阅读说明：本技术 一种用于微带天线rcs缩减的超材料天线 (Metamaterial antenna for reducing RCS (radar cross section) of microstrip antenna ) 是由 刘玥岑 费莉 牟雎 李文娟 于 2021-07-06 设计创作，主要内容包括：本发明涉及天线领域,公开了一种用于微带天线RCS缩减的超材料天线,包括公共接地板,设置在公共接地板上的介质基板,设置在介质基板几何中心的矩形辐射贴片,设置在公共接地板上并与所述矩形辐射贴片接触的同轴馈电端口,设置在所述矩形辐射贴片四周并正交排列的两种尺寸不同的超材料单元,所述超材料单元根据尺寸的不同可以产生不同谐振频率的反射波,使得两种尺寸不同的所述超材料单元的反射波相位差将在微带天线的工作频段发生改变,使得单元尺寸大小不同的超材料的反射波可以互相抵消,进而实现微带天线雷达散射截面积(RCS)缩减的目标。(The invention relates to the field of antennas, and discloses a metamaterial antenna for reducing the RCS of a microstrip antenna, which comprises a common ground plate, a dielectric substrate arranged on the common ground plate, a rectangular radiation patch arranged at the geometric center of the dielectric substrate, a coaxial feed port arranged on the common ground plate and in contact with the rectangular radiation patch, and two metamaterial units which are arranged around the rectangular radiation patch and are in orthogonal arrangement and have different sizes, wherein the metamaterial units can generate reflected waves with different resonant frequencies according to different sizes, so that the phase difference of the reflected waves of the metamaterial units with different sizes can be changed in the working frequency band of the microstrip antenna, the reflected waves of the metamaterials with different sizes of the units can be mutually counteracted, and the target of reducing the radar scattering cross section (RCS) of the microstrip antenna is realized.)

1. A metamaterial antenna for RCS reduction of a microstrip antenna,

the metamaterial unit comprises a common grounding plate, a medium substrate arranged on the common grounding plate, a rectangular radiation patch arranged at the geometric center of the medium substrate, a coaxial feed port arranged on the common grounding plate and in contact with the rectangular radiation patch, and two metamaterial units which are arranged around the rectangular radiation patch and are orthogonally arranged and have different sizes, wherein the metamaterial units can generate reflected waves with different resonant frequencies according to different sizes.

2. A metamaterial antenna for microstrip antenna RCS reduction as claimed in claim 1,

the metamaterial unit comprises a square metal ring, a square patch, two first U-shaped metal patches and two second U-shaped metal patches, wherein the size of each first U-shaped metal patch is larger than that of each first U-shaped metal patch, the square patch is arranged at the geometric center inside the square metal ring, the number of the first U-shaped metal patches is two, the second U-shaped metal patches are connected with the square patches, the two metal patches are symmetrically arranged on two sides of the square patch, the two metal patches are symmetrically arranged between the square patch and the second U-shaped metal patch, and the two metal patches are connected with the square metal ring.

3. A metamaterial antenna for microstrip antenna RCS reduction as claimed in claim 2,

and the distances from each part of the second U-shaped metal patch to the square metal ring are equal, and the distances from each part of the first U-shaped metal patch to the square patch are equal.

4. A metamaterial antenna for microstrip antenna RCS reduction as claimed in claim 3,

the distance between the second U-shaped metal patch and the square metal ring is adjusted to generate reflected waves with different resonant frequencies.

5. A metamaterial antenna for microstrip antenna RCS reduction as claimed in claim 2,

the metamaterial units are orthogonally arranged to form a metamaterial array, and the metamaterial arrays with two different sizes are arranged around the rectangular radiation patch and orthogonally arranged.

6. A metamaterial antenna for microstrip antenna RCS reduction as claimed in claim 1,

the inner conductor of the coaxial feed port is connected with the rectangular radiating patch, and the outer conductor of the coaxial feed port is connected with the common ground plate.

Technical Field

The invention relates to the field of antennas, in particular to a metamaterial antenna for reducing RCS of a microstrip antenna.

Background

With the development of wireless communication technology, radar, electronic countermeasure and reconnaissance, antenna technology has been rapidly developed. In the civil field, the development of 5G mobile communication technology, the leisure of various mobile terminals and multifunctional antennas are more widely applied.

