A dual circularly polarized ultra-wideband conformal antenna

Abstract

The present invention discloses a dual circularly polarized ultra-wideband conformal antenna. The antenna includes a conical radiation array and a cylindrical feeding network from top to bottom. The conical radiation array includes a coupled microstrip line, a hollow conical dielectric substrate and a conical Vivaldi array from outside to inside. The cylindrical feeding network includes a first feeding network, a first cylindrical dielectric substrate, a cylindrical metal floor, a second cylindrical dielectric substrate and a second feeding network from outside to inside. The cylindrical feeding network is connected to the conical radiation array by welding. By exciting the second port of the second feeding network, a right-handed circularly polarized beam is formed, and by exciting the fourth port of the first feeding network, a left-handed circularly polarized beam is formed. The present invention has the advantages of complete conformality, extremely wide bandwidth and low cost, and is suitable for an ultra-wideband conical conformal platform antenna system.

Description

Technical Field

[0001] The present invention relates to antenna technology, and in particular to a dual circularly polarized ultra-wideband conformal antenna, which can be applied to an ultra-wideband conformal platform antenna system for communication, detection, etc. Background Art

[0002] Circularly polarized antennas have the advantages of suppressing multipath interference and polarization mismatch, and have been widely used in various wireless systems, such as satellite communications, global positioning systems, wireless LANs, etc. At the same time, in order to support high data rate communications and high-resolution detection, the demand for ultra-wideband circularly polarized antennas is also increasing.

[0003] With the development of circular polarization technology, many ultra-wideband circularly polarized antennas with low profile, compact size and excellent radiation performance have emerged. However, most of the research is limited to planar antenna structures, and it is difficult to achieve conformal design with the carrier platform. With the development of airborne radar technology, the research on antennas with high gain, wide bandwidth and easy conformal integration with the platform has gradually become a hot topic. In previous conformal antenna research, the focus was mainly on cylindrical and spherical surfaces, while the front ends of aircraft and missiles were mostly conical in order to minimize wind resistance. When a conformal antenna needs to be conformal to such a platform, its main radiation direction is usually required to be the axial direction, so as to detect or communicate with the target in front. In addition, in order to maintain good aerodynamic characteristics, it is generally required that such conformal antennas cannot destroy the overall structure.

[0004] Therefore, it is of great practical significance to study a fully conformal, ultra-wideband, low-cost circularly polarized conformal antenna. Summary of the invention

[0005] Purpose of the invention: The purpose of the present invention is to provide an ultra-wideband conformal antenna with dual circular polarization.

[0006] Technical solution: A dual circularly polarized ultra-wideband conformal antenna of the present invention comprises a conical radiating array and a cylindrical feeding network, wherein the conical radiating array comprises a coupled microstrip line, a hollow conical dielectric substrate and a conical Vivaldi array, wherein the coupled microstrip line and the conical Vivaldi array are respectively arranged on the outer wall and the inner wall of the hollow conical dielectric substrate; the cylindrical feeding network comprises, from the outside to the inside, a first feeding network, a first cylindrical dielectric substrate, a cylindrical metal floor, a second cylindrical dielectric substrate and a second feeding network, wherein the first feeding network and the second feeding network are coupled and connected via a gap on the cylindrical metal floor; the first feeding network is connected to the coupled microstrip line, and the cylindrical metal floor is connected to the conical Vivaldi array.

[0007] Optionally, the coupled microstrip lines include a first coupled microstrip line, a second coupled microstrip line, a third coupled microstrip line and a fourth coupled microstrip line, and the conical Vivaldi array includes a first Vivaldi unit, a second Vivaldi unit, a third Vivaldi unit and a fourth Vivaldi unit.

[0008] Optionally, the first feeding network includes a first microstrip line, a second microstrip line and a third microstrip line, the first microstrip line is provided with a fourth output port, the second microstrip line is provided with a first isolation port, the third microstrip line is provided with a first feeding port and a second output port, the first feeding network also includes a first output port and a third output port, the first output port, the second output port, the third output port and the fourth output port are respectively connected to the first coupled microstrip line, the second coupled microstrip line, the third coupled microstrip line and the fourth coupled microstrip line.

[0009] Optionally, the cylindrical metal floor includes a first elliptical gap, a second elliptical gap, a third elliptical gap, a fourth elliptical gap, a fifth elliptical gap, a sixth elliptical gap, a first through hole and a second through hole, and the first feeding network and the second feeding network are connected through the first to sixth elliptical gaps and the first through hole and the second through hole, respectively.

