Antenna Unit

Abstract

The present invention relates to the research field of radar antenna technology, in particular to an antenna unit, which includes a PCB dielectric substrate, a metal bed, a power supply structure, a radiation wall and an impedance adjustment structure, the metal bed is disposed on the PCB dielectric substrate, the power supply structure, the radiation wall and the impedance adjustment structure are disposed on the metal bed, a plurality of metal through holes of the radiation wall surround the periphery of the power supply structure, and a plurality of metal through holes in the electrode direction of the radiation wall are connected to each other by a metal plate. The impedance adjustment structure is disposed between the power supply structure and the radiation wall, which makes the parallel impedance of the radiation resistance and the conduction impedance of the antenna unit much smaller than the coupling impedance between the antenna unit and the external adjacent antenna, and utilizes the principle that the current always flows to the low impedance part, converting the surface wave that would normally flow outside the antenna into effective radiation inside the antenna, achieving the effect of better surface wave suppression and radiation enhancement, and maintaining the compactness of the antenna.

Description

[Technical field]

[0001] The present invention relates to the field of radar antenna technology research, and in particular to an antenna unit that realizes high isolation degree of self-suppression of surface waves. [Background technology]

[0002] With the development of communication technology, the distance between antennas and wireless systems (embedded chips) has become closer than ever before, and at the same time, phased array antennas have also been widely applied to commercial systems. Under such circumstances, as shown in Figure 1, surface wave interference of antennas has become a factor affecting the performance of wireless systems. The main effects of surface wave interference are that surface waves reduce the isolation of adjacent antenna units, surface waves deteriorate the directional performance, and surface waves flow into the system to reduce the communication throughput of the system. As shown in Figures 1-3, there are two conventional methods for improving the isolation between antenna array units: physical blocking and active suppression. The physical blocking method is a method of blocking surface wave interference by a certain physical structure (e.g., metal wall, EBG, etc.), and this method usually requires a large size and a long separation distance to achieve the ideal effect. The active suppression method structures the suppression signal, and the width of the suppression signal and the surface wave signal are the same and the phase is opposite to form a cancellation, and the limitations of this method are as follows: 1. The bandwidth of active suppression is usually narrow, and it is not possible to form an effective suppression signal within a wide band. 2. In the case of a complex antenna, there are multiple propagation paths of the surface wave, making it difficult to construct a suppression signal. Summary of the Invention

[0003] SUMMARY OF THE PRESENT INVETION The object of the present invention is to provide an antenna unit that overcomes the problem that the prior art physical blocking and active suppression methods cannot effectively block surface wave propagation due to their localized nature, and achieves a high degree of isolation for self-suppression of surface waves.

[0004] In order to achieve the above object of the invention, the present invention provides the following technical solutions:

[0005] An antenna unit, comprising a PCB dielectric substrate, a metal bed 1, a feeding structure 5, a radiation wall and an impedance matching structure 2, the metal bed 1 is disposed on the PCB dielectric substrate, the feeding structure 5, the radiation wall and the impedance matching structure 2 are disposed on the metal bed 1, a plurality of metal through holes of the radiation wall surround the feeding structure 5, and a plurality of metal through holes in the electrode direction of the radiation wall are connected to each other by a metal plate. The impedance matching structure 2 is located between the feeding structure 5 and the radiation wall. A plurality of metal through holes of the impedance matching structure 2 are connected to each other by a ground radiation metal plate.

[0006] The antenna unit of the present invention, by designing an impedance adjustment structure inside the antenna, makes the equivalent impedance of the parallel conduction impedance and radiation resistance of the antenna unit itself much smaller than the coupling impedance between the antenna unit and the external adjacent antenna, and utilizes the principle that the current always flows to the low impedance part, converts the surface wave that would flow outside the antenna into effective radiation inside the antenna, achieving better surface wave suppression and radiation enhancement effects, and ensuring the compactness of the antenna. Meanwhile, since the surface wave suppression effect is realized inside the antenna, there is no need to add an additional isolation structure outside the antenna, which is favorable for saving production and manufacturing costs, maintaining the small size of the antenna, and is favorable for array application.

