conical units. The edge units of the array are also radiation units, which can maximize the use of the available aperture size while reducing the influence of the edge truncation effect. In addition, the array structure is simple and has high mechanical strength.

[0006] To achieve the above purpose, the application adopts the following technical scheme: a super-wideband dual-polarized full-metal array antenna based on heterogeneous conical units, comprising edge units, middle units, an antenna array bottom plate and a radio frequency connector; the unit spacing is 0.5λ0, and λ0 is the center working wavelength; the middle units and the edge units in the array adopt different structures, and the edge units are radiation units.

[0007] Further, the main body part of the edge unit is obtained by taper structure and bottom cylindrical cutting; bottom cutting leaves a rectangular column and four arc surface metal columns, and a threaded hole is left in the middle of the rectangular column; the middle of the unit bottom plate has two small through holes and a large through hole, the small through holes are used for embedding radio frequency connector medium and probe, and the large through hole is used for fastening the main body part and the bottom plate through screws.

[0008] Further, the generatrix of the taper structure of the edge unit is an exponential gradient curve, taking the center of the intersection of the taper and the cylinder as the origin, the horizontal direction as the x-axis, and the vertical direction as the z-axis to establish a coordinate system, and the exponential curve is written as x=C1*exp(Ra*(z))+C2; wherein C1=(x2-x1) / (exp(Ra*z2)-1), C2=(x1*exp(Ra*z2)-x2) / (exp(Ra*z2)-1), (x1, 0) and (x2, z2) are the initial and ending coordinate points of the exponential gradient curve; x1 is 0.25λ0, x2 is between 0.01λ0 and 0.02λ0, and z2 is between 1.2λ0 and 1.3λ0; Ra is the curvature change coefficient of the exponential gradient curve, and is between 0.01 and 0.05.

[0009] Further, the height of the bottom cylindrical structure of the edge unit is between 0.16λ0 and 0.2λ0, and the radius is equal to x1; the bottom cutting of the cylinder leaves four arc surface metal columns and a middle rectangular column, and the arc surface metal columns and the rectangular column form a resonant cavity; the chord of the arc surface metal column is 0.19λ0 away from the center, and the width is equal to that of the rectangular column; the length and width of the rectangular column are both 0.12λ0, and the height is between 0.18λ0 and 0.22λ0.

[0010] Further, the middle unit is composed of a taper main body structure, a metal partition plate and a unit bottom plate; the taper main body structure is cut at four corners based on the whole edge unit, so that it is a cross structure when viewed from above; the thickness of each arm of the cross structure is between 0.14λ0 and 0.18λ0, and the cross intersection part is rounded; the bottom cutting leaves four arc surface columns, the specifications of which are consistent with those of the edge unit, and the arc surface columns and the metal partition plate form a resonant cavity, the height of which is between 0.16λ0 and 0.20λ0; an orthogonal metal partition plate embedding groove with a width consistent with the specifications of the orthogonal metal partition plate and a depth of 1.5 mm is cut between the four arc surface columns after bottom cutting.

[0011] Further, the metal partition plate is composed of two metal plates combined in an "X" shape perpendicular to the XOY plane, the thickness of the metal plate is between 1 and 1.5 mm, and the height is 6 mm; a through hole is left after the center of the "X" is cut at an angle, which is used for fixing the taper main body structure, the metal partition plate and the bottom plate.

[0012] Furthermore, for the edge and middle elements, two adjacent elements are selected from the four arc-shaped pillars of each antenna element, and part of their height is cut off to form a horizontal gap between them and the metal base plate. The height of the horizontal gap is between 0.016λ0 and 0.024λ0.

[0013] Furthermore, the RF connector is a coaxial RF connector, with its coaxial dielectric portion and probe embedded in a metal base plate. The power supply probe passes through the base plate and contacts the bottom surface of the arc-shaped column with a horizontal slit cut out.

[0014] Compared with the prior art, the significant advantages of the present invention are:

[0015] This invention is entirely made of metal, which has high mechanical strength. Moreover, each component does not need to be welded together. Instead, the components are connected together with screws, which facilitates the maintenance and care of the antenna array. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the structure of the ultra-wideband dual-polarized all-metal array antenna based on heterogeneous conical units proposed in this invention.

[0017] Figure 2 This is an exploded view of the edge unit structure proposed in this invention.

[0018] Figure 3 This is a diagram showing the combination of two edge units proposed in this invention.

[0019] Figure 4 This is an exploded view of the intermediate unit structure proposed in this invention.

