An ultra-wideband dual-polarization array antenna unit

Abstract

The present invention relates to an ultra-wideband dual-polarization array antenna unit, and belongs to the field of radar antennas. The present invention proposes a metal vibrator antenna and its additional structure. The basic radiation structure of the vibrator antenna is composed of a metal base and a radiation arm, and two metal vibrator antennas with the same structure and size are orthogonally combined to form a dual-polarization radiation antenna structure. Two layers of dielectric plates are loaded directly above the antenna, the first layer of dielectric plates is the same size as the antenna unit plane grid, and two microstrip lines are etched on the top. The second layer of dielectric plates is located in the center of the first layer of dielectric plates, and the size is smaller than the first layer of dielectric plates. A cross-shaped microstrip strip is etched above the second layer of dielectric plates, and is connected to the bottom of the first layer of dielectric plates by means of a centrally loaded metallized via. The array unit antenna of the present invention can be used to construct an ultra-wideband dual-polarization array, and effectively achieve good matching and radiation stability within the ultra-wideband range of the array antenna.

Description

Technical Field

[0001] The invention belongs to the field of radar antennas. Background Art

[0002] At present, in the field of phased array radar, the receiving system usually adopts a dual-polarization working mode to ensure the high efficiency of the received signal. At the same time, due to the increasing requirements for lightweight and miniaturization of phased array systems, the active array form of tile-type integrated subarray structure is more eye-catching. Limited by the size of the equipment platform and the requirements of channel density, the spacing between antenna units cannot be very large, and the plane size is usually half a wavelength of the high frequency. It is very difficult to achieve ultra-wideband efficient matching of antennas in a compact space. Conventional means can usually achieve a standing wave ratio of less than 2 at 100% relative bandwidth in achieving dual-polarization ultra-wideband performance. However, the requirements for antenna matching efficiency in radar systems are increasing, so a more efficient matching method is needed to achieve a smaller standing wave ratio. At the same time, the coupling amount between two antennas with different polarizations in the dual-polarization working mode is also closely related to the working efficiency of the antenna. How to maintain high isolation while maintaining efficient matching has become a more important issue in this field.

[0003] The present invention mainly proposes an ultra-wideband dual-polarization unit antenna with high matching efficiency and high port isolation for an ultra-wideband dual-polarization array antenna. Summary of the invention

[0004] Aiming at the problem of improving unit matching efficiency and reducing coupling degree in a dual-polarized ultra-wideband array antenna, the present invention designs an ultra-wideband dual-polarized unit antenna.

[0005] The present invention is achieved through the following technical solutions:

[0006] An ultra-wideband dual-polarization array antenna unit, the antenna unit is a square grid stacked structure, which comprises, from bottom to top, a metal reflector 1, a horizontally polarized radio frequency connector (2-1), a vertically polarized radio frequency connector (2-2), a horizontally polarized metal vibrator (3-1) and a vertically polarized metal vibrator (3-2), a first dielectric plate (4), a horizontal microstrip line (5-1) and a vertical microstrip line (5-2), a second dielectric plate 6, and a cross-shaped microstrip strip 7; wherein the horizontal microstrip line (5-1) and the vertical microstrip line (5-2) are etched on the upper surface of the first dielectric plate 4, and the cross-shaped microstrip strip 7 is etched on the upper surface of the second dielectric plate 6.

[0007] Furthermore, the horizontally polarized metal vibrator 3-1 and the vertically polarized metal vibrator 3-2 are placed perpendicularly to each other on the upper layer of the metal reflector 1, and are fixedly mounted on the metal reflector 1 through the left metal base 3-3 and the right metal base 3-4. The horizontally polarized metal vibrator 3-1 and the vertically polarized metal vibrator 3-2 have the same appearance and size, and each individual metal vibrator includes a left metal base 3-3, a right metal base 3-4, a left curved metal strip 3-5, a right curved metal strip 3-6 and a middle curved metal strip 3-8.

