Integrated low-profile broadband programmable metasurface antenna

Abstract

The invention discloses an integrated low-profile broadband programmable metasurface antenna which comprises an antenna cover, an integrated low-profile programmable metasurface and a structural frame. The integrated low-profile programmable metasurface comprises an integrated low-profile programmable metasurface array surface; the integrated low-profile programmable metasurface array surface comprises a plurality of integrated low-profile programmable metasurface units; the integrated low-profile programmable metasurface unit is sequentially provided with a metal radiation patch, an upper dielectric substrate, a bias control line layer, a semi-cured bonding sheet layer and a strip line feed network layer; the metal radiation patch is printed on the front side of the upper dielectric substrate, the bias control line layer is printed on the rear side of the upper dielectric substrate, and the upper dielectric substrate is bonded with the strip line feed network layer through the semi-cured bonding sheet layer. The invention has the advantages of low profile, low power consumption and light weight; the antenna is high in radiation efficiency, and is suitable for the military fields of satellite communication, navigation, unmanned aerial vehicle data link terminals and the like with beam scanning and tracking capabilities.

Description

Technical Field

[0001] The present invention relates to the technical field of metasurface antennas, and in particular to an integrated low-profile broadband programmable metasurface antenna. Background Art

[0002] A metasurface is a two-dimensional ultra-thin array plane with significant advantages such as being light and thin and easy to integrate. By designing the metasurface unit structure and arrangement layout, a variety of novel physical properties can be obtained, achieving flexible control of electromagnetic waves. It is the latest research direction of artificial electromagnetic metamaterials in recent years.

[0003] Existing programmable digital metasurfaces mainly include two configurations: reflective and transmissive. Their common feature is that they both require additional spatial excitation feed antennas. Reflective digital metasurfaces have the advantages of simple unit structure and low design complexity, but there is a serious problem of feed source shielding. Transmissive digital metasurfaces solve this problem, but there is still a problem of profile height. Summary of the invention

[0004] The present invention mainly addresses the key constraints of the existing satellite-borne electronic reconnaissance payloads, such as poor direction finding and positioning accuracy, low sensitivity, and inability to conduct continuous and effective detection, and the traditional phased array system generally has high cost, power consumption and weight, and cannot be applied to low-orbit small satellite platforms. The integrated low-profile programmable metasurface adopts a high-efficiency microwave integrated stripline feeding network to replace the traditional space excitation feed source, and highly integrates the radiator, feeding network and bias circuit. It has the advantages of low profile, low power consumption, and light weight. It not only has excellent space scanning and beamforming capabilities, but also has good low sidelobe radiation capabilities, excellent space anti-interference capabilities and precise direction finding and positioning capabilities.

[0005] In order to achieve the above-mentioned objectives, the present invention provides an integrated low-profile broadband programmable metasurface antenna, comprising an antenna cover, an integrated low-profile programmable metasurface and a structural frame; the integrated low-profile programmable metasurface comprises an integrated low-profile programmable metasurface array.

[0006] Preferably, the integrated low-profile programmable metasurface array contains a plurality of integrated low-profile programmable metasurface units; the integrated low-profile programmable metasurface unit is sequentially provided with a metal radiation patch, an upper dielectric substrate, a bias control line layer, a semi-cured bonding sheet layer, and a stripline feeding network layer; the stripline feeding network layer adopts a 144-element unequal-amplitude and different-phase series-parallel hybrid feeding network to reduce beam sidelobes; the metal radiation patch is printed on the front side of the upper dielectric substrate, and the bias control line layer is printed on the back side, and is bonded to the stripline feeding network layer through a semi-cured bonding sheet layer.

[0007] Preferably, the stripline feed network layer comprises a metal floor, an intermediate dielectric substrate, a stripline center conductor, a semi-cured bonding sheet, a lower dielectric substrate and a metal floor in sequence; the metal floor is printed on the front side of the intermediate dielectric substrate, the stripline center conductor is printed on the back side, and is bonded to the front side of the lower dielectric substrate through a semi-cured bonding sheet; the metal floor is printed on the back side of the lower dielectric substrate; the stripline center conductor is located in the medium between the two metal floors, so that the electromagnetic field of the stripline center conductor is surrounded by the medium, thereby reducing electromagnetic radiation and signal interference.

