Broadband beam scanning conformal array antenna with biconical feed

Abstract

The invention discloses a broadband beam scanning conformal array antenna with a double cone feed, comprising a double cone feed, a semi-cylindrical bandpass array antenna, and a semi-cylindrical band-stop array antenna, wherein the semi-cylindrical bandpass array antenna and the semi-cylindrical band-stop array antenna are connected to form a hollow three-dimensional cylindrical array antenna, wherein the double cone feed is located at the center of the three-dimensional cylindrical array antenna, the double cone feed is used to transmit electromagnetic waves, the semi-cylindrical bandpass array antenna is used to transmit electromagnetic waves, and the semi-cylindrical band-stop array antenna is used to reflect electromagnetic waves, and the three-dimensional cylindrical array antenna is mechanically rotated to change the spatial positions of the semi-cylindrical bandpass array antenna and the semi-cylindrical band-stop array antenna in the three-dimensional cylindrical array antenna to obtain different beam pointing directions, thereby realizing 360° beam scanning in the horizontal plane. The array antenna has the advantages of simple structure, low cost, low loss, good broadband performance, etc.

Description

Technical Field

[0001] The present invention relates to the field of antenna technology, and in particular to a broadband beam scanning conformal array antenna with a double-conical feed. Background Art

[0002] In the prior art, there are two main types of scanning antenna arrays: one is a planar scanning antenna array, which has been widely used due to its excellent features such as thin profile, small size, light weight, and easy integration, but its beam scanning range is limited, its maximum scanning angle is about 120°, and the gain drops sharply as the scanning angle increases during the scanning process, making it impossible to achieve a wider range of scanning; the other is a conformal scanning antenna array, whose antenna units are no longer distributed on the same plane, but conformally on the surface of a three-dimensional carrier, so that its beam scanning range can easily achieve coverage of more than a hemispherical area, and the antenna gain fluctuates less during the scanning process. However, conformal scanning antenna arrays are usually redundant in volume and have a high overall profile, so it is a major challenge to achieve a large angle scanning range with the lowest possible profile.

[0003] Frequency selective surface is a technical means to adjust the characteristics of electromagnetic waves. It is composed of periodically arranged conductive patch units, or a single-layer or multi-layer two-dimensional periodic array structure formed by slotted units on the conductive patch. The frequency selective surface has selective permeability or selective reflectivity to frequency. When the resonant unit of the frequency selective surface resonates at a certain frequency, it can make the electromagnetic wave of this frequency almost completely transmitted, that is, a bandpass frequency selective surface; or the electromagnetic wave is almost completely reflected, that is, a band-stop frequency selective surface. Its unique performance has been widely used in various aspects of military and civilian use, covering most of the electromagnetic spectrum, including microwaves, millimeter waves and infrared bands.

[0004] The best solution for realizing ultra-large-scale spatial scanning with existing technologies is to use conformal antenna arrays. Among them, spherical conformal antenna arrays have the significant disadvantage of being too high in overall profile, resulting in redundant volume. In applications, they face difficulties such as high requirements for carrier space, complex structure, and difficult assembly. Summary of the invention

[0005] The technical problem to be solved by the present invention is how to provide a broadband beam scanning conformal array antenna with simple structure, low cost, low loss and good broadband performance.

[0006] In order to solve the above technical problems, the technical solution adopted by the present invention is: a broadband beam scanning conformal array antenna with a double cone feed, characterized in that it includes a double cone feed, a semi-cylindrical bandpass array antenna, and a semi-cylindrical band-stop array antenna. The semi-cylindrical bandpass array antenna and the semi-cylindrical band-stop array antenna are connected to form a hollow three-dimensional cylindrical array antenna. The double cone feed is located at the center of the three-dimensional cylindrical array antenna. The double cone feed is used to transmit electromagnetic waves. The semi-cylindrical bandpass array antenna is used to transmit electromagnetic waves. When it resonates at a certain working frequency, it can allow electromagnetic waves of this frequency to pass through; the semi-cylindrical band-stop array antenna is used to reflect electromagnetic waves. When it resonates at a certain working frequency, it can allow electromagnetic waves of this frequency to be reflected back on its surface; by mechanically rotating the three-dimensional cylindrical array antenna, the spatial positions of the semi-cylindrical bandpass array antenna and the semi-cylindrical band-stop array antenna in the three-dimensional cylindrical array antenna are changed to obtain different beam pointing directions, thereby realizing 360° beam scanning in the horizontal plane.