[0008] Furthermore, the horizontally polarized metal vibrator 3-1 and the vertically polarized metal vibrator 3-2 include a feeding point 3-7 and a right curved metal strip 3-6, wherein the feeding point 3-7 is located at the lower half of the right curved metal strip 3-6.

[0009] Furthermore, the left metal base 3-3 and the left curved metal strip 3-5 constitute the left half structure of the metal vibrator, and the right metal base 3-4 and the right curved metal strip 3-6 constitute the right half structure of the metal vibrator. The left metal base 3-3 and the right metal base 3-4 have a fixed spacing, and the left curved metal strip 3-5 and the right curved metal strip 3-6 have a gradual spacing, forming a middle curved metal strip 3-8.

[0010] Furthermore, the first dielectric plate 4 and the second dielectric plate 6 are both made of Rogers 5880 or materials with the same electrical properties. The first dielectric plate 4 and the metal reflector 1 have the same plane size and a thickness of 1 mm; the second dielectric plate 6 is located at the center of the first reflector, and the side length of the structure is 1 / 5 of the high-frequency wavelength and the thickness is 1 / 10 of the high-frequency wavelength.

[0011] Furthermore, the microstrip line includes a horizontal microstrip line 5-1 and a vertical microstrip line 5-2, which are etched on the upper surface of the first dielectric plate 4 and are located directly above the horizontally polarized metal vibrator 3-1 and the vertically polarized metal vibrator 3-2, respectively.

[0012] Furthermore, two microstrip lines are cross-etched on the upper surface of the second dielectric plate 6 to form a cross-shaped microstrip structure; the cross-shaped microstrip strip 7 has the same dimensions as the second dielectric plate 6. The center of the cross-shaped microstrip strip 7 is connected to the lower surface of the first dielectric plate 4 through a metallized through-hole structure.

[0013] Compared with the prior art, the present invention has the following beneficial effects:

[0014] (1) The unit antenna and array of the present invention can achieve a relative bandwidth exceeding 100%, and the port standing wave ratio is less than 1.5 within the 100% relative bandwidth;

[0015] (2) The unit antenna and array of the present invention can reduce the coupling degree of adjacent antenna ports with different polarizations to below -30 dB within an ultra-wideband range.

[0016] (3) The final form of the antenna model of the present invention can reduce the slope height to less than 60% of the original one compared with the traditional ultra-wideband antenna. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a structural exploded diagram of the unit antenna of the present invention;

[0018] Figure 2 This is a schematic diagram of the metal vibrator structure of the unit antenna of the present invention;

[0019] Figure 3 A schematic diagram of a 4×4 array antenna constructed for the unit antenna of the present invention;

[0020] Figure 4 It is the voltage standing wave at the port under the periodic boundary of the unit antenna of the present invention;

[0021] Figure 5 is the coupling size between different polarization ports at the periodic boundary of the unit antenna of the present invention;

[0022] Figure 6 A curve of the radiation gain of a 4×4 array constructed for the unit antenna of the present invention.

[0023] Description of the accompanying drawings: 1, metal reflector; 2-1, horizontally polarized RF connector; 2-2, vertically polarized RF connector; 3-1, horizontally polarized metal vibrator; 3-2, vertically polarized metal vibrator; 3-3, left metal base; 3-4, right metal base; 3-5, left curved metal strip; 3-6, right curved metal strip; 3-7, feeding point; 3-8, middle curved metal strip; 4 first layer of dielectric board; 5-1, horizontal microstrip line; 5-2, vertical microstrip line; 6, second layer of dielectric board; 7, cross-shaped microstrip strip. DETAILED DESCRIPTION

[0024] The present invention is further described in detail below with reference to the accompanying drawings and specific implementation examples:

[0025] In the embodiment, the frequency band is set in the S-C frequency band, and the relative bandwidth is maintained above 100%.