[0008] Preferably, the array surface size of the integrated low-profile programmable metasurface is 342 mm×152 mm×3.5 mm, and the array surface is composed of 18×8=144 integrated low-profile programmable metasurface units arranged periodically.

[0009] Preferably, the integrated low-profile programmable metasurface unit is provided with a diode PIN1 and a diode PIN2, and the two PIN diodes are placed in an anti-symmetrical manner and are located at the junction of the outer metal radiation patch and the inner metal radiation patch. By applying different bias voltages to the two PIN diodes, the radiation beam of the unit can present two different phases of 0 degrees and 180 degrees, corresponding to digital "0" and digital "1" respectively.

[0010] Preferably, the metal radiation patch is composed of an outer metal radiation patch and an inner metal radiation patch; the outer metal radiation patch is elliptical and connected to a metal floor bonded to a lower dielectric substrate through two pairs of symmetrically placed metallized vias; the inner metal radiation patch is Φ-shaped and connected to a bias control layer through a metallized bias connection hole, and transfers energy from a stripline feed network layer through a central metallized probe.

[0011] Preferably, the semi-cured bonding sheet layer is Roger RO4450F with a dielectric constant of 3.52 and a thickness of H3.

[0012] Preferably, the material used for the antenna cover has a dielectric constant of 5, a tangent loss of 0.02, and a thickness of H1.

[0013] Preferably, the material of the structural frame is aluminum plate.

[0014] Preferably, the size of the upper dielectric substrate is 19 mm×19 mm×1.524 mm, the dielectric constant is 3.55, and the thickness is H2; the dielectric constants of the middle dielectric substrate and the lower dielectric substrate are both 3.55, and the thickness is H4.

[0015] The effect achieved by the present invention is remarkable. By applying different bias voltages to the two PIN diodes, the one-piece integrated low-profile programmable metasurface unit can present a phase difference of 180 degrees. Compared with the existing reflection-transmission metasurface, the feed network is used to replace the traditional space excitation feed source, and the radiator, feed network and bias circuit are highly integrated, which has the advantages of low profile, low power consumption and light weight. Compared with the metasurface using a microstrip line feed network, the radiation efficiency is higher, and it is suitable for military fields such as satellite communications, navigation, and drone data link terminals with beam scanning and tracking capabilities. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a schematic diagram of the integrated low-profile broadband codable metasurface structure provided by the present invention.

[0017] Figure 2 This is a structural diagram of the integrated low-profile broadband codable metasurface array of the present invention.

[0018] Figure 3 It is an integrated low-profile broadband codable metasurface stripline feeding network of the present invention.

[0019] Figure 4 This is a structural diagram of the integrated low-profile broadband encodable metasurface unit of the present invention.

[0020] Figure 5 It is an exploded view of the integrated low-profile broadband encodable metasurface unit of the present invention.

[0021] Figure 6 This is a structural dimension diagram (in mm) of the integrated low-profile broadband encodable metasurface unit of the present invention.

[0022] Figure 7 It is a port VSWR characteristic diagram of the integrated low-profile broadband codable metasurface unit of the present invention in two digital states.

[0023] Figure 8 It is the far-field amplitude directional diagram of two digital states of the integrated low-profile broadband codable metasurface unit of the present invention at a frequency of 7.2 GHz.

[0024] Fig. 9 It is the two digital state far-field phase radiation pattern of the integrated low-profile broadband codable metasurface unit of the present invention at a frequency of 7.2 GHz.

[0025] Fig.10 It is a standing wave diagram of the integrated low-profile broadband codable metasurface of the present invention at different scanning angles.

[0026] Fig.11This is a scanning angle diagram of the integrated low-profile broadband codable metasurface of the present invention at a frequency of 7.2GHz phi=0°: wherein, Fig.11 (a) is a coding distribution diagram of the integrated low-profile broadband codable metasurface of the present invention at a scanning angle of phi=0° at a frequency of 7.2 GHz; Fig.11 (b) is the radiation pattern of the integrated low-profile broadband codable metasurface of the present invention at a frequency of 7.2 GHz and a scanning angle of phi=0°.