[0007] Preferably, the radiation wall includes a first opposing side wall 3 and a second opposing side wall 4, the plurality of metal through holes of the first opposing side wall 3 and the plurality of metal through holes of the second opposing side wall 4 surround the power supply structure 5, and the plurality of metal holes connected to each other by the metal plate in the electrode direction of the radiation wall are the second opposing side wall 4.

[0008] Preferably, the impedance matching structure 2 is located between the feeding structure 5 and the first opposing side wall 3 of the radiating wall.

[0009] Preferably, the first opposing side wall 3 and the second opposing side wall 4 form a rectangle.

[0010] Preferably, the quadrilateral is a square, a rectangle or a trapezoid.

[0011] Preferably, in the second opposing side wall 4, the number of the metal through holes on two opposing sides is equal.

[0012] Preferably, in the second opposing side wall 4, the center distance between any two adjacent metal through holes is 0.45 mm.

[0013] Preferably, in the first opposing side wall 3, the center distance between adjacent metal through holes is 0.8 mm.

[0014] Preferably, in the impedance adjusting structure 2, the center-to-center distance between adjacent metal through holes is 1.1 mm.

[0015] Preferably, the metal through hole has a diameter of 0.3 mm.

[0016] Compared with the prior art, the beneficial effects of the present invention are as follows: 1. The present invention provides an antenna unit that achieves high isolation with self-suppression of surface waves. By designing an impedance adjustment structure inside the antenna, the equivalent impedance of the parallel combination of the conduction impedance and radiation resistance of the antenna unit itself is made much smaller than the coupling impedance between the antenna unit and the external adjacent antenna. By utilizing the principle that current always flows through the low impedance part, the surface waves that would otherwise flow outside the antenna are converted into effective radiation inside the antenna, thereby achieving better surface wave suppression and radiation enhancement effects and ensuring the compactness of the antenna. 2. Since the present invention realizes the surface wave suppression function inside the antenna, there is no need to add an additional isolation structure outside the antenna, which is advantageous for saving production and manufacturing costs, maintains the small dimensions of the antenna, and is advantageous for array applications. [Brief description of the drawings]

[0017] [Figure 1] FIG. 1 is a schematic diagram of forming surface wave interference between adjacent antennas. [Diagram 2] FIG. 1 is a schematic diagram of the principle of surface wave interference suppression by a physical blocking method in the prior art. [Diagram 3] FIG. 1 is a schematic diagram of the principle of surface wave interference suppression by an active suppression method in the prior art. [Figure 4] 1 is a schematic diagram of the principle of surface wave interference suppression by adjusting the equivalent impedance. FIG. [Diagram 5] 1 is a schematic structural diagram of a highly isolated array antenna unit with self-suppression of surface waves in Example 1. FIG. [Figure 6] 11 is a structural schematic diagram of a highly isolated array antenna unit with self-suppression of surface waves in Example 2. FIG. [Figure 7] 13 shows the isolation simulation results of an array antenna unit with high isolation and self-suppression of surface waves in Example 2. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0018] The present invention will be described in more detail below with reference to test examples and specific embodiments. However, it should not be understood that the scope of the above subject matter of the present invention is limited to the following embodiments, and all technologies realized based on the content of the present invention belong to the scope of the present invention.

[0019] Example 1 The antenna unit achieves a high degree of isolation for self-suppression of surface waves, and as shown in FIG. 4, comprises a PCB dielectric substrate, a metal bed 1, a power supply structure 5, and a radiation wall, the metal bed 1 being arranged on the PCB dielectric substrate, and the power supply structure 5, the radiation wall, and the impedance adjustment structure 2 being arranged on the metal bed 1.

[0020] The power supply structure 5 is surrounded by a plurality of metal through holes of the radiation wall, and a plurality of metal through holes in the electrode direction of the radiation wall (X-axis direction in FIG. 4) are connected to each other by a metal piece. The impedance adjustment structure 2 is disposed between the power supply structure 5 and the radiation wall. A plurality of metal through holes of the impedance adjustment structure 2 are connected to each other by a ground radiation metal piece.