[0007] A further technical solution is that the semi-cylindrical bandpass array antenna includes a plurality of bandpass array units, the bandpass array units include a first dielectric layer, a first square metal patch is formed on the upper surface of the first dielectric layer, a second dielectric layer is arranged on the lower side of the first dielectric layer, a first square metal ring and a second square metal patch are formed between the first dielectric layer and the second dielectric layer, the second square metal patch is located in the first square metal ring and the two do not contact each other, and a third square metal patch is formed on the lower surface of the second dielectric layer.

[0008] A further technical solution is that the outer circle of the first square metal ring overlaps with the outer circle of the first dielectric layer, and the first square metal patch, the second square metal patch and the third square metal patch overlap in the upper and lower projection directions.

[0009] A further technical solution is that the semi-cylindrical band-stop array antenna includes a plurality of band-stop array units, the band-stop array unit includes a third dielectric layer, a fourth square metal patch is formed on the upper surface of the third dielectric layer, a fourth dielectric layer is arranged on the lower side of the third dielectric layer, a second square metal ring and a fifth square metal patch are formed between the third dielectric layer and the fourth dielectric layer, the fifth square metal patch is located in the second square metal ring and the two are connected together by a direction bar, and a sixth square metal patch is formed on the lower surface of the fourth dielectric layer.

[0010] A further technical solution is that four direction bars are provided, which are respectively connected to the four sides of the fifth square metal patch and the four sides inside the second square metal ring.

[0011] A further technical solution is that the outer circle of the second square metal ring overlaps with the outer circle of the third dielectric layer, and the fourth square metal patch, the fifth square metal patch and the sixth square metal patch overlap in the upper and lower projection directions.

[0012] The beneficial effects of adopting the above technical scheme are as follows: the bandpass array unit and the bandstop array unit in the scanning conformal array antenna described in the present invention have the advantages of light weight, low profile and simple structure, and the processing cost and difficulty of the array antenna are also greatly reduced; the bandpass array unit and the bandstop array unit structure are symmetrical about the origin center, can realize dual-polarization characteristics, and have low loss characteristics, and have good broadband performance due to their frequency selective surface structure; compared with the electrically controlled beam scanning antenna, the present invention only needs to mechanically rotate to obtain different beam pointing, and realize 360° beam scanning in the horizontal plane, which has the advantages of low cost and simple structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] The present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments.

[0014] Figure 1 is a side schematic diagram of a bandpass array unit in an embodiment of the present invention;

[0015] Figure 2 is a side schematic diagram of a band-stop array unit in an embodiment of the present invention;

[0016] Figure 3 Schematic diagram of a top view of a first square metal ring and a second square metal patch in a bandpass array unit in an embodiment of the present invention;

[0017] Figure 4 is a schematic top view of a second square metal ring and a fifth square metal patch in a band-stop array unit in an embodiment of the present invention;

[0018] Figure 5 is an S-parameter diagram of a bandpass array unit in an embodiment of the present invention;

[0019] Figure 6 is an S-parameter diagram of a band-stop array unit in an embodiment of the present invention;

[0020] Figure 7 A feed source for the conformal array antenna described in an embodiment of the present invention;

[0021] Figure 8 The S-parameter diagram of the broadband beam scanning conformal array antenna feed of the present invention;

[0022] Fig. 9 The directional pattern of the feed source in the broadband beam scanning conformal array antenna of the present invention;

[0023] Fig.10 It is a structural schematic diagram of the conformal array antenna of the present invention;

[0024] Fig.11 It is the normalized radiation pattern of the conformal array antenna of the present invention when mechanically rotated at different angles;

[0025] Among them: 1. first square metal patch; 2. first dielectric layer; 4. second dielectric layer; 5. third square metal patch; 6. fourth square metal patch; 7. third dielectric layer; 9. fourth dielectric layer; 10. sixth square metal patch; 11. first square metal ring; 12. second square metal patch; 13. second square metal ring; 14. fifth square metal patch; 15. directional strip; 16. double cone feed; 17. broadband beam scanning conformal array antenna. DETAILED DESCRIPTION