In civil use, how to reduce the influence of other electromagnetic radiation sources on the designed antenna has become a not negligible practical problem, and reducing the scattering property of the designed antenna is an effective way to solve the above problem. In military equipment, the antenna is used as the foremost end of the equipment and has strong radiation performance, so that the scattering of the carrier is poor, and the carrier is very easy to detect and attack by the other party. Therefore, reducing the scattering properties of the antenna is also an important means to achieve the stealth function.

The radar scattering area (RCS) is a physical quantity reflecting the scattering characteristics of a target object, and as the radar cross-sectional area of the target object increases, the scattering characteristics of the object are reduced, and the target is easily found.

The existing mode of additionally mounting camouflage and utilizing a band-pass frequency selection surface when an antenna does not work increases the complexity of the antenna for the reduction of the radar scattering area, so that the antenna is inconvenient to use.

Disclosure of Invention

The invention aims to provide a metamaterial antenna for reducing RCS of a microstrip antenna, which aims to adjust the size of metamaterial units designed by the invention, arrange the metamaterial units with different sizes around the microstrip antenna in an orthogonal arrangement mode, and enable the phase reflection difference of the metamaterial units in the working frequency band of the microstrip antenna to be 180 degrees when the metamaterial units are different in size. Reflected waves of the metamaterials with different sizes interfere with each other, and reflected energy in the normal direction of the antenna is transferred to other directions, so that the RCS (radar cross section) reduction design of the microstrip antenna is realized.

In order to achieve the above object, the present invention provides a metamaterial antenna for RCS reduction of a microstrip antenna, including a common ground plate, a dielectric substrate disposed on the common ground plate, a rectangular radiation patch disposed at a geometric center of the dielectric substrate, a coaxial feed port disposed on the common ground plate and contacting with the rectangular radiation patch, and two metamaterial units disposed around the rectangular radiation patch and arranged orthogonally, wherein the metamaterial units can generate reflected waves with different resonant frequencies according to different sizes.

The metamaterial unit comprises a square metal ring, a square patch, two first U-shaped metal patches and two second U-shaped metal patches, wherein the size of each second U-shaped metal patch is larger than that of each first U-shaped metal patch, the square patch is arranged at the geometric center inside the square metal ring, the second U-shaped metal patches are connected with the square patches and symmetrically arranged on two sides of the square patch, and the first U-shaped metal patches are symmetrically arranged between the square patch and the second U-shaped metal patches and connected with the square metal ring.

And the distances from each part of the second U-shaped metal patch to the square metal ring are equal, and the distances from each part of the first U-shaped metal patch to the square patch are equal.

And the distance between the second U-shaped metal patch and the square metal ring is adjusted to generate reflected waves with different resonant frequencies.

The metamaterial units are orthogonally arranged to form a metamaterial array, and the metamaterial arrays with two different sizes are arranged around the rectangular radiation patch and orthogonally arranged.

Wherein the inner conductor of the coaxial feed port is connected with the rectangular radiating patch, and the outer conductor of the coaxial feed port is connected with the common ground plate.

According to the metamaterial antenna for reducing the RCS of the microstrip antenna, the metamaterial units with different unit sizes are placed around the microstrip antenna in an orthogonal arrangement mode, the metamaterial units can generate reflected waves with different resonant frequencies by adjusting the size of the units, so that the phase difference of the reflected waves of the metamaterial units with two different sizes is changed in the working frequency band of the microstrip antenna, the reflected waves of the metamaterials with different unit sizes can be mutually counteracted, and the target of reducing the radar scattering cross section (RCS) of the microstrip antenna is achieved. The invention can break through the restriction that the reflection phase of the traditional chessboard type orthogonal reflection screen is restricted by the AMC reflection phase, so that the structure of the antenna is simpler, the mode of reducing the radar scattering sectional area (RCS) of the microstrip antenna is very simple, the processing is convenient, and the cost is low.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the drawings without creative efforts.

FIG. 1 is a diagram of simulation results of reflection phase differences varying with the width of a gap of a metal patch in a metamaterial unit designed according to the present invention when the unit size of the metamaterial unit is different;

FIG. 2 is a diagram of simulation results of radar reflection cross-sectional area (RCS) reduction for a microstrip antenna designed according to the present invention by loading metamaterials of different sizes in an orthogonal arrangement;

FIG. 3 is a top view of a metamaterial antenna for reduced RCS of a microstrip antenna of the present invention;

FIG. 4 is a side view of a reduced RCS metamaterial antenna for a microstrip antenna of the present invention;

FIG. 5 is a block diagram of a metamaterial unit of the present invention;

FIG. 6 is a block diagram of a metamaterial array for reduced RCS microstrip antenna of the present invention;

fig. 7 is a structural diagram of a reduced RCS metamaterial antenna for a microstrip antenna according to the present invention with a positioning post and a clamping post.

