A broadband high-gain planar reflectarray

Abstract

The present invention discloses a broadband high-gain planar reflective array. The present invention includes a horn feed and a planar reflective array. The horn feed is arranged directly above the center of the planar reflective array, and the emission center axis of the horn feed is perpendicular to the plane where the planar reflective array is located; the reflective 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 reflective array antenna. The planar reflective array includes a plurality of reflective units, and the horn feed generates an x-polarized or y-polarized illumination wave. Before and after the irradiation of the x-polarized or y-polarized illumination wave of the horn feed, the phase distribution of the plurality of reflective units on the planar reflective array remains unchanged. When the horn feed irradiates, the planar reflective array can generate a high-gain beam in a wide frequency band to achieve a broadband high-gain effect. The broadband high-gain reflective array provided by the present invention is a single-layer planar structure with a low profile, a wide bandwidth, and simple manufacture, and has broad application prospects in the fields of radar and wireless communications.

Description

Technical Field

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

[0002] As a key component of receivers and transmitters in wireless communications, antennas play an irreplaceable role in communication systems. Different communication situations and communication purposes have different requirements for antenna performance. Radar and satellite communication systems have high gain requirements for antennas due to their special communication environment and communication needs. Among all high-gain antennas, planar reflectarray 2 has attracted the attention and research of many companies and research institutes due to its planar structure and low cost. Planar reflectarray 2 converts spherical waves emitted by point sources into plane waves, and ultimately achieves high-gain directional radiation. However, planar reflectarray 2 also has obvious shortcomings: its narrow bandwidth affects its application, so expanding the bandwidth of reflectarray antennas is an inevitable requirement for the development of reflectarray antennas. 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-gain planar reflector array. The present invention improves the bandwidth of the antenna while ensuring the high gain of the antenna, so as to expand the practical application scope of the planar reflector array.

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

[0005] The invention comprises a horn feed source and a plane reflection array. The horn feed source is arranged just above the center of the plane reflection array, and the emission center axis of the horn feed source is perpendicular to the plane where the plane 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 an x-polarized or y-polarized illumination wave, and before and after the irradiation of the x-polarized or y-polarized illumination 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.

[0008] The metal patch layer is composed of a plurality of metal patches obtained by opening three regular hexagonal ring grooves on a regular hexagonal metal plate, which are attached to the dielectric layer in sequence. The three regular hexagonal ring grooves are concentric and the lengths of the sides increase from the inside to the outside. The line connecting the vertex and the center of the innermost regular hexagonal ring groove coincides with the line connecting the vertex and the center of the outermost regular hexagonal ring groove. The line connecting the vertex and the center of the middle regular hexagonal ring groove coincides with the line connecting the vertex and the center of the regular hexagonal metal plate. An angle of 30 degrees is set between the line connecting the vertex and the center of the innermost regular hexagonal ring groove and the line connecting the vertex and the center of the regular hexagonal metal plate. The widths of the three regular hexagonal ring grooves are all the same, which is 0.4 mm.

[0009] The dielectric layer has a relative dielectric constant of 2.2, a relative magnetic permeability of 1, and a thickness of 0.5 mm.

[0010] The relative dielectric constant of the air layer is 1, the relative magnetic permeability is 1, and the thickness is 3 mm.

[0011] The phase distribution of the multiple reflection units on the planar reflection array is a focusing phase distribution.

[0012] The beneficial effects of the present invention are as follows:

[0013] The broadband high-gain reflective array provided by the present invention is a single-layer planar structure with a low profile, a wide bandwidth, and simple manufacturing, and has broad application prospects in the fields of radar and wireless communications. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 Schematic diagram of a reflection unit in a planar reflection array 2 of the present invention;

[0015] Figure 2 It is a schematic diagram of the size change of the metal patch of the reflection unit in the planar reflection array 2 of the present invention;

[0016] Figure 3 It is a schematic structural diagram of a planar reflective array 2 of the present invention;

[0017] Figure 4 16GHz reflectivity and phase curve of the reflection unit of the present invention;

[0018] Figure 5 It is a two-dimensional far-field effect diagram of the E-plane and H-plane of the present invention;

[0019] Figure 6 It is the gain bandwidth diagram of the present invention.

[0020] Figure 7 It is a schematic diagram of the three-dimensional structure of the present invention.

[0021] 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

[0022] 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.

[0023] The technical solution of the present invention is further described in detail below in conjunction with the accompanying drawings and specific implementation plans.

[0024] like Figure 3 and Figure 7 As shown, Figure 3 (a) is the top view of the planar reflectarray antenna structure. Figure 3 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; the phase center of the horn antenna coincides with the focus of the planar reflectarray 2, and the planar reflectarray 2 generates a high-gain beam in a wide frequency band to achieve a wideband high-gain effect.

[0025] like Figure 3 As shown in a, the plane reflection array 2 is arranged symmetrically about the center, the plane reflection array 2 includes a plurality of reflection units 3, the shape of the plane reflection array 2 is a regular hexagon, and the plurality of reflection units 3 are arranged at intervals or not at intervals to form a honeycomb reflection array, and the reflection units 3 with the same center distance as the plane reflection array 2 have the same structure. ; The horn feed source 1 generates an x-polarized or y-polarized illumination wave, and before and after the irradiation of the x-polarized or y-polarized illumination wave of the horn feed source 1, the phase distribution of the plurality of reflection units 3 on the plane reflection array 2 remains unchanged.