[0026] The following is a clear and complete description of the technical solutions in the embodiments of the present invention in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0027] In the following description, many specific details are set forth to facilitate a full understanding of the present invention, but the present invention may also be implemented in other ways different from those described herein, and those skilled in the art may make similar generalizations without violating the connotation of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0028] like Fig.10 As shown, an embodiment of the present invention discloses a broadband beam scanning conformal array antenna with a double cone feed, including a double cone feed 16, a semi-cylindrical bandpass array antenna, and a semi-cylindrical band-stop array antenna. The semi-cylindrical bandpass array antenna and the semi-cylindrical band-stop array antenna are connected to form a hollow three-dimensional cylindrical array antenna. The double cone feed 16 is located at the center of the three-dimensional cylindrical array antenna. The double cone feed 16 is used to transmit electromagnetic waves. The semi-cylindrical bandpass array antenna is used to transmit electromagnetic waves. When it resonates at a certain working frequency, it can allow electromagnetic waves of this frequency to pass through; the semi-cylindrical band-stop array antenna is used to reflect electromagnetic waves. When it resonates at a certain working frequency, it can allow electromagnetic waves of this frequency to be reflected back on its surface; by mechanically rotating the three-dimensional cylindrical array antenna, the spatial positions of the semi-cylindrical bandpass array antenna and the semi-cylindrical band-stop array antenna in the three-dimensional cylindrical array antenna are changed to obtain different beam pointing directions, thereby realizing 360° beam scanning in the horizontal plane.

[0029] The biconical feed 16 is placed at the center of the three-dimensional cylindrical array antenna, and the feed is used to transmit electromagnetic waves; the semi-cylindrical bandpass array antenna unit is used to transmit electromagnetic waves, and when it resonates at a certain working frequency, it can make the electromagnetic waves of this frequency pass through the bandpass array antenna unit; the semi-cylindrical band-stop array antenna unit is used to reflect electromagnetic waves, and when it resonates at a certain working frequency, it can make the electromagnetic waves of this frequency reflected back from the band-stop array antenna unit, unlike the bandpass array antenna unit;

[0030] The bandpass array unit and the bandstop array unit are symmetrical about the origin. In the x and y directions on the xoy horizontal plane, the units have the same performance and dual-polarization characteristics. The array antenna can operate at 10GHz, the unit number N×M is 10×10, the antenna diameter is less than 80mm, and the height is less than 200mm. Due to the strong scalability of the array, the design can also be extended to other antenna aperture sizes and frequency bands.

[0031] For further information, see Figure 1 and Figure 3 The semi-cylindrical bandpass array antenna includes 5×10 bandpass array units, and the semi-cylindrical bandpass array antenna includes a plurality of bandpass array units, and the bandpass array unit includes a first dielectric layer 2, a first square metal patch 1 is formed on the upper surface of the first dielectric layer 2, a second dielectric layer 4 is arranged on the lower side of the first dielectric layer 2, a first square metal ring 11 and a second square metal patch 12 are formed between the first dielectric layer 2 and the second dielectric layer 4, the second square metal patch 12 is located in the first square metal ring 11 and the two do not contact each other, and a third square metal patch 5 is formed on the lower surface of the second dielectric layer 4. The outer ring of the first square metal ring 11 overlaps with the outer ring of the first dielectric layer 2, and the first square metal patch 1, the second square metal patch 12 and the third square metal patch 5 overlap in the upper and lower projection directions.

[0032] The first square metal patch 1, the first square metal ring 11, the second square metal patch 12 and the third square metal patch 5 of the proposed bandpass array unit are horizontally placed along the xoy plane, and the bandpass array unit structure is symmetrical about the origin center and presents a three-dimensional structure;

[0033] In the example, the height of the dielectric layer of the bandpass array unit can be selected to be very thin or even non-existent, but considering that a dielectric plate with a certain hardness is required for support, the thickness of the plate is selected to be 0.05 wavelength, that is, h1=2mm; the dielectric layer material of the bandpass array unit is Rogers Ro3003, and the relative dielectric constant is 3.0; in order to make the bandpass array unit transmit electromagnetic waves, the first square metal ring 11 is not connected to the second square metal patch 12, and the width of the first square metal ring 11 is L 13=10mm, the width of the second square metal patch 12 is L 12 =6mm; the first square metal patch 1, the second square metal patch 12 and the third square metal patch 5 of the bandpass array unit are equal in cross-sectional area along the xoy plane, and the width is L 11 =6mm;

[0034] For further information, see Figure 2 and Figure 4 The semi-cylindrical band-stop array antenna is composed of 5×10 band-stop array units, and the semi-cylindrical band-stop array antenna includes a plurality of band-stop array units, and the band-stop array unit includes a third dielectric layer 7, a fourth square metal patch 6 is formed on the upper surface of the third dielectric layer 7, a fourth dielectric layer 9 is arranged on the lower side of the third dielectric layer 7, a second square metal ring 13 and a fifth square metal patch 14 are formed between the third dielectric layer 7 and the fourth dielectric layer 9, the fifth square metal patch 14 is located in the second square metal ring 13 and the two are connected together through a direction bar 15, and a sixth square metal patch 10 is formed on the lower surface of the fourth dielectric layer 9.

