A high power capacity electronically controlled phase-modulating reflectarray antenna based on variable capacitance

Abstract

The application discloses a high-power-capacity electrically-controlled phase-modulated reflective array antenna based on variable capacitance, which comprises a feed source and a reflective array, the feed source is arranged above the reflective array, the reflective array comprises 11*11 reflective array units arranged in a rectangular grid mode, and the reflective array unit comprises, from top to bottom, an upper dielectric plate, a radiation unit, a lower dielectric plate, a variable capacitor, a foam layer and a reflecting surface, and the radiation unit is composed of two radiation patches. The application overcomes the limitation that the response time is long due to the fact that the traditional high-power-capacity antenna adopts a mechanical rotating array surface to control the beam, and has the performances of high power capacity, electrically-controllable beam scanning, flexible array arrangement and easy conforming.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of microwave technology, in particular to a high-power capacity electrically-controlled phase-adjusting reflectarray antenna based on variable capacitance. BACKGROUND

[0002] High-power capacity microwave antenna is one of the key components of high-power microwave system, which realizes the radiation of high-power microwave in a specified direction. With the in-depth development of high-power microwave technology, high-power capacity beam scanning array antenna has been studied to some extent. These studies are mainly devoted to realizing the beam scanning of high-power microwave antenna by using phase shifters or realizing the beam scanning by mechanically rotating the array surface.

[0003] However, these technologies improve the beam scanning performance of high-power capacity antenna, but due to their use of phase shifters, they result in high cost, or their use of mechanical rotation of the array surface results in a heavy body and slow response speed of the beam scanning. SUMMARY

[0004] In view of the above deficiencies in the prior art, the high-power capacity electrically-controlled phase-adjusting reflectarray antenna based on variable capacitance provided by the present application solves the problems of high cost and slow response speed in the prior art.

[0005] In order to achieve the above-mentioned application purposes, the technical scheme adopted by the present application is to provide a high-power capacity electrically-controlled phase-adjusting reflectarray antenna based on variable capacitance, which comprises: a feed source and a reflectarray, the feed source being placed above the reflectarray, the reflectarray comprising 11x11 reflectarray units arranged in a rectangular grid, the reflectarray unit comprising an upper dielectric plate, a radiation unit, a lower dielectric plate, a variable capacitor, a foam layer and a reflecting surface stacked from top to bottom, the radiation unit being composed of two radiation patches.

[0006] Further, the spacing of the reflectarray unit is 22.6mm, the thickness of the radiation patch is 0.15mm, the thickness of the foam layer is 4mm, the thickness of the lower dielectric plate is 0.381mm, and the thickness of the upper dielectric plate is 0.254mm.

[0007] Further, the dielectric constant of the upper dielectric plate and the lower dielectric plate is 2.2, and the loss tangent is 0.0009; the dielectric constant of the foam layer is 1.03, and the loss tangent is 0.0001.

[0008] The beneficial effects of the above-mentioned further scheme are that the limited parameters can realize good reflection amplitude and phase response of the unit antenna at different incident angles, which is the basis for the high performance index of the array antenna of the present application.

[0009] Further, the radiation patch is embedded between the upper dielectric plate and the lower dielectric plate by etching.

[0010] Further, the radiation patch is a "mountain" shaped patch, and the radiation unit is composed of a pair of mirror-symmetrical "mountain" shaped patch structures, and the two "mountain" shaped patch structures are connected by a variable capacitor.

[0011] The above further scheme has the beneficial effect that the beam scanning can be quickly realized by controlling the voltage at both ends of the radiation patch.

[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 the feed mode is normal feed or offset feed.

[0015] Further, the foam layer is made of polymethylacrylimide closed-cell hard material.

[0016] Further, the forming method of the reflecting array is to make the radiation patch layer into a periodic structure, and to splice multiple layers according to the unit structure features to form the overall reflecting array.

[0017] The present application has the beneficial effects that:

[0018] 1. The radiation patch and the variable capacitor are both embedded in the dielectric plate to form a sandwich structure, thereby improving the power capacity of the reflecting array antenna.

[0019] 2. The variable capacitor with high voltage resistance realizes the electrically controlled phase modulation performance with fast response, and overcomes the limitation of long response time caused by the mechanical rotating array surface of the traditional high power capacity antenna for beam control.

[0020] 3. The limitation of antenna efficiency caused by the insertion loss of forced feed is eliminated, and the high efficiency performance can be maintained when high gain is realized. BRIEF DESCRIPTION OF DRAWINGS

[0021] Figure 1 is a top view of the reflecting array of the present application.

[0022] Figure 2 is a three-dimensional view of the high power capacity electrically controlled phase modulation reflecting array antenna based on the variable capacitor of the present application.

[0023] Figure 3 is a top view of the radiation unit of the present application.

[0024] Figure 4 Front view of the reflective array unit of the present application.

[0025] Figure 5 Numerical simulation results of the reflection amplitude and phase response of the example electronically controlled phase-modulated reflective array antenna at 9.3 GHz, normal incidence and 25° oblique incidence.

