A radome

Abstract

This invention discloses an antenna radome, belonging to the field of communication technology, comprising a substrate, an upper resonant layer and a lower resonant layer symmetrically arranged on the upper and lower surfaces of the substrate respectively; the upper resonant layer includes two vertically arranged first resonators and two horizontally arranged second resonators, each composed of two symmetrically arranged arcs, a hexagonal ring located between the two arcs, and a graphene layer attached to the inner wall of the arcs; the lower resonant layer includes two third resonators and two fourth resonators, each composed of two symmetrically arranged arcs and a hexagonal ring located between the two arcs; the size of the first resonator is 1.08-1.28 times the size of the second resonator, the third resonator is the same size as the first resonator, and the fourth resonator is the same size as the second resonator. Polarization adjustment is achieved by changing the Fermi level of the graphene layer through changing the external voltage, and the slow light effect is achieved through the cooperation of the upper and lower resonant layers, thus realizing both the slow light effect and polarization adjustment.

Description

Technical Field

[0001] The invention relates to an antenna cover and belongs to the technical field of communications. Background Art

[0002] With the continuous development of wireless communication technology, radar and satellite communication, the use of radomes is becoming more and more widespread. Radomes can prevent antennas from possible damage in various harsh environments. For example, radomes used for large antennas on the ground can reduce wind resistance and avoid the accumulation of ice and snow. They are usually in the shape of a spherical shell. On airborne and missile-borne platforms, in order to reduce air resistance, conical radomes are required.

[0003] Although the radome plays a role in protecting the antenna, side effects are often inevitable. For example, the electromagnetic waves emitted by the antenna are reflected on the surface of the radome and absorbed in the dielectric layer of the radome, causing power loss and reducing the operating range of the electronic system. Refraction in the dielectric layer causes angle measurement errors. Multiple reflections in the dielectric layer are similar to the multipath effect and will cause an increase in nearby clutter. Therefore, in the design, it is required that after the radome is added, the specified limit indicators cannot be exceeded.

[0004] At the same time, the rapid development of modern wireless communication technology, satellite communication and navigation, radar systems and military electronic countermeasure equipment has put forward higher requirements on the polarization characteristics, size, miniaturization, low loss, integration and other performance of the antenna cover; currently, the antenna cover is usually used in the high-frequency band, which is easy to cause low radiation efficiency due to the large metal loss, and the geometric size of the metal antenna is large in the low-frequency band, which is not suitable for the requirements of system miniaturization.

[0005] Although some radomes have many advantages such as light weight, low cost, and easy integration, they cannot avoid the above technical bottlenecks. The above shortcomings of traditional radomes limit their development and affect the performance of the radomes. Summary of the invention

[0006] The object of the present invention is to provide a radome that solves the defects of limited performance in the prior art, and can simultaneously realize slow light effect and linear circular polarization conversion and polarization adjustment while playing a traditional protective role.

[0007] To achieve the above objectives, the present invention is implemented by adopting the following technical solutions:

[0008] In a first aspect, the present invention provides a radome, comprising a substrate, an upper resonance layer and a lower resonance layer respectively connected to the upper and lower surfaces of the substrate; the upper resonance layer comprises two vertically arranged first resonators and two horizontally arranged second resonators, the first resonator and the second resonator both consisting of two symmetrically arranged circular arcs, a hexagonal ring located between the two circular arcs, and a graphene layer attached to the inner wall of the circular arc; the lower resonance layer comprises two third resonators and two fourth resonators respectively symmetrically arranged with the first resonator and the second resonator about the substrate, the third resonator and the fourth resonator both consisting of two symmetrically arranged circular arcs and a hexagonal ring located between the two circular arcs;

[0009] The size of the first resonator is 1.08-1.28 times the size of the second resonator, the third resonator is the same size as the first resonator, and the fourth resonator is the same size as the second resonator. The Fermi level of the graphene layer is adjusted by changing the external voltage to achieve polarization adjustment, and the slow light effect is achieved through the cooperation of the upper resonance layer and the lower resonance layer.

[0010] In combination with the first aspect, further, the relative dielectric constant of the substrate is 3.9-4.1.

[0011] In combination with the first aspect, further, the thickness of the substrate is 40-46 μm.