[0026] Reference Figure 1 , Figure 2 and Figure 3, an ultra-wideband dual-polarization array antenna unit, characterized in that: the antenna unit is a square grid stacked structure, which is composed of a metal reflector (1), a horizontally polarized radio frequency connector (2-1), a vertically polarized radio frequency connector (2-2), a horizontally polarized metal vibrator (3-1) and a vertically polarized metal vibrator (3-2), a first dielectric plate (4), a horizontal microstrip line (5-1) and a vertical microstrip line (5-2), a second dielectric plate (6), and a cross-shaped microstrip strip (7); the horizontal microstrip line (5-1) and the vertical microstrip line (5-2) are etched on the upper surface of the first dielectric plate (4), and the cross-shaped microstrip strip (7) is etched on the upper surface of the second dielectric plate (6). The horizontally polarized metal vibrator (3-1) and the vertically polarized metal vibrator (3-2) are placed perpendicular to each other on the upper layer of the metal reflector (1), and are fixedly mounted on the metal reflector (1) through a left metal base (3-3) and a right metal base (3-4). The horizontal polarization metal vibrator (3-1) and the vertical polarization metal vibrator (3-2) have the same appearance and size, and each individual metal vibrator is composed of a left metal base (3-3), a right metal base (3-4), a left curved metal strip (3-5), a right curved metal strip (3-6) and a middle curved metal strip (3-8). The feeding point (3-7) is located at the lower half of the right metal strip (3-6).

[0027] The size of the metal reflector (1) is set to 27mm×27mm. The horizontally polarized metal vibrator (3-1) and the vertically polarized metal vibrator (3-2) have the same appearance and size. Each individual metal vibrator consists of a left metal base (3-3) and a right metal base (3-4), with a height of 12mm and a metal edge thickness of 2.8mm. The metal ring composed of the left curved metal strip (3-5), the right curved metal strip (3-6) and the middle curved metal strip (3-8) has a height of 21.4mm and a metal edge thickness of 2.8mm. The interval between the left half and the right half of the metal vibrator is 1mm. The first layer of dielectric plate (4) is 1mm thick, and the second layer of dielectric plate (6) is 5mm thick, both of which are made of Rogers 5880. The horizontal microstrip line (5-1) and the vertical microstrip line (5-2) are located directly above the horizontal polarization metal vibrator (3-1) and the vertical polarization metal vibrator (3-2), and have a size of 2.8 mm×10 mm. The cross-shaped microstrip strip (7) is located in the middle of the first dielectric plate (4), and is composed of two cross-shaped microstrip lines with a size of 2.8 mm×10 mm.

[0028] 1. Simulation conditions and contents

[0029] The unit antenna and array antenna in the implementation case are simulated using commercial simulation software. The unit antenna is set to periodic boundary conditions, and the simulation obtains the active standing waves of the unit in the infinite array and the polarization components of the far field in the maximum radiation direction.

[0030] 2. Analysis of simulation results

[0031] Reference Figure 4 , the simulation result is the active voltage standing wave ratio during normal scanning under periodic boundary conditions. It can be seen that within at least 100% relative bandwidth, the active standing wave is less than 1.5, and has good impedance matching characteristics within the triple frequency bandwidth;

[0032] Reference Figure 5 , the simulation result is the coupling degree between the horizontal polarization antenna port and the vertical polarization antenna port during normal scanning under periodic boundary conditions. It can be seen that within at least 100% relative bandwidth, the port isolation is less than -30dB, and has a good port isolation effect within the triple frequency bandwidth;

[0033] Reference Figure 6 , the simulation object is a 4×4 array antenna, and the result corresponds to the normal radiation beam gain value. It can be seen that within at least 100% relative bandwidth, the radiation gain of the array antenna is efficient and stable, and has a high radiation gain value within the triple frequency bandwidth;

[0034] In addition, the total height of the unit antenna is 39.4 mm, which is less than 0.26 times the wavelength corresponding to the low frequency point. Compared with the ultra-wideband antenna in the same frequency band, the total height is 55% of the latter, which has a certain advantage of low profile.