The antenna comprises a 1-common ground plate, a 2-rectangular radiation patch, a 3-coaxial feed port, a 4-metamaterial unit, a 5-dielectric substrate, 11-positioning columns, 12-clamping columns, 41-square metal rings, 42-square patches, 43-first U-shaped metal patches, 44-second U-shaped metal patches, 51-positioning grooves and 52-protrusions.

Detailed Description

Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like or similar reference numerals refer to the same or similar elements or elements having the same or similar function throughout. The embodiments described below with reference to the drawings are illustrative and intended to be illustrative of the invention and are not to be construed as limiting the invention.

Referring to fig. 1 to 7, the present invention provides a metamaterial antenna for RCS reduction of a microstrip antenna, including:

the antenna comprises a common grounding plate 1, a dielectric substrate 5 arranged on the common grounding plate 1, a rectangular radiation patch 2 arranged at the geometric center of the dielectric substrate 5, a coaxial feed port 3 arranged on the common grounding plate 1 and contacted with the rectangular radiation patch 2, and two metamaterial units 4 which are arranged around the rectangular radiation patch 2 and are in orthogonal arrangement and have different sizes, wherein the metamaterial units 4 can generate reflected waves with different resonant frequencies according to different sizes.

In this embodiment, the metamaterial units 4 with different unit sizes are placed around the microstrip antenna in an orthogonal arrangement mode, the metamaterial units 4 can generate reflected waves with different resonant frequencies by adjusting the size of the units, so that the phase difference of the reflected waves of the metamaterial units 4 with two different sizes can be changed in the working frequency band of the microstrip antenna, the reflected waves of the metamaterials with different unit sizes can be mutually offset, and the target of reducing the radar scattering cross section (RCS) of the microstrip antenna is realized. The invention can break through the restriction that the reflection phase of the traditional chessboard type orthogonal reflection screen is restricted by the AMC reflection phase, so that the structure of the antenna is simpler, the mode of reducing the radar scattering sectional area (RCS) of the microstrip antenna is very simple, the processing is convenient, and the cost is low.

Further, the metamaterial unit 4 comprises a square metal ring 41, a square patch 42, two first U-shaped metal patches 43 and two second U-shaped metal patches 44 with the size larger than that of the first U-shaped metal patches 43, the square patch 42 is arranged at the geometric center inside the square metal ring 41, the two second U-shaped metal patches 44 are connected with the square patch 42 and symmetrically arranged at two sides of the square patch 42, and the two first U-shaped metal patches 43 are symmetrically arranged between the square patch 42 and the second U-shaped metal patches 44 and connected with the square metal ring 41. Each part of the second U-shaped metal patch 44 is equidistant from the square metal ring 41, and each part of the first U-shaped metal patch 43 is equidistant from the square patch 42. The distance between the second U-shaped metal patch 44 and the square metal ring 41 is adjusted to generate reflected waves with different resonant frequencies, and when the phase of the reflected waves of the two types of metamaterial units 4 with different sizes is 180 degrees, the reflected waves eliminate interference.

In this embodiment, when the square metal ring 41 and the square patch 42 are energized, capacitance is generated, and inductance is generated by the metal patches of the inner and outer portions, respectively, L1 and L2. Thus, the AMC structure is designed to have two resonant frequencies, f1 and f 2. When the distance between the second U-shaped metal patch and the square metal ring 41 is adjusted, the resonant frequency of the metamaterial unit 4 is changed.

The metamaterial units 4 of different unit sizes will together with the commoned ground plate 1 constitute two artificial magnetic conductors AMC1 and AMC 2. And the phase difference of the reflected waves of AMC1 and AMC2 will change in the working frequency band of the microstrip antenna.

Furthermore, a plurality of metamaterial units 4 are orthogonally arranged to form a metamaterial array, and two metamaterial arrays with different sizes are arranged around the rectangular radiation patch and orthogonally arranged.

In the present embodiment, the reduction effect can be enhanced by providing a plurality of the metamaterial units 4.

Further, the inner conductor of the coaxial feed port 3 is connected to the rectangular radiating patch 2, and the outer conductor of the coaxial feed port 3 is connected to the common ground plate 1.