[0012] In combination with the first aspect, further, the substrate is made of silicon.

[0013] In combination with the first aspect, further, the size of the first resonator is 1.18 times the size of the second resonator, and the opening rotation directions of the first resonator and the second resonator differ by 90°.

[0014] In combination with the first aspect, further, the upper resonance layer and the lower resonance layer are connected to the substrate by using a coating process.

[0015] In combination with the first aspect, further, the arc and the hexagonal ring are made of gold with a thickness of 0.05-0.15 μm.

[0016] In combination with the first aspect, further, the central angle of the arc is 159.18-163.18°.

[0017] In combination with the first aspect, further, adjusting the Fermi level of the graphene layer by changing the external voltage to achieve polarization adjustment includes:

[0018] The polarization adjustment is linear-circular polarization conversion, and the frequency points of the linear-circular polarization conversion are 1.432THz and 1.676THz respectively;

[0019] By changing the external voltage, the Fermi level of the graphene layer changes in the range of 0.1-0.9 eV, and the achievable polarization adjustment ranges are 1.438-1.452 THz and 1.689-1.696 THz respectively.

[0020] In combination with the first aspect, further, the intervals of the slow light effect are respectively located at 1.452-1.661 THz and 1.348-1.683 THz.

[0021] Compared with the prior art, the beneficial effects achieved by the present invention are:

[0022] The present invention provides an antenna cover, which is composed of a substrate and an upper resonance layer and a lower resonance layer respectively connected to the upper and lower surfaces of the substrate; wherein the four resonators in the upper resonance layer and the lower resonance layer respectively include two circular arcs and a hexagonal ring located in the center of the two circular rings, thereby realizing the slow light effect; when the electromagnetic waves emitted by the antenna excite the two resonance layers, the two resonance layers will generate currents, thereby exciting corresponding electric resonance and magnetic resonance, thereby making the slow light effect better; the upper resonance layer is composed of two vertically arranged first resonators and two horizontally arranged second resonators, and the size of the first resonator is 1.08-1.28 times the size of the second resonator When the x-polarized wave and the y-polarized wave are incident, the slow light effect of the x-polarized wave and the slow light effect of the y-polarized wave can be different. Due to the dispersion characteristics of the slow light effect, when the x-polarized wave and the y-polarized wave are incident, conditions can be provided for the realization of linear circular polarization. By limiting the size of the resonator, the conditions for linear circular polarization conversion are met, thereby realizing linear circular polarization conversion. Similarly, the lower resonance layer can also realize linear circular polarization conversion. In the first resonator and the second resonator, a graphene layer is provided on the inner wall of the arc. The adjustable conductivity of the graphene layer is utilized, and the Fermi level of the graphene layer is adjusted by changing the external voltage to realize polarization adjustment. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 is a schematic structural diagram of a radome provided by an embodiment of the present invention;

[0024] Figure 2 is a schematic structural diagram of an upper resonance layer provided by an embodiment of the present invention;

[0025] Figure 3 is a schematic structural diagram of a graphene layer provided by an embodiment of the present invention;

[0026] Figure 4 It is a schematic diagram of the electromagnetically induced transparency phenomenon caused by the incident x-polarized wave and y-polarized wave provided in an embodiment of the present invention;

[0027] Figure 5It is a schematic diagram of the ellipticity of the linear circular polarization conversion generated by a radome in a slow light effect window provided by an embodiment of the present invention;

[0028] Figure 6 It is a schematic diagram of the axial ratio of the linear circular polarization conversion generated by a radome in a slow light effect window provided by an embodiment of the present invention;

[0029] Figure 7 This is one of the schematic diagrams of the change of the axial ratio of a radome with the Fermi level of a graphene layer provided by an embodiment of the present invention;

[0030] Figure 8 This is the second schematic diagram of the change of the axial ratio of a radome with the Fermi level of a graphene layer provided in an embodiment of the present invention.

[0031] In the figure: 1, substrate; 2, arc; 3, hexagonal ring; 4, graphene layer. DETAILED DESCRIPTION

[0032] The present invention will be further described below in conjunction with the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solutions of the present invention and are not intended to limit the protection scope of the present invention.

[0033] Example 1

[0034] like Figure 1 As shown, an embodiment of the present invention provides a radome, comprising a substrate 1 and an upper resonance layer and a lower resonance layer respectively connected to the substrate 1 .