[0010] Optionally, the second feeding network includes a fourth microstrip line, a fifth microstrip line and a sixth microstrip line, the fourth microstrip line is provided with a second feeding port and a first metal through hole, the fifth microstrip line is provided with a second metal through hole, and the sixth microstrip line is provided with a second isolation port; the fourth microstrip line passes through the first metal through hole, passes through the first through hole in the cylindrical metal floor, and is connected to the first output port of the first feeding network; the fifth microstrip line passes through the second metal through hole, passes through the second through hole in the cylindrical metal floor, and is connected to the third output port of the first feeding network; the first through hole and the second through hole are both insulating holes.

[0011] Optionally, the first isolation port in the first feeding network and the second isolation port in the second feeding network are connected to a 50-ohm matching load.

[0012] Optionally, the hollow conical dielectric substrate, the first cylindrical dielectric substrate and the second cylindrical dielectric substrate are all wound with F4B material having a thickness of 0.5 mm, a dielectric constant of 2.65 and a loss tangent of 0.001.

[0013] Optionally, the coupled microstrip line, the conical Vivaldi array, the cylindrical metal floor, the first feeding network and the second feeding network are all made of metal copper with a thickness of 0.035 mm.

[0014] Optionally, the first feeding port in the first feeding network is stimulated, the first feeding network and the second feeding network are coupled and connected through the gaps on the cylindrical metal floor, and four currents are output to four coupled microstrip lines in the coupled microstrip line, so that the phases of the four Vivaldi units of the conical Vivaldi array differ by 90°, respectively, to form a left-handed circularly polarized beam;

[0015] The second feeding port in the second feeding network is stimulated, and the first feeding network and the second feeding network are coupled and connected through the gaps on the cylindrical metal floor, and four currents are output to the four coupled microstrip lines in the coupled microstrip line, so that the phases of the four Vivaldi units of the conical Vivaldi array differ by -90°, respectively, to form a right-handed circularly polarized beam.

[0016] Based on the same inventive concept, a wireless communication device of the present invention includes the above-mentioned dual circularly polarized ultra-wideband conformal antenna.

[0017] Beneficial effects: Compared with the prior art, the significant technical effects of the present invention are:

[0018] The present invention utilizes the relatively soft property of the F4B dielectric substrate material to wind it, thereby achieving complete conformality of the antenna; the antenna of the present invention achieves the advantages of high radiation efficiency, dual circular polarization, and high port isolation while maintaining ultra-wideband and easy conformality, and is suitable for ultra-wideband conical conformal platform antenna systems. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a schematic diagram of the antenna structure of the present invention;

[0020] Figure 2 The expanded view of the conical radiation array of the antenna of the present invention, wherein (a) is the outer wall and (b) is the inner wall;

[0021] Figure 3 It is a side cross-sectional view of the cylindrical feeding network of the antenna of the present invention;

[0022] Figure 4 1 is an expanded view of a cylindrical feeding network of an antenna of the present invention, wherein (a) is an expanded view of a first feeding network, (b) is an expanded view of a cylindrical metal floor, and (c) is an expanded view of a second feeding network;

[0023] Figure 5 The standing wave ratio, gain and axial ratio diagrams of the antenna of the present invention are shown in Figure 1, wherein (a) is a standing wave ratio diagram, and (b) is a gain and axial ratio diagram;

[0024] Figure 6The radiation patterns of the antenna of the present invention are as follows: (a) is a left-hand circularly polarized beam at 5 GHz, (b) is a right-hand circularly polarized beam at 5 GHz, (c) is a left-hand circularly polarized beam at 7.5 GHz, (d) is a right-hand circularly polarized beam at 7.5 GHz, (e) is a left-hand circularly polarized beam at 10 GHz, and (f) is a right-hand circularly polarized beam at 10 GHz. DETAILED DESCRIPTION

[0025] The present invention is described in detail below with reference to the accompanying drawings and specific embodiments.

[0026] The dual circularly polarized ultra-wideband conformal antenna of the present invention adopts a two-piece structure, such as Figure 1 As shown, a conical radiation array 1 is used as a radiation part, and a cylindrical feeding network 2 is used as a feeding part. The conical radiation array 1 is connected to the cylindrical feeding network 2 by welding.

[0027] like Figure 2 As shown in (a) and (b), the conical radiation array of the dual circularly polarized ultra-wideband conformal antenna includes: a coupled microstrip line 11, a hollow conical dielectric substrate 12 and a conical Vivaldi array 13, wherein the coupled microstrip line 11 and the conical Vivaldi array 13 are respectively arranged on the outer wall and the inner wall of the hollow conical dielectric substrate 12. The coupled microstrip line 11 includes a first coupled microstrip line 111, a second coupled microstrip line 112, a third coupled microstrip line 113 and a fourth coupled microstrip line 114. The conical Vivaldi array 13 includes a first Vivaldi unit 131, a second Vivaldi unit 132, a third Vivaldi unit 133 and a fourth Vivaldi unit 134.