[0020] Figure 5 This is a structural diagram of the orthogonal metal isolation plate of the intermediate unit proposed in this invention.

[0021] Figure 6 This is a structural diagram of the antenna array base plate proposed in this invention.

[0022] Figure 7 The present invention provides a polarization active S-parameter curve of the array.

[0023] Figure 8 This invention proposes a homopolarized port isolation degree for the array center port.

[0024] Figure 9 This invention proposes a heteropolarized port isolation degree for the array center port.

[0025] Figure 10 The present invention proposes a 6GHz XOZ and YOZ plane radiation pattern for the array.

[0026] Figure 11 The present invention proposes XOZ and YOZ plane radiation patterns for the array at 12 GHz.

[0027] Figure 12 The present invention proposes an XOZ and YOZ plane radiation pattern for the array at 18 GHz.

[0028] Figure 13 The present invention provides a graph showing the maximum gain of the array as a function of frequency. Detailed Implementation

[0029] Combination Figures 1-6 This invention proposes an ultra-wideband dual-polarized all-metal array antenna based on heterogeneous conical elements, comprising: two types of metal conical antenna elements, one at the edge and one in the middle, a metal base plate, and a coaxial RF connector for feeding.

[0030] The middle m*n units are arranged at a spacing of 0.5λ0 and mounted on a metal base plate, with the edge units completely surrounding the middle units. The final array size is (m+2)*(n+2). m and n are the number of middle units in the two directions of the array arrangement. If they are equal, it is a square array; if they are not equal, it is a rectangular array.

[0031] The edge unit also participates in radiation rather than acting as a dummy element. While reducing the edge truncation effect, it also has good radiation performance.

[0032] Both types of antenna elements have conical structures obtained by rotating an exponentially gradient curve. A coordinate system is established with the center of the intersection of the cone and cylinder as the origin, the horizontal axis as the x-axis, and the vertical axis as the z-axis. The exponential curve is written as x = C1 * exp(Ra * (z)) + C2. Where C1 = (x2 - x1) / (exp(Ra * z2) - 1), C2 = (x1 * exp(Ra * z2) - x2) / (exp(Ra * z2) - 1), and the points (x1, 0) and (x2, z2) are the initial and final coordinates of the exponentially gradient curve. x1 takes the value 0.25λ0, x2 takes the value between 0.01λ0 and 0.02λ0, and z2 takes the value between 1.2λ0 and 1.3λ0. Ra is the curvature coefficient of the exponentially gradient curve, taking the value between 0.01 and 0.05.

[0033] The resonant cavity is cut out of the bottom cylinder of the edge unit conical body. After cutting, the cylindrical structure leaves four arc-shaped metal pillars and a central rectangular pillar. The rectangular pillar has screw holes in the middle for fixing the unit conical body to the base plate.

[0034] The intermediate unit comprises a metal conical and cylindrical main body, orthogonal metal partitions, and a base plate. The main body is cut at its four corners to optimize impedance matching, and the bottom cylindrical section is cut to leave four curved metal pillars. The orthogonal metal partitions and the curved metal pillars form four resonant cavities. The top of each resonant cavity has an embedded groove in the partition, with a threaded hole at the center of the groove. The threaded hole, the central through hole in the metal partition, and the countersunk hole in the base plate are coaxial, and all components are fastened with screws.

[0035] The array is powered by a commercial coaxial RF connector. The dielectric and probe portions of the coaxial RF connector are embedded in a metal base plate, and the probe penetrates to contact the bottom surface of the arc-shaped column with a horizontal slit cut out. The flange through-hole of the connector is coaxial with the screw holes of the base plate and is fixed with screws.

[0036] The aforementioned array antenna and antenna elements can be cut and processed from metal materials such as brass and aluminum alloy, and then plated with gold or subjected to conductive oxidation.

[0037] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0038] Example

[0039] like Figure 1 As shown, the ultra-wideband dual-polarized all-metal array antenna based on heterogeneous conical elements includes: edge element 1, middle element 2, antenna array base plate 3, and RF connector 4.

[0040] The array design in this embodiment operates in the frequency band of 6GHz to 18GHz, with an intermediate frequency of 12GHz, corresponding to λ0 = 25mm. The intermediate elements are arranged in square grids with a spacing of 0.5λ0 on the antenna base plate, with λ0 being the center operating wavelength. The intermediate elements are 3*3 in size, and the edge elements surround and arrange the intermediate elements, ultimately forming a 5*5 array.