[0035] The fourth square metal patch 6, the second square metal ring 13, the fifth square metal patch 14, the direction bar 15 and the sixth square metal patch 10 of the proposed band-stop array unit are placed horizontally along the xoy plane, and the band-stop array unit structure is symmetrical about the origin center and presents a three-dimensional structure; further, the direction bar 15 is provided with four strips, which are respectively connected to the four edges of the fifth square metal patch 14 and the four edges on the inner side of the second square metal ring 13. Further, the outer ring of the second square metal ring 13 overlaps with the outer ring of the third dielectric layer 7, and the fourth square metal patch 6, the fifth square metal patch 14 and the sixth square metal patch 10 overlap in the upper and lower projection directions.

[0036] In the example, the dielectric layer height and material of the band-stop array unit are the same as those of the band-pass array unit, which has the advantages of simple design and simple array antenna processing. In order to make the band-stop array unit reflect electromagnetic waves, the second square metal ring 13 and the fifth square metal patch 14 are connected by a four-channel direction bar 15. The length of the direction bar 15 is L3=1mm, the width is W3=1mm, and the width of the second square metal ring 13 is L 23 = 10mm, the width of the fifth square metal patch 14 is L 22 =6mm;

[0037] Figure 5This is the S-parameter diagram of the bandpass array unit when the operating frequency is 10.0GHz. The unit has a maximum transmission amplitude loss of 0.869dB in the frequency range of 8.0GHz to 12.0GHz. The transmission amplitude loss of the unit is small, and it can be seen from the figure that the bandpass array unit has good broadband performance.

[0038] Figure 6 This is the S-parameter diagram of the bandpass array unit when the band-stop array unit operates at a frequency of 10.0 GHz. The maximum reflection amplitude loss of the unit is 1.525 dB in the frequency range of 8.0 GHz to 12.0 GHz. The reflection amplitude loss of the unit is small, and it can be seen from the figure that the bandpass array unit has good broadband performance.

[0039] Figure 7 The double-cone feed 16 of the broadband beam scanning conformal array antenna of the present invention is located at the center of the three-dimensional cylindrical array antenna, and the feed is used to emit electromagnetic waves;

[0040] Figure 8 The figure is an S-parameter diagram of the double-cone feed of the present invention. The return loss of the double-cone feed is below -10.0 dB in the frequency range of 8.0 GHz to 12.0 GHz, and the double-cone feed has good bandwidth performance.

[0041] Fig. 9 The directional diagram of the biconical feed of the present invention, the gain in each direction of the azimuth plane is substantially the same, indicating that the biconical antenna has a beam coverage of 360° in the horizontal plane;

[0042] See also Fig.10 , the semi-cylindrical bandpass array antenna and the semi-cylindrical band-stop array antenna are sequentially connected along a certain radius of curvature to form a cylindrical broadband beam scanning conformal array antenna 17; relative to the electrically controlled beam scanning antenna, the broadband beam scanning conformal array antenna with a low-profile frequency selective surface of the present invention only needs to mechanically rotate to change the spatial position of the bandpass array antenna and the band-stop array antenna in the array antenna to obtain different beam pointing directions, thereby realizing 360° beam scanning in the horizontal plane;

[0043] Fig.11 The figure is the normalized radiation pattern of the broadband beam scanning conformal array antenna of the low-profile frequency selective surface of the present invention at different mechanical rotation angles when the operating frequency is 10.0 GHz; it can be seen from the figure that the array antenna can realize 360° beam scanning in the horizontal plane;

[0044] In summary, the array antenna described in the embodiment of the present invention has the following advantages:

[0045] (1) The bandpass array unit and the bandstop array unit of the present invention have the advantages of light weight, low profile and simple structure, and the processing cost and difficulty of the array antenna are greatly reduced;

[0046] (2) The bandpass array unit and the bandstop array unit structure of the present invention are symmetrical about the origin center, can realize dual polarization characteristics, and have low loss characteristics, and have good broadband performance due to their frequency selective surface structure;

[0047] (3) Compared with the electrically controlled beam scanning antenna, the broadband beam scanning conformal array antenna based on the low-profile frequency selective surface of the present invention can obtain different beam pointing directions only through mechanical rotation and realize 360° beam scanning in the horizontal plane, which has the advantages of low cost and simple structure.