[0026] Figure 6 Patterns of the example electronically controlled phase-modulated reflective array antenna in two orthogonal planes of the reflective array antenna at 9.3 GHz.

[0027] Figure 7 3D patterns of the example electronically controlled phase-modulated reflective array antenna at 9.3 GHz at different scanning angles.

[0028] Figure 8 Antenna gain results of the example electronically controlled phase-modulated reflective array antenna at 9.3 GHz at different scanning angles.

[0029] Figure 9 Electric field distribution of the example electronically controlled phase-modulated reflective array antenna at 9.3 GHz on the surface of the dielectric of the reflective array antenna.

[0030] Figure 10 Electric field distribution of the example electronically controlled phase-modulated reflective array antenna at 9.3 GHz on the surface of the dielectric of the reflective array antenna.

[0031] Wherein: 1, feed source; 2, reflective array; 3, radiating patch; 4, upper dielectric plate; 5, lower dielectric plate; 6, variable capacitor; 7, polymethacrylimide closed-cell rigid foam; 8, reflecting surface. DETAILED DESCRIPTION

[0032] The specific embodiments of the present application are described below to facilitate the understanding of the present application for those skilled in the art, but it should be clear that the present application is not limited to the scope of the specific embodiments, and for those skilled in the art, it is obvious that various changes are within the spirit and scope of the present application as defined and determined by the appended claims, and all the applications utilizing the concept of the present application are within the scope of protection.

[0033] As Figure 1 , Figure 2 and Figure 4As shown in the figure, in one embodiment of the present application, a rectangular grid arrangement of the reflectarray antenna is constructed by using the above-mentioned antenna unit, which comprises a feed source 1 and a reflectarray 2, the feed source 1 is placed above the reflectarray 2, the reflectarray 2 comprises 11x11 reflectarray units arranged in a rectangular grid, the reflectarray unit comprises an upper layer dielectric plate 4, a radiation unit, a lower layer dielectric plate 5, a variable capacitor 6, a foam layer 7 and a reflecting surface 8 stacked from top to bottom, and the radiation unit is composed of two radiation patches 3. The forming method of the reflectarray 2 is to manufacture the radiation patch layer into a periodic structure, and to splice multiple layers according to the unit structure characteristics to form the overall reflectarray 2.

[0034] Wherein, the feed source 1 is an antenna capable of radiating linearly polarized waves, the antenna beam is a pencil beam or a shaped beam, and the feeding mode is normal feeding or offset feeding. The interval of the reflectarray unit is 22.6mm, the thickness of the radiation patch 3 is 0.15mm, the thickness H1 of the foam layer 7 is 4mm, the thickness H2 of the lower layer dielectric plate 5 is 0.381mm, the thickness H3 of the upper layer dielectric plate 4 is 0.254mm, the dielectric constant of the upper layer dielectric plate 4 and the lower layer dielectric plate 5 is 2.2, and the loss tangent is 0.0009; the dielectric constant of the foam layer 7 is 1.03, and the loss tangent is 0.0001; the radiation patch 3 is embedded between the upper layer dielectric plate 4 and the lower layer dielectric plate 5 by etching method, and the feed source 1, the radiation patch 3 and the reflecting surface 8 are all metal bodies.

[0035] As shown in the figure, Figure 3 In one embodiment of the present application, the radiation unit is composed of two radiation patches 3, the radiation patch 3 is a "mountain" shaped patch, the radiation unit is composed of a pair of mirror-symmetrical "mountain" shaped structure patches, and the two "mountain" shaped structure patches are connected through a variable capacitor. The radiation unit is a square, the longer side L1 of the "mountain" shaped structure patch is 21.2mm, the length L2 of the "mountain" shaped structure patch between the vertical reflecting surfaces is 9.5mm, the length L3 of the "mountain" shaped patch between the vertical reflecting surface and the vertical boundary of the radiation unit is 4.1mm, the length W1 of the "mountain" shaped patch between the horizontal reflecting surface and the boundary of the radiation unit is 7.6mm, the width W2 of the horizontal reflecting surface is 1.4mm, and the length W3 of the "mountain" shaped patch between the vertical reflecting surface and the horizontal boundary of the radiation unit is 2.4mm.

[0036] The present application replaces the existing technology using phase shifters by using a mature technology with low manufacturing process cost and a low-cost variable capacitor structure, realizes the manufacturing of the radiation structure based on the PCB etching process with low cost and mature technology, and reduces the cost of the antenna.

[0037] In an embodiment of the present application, the operating frequency of the antenna is 9.3 GHz, TM linearly polarized plane wave is input into the plane wave port to excite the reflective array unit, and the reflection amplitude and phase response results corresponding to different capacitance values at normal incidence and 25° oblique incidence are shown in Figure 5 At the operating frequency of 9.3 GHz, the reflection phase responses at normal incidence and 25° oblique incidence both satisfy 360° phase compensation, the reflection amplitude at normal incidence is greater than -0.06 dB, and the reflection amplitude at 25° oblique incidence is lower than -0.37 dB. The unit can achieve good reflection amplitude and phase response at different incidence angles. Since the designed unit uses the method of loading multiple capacitors to adjust the phase, a large phase shift is achieved, and the reflection loss is small.