[0027] Fig.12 This is a scanning angle diagram of the integrated low-profile broadband codable metasurface of the present invention at a frequency of 7.2GHz phi=15°: wherein, Fig.12 (a) is a coding distribution diagram of the integrated low-profile broadband codable metasurface of the present invention at a frequency of 7.2 GHz and a scanning angle of phi=15°; Fig.12 (b) is the radiation pattern of the integrated low-profile broadband codable metasurface of the present invention at a frequency of 7.2 GHz and a scanning angle of phi=15°.

[0028] Fig.13 This is a scanning angle diagram of the integrated low-profile broadband codable metasurface of the present invention at a frequency of 7.2GHz phi=30°: wherein, Fig.13 (a) is a coding distribution diagram of the integrated low-profile broadband codable metasurface of the present invention at a frequency of 7.2 GHz and a scanning angle of phi=30°; Fig.13 (b) is the radiation pattern of the integrated low-profile broadband codable metasurface of the present invention at a frequency of 7.2 GHz and a scanning angle of phi=30°.

[0029] Fig.14 This is a scanning angle diagram of the integrated low-profile broadband codable metasurface of the present invention at a frequency of 7.2GHz phi=45°: wherein, Fig.14 (a) is a coding distribution diagram of the integrated low-profile broadband codable metasurface of the present invention at a frequency of 7.2 GHz and a scanning angle of phi=45°; Fig.14 (b) is the radiation pattern of the integrated low-profile broadband codable metasurface of the present invention at a frequency of 7.2 GHz and a scanning angle of phi=45°.

[0030] Figure numerals: 1 is the antenna cover; 2 is the integrated low-profile programmable metasurface; 3 is the structural frame; 4 is the integrated low-profile programmable metasurface array; 5 is the stripline feeding network; 6 is the integrated low-profile programmable metasurface unit; 101 is the PIN1 diode; 102 is the PIN2 diode; 103 is the metal radiation patch; 104 is the metallized bias connection hole; 105 is the metallized via; 106 is the center metallized probe; 107 is the upper dielectric substrate; 108 is the bias control line layer; 109 is the semi-cured bonding sheet layer; 110 is the stripline feeding network layer; 111 is the metal floor; 112 is the middle dielectric substrate; 113 is the stripline center guide strip; 114 is the semi-cured bonding sheet; 115 is the lower dielectric substrate; 116 is the metal floor; 117 is the inner metal radiation patch; 118 is the outer metal radiation patch. DETAILED DESCRIPTION

[0031] The integrated low-profile broadband encodable metasurface of the present invention is described in detail below with reference to the accompanying drawings:

[0032] The present invention discloses an integrated low-profile broadband programmable metasurface antenna, such as Figure 1 As shown, it includes a radome 1, an integrated low-profile programmable metasurface 2 and a structural frame 3;

[0033] like Figure 2 As shown, the integrated low-profile programmable metasurface 2 includes an integrated low-profile programmable metasurface array 4;

[0034] like Figure 4 As shown, the integrated low-profile programmable metasurface array 4 includes a plurality of integrated low-profile programmable metasurface units;

[0035] like Figure 4 As shown, the integrated low-profile programmable metasurface unit is provided with a metal radiation patch 103, an upper dielectric substrate 107, a bias control line layer 108, a semi-cured bonding sheet layer 109, and a stripline feed network layer 110 in sequence; the stripline feed network layer 110 adopts a 144-element unequal amplitude and different phase series-parallel hybrid feeding network to reduce beam sidelobes; the metal radiation patch 103 is printed on the front side of the upper dielectric substrate 107, and the bias control line layer 108 is printed on the back side, and is bonded to the stripline feed network layer 110 through the semi-cured bonding sheet layer 109.

[0036] like Figure 5As shown, the stripline feed network layer 110 includes a metal floor 111, an intermediate dielectric substrate 112, a stripline center conductor 113, a semi-cured bonding sheet 114, a lower dielectric substrate 115 and a metal floor 116 in sequence; the metal floor 111 is printed on the front side of the intermediate dielectric substrate 112, and the stripline center conductor 113 is printed on the back side, and is bonded to the front side of the lower dielectric substrate 115 through the semi-cured bonding sheet 114; the metal floor 116 is printed on the back side of the lower dielectric substrate 115; the stripline center conductor 113 is located in the medium between the metal floor 111 and the metal floor 116, so that the electromagnetic field of the stripline center conductor 113 is surrounded by the medium, thereby reducing electromagnetic radiation and signal interference.

