A broadband and high aperture efficiency planar reflectarray

Abstract

The present invention discloses a broadband high-aperture efficiency planar reflection array. The present invention includes a horn feed and a planar reflection array. The horn feed is located directly above the center of the planar reflection array, and the emission center axis of the horn feed is perpendicular to the plane where the planar reflection array is located; the reflection array performs phase compensation on the electromagnetic signal radiated by the horn feed; the phase center of the horn feed coincides with the focus of the planar reflection array antenna. The planar reflection array includes a plurality of reflection units, and the horn feed generates an irradiation wave. Before and after the horn feed irradiates, the phase distribution of the plurality of reflection units on the planar reflection array remains unchanged. When the horn feed irradiates, the planar reflection array can generate a beam with a higher gain in a wide frequency band, achieving a broadband high-aperture efficiency effect. The planar reflection array of the present invention is a single-layer planar structure with a low profile, a wide bandwidth, a high aperture efficiency, and simple manufacture. It has broad application prospects in the fields of long-distance wireless communications such as radars and satellites.

Description

Technical Field

[0001] The invention relates to an antenna, in particular to a broadband high-aperture efficiency planar reflection array. Background Art

[0002] In wireless communication systems such as communications, radar, navigation, broadcasting, and television, antennas, as devices for receiving and sending electromagnetic waves, have always been an indispensable component. Different application fields have different requirements for antennas. For example, the field of long-distance communications requires antennas with functions such as broadband, high aperture efficiency, and high gain. Among the many existing high-gain antennas, planar reflectarrays have attracted the attention and research of many companies and research institutes due to their advantages such as simple planar structure and low processing cost. However, planar reflectarrays generally have the problems of low aperture efficiency and narrow bandwidth. The aperture efficiency will cause large energy loss, and the narrow bandwidth will limit its application in many scenarios. Summary of the invention

[0003] In order to solve the technical problems mentioned in the background technology, the purpose of the present invention is to provide a broadband and high-aperture-efficiency planar reflectarray. The present invention improves the bandwidth and aperture efficiency of the antenna while ensuring a high gain of the antenna, in order to expand the practical application scope of the planar reflectarray.

[0004] The present invention solves the above technical problems through the following technical solutions:

[0005] The planar reflection array comprises a horn feed and a planar reflection array. The horn feed is placed just above the center of the planar reflection array, and the emission center axis of the horn feed is perpendicular to the plane where the planar reflection array is located.

[0006] The planar reflection array is arranged symmetrically about the center, the planar reflection array includes a plurality of reflection units, the shape of the planar reflection array is a regular hexagon, and the plurality of reflection units are arranged to form a honeycomb reflection array; the horn feed source generates a TE wave or a TM wave, and before and after the irradiation of the TE wave or the TM wave of the horn feed source, the phase distribution of the plurality of reflection units on the planar reflection array remains unchanged.

[0007] Each of the reflection units is composed of a metal patch layer, a dielectric layer, an air layer and a metal back plate which are stacked in sequence from top to bottom.

[0008] The metal patch layer includes a regular hexagonal metal ring and a regular hexagonal metal sheet, which are both laid on the dielectric layer, and the regular hexagonal metal sheet is arranged in the regular hexagonal metal ring. The regular hexagonal metal ring and the regular hexagonal metal sheet are arranged at intervals and the intervals are the same. A rectangular slit extending toward the center of the regular hexagonal metal sheet is respectively opened at each vertex corner of the regular hexagonal metal sheet, and each rectangular slit has a width of 0.2 mm and a length extending to the center of the regular hexagon of 1.4 mm.

[0009] The width of the regular hexagonal metal ring is in the range of 0.3-0.6 mm.

[0010] The spacing between the regular hexagonal metal ring and the regular hexagonal metal sheet is in the range of 0.3-0.6 mm.

[0011] The dielectric layer has a relative dielectric constant of 2.2, a relative magnetic permeability of 1, and a thickness of 1.5 mm.