[0035] The upper resonance layer and the lower resonance layer are connected to the upper surface and the lower surface of the substrate 1 respectively by using a coating process. The coating process is a method of forming a new surface on the surface of the substrate 1 by using different materials.

[0036] The material of the substrate 1 is silicon.

[0037] like Figure 2 As shown, the upper resonance layer includes two vertically arranged first resonators and two horizontally arranged second resonators. The first resonator and the second resonator are both composed of two symmetrically arranged arcs 2, a hexagonal ring 3 located between the two arcs 2, and a graphene layer 4 attached to the inner wall of the arc 2. The slow light effect is achieved by the above two rings and one hexagonal ring 3. The opening rotation directions of the first resonator and the second resonator differ by 90°. The two rings and one hexagonal ring 3 are made of gold, and its conductivity is 4.0×10 7 -4.2×10 7 S / m, its thickness is 0.05-0.15μm, preferably 0.1μm, the central angle of the arc 2 is 159.18-163.18°, preferably 161.18°, the thickness of the graphene layer 4 is 0.34nm, and the structure of the graphene layer 4 is as follows Figure 3As shown, a layer of carbon atoms is arranged in a hexagonal form.

[0038] The lower resonance layer includes two vertically arranged third resonators and two horizontally arranged fourth resonators, which are symmetrically arranged with the first resonator and the second resonator about the substrate 1; the third resonator and the fourth resonator are both composed of two symmetrically arranged arcs 2 and a hexagonal ring 3 located between the two arcs 2, and the slow light effect is realized by the above two rings and one hexagonal ring 3, and the opening rotation directions of the third resonator and the fourth resonator differ by 90°.

[0039] The third resonator is the same size as the first resonator, the fourth resonator is the same size as the second resonator, the two first resonators and the two second resonators are respectively located at the four vertices of the rhombus, and the two third resonators and the two fourth resonators are respectively located at the four vertices of the rhombus.

[0040] When the electromagnetic waves emitted by the antenna excite the two resonant layers, the two resonant layers will generate current, thereby exciting corresponding electric resonance and magnetic resonance, thereby making the slow light effect better.

[0041] The size of the first resonator is 1.08-1.28 times the size of the second resonator. When the x-polarized wave and the y-polarized wave are incident, the slow light effect of the x-polarized wave and the slow light effect of the y-polarized wave can be different. Due to the dispersion characteristics of the slow light effect, when the x-polarized wave and the y-polarized wave are incident, conditions can be provided for the realization of linear circular polarization. By limiting the size of the resonator, the conditions for linear circular polarization conversion are met, thereby realizing linear circular polarization conversion. When the size of the first resonator is 1.18 times the size of the second resonator, the effect is best.

[0042] The size of the third resonator is 1.08-1.28 times the size of the fourth resonator. When the x-polarized wave and the y-polarized wave are incident, the slow light effect of the x-polarized wave and the slow light effect of the y-polarized wave can be different. Due to the dispersion characteristics of the slow light effect, when the x-polarized wave and the y-polarized wave are incident, conditions can be provided for the realization of linear circular polarization. By limiting the size of the resonator, the conditions for linear circular polarization conversion are met, thereby realizing linear circular polarization conversion. When the size of the third resonator is 1.18 times the size of the fourth resonator, the effect is best.

[0043] The above slow light effect has an interval of 1.452-1.661THz and 1.348-1.683THz, respectively. For the x-polarized wave, the maximum group delay and group index are 225ps and 1636 at a frequency of 1.48THz, and for the y-polarized wave, the maximum group delay and group index are 162ps and 1177 at a frequency of 1.44THz.

[0044] In both the first resonator and the second resonator, a graphene layer 4 is provided on the inner wall of the arc 2. By utilizing the adjustable conductivity of the graphene layer 4, the Fermi level of the graphene layer 4 is adjusted by changing the external voltage to achieve polarization adjustment.

[0045] The frequencies of linear and circular polarization conversion are 1.432THz and 1.676THz respectively; by changing the external voltage, the Fermi level of the graphene layer 4 changes in the range of 0.1-0.9eV, and the achievable polarization adjustment ranges are 1.438-1.452THz and 1.689-1.696THz respectively.

