A high-power-capacity electrically controlled phase-modulated reflective array antenna based on liquid crystal materials

Abstract

The present invention discloses a high-power, electrically controlled, phase-modulated reflectarray antenna based on liquid crystal materials. The antenna comprises a feed source and a reflectarray, wherein the feed source is positioned above the reflectarray. The reflectarray comprises a plurality of reflectarray units, each comprising a radiating patch, a dielectric plate, a liquid crystal layer, and a reflective surface. The dielectric plate is positioned above the liquid crystal layer, the radiating patch is positioned between the dielectric plate and the liquid crystal layer, and the reflective surface is positioned below the liquid crystal layer. The present invention achieves fast-response, electrically controlled phase-modulated performance, overcoming the long response time limitations of conventional high-power antennas that use mechanically rotating arrays for beam steering. It also eliminates the limitations on antenna efficiency caused by insertion loss from forced feeding, maintaining high efficiency while achieving high gain.

Description

Technical Field

[0001] The present invention relates to the field of microwave technology, and in particular to a high-power capacity electrically controlled phase-modulated reflective array antenna based on liquid crystal materials. Background Art

[0002] High-power microwave antennas are a key component of high-power microwave systems, enabling high-power microwave radiation in a specified direction. With the advancement of high-power microwave technology, research on high-power microwave beam-scanning array antennas has been conducted. This research focuses on achieving beam scanning through the use of phase shifters and mechanical rotation of the array aperture.

[0003] However, these technologies improve the beam scanning performance of high-power capacity antennas, but because they use phase shifters, their costs are relatively high, or they use mechanically rotating arrays to achieve beam scanning, resulting in a bulky body and slow response speed for beam scanning. Summary of the Invention

[0004] In view of the above-mentioned deficiencies in the prior art, the present invention provides a high-power capacity electrically controlled phase-modulated reflective array antenna based on liquid crystal materials, which solves the problems of high cost and slow response speed in the prior art.

[0005] In order to achieve the above-mentioned purpose of the invention, the technical solution adopted by the present invention is: to provide a high-power capacity electrically controlled phase-modulated reflective array antenna based on liquid crystal material, which includes: a feed source and a reflective array, the feed source is placed above the reflective array, the reflective array includes a plurality of reflective array units, the reflective array units include a radiation patch, a dielectric plate, a liquid crystal layer, and a reflective surface, the dielectric plate is placed above the liquid crystal layer, the radiation patch is placed between the dielectric plate and the liquid crystal layer, and the reflective surface is placed below the liquid crystal layer.

[0006] Furthermore, the reflective array is composed of a periodic structure of reflective array units, the reflective array units are arranged in a rectangular grid, the radiation patches are made into a periodic structure, and the reflective array units are spliced ​​in multiple layers to form an overall reflective array.

[0007] Furthermore, the spacing between the reflective array units is 4.5 mm, the thickness of the radiation patch is 0.15 mm, the thickness of the liquid crystal layer is 100 μm, and the thickness of the dielectric plate is 2 mm.

[0008] Furthermore, the dielectric constant of the dielectric plate is 2.2, and the loss tangent is 0.0009; the dielectric constant of the liquid crystal layer varies in the range of 2.42 to 3.4.

[0009] The beneficial effects of the above further solution are as follows: The defined parameter enables the unit antenna to have good reflection amplitude, phase response, and high-performance indicators at different incident angles.

[0010] Further: The radiation patch is embedded in the reflection array by an etching method.

[0011] The beneficial effects of the above further solution are as follows: By adjusting the voltage of each unit patch, rapid phase adjustment of high-power microwaves can be achieved.

[0012] Further: The feed source, the radiation patch, and the reflecting surface are all metal bodies.

[0013] Further: The feed source is an antenna capable of radiating linearly polarized waves.

[0014] Further: The antenna beam of the feed source is a pencil beam or a shaped beam, and its feeding method is forward feeding or offset feeding.

[0015] Further: The reflecting surface is a metal surface.

[0016] The beneficial effects of the above further solution are as follows: The effective area of the patch is increased, and the electric field strength on the surface of the patch is effectively reduced.

[0017] The beneficial effects of the present invention are as follows:

[0018] 1. The radiation patch uses a "mesh" - shaped patch as the radiation unit, increasing the effective area of the patch and effectively reducing the electric field strength on the surface of the patch.

[0019] 2. The radiation patch is embedded inside the reflection array, and by adjusting the voltage of each unit patch, rapid phase adjustment of high - power microwaves can be achieved.

[0020] 3. It gets rid of the limitation of antenna efficiency caused by the insertion loss of forced feeding, and when achieving high gain, it can maintain high - efficiency performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a top view of the reflection array according to the present invention. [[ID=4l]]

[0022] Figure 2 It is a three - dimensional view of the reflection array antenna according to the present invention.

[0023] Figure 3 It is a top view of the radiation patch according to the present invention.

[0024] Figure 4 It is a front view of the reflection array unit according to the present invention.