[0026] 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. 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.

[0027] The metal patch layer 4 is formed by opening three regular hexagonal ring grooves on a regular hexagonal metal plate to obtain a plurality of metal patches, such as Figure 2 As shown in (a)-(c), multiple metal patches are attached to the dielectric layer 5 in sequence according to their original positions, i.e., positions on the regular hexagonal metal plate. The three regular hexagonal grooves are concentric and the sides lengthen from the inside to the outside. The line connecting the vertex and the center of the innermost regular hexagonal groove coincides with the line connecting the vertex and the center of the outermost regular hexagonal groove. The line connecting the vertex and the center of the middle regular hexagonal groove coincides with the line connecting the vertex and the center of the regular hexagonal metal plate. An angle of 30 degrees is set between the line connecting the vertex and the center of the innermost regular hexagonal groove and the line connecting the vertex and the center of the regular hexagonal metal plate. The widths of the three regular hexagonal grooves are all the same, which is 0.4 mm. The phase modulation of the x-polarization component and the y-polarization component is jointly achieved by adjusting the size of the metal patch and the position of the three regular hexagonal grooves, which jointly determines the reflection phase shift and the effective radiation linear polarization wave in the range of 14-22 GHz. In a specific implementation, the planar reflective array 2 is composed of 850 reflective units; the center interval between adjacent reflective units is 10 mm.

[0028] The dielectric layer 5 has a relative dielectric constant of 2.2, a relative magnetic permeability of 1, and a thickness of 0.5 mm.

[0029] The relative dielectric constant of the air layer 6 is 1, the relative magnetic permeability is 1, and the thickness is 3 mm.

[0030] The phase distribution of the multiple reflection units 3 on the planar reflection array 2 is a focusing phase distribution.

[0031] In a specific implementation, in order to convert the spherical wave emitted by the horn feed source into a plane wave, the plane reflection array 2 needs to present a phase distribution as shown in the following formula:

[0032] φ R (x i ,y i )=k0d i

[0033] in, is the coordinate x i ,y i The phase at k0 is the free space wave vector, d i is the coordinate x i ,y i The distance difference relative to the coordinate origin.

[0034] 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 constituent units. Based on this, the planar reflective array 2 is designed. Figure 1The 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 0.5 mm, the thickness of the air layer is 3 mm, and the planar reflection array 2 realizes the modulation of the reflection phase by adjusting the size of the metal patch layer 4 and the position of the regular hexagonal ring groove.

[0035] 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 dielectric substrate, air layer thickness, gap position, and gap width respectively, and finally determines that the dielectric substrate thickness is 0.5mm, the air layer thickness is 3mm, and the gap width is 0.4mm, thereby obtaining the optimal unit reflection phase curve.

[0036] from Figure 4 It can be seen that the reflection phase of the unit at the center frequency of 16GHz changes greatly, and can achieve a phase change of more than 700 degrees, with high reflection ability and extremely 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.

[0037] The present invention then studies the far-field performance of a single-layer reflective array when illuminated by a horn feed source. Figure 5 The two-dimensional far-field effect diagrams of the E and H surfaces are given. It can be seen that the far-field values ​​of both are almost equal, 30dB, representing a higher gain value. Figure 6 The gain bandwidth diagram is given, and it can be seen that the 1-dB gain bandwidth of the reflective array is greater than 30%, and the 3-dB gain bandwidth is greater than 40%, which has an extremely wide gain bandwidth.

Claims

1. A broadband high-gain planar reflective array, characterized in that: It comprises a horn feed source (1) and a plane reflection array (2), wherein the horn feed source (1) is arranged directly above the center of the plane reflection array (2), and the emission center axis of the horn feed source is perpendicular to the plane where the plane reflection array (2) is located; The planar reflection array (2) is arranged symmetrically about the center, the planar reflection array (2) comprises a plurality of reflection units (3), the planar 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 an x-polarized or y-polarized illumination wave, and before and after the irradiation of the x-polarized or y-polarized illumination wave of the horn feed source (1), the phase distribution of the plurality of reflection units (3) on the planar 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 sequentially stacked up and down; The metal patch layer (4) is composed of a plurality of metal patches obtained by opening three regular hexagonal ring grooves on a regular hexagonal metal plate, which are sequentially attached to the dielectric layer (5), the three regular hexagonal ring grooves are concentric and the length of the sides increases from the inside to the outside, the line connecting the vertex and the center of the innermost regular hexagonal ring groove coincides with the line connecting the vertex and the center of the outermost regular hexagonal ring groove, the line connecting the vertex and the center of the middle regular hexagonal ring groove coincides with the line connecting the vertex and the center of the regular hexagonal metal plate, an angle of 30 degrees is set between the line connecting the vertex and the center of the innermost regular hexagonal ring groove and the line connecting the vertex and the center of the regular hexagonal metal plate, and the width of the three regular hexagonal ring grooves is the same, which is 0.4 mm.

2. A broadband high-gain 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 0.5 mm.

3. A broadband high-gain 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 3 mm.

4. The broadband high-gain planar reflective array according to claim 1, characterized in that: The phase distribution of the multiple reflection units (3) on the planar reflection array (2) is a focusing phase distribution.

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