[0041] The middle and edge units of the array adopt different structures to reduce the impact of the truncation effect on the performance degradation of small arrays; at the same time, the edge units are still radiating units, rather than dummy units that do not radiate energy.

[0042] like Figure 2 As shown, the main body 5 of the edge unit is formed by a tapered structure and a bottom cylindrical cut. The bottom cut leaves a rectangular post 6 and four curved metal posts 7, with threaded holes in the middle of the rectangular post. The unit base plate 8 has two small through holes 10 and one large through hole 9 in the middle. The small through holes are used to embed the RF connector medium 12 and probe 13, and the large through hole is used to fasten the main body to the base plate with screws. The RF connector adopts an SMP-J type connector.

[0043] like Figure 3The diagram shows a front view of a double-edge element. The conical curve 14 of the edge element is an exponential gradient curve. A coordinate system is established with the center of the intersection of the cone and cylinder as the origin, the horizontal axis as the x-axis, and the vertical axis as the z-axis. The exponential curve is defined as x = C1 * exp(Ra * (z)) + C2. Where C1 = (x2 - x1) / (exp(Ra * z2) - 1), and C2 = (x1 * exp(Ra * z2) - x2) / (exp(Ra * z2) - 1), with points (x1, 0) and (x2, z2) being the initial and final coordinates of the exponential gradient curve. x1 is 6 mm, x2 is between 0.25 and 0.5 mm, and z2 is between 30 and 32 mm. Ra is the curvature coefficient of the exponential gradient curve, ranging from 0.01 to 0.05. The cylinder height is 4.5 mm, and its radius is equal to x1. The resonant cavity 15 is obtained by cutting the bottom of the main body. The resonant cavity has a height of 5.5 mm and a length between 3.3 and 3.4 mm. A portion of each of the two curved metal plates is removed to leave a horizontal gap 16, which is between 0.4 and 0.6 mm. The unit spacing W between the two units is 12.5 mm.

[0044] like Figure 4 The diagram shown is an exploded view of the middle unit. The main structure 17 is an improvement on the edge unit, with optimized impedance matching achieved by removing the four corners to create a cross shape when viewed from above, and rounded corners at the intersections. Based on the edge unit, the cylinder height is changed to 5mm, and the resonant cavity height to 4.5mm. The central rectangular column is replaced with an orthogonal metal isolation plate 20. A 1.5mm deep metal groove 21 is pre-drilled at the bottom of the main body to facilitate the embedding of the metal isolation plate. The threaded holes at the bottom of the main body, the unit base plate, and the RF connector are consistent with the specifications of the edge unit.

[0045] like Figure 5 The diagram shows the structure of an orthogonal metal partition plate. After the corners of the partition plates are chamfered, a through hole 24 is drilled in the center. The two partition plates 23 are 6mm high, 1.5mm thick, and 10mm long.

[0046] like Figure 6 The diagram shows the base plate structure of the ultra-wideband dual-polarized all-metal Vivaldi miniature array antenna. Mounting holes are provided at the four corners and sides of the base plate for array fixation. The base plate and radiating section are secured with standard M2 screws, and the base plate and RF connector are secured with two standard M1.2 screws.

[0047] like Figure 7 As shown, this is the active S-parameter of one polarization port of an ultra-wideband dual-polarized all-metal array antenna based on heterogeneous conical elements. Each port has an active S-parameter of less than -10dB in the frequency band of 6GHz to 18GHz. Since the two polarization ports are symmetrical, the active S-parameter of the other polarization is consistent with it.

[0048] likeFigure 8 , Figure 9 The figures show the port isolation between the center 11 ports of the array and the same-polarization and different-polarization ports, respectively. At low frequencies, the isolation between adjacent ports is generally below -10dB, and at mid-to-high frequencies, it is generally below -15dB.

[0049] like Figures 10-12 The diagram shows the XOZ and YOZ radiation patterns of the array at different frequencies. The radiation patterns demonstrate that the array exhibits good directivity within the 6–18 GHz range.

[0050] like Figure 13 As shown, this is the maximum gain of the array across the entire frequency band, and it can be seen that the array gain increases with increasing frequency.