Claims

1. A broadband beam scanning conformal array antenna with a double cone feed, characterized in that: The invention comprises a double cone feed source (16), a semi-cylindrical bandpass array antenna, and a semi-cylindrical band-stop array antenna. The semi-cylindrical bandpass array antenna and the semi-cylindrical band-stop array antenna are connected to form a hollow three-dimensional cylindrical array antenna. The double cone feed source (16) is located at the center of the three-dimensional cylindrical array antenna. The double cone feed source (16) is used to transmit electromagnetic waves. The semi-cylindrical bandpass array antenna is used to transmit electromagnetic waves. When it resonates at a certain working frequency, it can allow electromagnetic waves of this frequency to pass through. The semi-cylindrical band-stop array antenna is used to reflect electromagnetic waves. When it resonates at a certain working frequency, it can allow electromagnetic waves of this frequency to be reflected back on its surface. By mechanically rotating the three-dimensional cylindrical array antenna, the spatial positions of the semi-cylindrical bandpass array antenna and the semi-cylindrical band-stop array antenna in the three-dimensional cylindrical array antenna are changed to obtain beams with different directions, thereby realizing 360° beam scanning in the horizontal plane. The semi-cylindrical bandpass array antenna comprises a plurality of bandpass array units, wherein the bandpass array units comprise a first dielectric layer (2), a first square metal patch (1) is formed on the upper surface of the first dielectric layer (2), a second dielectric layer (4) is arranged on the lower side of the first dielectric layer (2), a first square metal ring (11) and a second square metal patch (12) are formed between the first dielectric layer (2) and the second dielectric layer (4), the second square metal patch (12) is located inside the first square metal ring (11) and the two do not contact each other, and a third square metal patch (5) is formed on the lower surface of the second dielectric layer (4); the outer ring of the first square metal ring (11) overlaps with the outer ring of the first dielectric layer (2), and the first square metal patch (1), the second square metal patch (12) and the third square metal patch (5) overlap in the upper and lower projection directions; the thickness of the first dielectric plate (2) and the second dielectric plate (4) is h1=2 mm, the relative dielectric constant is 3.0, and the side length of the first square metal patch (1) is L 11 =6mm; the side length L of the first square metal ring (11) 13 =10mm; The semi-cylindrical band-stop array antenna comprises a plurality of band-stop array units, wherein the band-stop array units comprise a third dielectric layer (7), a fourth square metal patch (6) is formed on the upper surface of the third dielectric layer (7), a fourth dielectric layer (9) is arranged on the lower side of the third dielectric layer (7), a second square metal ring (13) and a fifth square metal patch (14) are formed between the third dielectric layer (7) and the fourth dielectric layer (9), the fifth square metal patch (14) is located in the second square metal ring (13) and the two are connected together through a direction bar (15), and a second square metal ring (13) is formed on the lower surface of the fourth dielectric layer (9). a sixth square metal patch (10); four direction bars (15) are provided, which are respectively connected to the four sides of the fifth square metal patch (14) and the four sides on the inner side of the second square metal ring (13); the outer circle of the second square metal ring (13) overlaps with the outer circle of the third dielectric layer (7); the fourth square metal patch (6), the fifth square metal patch (14) and the sixth square metal patch (10) overlap in the upper and lower projection directions; the thickness of the third dielectric plate (7) and the fourth dielectric plate (9) is h1=2 mm, the relative dielectric constant is 3.0, and the side length of the fourth square metal patch (6) is L 21 =6mm; the side length L of the second square metal ring (13) 23 =10mm, the length of the direction strip (15) is L3=1mm, and the width is W3=1mm.

2. The broadband beam scanning conformal array antenna with a double-conical feed according to claim 1, characterized in that: The bandpass array unit operates in the frequency range of 8 GHz to 12 GHz, and the maximum transmission amplitude loss is 0.869 dB.

3. The broadband beam scanning conformal array antenna with a double-conical feed according to claim 1, characterized in that: The band-stop array unit operates in the frequency range of 8 GHz to 12 GHz, and the maximum reflection amplitude loss is 1.525 dB.

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