Claims

1. An ultra-wideband dual-polarization array antenna unit, characterized in that: The antenna unit is a square grid stacked structure, which comprises, from bottom to top, a metal reflector (1), a horizontally polarized radio frequency connector (2-1), a vertically polarized radio frequency connector (2-2), a horizontally polarized metal vibrator (3-1) and a vertically polarized metal vibrator (3-2), a first layer of dielectric plate (4), a horizontal microstrip line (5-1) and a vertical microstrip line (5-2), a second layer of dielectric plate (6), and a cross-shaped microstrip strip (7); wherein the horizontal microstrip line (5-1) and the vertical microstrip line (5-2) are etched on the upper surface of the first layer of dielectric plate (4), and the cross-shaped microstrip strip (7) is etched on the upper surface of the second layer of dielectric plate (6). The cross-shaped microstrip strip (7) is composed of two horizontal microstrip lines (5-1) and the vertical microstrip line ( 5-2) are orthogonally composed of microstrip lines of the same width; and the horizontally polarized metal vibrator (3-1) and the vertically polarized metal vibrator (3-2) are placed perpendicularly to each other on the upper layer of the metal reflector (1), and are fixedly installed on the metal reflector (1) through the left metal base (3-3) and the right metal base (3-4); the tops of the horizontally polarized metal vibrator (3-1) and the vertically polarized metal vibrator (3-2) are not directly in contact with each other, leaving a gap, and the bottoms are electrically connected through the metal reflector (1); the horizontally polarized metal vibrator (3-1) and the vertically polarized metal vibrator (3-2) are both left-right mirror-symmetrical structures, wherein a rectangular notch is present at the bottom of the right metal base (3-4) near the symmetry axis.

2. The ultra-wideband dual-polarization array antenna unit according to claim 1, characterized in that: The horizontally polarized metal vibrator (3-1) and the vertically polarized metal vibrator (3-2) have the same appearance and size, and each individual metal vibrator comprises a left metal base (3-3), a right metal base (3-4), a left curved metal strip (3-5), a right curved metal strip (3-6) and a middle curved metal strip (3-8).

3. The ultra-wideband dual-polarization array antenna unit according to claim 1, characterized in that: The metal vibrator comprises a feeding point (3-7) and a right-side curved metal strip (3-6), wherein the feeding point (3-7) is located at the lower half of the right-side curved metal strip (3-6).

4. The ultra-wideband dual-polarization array antenna unit according to claim 2, characterized in that: The left metal base (3-3) and the left curved metal strip (3-5) constitute the left half structure of the metal vibrator, and the right metal base (3-4) and the right curved metal strip (3-6) constitute the right half structure of the metal vibrator; the left metal base (3-3) and the right metal base (3-4) are spaced at a fixed distance, and the left curved metal strip (3-5) and the right curved metal strip (3-6) are spaced at a gradually varying distance, forming a middle curved metal strip (3-8).

5. The ultra-wideband dual-polarization array antenna unit according to claim 1, characterized in that: The first dielectric plate (4) and the second dielectric plate (6) are both made of Rogers 5880 or materials with the same electrical properties.

6. The ultra-wideband dual-polarization array antenna unit according to claim 1, characterized in that: The first dielectric plate (4) and the metal reflector (1) have the same plane dimensions and a thickness of 1 mm; the second dielectric plate (6) is located at the center of the first reflector, has a structural side length of 1 / 5 of the high-frequency wavelength, and a thickness of 1 / 10 of the high-frequency wavelength.

7. The ultra-wideband dual-polarization array antenna unit according to claim 1, characterized in that: The horizontal microstrip line (5-1) and the vertical microstrip line (5-2) are etched on the upper surface of the first dielectric plate (4), and are respectively located directly above the horizontally polarized metal vibrator (3-1) and the vertically polarized metal vibrator (3-2).

8. The ultra-wideband dual-polarization array antenna unit according to claim 1, characterized in that: Two microstrip lines are cross-etched on the upper surface of the second dielectric plate (6) to form a cross-shaped microstrip structure; the cross-shaped microstrip strip (7) has the same external dimensions as the second dielectric plate (6).

9. The ultra-wideband dual-polarization array antenna unit according to claim 1, characterized in that: The center position of the cross-shaped microstrip (7) is connected to the lower surface of the first dielectric plate (4) via a metallized through-hole structure.

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