[0021] Furthermore, the radiation wall includes a first opposing side wall 3 and a second opposing side wall 4, the first opposing side wall 3 includes two rows of metal through holes arranged opposite to each other, the second opposing side wall 4 includes two rows of metal through holes arranged opposite to each other, the first opposing side wall 3 and the second opposing side wall 4 form a rectangle and surround the periphery of the power supply structure 5, the second opposing side wall 4 is a plurality of metal through holes connected to each other by a metal plate in the electrode direction of the radiation wall, and in the direction perpendicular to the electrode direction of the radiation wall, the metal through holes are not connected to each other by any other medium other than the metal bed.

[0022] Furthermore, the impedance matching structure 2 is located between the feeding structure 5 and a first opposing side wall 3 of the radiating wall.

[0023] As shown in FIG. 5, the impedance adjusting structure 2 adjusts the radiation resistance R s and configured to make the parallel impedance of the conduction impedance R1 much smaller than the coupling impedance R2 between the antenna unit and an external adjacent antenna (antenna 2).

[0024] The metal through hole of the present invention may be hollow or solid, and the resin material can be filled into the solid metal through hole without affecting the separation effect.

[0025] The principle of the present invention is to design a distributed impedance adjustment structure inside the antenna, so that the equivalent impedance of the parallel connection of the conduction impedance and radiation resistance of the antenna unit itself is much smaller than the coupling impedance between the antenna unit and the external adjacent antenna, and by utilizing the principle that current always tends to flow to the low impedance part, the surface wave energy is guided to flow inside the antenna and be converted into effective radiation instead of being coupled outward, thereby achieving the effect of better surface wave suppression and radiation enhancement, and ensuring the compactness of the antenna.

[0026] Referring again to Fig. 4, a current flows from the feeding structure 5 to the first opposing side wall 3 of the radiation wall through the metal floor, while the first opposing side wall 3 of the radiation wall functions as a radiator of the antenna, and thus becomes an open circuit with an infinite impedance during operation. However, the impedance adjustment structure 2 is connected to the metal floor between the feeding structure 5 and the first opposing side wall 3, and the first opposing side wall 3 and the impedance adjustment structure 2 together form a transmission line with an open circuit at the end. Therefore, the equivalent resistance obtained by connecting the conduction impedance and the radiation resistance of the antenna unit itself in parallel is much smaller than the coupling impedance between the antenna unit and the external adjacent antenna, and thus an equivalent circuit as shown in Fig. 5 is formed. Since the coupling impedance R2 between the antenna unit and the external adjacent antenna in Fig. 5 is an infinite open circuit impedance, the surface wave energy is radiated to the outside from the slit formed by the first opposing side wall 3 and the impedance adjustment structure 2, and the propagation to the outside beyond the first opposing side wall 3 is reduced, and the surface wave that should flow to the outside of the antenna is converted into effective radiation inside the antenna, improving the suppression of the surface wave and the enhancement of radiation, and maintaining the compactness of the antenna.

[0027] Since the present invention realizes the surface wave suppression effect inside the antenna, there is no need to add an extra isolation structure outside the antenna, which is advantageous in saving production and manufacturing costs.

[0028] Example 2 The PCB dielectric substrate of the antenna unit in this embodiment is realized by a four-layer board, the medium material is Rogers 4350B, and the feeding structure 5 is a strip line.

[0029] As shown in FIG. 6, one set of two opposing metal through holes in the first opposing side walls 3 of the radiating wall has 15 metal through holes and the other set has 14 metal through holes, the diameter of the holes is 0.3 mm, and the distance between the holes (the center distance between the two holes) is 0.8 mm.

[0030] The two sets of opposing metal through holes in the second opposing side wall 4 each have 33 metal through holes, which are arranged in a left brace "[" shape and a right brace "[]" shape, respectively, with a hole diameter of 0.3 mm and a hole spacing (center-to-center distance between two holes) of 0.45 mm.