[0037] like Figure 2 As shown, the array surface size of the integrated low-profile programmable metasurface 4 is 342mm×152mm×3.5mm, and the array surface is composed of 18×8=144 integrated low-profile programmable metasurface units arranged periodically.

[0038] like Figure 5 As shown, the integrated low-profile programmable metasurface unit is provided with a PIN1 diode 101 and a PIN2 diode 102; the two PIN diodes are placed in an anti-symmetrical manner and are located at the junction of the outer metal radiation patch 118 and the inner metal radiation patch 117.

[0039] like Figure 5 As shown, the metal radiation patch 103 is composed of an outer metal radiation patch 118 and an inner metal radiation patch 117; the outer metal radiation patch 118 is elliptical, and is directly connected to the metal floor 116 by penetrating all the middle layers from the outer metal radiation patch 118 through two symmetrically placed metallized vias 105; the inner metal radiation patch 117 is Φ-shaped, and is connected to the bias control line layer 108 by penetrating the upper layer medium through the metallized bias connection hole 104, and transfers energy from the stripline center conductor layer 113 to the inner metal radiation patch 117 through the center metallized probe 106.

[0040] Preferably, the semi-cured bonding sheet layer 109 and the semi-cured bonding sheet layer 114 are both RogerRO4450F with a dielectric constant of 3.52 and a thickness of 0.203 mm.

[0041] Preferably, the material used for the antenna cover 1 has a dielectric constant of 5, a tangent loss of 0.02, and a thickness of 5.5 mm.

[0042] Preferably, the material of the structural frame 3 is an aluminum plate.

[0043] Preferably, the size of the upper dielectric substrate is 19 mm×19 mm×1.524 mm, the dielectric constant is 3.55, and the thickness is 1.524 mm; the dielectric constants of the middle dielectric substrate and the lower dielectric substrate are both 3.55, and the thicknesses are both 0.508 mm.

[0044] The present invention has a significant effect. By applying different bias voltages to the two PIN diodes, the radiation beam of the unit can present two different phases of 0 degree and 180 degree, which correspond to digital "0" and digital "1" respectively; wherein, when encoding "0", the PIN1 diode 101 is in a closed state, and the PIN2 diode 102 is in a conducting state; when encoding "1", the PIN1 diode 101 is in a conducting state, and the PIN2 diode 102 is in a closed state; when any one of the PIN diodes is in a conducting state, it can be equivalent to a series resistance Ron=5.2Ohms, and when any one of the PIN diodes is in a closed state, it can be equivalent to a parallel capacitance Coff=0.025pF.

[0045] In this embodiment, Figure 7 To achieve VSWR<2 in the frequency band of 7.1~7.3GHz, the integrated low-profile programmable metasurface unit has two coding states.

[0046] Figure 8 When the operating frequency is 7.2GHz, the integrated low-profile programmable metasurface unit has two digital state far-field amplitude radiation patterns. When encoding "0", the unit gain is 5.82dB, and when encoding "1", the unit gain is 5.73dB. The gains are similar in the two coding states.

[0047] Fig. 9 When the center operating frequency is 7.2GHz, the integrated low-profile programmable metasurface unit has two digital state far-field radiation phase diagrams, and the phase difference in the two coding states is maintained at 180°.

[0048] By applying different bias voltages on the integrated low-profile programmable metasurface unit, beams in different scanning directions can be achieved. Fig.10 The standing wave diagrams at different scanning angles show that VSWR is less than 2 in the frequency range from 6.62G to 7.7G.

[0049] Figure 11 to Figure 14 It is an integrated low-profile programmable metasurface with coding distribution and corresponding radiation patterns at different scanning angles at the center frequency of 7.2G. The digital code "0" represents a phase of 0°, and the digital code "1" represents a phase of 180°. It realizes real-time dynamic control of the coding state of the integrated low-profile programmable metasurface unit, and the pointing gain reaches 19.9dB at 0°.