[0012] The relative dielectric constant of the air layer is 1, the relative magnetic permeability is 1, and the thickness is 2 mm.

[0013] The phase distribution of the multiple regular hexagonal reflection units on the plane reflection array is a focusing phase distribution.

[0014] The phase distribution of the multiple reflection units on the planar reflection array is a focusing phase distribution.

[0015] The beneficial effects of the present invention are as follows:

[0016] The broadband high aperture efficiency reflector array provided by the present invention is a single-layer planar structure with a low profile, a wide bandwidth, a high aperture efficiency, and simple manufacture, and has broad application prospects in the fields of radar and wireless communications. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a schematic diagram of a reflection unit in a planar reflection array of the present invention.

[0018] Figure 2 It is a schematic diagram of the structure of the planar reflection array of the present invention.

[0019] Figure 3 It is the reflection phase curve of the center frequency (10 GHz) and the nearby frequencies of the reflection unit of the present invention.

[0020] Figure 4 It is a two-dimensional far-field effect diagram of the E-plane and H-plane of the present invention.

[0021] Figure 5 It is a gain bandwidth diagram of the present invention and a schematic diagram of aperture efficiency at different frequencies.

[0022] Figure 6 It is a schematic diagram of the three-dimensional structure of the present invention.

[0023] In the figure: 1. Speaker feed, 2. Planar reflection array, 3. Reflection unit, 4. Metal patch layer, 5. Dielectric layer, 6. Air layer, 7. Metal backplane. DETAILED DESCRIPTION

[0024] To make the purpose, technical solution and advantages of the present invention clearer, the technical solution is described clearly and completely below. Based on the present invention, all other improvements and applications obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0025] The technical solution of the present invention is further described in detail below in conjunction with the accompanying drawings and specific implementation plans.

[0026] like Figure 2 and Figure 6 As shown, Figure 2 (a) is the top view of the planar reflectarray antenna structure. Figure 2 The side view (b) is a top view of the structure of the planar reflectarray antenna; the present invention includes a horn feed 1 and a single-layer planar reflectarray 2, the horn feed 1 is arranged directly above the center of the planar reflectarray 2, the horn feed 1 and the planar reflectarray 2 are arranged at intervals, the emission centerline of the horn feed is perpendicular to the plane where the planar reflectarray 2 is located, the x-axis and y-axis are established with the plane where the planar reflectarray 2 is located, the z-axis is perpendicular to the x-axis and the y-axis, and an xyz coordinate system is constructed, the angle between the emission centerline of the horn feed and the z-axis is 0 degrees, and the planar reflectarray 2 performs phase compensation on the electromagnetic signal radiated by the horn feed 1; the phase center of the horn feed 1 coincides with the focus of the planar reflectarray 2, and the planar reflectarray 2 generates a beam with higher gain in a wide frequency band and has higher aperture efficiency.

[0027] like Figure 2 As shown in (a), the plane reflection array 2 is arranged symmetrically about the center, and the plane reflection array 2 is composed of a plurality of regular hexagonal reflection units 3 arranged in a honeycomb shape, that is, the plane reflection array 2 is a honeycomb reflection array, the shape of the plane reflection array 2 is a regular hexagon, and the reflection units 3 with the same center distance from the plane reflection array 2 have the same size. The horn feed 1 generates a TE irradiation wave (x-polarization) or a TM irradiation wave (y-polarization), and before and after the TE wave or TM wave of the horn feed 1 is irradiated, the phase distribution of the plurality of reflection units 3 on the plane reflection array 2 remains unchanged.

[0028] like Figure 1 As shown, each reflection unit 3 is composed of a metal patch layer 4, a dielectric layer 5, an air layer 6 and a metal back plate 7 which are stacked in sequence from top to bottom. The metal patch layer 4, the dielectric layer 5, the air layer 6 and the metal back plate 7 are all regular hexagons. According to actual needs, the metal back plates 7 between two adjacent reflection units are arranged at intervals or connected as a whole.