[0031] The straight lines on which the two sets of metal through holes in the first opposing side wall 3 are located are perpendicular to the straight lines on which the two sets of metal through holes in the second opposing side wall 4 are located, forming a “mouth” shape to surround the power supply structure 5.

[0032] The power supply structure 5 has an impedance matching structure 2 between two sets of metal through holes in the first opposing side wall 3, and the impedance matching structure 2 includes a first section and a second section, the first section is located between the power supply structure 5 and one set of metal through holes in the first metal through hole array, has six metal through holes, one ends of the six metal through holes are connected to the metal bed 1, and the other ends are connected to each other by a ground radiation metal plate, the second section is located between the power supply structure 5 and another set of metal through holes in the first opposing side wall 3, has four metal through holes, the diameter of the metal through holes is 0.3 mm, the hole spacing (center distance between two holes) is 0.45 mm, one ends of the four metal through holes are connected to the metal bed 1, and the other ends are connected to each other by a ground radiation metal plate.

[0033] In this embodiment, the matching structure 6 is a number of metal through-holes to achieve impedance matching of the antenna unit.

[0034] As shown in FIG. 7, the simulation results of the isolation at approximately one wavelength using two antenna units of this embodiment, it can be seen that the surface wave self-suppressing antenna unit of the present invention achieves an isolation level of 40 dB or more at the same array spacing compared to a conventional phased array antenna, and the isolation is improved by 20 dB (100 times).

[0035] The above description is only a preferred embodiment of the present invention, and is not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention. [Explanation of symbols]

[0036] 1—metal bed, 2—impedance adjustment structure, 3—first opposing side wall, 4—second opposing side wall, 5—feed structure, 6—matching structure

Claims

1. An antenna unit, comprising: a PCB dielectric substrate, a metal bed (1), a feeding structure (5), a radiating wall and an impedance matching structure (2); an impedance matching structure (2) connected to a ground radiating metal plate; a metal bed (1) disposed on the PCB dielectric substrate; a feeding structure (5), a radiation wall and an impedance matching structure (2) disposed on the metal bed (1); a plurality of metal through holes of the radiation wall surround the feeding structure (5), and a plurality of metal through holes in the electrode direction of the radiation wall are connected to each other by a metal plate; the impedance matching structure (2) is located between the feeding structure (5) and the radiation wall; and a plurality of metal through holes of the impedance matching structure (2) are connected to each other by a ground radiating metal plate.

2. 2. The antenna unit of claim 1, wherein the radiating wall includes a first opposing side wall (3) and a second opposing side wall (4), the plurality of metal through holes in the first opposing side wall (3) and the plurality of metal through holes in the second opposing side wall (4) surround the periphery of the power supply structure (5), and the plurality of metal through holes connected to each other by the metal plate in the electrode direction of the radiating wall are in the second opposing side wall (4).

3. 3. An antenna unit according to claim 2, characterized in that the impedance matching structure (2) is located between the feeding structure (5) and the first opposing side wall (3) of the radiating wall.

4. 4. The antenna unit according to claim 3, wherein the first opposing side wall (3) and the second opposing side wall (4) form a rectangle.

5. 5. The antenna unit according to claim 4, wherein the quadrilateral is a square, a rectangle or a trapezoid.

6. 6. The antenna unit according to claim 5, characterized in that in the second opposing side wall (4), the number of said metal through holes on two opposite sides is equal.

7. 7. The antenna unit according to claim 6, wherein the distance between the centers of adjacent metal through-holes in the second opposing side wall is 0.45 mm.

8. 8. The antenna unit according to claim 7, characterized in that in the first opposing side wall (3), the center-to-center distance between adjacent metal through-holes is 0.8 mm.

9. 9. The antenna unit according to claim 8, wherein in the impedance adjustment structure (2), the center-to-center distance between adjacent metal through-holes is 1.1 mm.

10. 10. The antenna unit according to claim 1, wherein the metal through-hole has a diameter of 0.3 mm.

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