[0038] In an embodiment of the present application, a linearly polarized corner feed antenna is used as a feed antenna to positively feed the reflective array, and the capacitance of each unit variable capacitor is adjusted to achieve corresponding phase compensation. At the operating frequency of 9.3 GHz, when the main beam direction is axial, the far-field pattern results of the antenna in two orthogonal planes are shown in Figure 6 The antenna gain is 23.1 dB, and the sidelobe level is -9.2 dB, achieving good directional beam radiation. At different beam scanning angles, the 3D pattern and gain results at the center frequency of 9.3 GHz are shown in Figure 7 and Figure 8 Within the scanning range of 0-20°, the gain variation of the antenna is about 2 dB, and the pencil beam radiation in the specified direction is achieved, wherein when the main beam is 10°, the antenna achieves a maximum gain of 23.4 dB. The above results prove the beam scanning performance of the designed antenna.

[0039] In an embodiment of the present application, at the operating frequency of 9.3 GHz, the dielectric internal patch electric field distribution and the dielectric surface electric field distribution of the electrically controlled phase-adjusting reflective array antenna are shown in Figure 9 and Figure 10 At an input power of 1 W, the maximum field strength of the internal patch is 3921 V / m, the breakdown threshold in the dielectric substrate is 40 MV / m, the calculated power capacity of the internal patch is 104 MW, and the maximum field strength on the surface of the antenna is 2197 V / m. With a breakdown threshold of 11 MV / m, the power capacity of the reflective array surface is 25 MW. Therefore, the main limiting point of the power capacity of the reflective array antenna is the array surface, and the power capacity is 25 MW. The results show that the reflective array antenna has the potential for high-power capacity microwave applications.

[0040] In the description of the present application, it needs to be understood that the terms "center", "thickness", "upper", "lower", "horizontal", "top", "bottom", "inner", "outer", "radial" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application. In addition, the terms "first", "second", "third" are only for the purpose of description, and cannot be understood as indicating or implying relative importance or implying the number of technical features indicated. Therefore, the features defined by "first", "second", "third" can explicitly or implicitly include one or more of the features.

[0041] The high-power-capacity electrically-controlled phase-modulated reflective array antenna based on variable capacitance provided by the present application has the performance of high power capacity, electrically controllable beam scanning, flexible arraying and easy conforming, and overcomes the limitation that the traditional high-power-capacity antenna uses a mechanically rotating array surface for beam control, resulting in a long response time.

Claims

1. A high-power capacity electrically controlled phase-modulated reflective array antenna based on a variable capacitor, characterized in that, include: Feed source (1) and reflective array (2), the feed source (1) is placed above the reflective array (2), the reflective array (2) includes 11×11 reflective array units arranged in a rectangular grid, the reflective array unit includes an upper dielectric plate (4), a radiating unit, a lower dielectric plate (5), a variable capacitor (6), a foam layer (7) and a reflective surface (8) stacked from top to bottom, and the radiating unit is composed of two radiating patches (3); The spacing of the reflective array units is 22.6 mm, the thickness of the radiation patch (3) is 0.15 mm, the thickness of the foam layer (7) is 4 mm, the thickness of the lower dielectric plate (5) is 0.381 mm, and the thickness of the upper dielectric plate (4) is 0.254 mm. The radiation patch (3) is embedded between the upper dielectric substrate (4) and the lower dielectric substrate (5) by etching. The radiation patch (3) is a "mountain" shaped patch. The radiation unit is composed of a pair of mirror-symmetrical "mountain" shaped structure patches, and the two "mountain" shaped structure patches are connected by a variable capacitor.

2. The high-power capacity electrically controlled phase-modulated reflective array antenna based on variable capacitor according to claim 1, characterized in that: The dielectric constant of the upper dielectric plate (4) and the lower dielectric plate (5) are both 2.2, and the loss tangent is 0.0009; the dielectric constant of the foam layer (7) is 1.03, and the loss tangent is 0.0001.

3. The high-power capacity electrically controlled phase-modulated reflective array antenna based on variable capacitor according to claim 1, characterized in that: The feed source (1), the radiation patch (3), and the reflective surface (8) are all metallic.

4. The high-power capacity electrically controlled phase-modulated reflective array antenna based on variable capacitor according to claim 3, characterized in that: The feed source (1) is an antenna capable of radiating linearly polarized waves.

5. The high-power capacity electrically controlled phase-modulated reflective array antenna based on a variable capacitor according to claim 4, characterized in that: The antenna beam of the feed source (1) is a pencil beam or a shaped beam, and the feeding method is positive feeding or offset feeding.

6. The high-power capacity electrically controlled phase-modulated reflective array antenna based on variable capacitor according to claim 1, characterized in that: The foam layer (7) is made of polymethacrylimide closed-cell rigid material.

7. The high-power capacity electrically controlled phase-modulated reflective array antenna based on variable capacitor according to claim 1, characterized in that: The method for forming the reflective array (2) is as follows: the radiation patch layer is made into a periodic structure, and multiple layers are spliced ​​together with unit structure features to form an overall reflective array (2).

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