[0051] The above description is only a preferred example of the present invention and is not intended to limit the present invention. Any modifications or substitutions made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

[0052] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

Claims

1. An ultra-wideband dual-polarized all-metal array antenna based on heterogeneous conical elements, characterized in that, It includes edge unit (1), middle unit (2), antenna array base plate (3) and radio frequency connector (4); the unit spacing is 0.5λ0, where λ0 is the center working wavelength; the array middle unit (2) and edge unit (1) adopt different structures, and the edge unit (1) is a radiating unit; the main body (5) of the edge unit (1) is obtained by a conical structure and bottom cylindrical cutting; The bottom is cut to leave a rectangular column (6) and four curved metal columns (7), with threaded holes in the middle of the rectangular column; the middle unit (2) is composed of a conical main structure (17), a metal partition (20) and a unit base plate; the conical main structure (17) is cut at the four corners on the basis of the edge unit as a whole, so that it is a cross structure when viewed from above; the thickness of each arm of the cross structure is between 0.14λ0 and 0.18λ0, and the corners of the cross intersection are rounded; Four arc-shaped columns are left after the bottom is cut. The specifications of the arc-shaped columns are the same as those of the edge units. The arc-shaped columns and the metal partition (20) form a resonant cavity with a height of 0.16λ0~0.20λ0. An orthogonal metal partition groove with a width consistent with the specifications of the orthogonal metal partition is cut between the four arc-shaped columns after the bottom is cut.

2. The ultra-wideband dual-polarized all-metal array antenna based on heterogeneous conical elements according to claim 1, characterized in that, The unit base plate (8) has two small through holes (10) and one large through hole (9) in the middle. The small through holes (10) are used to embed the radio frequency connector medium (12) and probe (13), and the large through hole (9) is used to fasten the main body (5) to the base plate with screws.

3. The ultra-wideband dual-polarized all-metal array antenna based on heterogeneous conical elements according to claim 2, characterized in that, The generatrix of the conical structure of the edge unit (1) is an exponential gradient curve. A coordinate system is established with the center of the intersection of the cone and the cylinder as the origin, the horizontal axis as the x-axis, and the vertical axis as the z-axis. The exponential curve is written as x=C1*exp(Ra*(z))+C2; where C1=(x2-x1) / (exp(Ra*z2)-1), C2=(x1*exp(Ra*z2)-x2) / (exp(Ra*z2)-1), (x1,0) and (x2,z2) are the initial and final coordinate points of the exponential gradient curve; x1 takes the value of 0.25λ0, x2 takes the value between 0.01λ0 and 0.02λ0, and z2 takes the value between 1.2λ0 and 1.3λ0; Ra is the curvature change coefficient of the exponential gradient curve, which takes the value between 0.01 and 0.

05.

4. The ultra-wideband dual-polarized all-metal array antenna based on heterogeneous conical elements according to claim 3, characterized in that, The bottom cylindrical structure of the edge unit (1) has a height of 0.16λ0~0.2λ0 and a radius equal to x1. The bottom of the cylinder is cut to leave four arc-shaped metal pillars (7) and a middle rectangular pillar (6). The arc-shaped metal pillars (7) and the rectangular pillars (6) form a resonant cavity. The distance between the secant line of the arc-shaped metal pillar (7) and the center of the circle is 0.19λ0, and the width is the same as that of the rectangular pillar. The length and width of the rectangular pillar are both 0.12λ0, and the height is between 0.18λ0 and 0.22λ0.

5. The ultra-wideband dual-polarized all-metal array antenna based on heterogeneous conical elements according to claim 1, characterized in that, The depth of the groove embedded in the orthogonal metal partition is 1.5mm.

6. The ultra-wideband dual-polarized all-metal array antenna based on heterogeneous conical elements according to claim 1, characterized in that, The metal partition (20) is composed of two metal plates arranged in an "X" shape perpendicular to the XOY plane. After the center of the "X" is cut, a through hole is left for fixing the conical main structure, the metal partition, and the base plate.

7. The ultra-wideband dual-polarized all-metal array antenna based on heterogeneous conical elements according to claim 6, characterized in that, The metal plate is 1-1.5mm thick and 6mm high.

8. The ultra-wideband dual-polarized all-metal array antenna based on heterogeneous conical elements according to claim 1, characterized in that, For edge and middle elements, select two adjacent elements from the four arc-shaped pillars of each antenna element, cut off part of the height to form a horizontal gap between them and the metal base plate. The height of the horizontal gap is between 0.016λ0 and 0.024λ0.

9. The ultra-wideband dual-polarized all-metal array antenna based on heterogeneous conical elements according to claim 1, characterized in that, The radio frequency connector (4) adopts a coaxial radio frequency connector. Its coaxial dielectric part and probe are embedded in the metal base plate. The power supply probe passes through the base plate and contacts the bottom surface of the arc-shaped column with a horizontal slit cut out.

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