[0025] Figure 5The numerical simulation results of the reflection amplitude and phase response of the example unit antenna at 35 GHz, normal incidence and 30° oblique incidence.

[0026] Figure 6 For example, the array antenna is at 35 GHz. Directional pattern of a surface and its orthogonal plane.

[0027] Figure 7 3D radiation patterns of the embodiment array antenna at different scanning angles at 35 GHz.

[0028] Figure 8 1 is the antenna gain result of the embodiment array antenna at different scanning angles at 35 GHz.

[0029] Figure 9 The electric field distribution of the dielectric patch inside the embodiment array antenna at 35 GHz.

[0030] Figure 10 The electric field distribution on the dielectric surface of the embodiment array antenna at 35 GHz is shown in FIG.

[0031] Among them: 1. Feed source; 2. Reflection array; 3. Radiation patch; 4. Dielectric plate; 5. Liquid crystal layer; 6. Reflection surface. DETAILED DESCRIPTION

[0032] The specific embodiments of the present invention are described below to facilitate understanding of the present invention by those skilled in the art. However, it should be clear that the present invention is not limited to the scope of the specific embodiments. For those skilled in the art, as long as various changes are within the spirit and scope of the present invention as defined and determined by the appended claims, these changes are obvious, and all inventions and creations utilizing the concepts of the present invention are protected.

[0033] In one embodiment of the present invention, it includes a feed source 1 and a reflective array 2, wherein the feed source 1 is placed above the reflective array 2, and the reflective array unit includes a radiation patch 3, a dielectric plate 4, a liquid crystal layer 5, and a reflective surface 6, wherein the dielectric plate 4 is placed above the liquid crystal layer 5, the radiation patch 3 is placed between the dielectric plate 4 and the liquid crystal layer 5, and the reflective surface 6 is placed below the liquid crystal layer 5.

[0034] The present invention replaces the existing technical method of using phase shifters by adopting a mature technical method with low manufacturing process price combined with a low-cost variable capacitor structure. Based on the low-cost and mature PCB etching process, the radiation structure can be more conveniently manufactured, thereby reducing the cost of the antenna.

[0035] like Figure 1As shown, the reflection array 2 is composed of reflection array units with a periodic structure having a pitch of 4.5 mm. The reflection array units are arranged in a rectangular grid pattern. The radiation patch 3 is fabricated into a periodic structure. The reflection array units are spliced in multiple layers to form the overall reflection array 2.

[0036] As Figure 2 shown, the feed source 1 is an antenna placed above the reflection array 2 and capable of radiating linearly polarized waves. Moreover, the feed source 1 is a metal body, its antenna beam is a pencil beam or a shaped beam, and its feeding method is front-feed or offset-feed.

[0037] As Figure 3 shown, the side length L1 of the square is 2.1 mm, the shortest distance L2 between the square and the "eye" - shaped patch is 0.3 mm, the outer length L3 of the "eye" - shaped patch is 0.15 mm, the inner length L4 of the "eye" - shaped patch is 0.2 mm, the shorter side W of the "eye" - shaped patch is 0.8 mm, and the radiation patch 3 is a metal body.

[0038] As Figure 4 shown, the dielectric plate 4 is placed above the liquid crystal layer 5, the radiation patch 3 is placed between the dielectric plate 4 and the liquid crystal layer 5, the reflecting surface 6 is placed below the liquid crystal layer 5. The thickness of the radiation patch 3 is 0.15 mm, the thickness of the liquid crystal layer 5 is 100 μm, and the thickness of the dielectric plate 4 is 2 mm. The dielectric plate 4 uses Rogers 5880, its dielectric constant is 2.2, and its loss tangent is 0.0009. The dielectric constant variation range of the liquid crystal layer 5 is 2.42 - 3.4. The radiation patch 3 uses the "eye" - shaped patch as the radiation unit, which increases the effective area of the radiation patch 3, effectively reduces the electric field strength on the patch surface. At the same time, burying the radiation patch between the dielectric plate 4 and the liquid crystal layer 5 forms a sandwich structure, which improves the power capacity of the reflection array 2 antenna.

[0039] In this embodiment, the operating frequency point of the antenna is 35 GHz. When a TM - polarized plane wave is input at the plane - wave port to excite the reflection array 2 units, the reflection amplitude - phase response results corresponding to different dielectric constants are as Figure 5 shown. At the operating frequency of 35 GHz, the reflection amplitude - phase response stability is good under normal incidence and 30° oblique incidence. When the dielectric constant changes from 2.42 to 3.4, a phase compensation of 305° can be achieved, and the reflection amplitude remains greater than - 8.6 dB. At different incident angles, the unit can achieve good reflection amplitude and phase responses. At the operating frequency, about 35% of the dielectric constants correspond to a reflection amplitude lower than - 3 dB. Therefore, for a relatively large antenna array, the loss results of the unit are relatively good.