In this embodiment, the present invention feeds the antenna by using a coaxial feeding point, the inner conductor of the coaxial feeding port 3 is connected to the rectangular radiation patch 2, and the outer conductor is connected to the common ground plane 1 for balanced feeding.

Further, the common ground plate is provided with a positioning column 11, the medium substrate is provided with a positioning groove 51, and the positioning column 11 is located in the positioning groove 51; the commoned ground plate has a card post 12 and the dielectric substrate has a protrusion 52, the protrusion 52 being removably attached to the card post 12 and located on one side of the card post 12.

In this embodiment, the positioning column 11 is disposed in the positioning groove 51, so that the medium substrate and the common ground plate can be attached more stably, the position is more accurate without deviation, the clamping column 12 is made of an elastic material, and the protrusion 52 is enclosed by the clamping column 12 to strengthen the connection between the medium substrate and the common ground plate, so that the placement is more stable.

The traditional chessboard type artificial magnetic conductor can achieve the purpose of reducing the radar scattering cross section (RCS) of an antenna, but one Artificial Magnetic Conductor (AMC) in the technology is a rectangular metal patch, so that the unit is greatly limited by space size and can only adjust another artificial magnetic conductor unit. Compared with the traditional technology, the metamaterial designed by the invention is less influenced by the limitation of space size, and the metamaterial unit 4 can be flexibly adjusted to further achieve the purpose of mutual cancellation of reflected waves.

In order to verify the effectiveness of the invention, the distance between the second U-shaped metal patch and the square metal ring 41 is set as t, since the resonant frequency of the metamaterial unit is formed by the combined action of the inductance and the inductance of the metamaterial unit, the gap between the metamaterial metal patches mainly affects the capacitance of the metamaterial unit, and the size of the whole dimension of the metamaterial unit mainly affects the inductance of the metamaterial unit. When the overall size of the metamaterial unit becomes large, the inductance of the metamaterial unit itself increases, and thus the resonance frequency becomes small. When the whole size of the metamaterial unit is not changed and the gap between the metal patches is enlarged, the capacitance of the metamaterial unit is enlarged, and therefore the resonant frequency of the metamaterial unit is reduced. Therefore, when the overall size of the metamaterial unit is adjusted to be smaller than the width of the gap between the metal patches, the reflection phase of the metamaterial unit is changed. Therefore, for the metamaterial unit, when the whole size of the unit and the width of the gap between the metal patches are changed, the reflection phase of the metamaterial unit is changed along with the resonant frequency. Because the same metamaterial unit is adopted, but two metamaterials with different sizes are arranged in a checkerboard mode, a phase difference naturally exists between the two metamaterial units. Therefore, when the overall size of the two metamaterial units and the width of the gap between the metal patches are adjusted, the phase difference between the two metamaterial units can be adjusted. In the invention, in order to reduce the adjustment workload of the overall size of the two metamaterial units, the two metamaterials are set to be fixed 6mm and 3.5mm, and at the moment, the phase difference caused by the difference of the sizes of the two metamaterial units is most obvious. Secondly, the width of the gap between the two metamaterial unit metal patches can be adjusted, and the phase difference between the two metamaterial units can be finely adjusted. FIG. 1 is a graph of simulation results of reflection phase differences of two fixed-size metamaterial units designed in the present invention as a function of gap width of metal patches in the units, showing that as the gap width between the metal patches of the two metamaterial units increases, the reflection phase difference between the two metamaterial units increases first and then decreases. At a gap width of 0.25mm, the phase difference between the two metamaterial units is at most 180 °. Namely, the requirement of mutual cancellation of the reflected wave inversions can be satisfied.

Fig. 2 is a simulation result diagram of radar reflection cross-sectional area (RCS) reduction of a microstrip antenna loaded with metamaterials of different sizes in an orthogonal arrangement according to the present invention, and the diagram shows that after two metamaterials distributed in an orthogonal arrangement are added around the microstrip antenna, the RCS of a single station of the microstrip antenna after an artificial magnetizer orthogonal reflection screen is added is significantly reduced compared with the RCS of an orthogonal reflection screen without the artificial magnetizer. The RCS in the maximum radiation direction is reduced by about 25dB, and the radar cross-sectional area of the antenna in the normal direction is minimized due to the total reflection characteristics of the antenna. As can be seen from fig. 2, the minimum radar cross-sectional area of the beam in the normal direction of the antenna is-29 dB.

While the invention has been described with reference to a preferred embodiment, it will be understood by those skilled in the art that various changes in form and detail may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.