[0046] The thickness of the silicon substrate 1 is 40-46 μm, preferably 43 μm, and the relative dielectric constant is 3.9-4.1, preferably 4.

[0047] When electromagnetic waves with different polarizations, an x-polarized electromagnetic wave (TM wave) and a y-polarized electromagnetic wave (TE wave), are incident on the radome provided by this embodiment at the same time, the two different responses to the TM and TE waves are as follows: Figure 4 As shown, a significant EIT (electromagnetically induced transparency) phenomenon can be observed in the case of two polarization waves; utilizing the low loss and dispersion characteristics of EIT, linear-circular polarization conversion can be obtained at 1.432THz and 1.676THz.

[0048] like Figure 5 The figure shows the schematic diagram of the ellipticity of the linear circular polarization conversion generated by the antenna cover in the slow light effect window. The ellipticities at 1.432THz and 1.676THz reach 0.963 and 0.989 respectively. It can be seen that the polarization conversion performance of the antenna cover is excellent.

[0049] like Figure 6 The figure shows the axial ratio diagram of the linear circular polarization conversion produced by the antenna cover in the slow light effect window. The optimal axial ratio is below 1dB.

[0050] like Figure 7 and Figure 8 As shown, by adjusting the external voltage, the Fermi level of the graphene layer 4 can be changed from 0.1 eV to 0.9 eV, and the frequency corresponding to the axial ratio of circular polarization can be adjusted from 1.438 THz to 1.452 THz and from 1.689 THz to 1.696 THz, respectively.

[0051] Through specific design, an antenna cover provided by an embodiment of the present invention can realize both high-transmittance linear circular polarization conversion and slow light effect. In addition, an antenna cover provided by an embodiment of the present invention has the characteristics of thin thickness, low loss and functional diversity.

[0052] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the technical principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A radome, characterized in that: The invention comprises a substrate, an upper resonance layer and a lower resonance layer respectively connected to the upper and lower surfaces of the substrate; the upper resonance layer comprises two vertically arranged first resonators and two horizontally arranged second resonators, the first resonator and the second resonator both consist of two symmetrically arranged arcs, a hexagonal ring located between the two arcs, and a graphene layer attached to the inner wall of the arc; the lower resonance layer comprises two third resonators and two fourth resonators respectively symmetrically arranged with the first resonator and the second resonator about the substrate, the third resonator and the fourth resonator both consist of two symmetrically arranged arcs and a hexagonal ring located between the two arcs; The size of the first resonator is 1.08-1.28 times the size of the second resonator, the size of the third resonator is the same as the first resonator, and the size of the fourth resonator is the same as the second resonator. The Fermi level of the graphene layer is adjusted by changing the external voltage to achieve polarization adjustment, and the slow light effect is achieved by the cooperation of the upper resonance layer and the lower resonance layer. Wherein, adjusting the Fermi level of the graphene layer by changing the external voltage to achieve polarization adjustment includes: The polarization adjustment is linear-circular polarization conversion, and the frequency points of the linear-circular polarization conversion are 1.432THz and 1.676THz respectively; By changing the external voltage, the Fermi level of the graphene layer changes in the range of 0.1-0.9 eV, and the achievable polarization adjustment ranges are 1.438-1.452 THz and 1.689-1.696 THz, respectively.

2. A radome according to claim 1, characterized in that: The relative dielectric constant of the substrate is 3.9-4.

1.

3. The radome according to claim 1, characterized in that: The thickness of the substrate is 40-46 μm.

4. The radome according to claim 1, characterized in that: The substrate is made of silicon.

5. The radome according to claim 1, characterized in that: The size of the first resonator is 1.18 times that of the second resonator, and the opening directions of the first resonator and the second resonator differ by 90°.

6. The radome according to claim 1, characterized in that: The upper resonance layer and the lower resonance layer are connected to the substrate by using a coating process.

7. The radome according to claim 1, characterized in that: The arc and the hexagonal ring are made of gold with a thickness of 0.05-0.15 μm.

8. The radome according to claim 1, characterized in that: The central angle of the arc is 159.18-163.18°.

9. The radome according to claim 1, characterized in that: The slow light effect has an interval of 1.452-1.661 THz and 1.348-1.683 THz respectively.

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