[0040] In this embodiment, the above-mentioned reflectarray 2 units are used to construct an 11×11 reflectarray antenna with a rectangular grid arrangement. A linearly polarized pyramidal feed antenna is used as the feed antenna. The reflectarray is fed with a 10° offset and the dielectric constant of the unit is adjusted to achieve the corresponding phase compensation. The simulation results show that at an operating frequency of 35GHz, the main beam direction is (θ = 10°, ), the far-field pattern of the antenna is as follows Figure 6 As shown, the antenna gain is 20.7dB, the corresponding aperture efficiency is 28%, and the sidelobe level is -18.1dB, achieving good directional beam radiation.

[0041] In this embodiment, under different beam scanning angles, the 3D radiation pattern and its gain results at the center frequency of 35 GHz are as follows: Figure 7 and Figure 8 As shown, within the scanning range of 0 to 40 degrees, the antenna gain varies by approximately 3 dB, achieving pencil beam radiation in the specified direction. When the main beam is 20 degrees, the antenna achieves a maximum gain of 21.7 dB, corresponding to an aperture efficiency of 35.3%, demonstrating the beam scanning performance of the designed antenna.

[0042] In this embodiment, when the operating frequency is 35 GHz, the electric field distribution of the electrically controlled phase-modulated reflective array antenna is as follows: Figure 9 and Figure 10 As shown, when the input power is 0.5W, the maximum electric field strength of the internal patch is 11118V / m. Calculated based on the internal breakdown threshold of the liquid crystal of 30MV / m, its power capacity is about 3.6MW; the maximum electric field strength on the antenna surface is 750V / m; calculated based on the breakdown threshold in air of 3MV / m, its surface power capacity is 8MW, so the main limiting point of the power capacity of the reflectarray antenna is on the internal patch, and its power capacity is 3.6MW. The results show that the reflectarray antenna has the potential for high-power-capacity microwave applications.

[0043] In the description of the present invention, it should be understood that the terms "center", "thickness", "upper", "lower", "horizontal", "top", "bottom", "inner", "outer", "radial", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only and cannot be understood as indicating or implying the relative importance or the number of technical features implicitly specified. Therefore, the features defined by "first", "second", and "third" may explicitly or implicitly include one or more of such features.

[0044] This invention utilizes a nematic liquid crystal material of a defined thickness to achieve fast-response, electrically controlled phase modulation, overcoming the long response times associated with conventional high-power antennas that rely on mechanically rotating beamforms for beam steering. The reflectarray antenna overcomes the efficiency limitations imposed by insertion loss associated with forced feeds, maintaining high efficiency while achieving high gain.

Claims

1. A high power capacity electrically controlled phase-modulated reflective array antenna based on liquid crystal material, characterized in that: include: A feed source (1) and a reflective array (2), wherein the feed source (1) is placed above the reflective array (2), the reflective array (2) comprises a plurality of reflective array units, the reflective array units comprising a radiation patch (3), a dielectric plate (4), a liquid crystal layer (5) and a reflective surface (6), the dielectric plate (4) is placed above the liquid crystal layer (5), the radiation patch (3) is placed between the dielectric plate (4) and the liquid crystal layer (5), and the reflective surface (6) is placed below the liquid crystal layer (5); the unit spacing of the reflective array (2) is 4.5 mm, the thickness of the radiation patch (3) is 0.15 mm, the thickness of the liquid crystal layer (5) is 100 μm, and the thickness of the dielectric plate (4) is 2 mm; the dielectric constant of the dielectric plate (4) is 2.2, and the loss tangent is 0.0009; the dielectric constant of the liquid crystal layer (5) varies in the range of 2.42 to 3.4; the radiation patch (3) uses a "mesh"-shaped patch as a radiation unit.

2. The high power capacity electrically controlled phase-modulated reflective array antenna based on liquid crystal material according to claim 1, characterized in that: The reflective array (2) is composed of a periodic structure of reflective array units, the reflective array units are arranged in a rectangular grid, the radiation patch (3) is made into a periodic structure, and the reflective array units are multi-layered to form an overall reflective array (2).

3. The high power capacity electrically controlled phase-modulated reflectarray antenna based on liquid crystal material according to claim 1, characterized in that: The radiation patch (3) is embedded between the dielectric plate (4) and the liquid crystal layer (5) by an etching method.

4. The high power capacity electrically controlled phase-modulated reflective array antenna based on liquid crystal material according to claim 1, characterized in that: The feed source (1), the radiation patch (3) and the reflection surface (6) are all metal bodies.

5. The high power capacity electrically controlled phase-modulated reflectarray antenna based on liquid crystal material according to claim 4, characterized in that: The feed source (1) is an antenna capable of radiating linearly polarized waves.

6. The high power capacity electrically controlled phase-modulated reflectarray antenna based on liquid crystal material according to claim 5, characterized in that: The antenna beam of the feed source (1) is a pencil beam or a shaped beam, and its feeding mode is forward feeding or offset feeding.

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