[0050] The above content describes the specific embodiments of the present invention in detail. It should be emphasized that the present invention is not limited to the above specific embodiments, and technicians in related fields can make various deformations and modifications within the scope of the claims, but this does not affect the essential content of the present invention.

Claims

1. An integrated low-profile broadband programmable metasurface antenna, characterized in that: It comprises a radome (1), an integrated low-profile programmable metasurface (2) and a structural frame (3); The integrated low-profile programmable metasurface includes an integrated low-profile programmable metasurface array (4); The integrated low-profile programmable metasurface array contains a plurality of integrated low-profile programmable metasurface units (6); The integrated low-profile programmable metasurface unit (6) is provided with a metal radiation patch (103), an upper dielectric substrate (107), a bias control line layer (108), a semi-cured bonding sheet layer (109), and a stripline feed network layer (110) in sequence; The upper dielectric substrate (107) has a metal radiation patch (103) printed on the front side and a bias control line layer (108) printed on the rear side, and is bonded to a stripline feed network layer (110) via a semi-cured adhesive layer (109).

2. The integrated low-profile broadband programmable metasurface antenna according to claim 1, characterized in that: The metal radiation patch (103) is composed of an outer metal radiation patch (118) and an inner metal radiation patch (117).

3. The integrated low-profile broadband programmable metasurface antenna according to claim 1, characterized in that: The stripline feed network layer (110) comprises in sequence a metal floor (111), an intermediate dielectric substrate (112), a stripline center conductor (113), a semi-cured bonding sheet layer (114), a lower dielectric substrate (115) and a metal floor (116); A layer of metal floor (111) is printed on the front side of the intermediate dielectric substrate (112) by a printing process, and a stripline center guide (113) is printed on the rear side, and is bonded to the front side of the lower dielectric substrate (115) by a semi-cured bonding sheet (114); A metal floor (116) is printed on the rear side of the lower dielectric substrate (115).

4. The integrated low-profile broadband programmable metasurface antenna according to claim 1, characterized in that: The array surface (4) of the integrated low-profile programmable metasurface has a size of 342 mm×152 mm×3.5 mm and is composed of 18×8=144 integrated low-profile programmable metasurface units (6) arranged periodically.

5. The integrated low-profile broadband programmable metasurface antenna according to claim 1, characterized in that: The integrated low-profile programmable metasurface unit (6) is provided with a diode PIN1 (101) and a diode PIN2 (102); the diode PIN1 (101) and the diode PIN2 (102) are placed in an anti-symmetrical manner and are located at the junction of an outer metal radiation patch (118) and an inner metal radiation patch (117).

6. The integrated low-profile broadband programmable metasurface antenna according to claim 1, characterized in that: The upper dielectric substrate (107) is symmetrically provided with two metallized vias (105), a metallized bias connection hole (104) and a central metallized probe (106).

7. The integrated low-profile broadband programmable metasurface antenna according to claim 1, characterized in that: The outer metal radiation patch (118) is elliptical, and is connected to the metal floor (116) bonded to the lower dielectric substrate (115) by directly penetrating all the middle layers from the layer of the outer metal radiation patch (118) through two pairs of symmetrically placed metallized vias (105); the inner metal radiation patch (117) is Φ-shaped, and is connected to the bias control line layer (108) by penetrating the upper dielectric substrate (107) through the metallized bias connection hole (104), and transfers energy from the stripline center conductor (113) to the layer of the inner metal radiation patch (117) through the center metallized probe (106).

8. The integrated low-profile broadband programmable metasurface antenna according to claim 1, characterized in that: The antenna cover (1) is made of a material with a dielectric constant of 5, a tangent loss of 0.02 and a thickness of 5.5 mm.

9. The integrated low-profile broadband programmable metasurface antenna according to claim 1, characterized in that: The material of the structural frame (3) is an aluminum plate.

10. The integrated low-profile broadband programmable metasurface antenna according to claim 2, characterized in that: The upper dielectric substrate (107) has a size of 19 mm×19 mm×1.524 mm, a dielectric constant of 3.55, and a thickness of 1.524 mm; the intermediate dielectric substrate (112) and the lower dielectric substrate (115) both have a dielectric constant of 3.55 and a thickness of 0.508 mm.

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