[0029] Each metal patch layer 4 is laid in the middle of the dielectric layer 5. The metal patch layer 4 is a symmetrical structure. The metal patch layer 4 includes a regular hexagonal metal ring and a regular hexagonal metal sheet. The regular hexagonal metal ring and the regular hexagonal metal sheet are laid on the dielectric layer 5. The regular hexagonal metal sheet is arranged in the regular hexagonal metal ring. The center of the regular hexagonal metal patch with hexagonal slits is located at the same position as the center of the regular hexagonal ring metal patch, and the diagonal directions of the two are consistent; the regular hexagonal metal ring and the regular hexagonal metal sheet are arranged at intervals and the intervals are the same. The regular hexagonal metal sheet is respectively provided with a rectangular slit extending toward the center of the regular hexagonal metal sheet at each vertex. The rectangular slits at each vertex are not connected to each other. After the inner end points of the corresponding rectangular slits at each vertex are connected, the regular hexagonal metal sheet is composed of six trapezoidal metal sheets and a regular hexagonal metal sheet with a smaller side length. The width of each rectangular slit is 0.2mm, and the length extending to the center of the regular hexagon is 1.4mm. The width of the regular hexagonal metal ring ranges from 0.3 to 0.6 mm, and in this embodiment, the width of the regular hexagonal metal ring is 0.5 mm. The spacing between the regular hexagonal metal ring and the regular hexagonal metal sheet ranges from 0.3 to 0.6 mm, and in this embodiment, the spacing is set to 0.5 mm. Phase modulation of the x-polarization component and the y-polarization component of the irradiated wave is achieved by adjusting the size of the metal patch, which determines the reflected phase shift and the effective radiation linear polarization wave in the range of 8-14 GHz. In a specific implementation, the planar reflection array 2 is composed of 271 reflection units 3; the center spacing between adjacent reflection units is 15 mm.

[0030] When the width of the hexagonal metal ring and the spacing between the hexagonal metal ring and the hexagonal metal sheet are changed within the above range, the phase curve of the unit will also change. If the 0.5mm example used in the present invention is not taken, the value will need to be reset, and then the new phase-size (i.e., the size of the reflection unit) curve will be simulated again. Then, the array will be rearranged according to the corresponding relationship between the phase and the size according to the array method described in the present invention.

[0031] The dielectric layer 5 has a relative dielectric constant of 2.2, a relative magnetic permeability of 1, and a thickness of 1.5 mm.

[0032] The relative dielectric constant of the air layer 6 is 1, the relative magnetic permeability is 1, and the thickness is 2 mm.

[0033] The phase distribution of the multiple reflection units 3 on the planar reflection array 2 is a focusing phase distribution.

[0034] In a specific implementation, in order to convert the spherical wave emitted by the horn feed source 1 into a plane wave, it is necessary to make the plane reflection array 2 present the phase distribution shown in the following formula:

[0035]

[0036] in, is the coordinate (xi ,y i ) is the compensation phase provided by the reflection unit 3, k0 is the free space wave vector, d i is the coordinate (x i ,y i ) relative to the phase center point of the horn feed source 1.

[0037] It can be seen that the key to achieving a high-gain reflective array is to set a suitable phase distribution of the reflective units for the incident wave. In order to achieve this phase distribution, it is necessary to control the components of the planar reflective array 2. Based on this, the planar reflective array 2 is designed Figure 1 The reflection unit 3 shown is composed of a metal patch layer 4, a dielectric layer 5, an air layer 6 and a metal back plate 7. In the figure, the thickness of the dielectric substrate is 1.5 mm, the thickness of the air layer is 2 mm, and the planar reflection array 2 realizes the modulation of the reflection phase by adjusting the size of the metal patch layer 4.

[0038] In order to optimize the performance of the reflection unit 3 in the planar reflection array 2 of the invention, the planar reflection array 2 adjusts and controls the thickness of the dielectric substrate and the air layer respectively, and finally determines that the thickness of the dielectric substrate is 1.5 mm and the thickness of the air layer is 2 mm, and obtains the optimal unit reflection phase curve.

