Low-loss metamaterial antenna housing

[0025] Metamaterials are artificial composite structural materials with supernormal physical properties that natural materials do not have. The orderly arrangement of microstructures can change the relative permittivity and magnetic permeability of each point in space. Metamaterials can achieve refractive index, impedance, and wave transmission performance that ordinary materials cannot have within a certain range, thereby effectively controlling the propagation characteristics of electromagnetic waves. The metamaterial radome based on artificial microstructures can change the relative permittivity, refractive index and impedance of the material by adjusting the shape and size of the artificial microstructure, so as to achieve impedance matching with air to maximize the incident electromagnetic wave. transmission. The frequency can be selected by adjusting the size of the microstructure, and the corresponding transmission and filtering frequencies can be adjusted according to needs.

[0026] The present invention provides a low-loss metamaterial radome, which includes at least one metamaterial layer 1, such as figure 1 with figure 2 Shown. Each metamaterial sheet 1 includes two oppositely arranged substrates and an array of artificial microstructures attached between the two substrates. When there are multiple metamaterial sheets 1, each metamaterial sheet 1 is superimposed in a direction perpendicular to the sheets, and assembled into a whole by mechanical connection, welding or bonding, such as figure 2 Shown. Generally, when the performance can be satisfied, a metamaterial sheet can be used as a metamaterial radome. The plane of the artificial microstructures arranged in the array is parallel to the direction of the electric and magnetic fields of the electromagnetic wave, and perpendicular to the direction of the incident electromagnetic wave. The first substrate 10 in the metamaterial sheet 1 can be divided into a plurality of metamaterial units, and each metamaterial unit is arranged with an artificial microstructure.

[0027] image 3 A schematic diagram (perspective view) of the structure of the metamaterial sheet is shown. The metamaterial sheet layer 1 includes two sheet-like substrates of the same uniform thickness: a first substrate 10 and a second substrate 20, which are arranged opposite to each other. The surface of the first substrate 10 facing the second substrate 20 is attached with array rows. Artificial microstructure of cloth 30. The metamaterial sheet 1 can be divided into a plurality of metamaterial units, and each metamaterial unit is arranged with one of the artificial microstructures. In an embodiment of the present invention, the length and width of each metamaterial unit are b=2mm. Here, two substrates are taken as an example for description, but in actual design, only the first substrate may be used, and the artificial microstructure array is arranged on the first substrate 10, which can also achieve the objective of the present invention. The number of metamaterial units shown in the figure is only indicative. In order to illustrate the arrangement of artificial microstructures, the number of metamaterial units is not limited. The size of the radome can be determined according to actual needs to determine the metamaterial The number of units.

[0028] Such as Figure 4 As shown, each artificial microstructure 30 is a cross-shaped structure. The cross-shaped structure is composed of two metal wires that are perpendicular to each other. The width of the metal wires is w=0.2mm, and the length is a=1.4~1.8mm. The length and width of the metamaterial unit where each artificial microstructure 30 is located is b=2mm. The distance between each artificial microstructure and the boundary of the metamaterial unit where it is located is c=0.1~0.3mm.

[0029] The thickness of the first substrate 10 and the second substrate 20 are both 0.4 mm, and the thickness of the artificial microstructure is 0.018 mm. The numerical value here is only an example, in actual application, it can be adjusted according to actual demand, and the present invention does not limit this.

[0030] In an embodiment of the present invention, the first substrate 10 and the second substrate 20 are made of F4B or FR4 composite material. The first substrate 10 and the second substrate 20 are connected to each other by filling liquid substrate materials or by assembling. The artificial microstructure 30 is attached to the first substrate 10 by etching. Of course, the artificial microstructure 30 can also be attached to the first substrate 10 or the second substrate 20 by means of electroplating, drilling, photolithography, electron etching, or ion etching. on. The first substrate 10 and the second substrate 20 may also be made of other materials, such as ceramics, polytetrafluoroethylene, ferroelectric materials, ferrite materials or ferromagnetic materials. The artificial microstructure 30 is made of copper wire, of course, it can also be made of conductive materials such as silver wire, ITO, graphite or carbon nanotubes. The shape of the radome shown in the drawings is flat. In actual design, the shape of the radome can also be designed according to actual needs. For example, it can be designed into a spherical shape or a shape that matches the shape of the antenna (conformal radome), etc. The present invention does not limit this.

[0031] The schematic diagram of the S parameters of the metamaterial radome in this embodiment changing with frequency is as follows: Figure 5 As shown, the first substrate 10 and the second substrate 20 used are F4B composite materials, S11_1 and S21_1 are simulation results when artificial microstructures are not attached to the substrate, and S11 and S21 are simulation results when artificial microstructures are attached to the substrate. It can be seen that S11 near 33GHz is much smaller than S11_1, that is, less reflected energy. Figure 5 Partially amplified around 33GHz Image 6 It can be seen that when the radome works at 33GHz, S21 (-0.054222) is much larger than S21_1 (-0.21235), which means that the transmission effect is very good. According to the data in the figure, the wave transmission rate can be as high as 98.75%. The magnetic permeability μ can be obtained through the CST simulation algorithm, such as Figure 7-8 As shown, the imaginary part of μ is -0.0008751 at 33.01 GHz, and the real part is -0.9749. That is, the magnetic permeability μ at the 33.01GHz frequency point has a loss as low as 0.0008751, which matches well with air, so the wave transmission efficiency can reach a very high standard.

[0032] The invention obtains the required electromagnetic response by attaching the artificial microstructure of a specific shape on the substrate, so that the radome based on the metamaterial has enhanced wave transmission performance and increased anti-interference ability. The relative permittivity, refractive index and impedance of the material can be changed by adjusting the shape and size of the man-made microstructures, so as to achieve impedance matching with air to maximize the transmission of incident electromagnetic waves and reduce the design time of traditional radome Limits on material thickness and dielectric constant.

[0033] The embodiments of the present invention are described above with reference to the accompanying drawings, but the present invention is not limited to the above-mentioned specific embodiments. The above-mentioned specific embodiments are only illustrative and not restrictive. Those of ordinary skill in the art are Under the enlightenment of the present invention, many forms can be made without departing from the purpose of the present invention and the protection scope of the claims, and these all fall within the protection of the present invention.