[0039] from Figure 3 It can be seen that the reflection phase of the unit at the center frequency of 10GHz changes greatly, and can achieve a phase change of more than 400 degrees, and has a high reflection ability and a strong phase control ability. Using this type of unit, setting the focusing phase distribution, the final comprehensive result is Figure 3 The single-layer planar reflective array 2 is shown.

[0040] This paper studies the far-field performance of a single-layer reflective array when illuminated by a horn feed source. Figure 4 The two-dimensional far-field effect diagrams of the E and H planes are given. It can be seen that the far-field values ​​of both are about 25dB, which is almost the same, representing a higher gain value. Figure 5 The gain bandwidth diagram and the aperture efficiency diagram at different frequencies are given. It can be seen that the 1.5-dB gain bandwidth of this reflectarray is greater than 30%, and the 3-dB gain bandwidth is about 50%. It has an extremely wide gain bandwidth. At the same time, the aperture efficiency is maintained above 40% in the bandwidth of 9-14 GHz, especially in the bandwidth of 11-12 GHz, the aperture efficiency exceeds 70%, and the energy loss is less.

[0041] The above embodiments are used to illustrate the present invention rather than to limit the present invention. Any modification and change made to the present invention within the spirit of the present invention and the protection scope of the claims shall fall within the protection scope of the present invention.

Claims

1. A broadband high aperture efficiency planar reflector array, characterized in that: It comprises a horn feed source (1) and a plane reflection array (2), wherein the horn feed source (1) is placed directly above the center of the plane reflection array (2), and the emission center axis of the horn feed source (1) is perpendicular to the plane where the plane reflection array (2) is located; The plane reflection array (2) is arranged symmetrically about the center, the plane reflection array (2) comprises a plurality of reflection units (3), the plane reflection array (2) is in the shape of a regular hexagon, and the plurality of reflection units (3) are arranged to form a honeycomb reflection array; the horn feed source (1) generates a TE wave or a TM wave, and before and after the TE wave or the TM wave of the horn feed source (1) is irradiated, the phase distribution of the plurality of reflection units (3) on the plane reflection array (2) remains unchanged; Each of the reflection units (3) is composed of a metal patch layer (4), a dielectric layer (5), an air layer (6) and a metal back plate (7) which are stacked in sequence from top to bottom; The metal patch layer (4) comprises a regular hexagonal metal ring and a regular hexagonal metal sheet, the regular hexagonal metal ring and the regular hexagonal metal sheet are both laid on the dielectric layer (5), the regular hexagonal metal sheet is arranged inside the regular hexagonal metal ring, the regular hexagonal metal ring and the regular hexagonal metal sheet are arranged at intervals and the intervals are the same, and each vertex of the regular hexagonal metal sheet is provided with a rectangular slit extending toward the center of the regular hexagonal metal sheet, each rectangular slit has a width of 0.2 mm and a length extending toward the center of the regular hexagon of 1.4 mm; The phase distribution of the multiple reflection units (3) on the planar reflection array (2) is a focusing phase distribution.

2. A broadband high aperture efficiency planar reflective array according to claim 1, characterized in that: The width of the regular hexagonal metal ring is in the range of 0.3-0.6 mm.

3. The broadband high aperture efficiency planar reflective array according to claim 1, characterized in that: The spacing between the regular hexagonal metal ring and the regular hexagonal metal sheet is in the range of 0.3-0.6 mm.

4. The broadband high aperture efficiency planar reflective array according to claim 1, characterized in that: The dielectric layer (5) has a relative dielectric constant of 2.2, a relative magnetic permeability of 1, and a thickness of 1.5 mm.

5. The broadband high aperture efficiency planar reflective array according to claim 1, characterized in that: The air layer (6) has a relative dielectric constant of 1, a relative magnetic permeability of 1, and a thickness of 2 mm.

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