[0028] like Figure 3 and Figure 4As shown in (a), (b) and (c) of FIG. 1 , the cylindrical feeding network of the dual circularly polarized ultra-wideband conformal antenna includes, from outside to inside, a first feeding network 21, a first cylindrical dielectric substrate 22, a cylindrical metal floor 23, a second cylindrical dielectric substrate 24 and a second feeding network 25. The first feeding network 21 includes a first isolation port 211, a first feeding port 212, a first output port 213, a second output port 214, a third output port 215, a fourth output port 216, a first microstrip line 217, a second microstrip line 218 and a third microstrip line 219. The cylindrical metal floor 23 includes a first elliptical slot 233, a second elliptical slot 234, a third elliptical slot 235, a fourth elliptical slot 236, a fifth elliptical slot 237, a sixth elliptical slot 238, a first through hole 231 and a second through hole 232. The second feeding network 25 includes a second feeding port 251 , a second isolation port 252 , a fourth microstrip line 253 , a fifth microstrip line 254 , a sixth microstrip line 255 , a first metal via 256 , and a second metal via 257 .

[0029] The fourth microstrip line 253 in the second feeding network 25 passes through the first metal through hole 256, passes through the first through hole 231 in the cylindrical metal floor 23 and does not contact the cylindrical metal floor 23, and is connected to the first output port 213 of the first feeding network 21; the fifth microstrip line 254 in the second feeding network 25 passes through the second metal through hole 257, passes through the second through hole 232 in the cylindrical metal floor 23 and does not contact the cylindrical metal floor 23, and is connected to the third output port 215 of the first feeding network 21.

[0030] In this embodiment, the cylindrical feeding network is connected to the conical radiating array by welding the first output port 213, the second output port 214, the third output port 215, and the fourth output port 216 to the coupled microstrip line 11, and welding the cylindrical metal floor 23 to the bottom of the conical Vivaldi array 13.

[0031] In this embodiment, the first isolation port 211 and the second isolation port 252 are connected to a 50-ohm matching load.

[0032] In this embodiment, the hollow cone dielectric substrate 12, the first cylindrical dielectric substrate 22 and the second cylindrical dielectric substrate 24 are all wound with F4B material with a thickness of 0.5 mm, a dielectric constant of 2.65 and a loss tangent of 0.001. The coupled microstrip line 11, the conical Vivaldi array 13, the first feeding network 21, the second feeding network 25 and the cylindrical metal floor 23 are all made of metal copper with a thickness of 0.035 mm.

[0033] When the antenna is working, the first feeding port 212 is excited, and one current is coupled to the sixth microstrip line 255 through the fifth elliptical slot 237, and then coupled to the first microstrip line 217 through the sixth elliptical slot 238, and then coupled to the fourth microstrip line 253 through the first elliptical slot 233, and output to the first coupled microstrip line 111 through the first output port 213; one current is directly output to the second coupled microstrip line 112 through the third microstrip line 219 and the second output port 214; one current is coupled to the fifth microstrip line 254 through the fourth elliptical slot 236, and then output to the third coupled microstrip line 113 through the second metal through hole 257 and the third output port 215; one current is coupled to the sixth microstrip line 255 through the fifth elliptical slot 237, and then coupled to the first microstrip line 217 through the sixth elliptical slot 238, and output to the fourth coupled microstrip line 114 through the fourth output port 216, so that the phases of the four Vivaldi units differ by 90°, forming a left-handed circularly polarized beam.

[0034] The second feeding port 251 is stimulated, a current passes through the fourth microstrip line 253, and then is output to the first coupled microstrip line 111 through the first metal through hole 256 and the first output port 213; a current is coupled to the second microstrip line 218 through the second elliptical slot 234, and then is coupled to the fifth microstrip line 254 through the third elliptical slot 235, and then is coupled to the third microstrip line 219 through the fourth elliptical slot 236, and finally is output to the second coupled microstrip line 112 through the second output port 214; a current It is coupled to the second microstrip line 218 through the second elliptical slot 234, coupled to the fifth microstrip line 254 through the third elliptical slot 235, and output to the third coupled microstrip line 113 through the second metal through hole 257 and the third output port 215; one current is coupled to the first microstrip line 217 through the first elliptical slot 233, and output to the fourth coupled microstrip line 114 through the fourth output port 216, so that the phases of the four Vivaldi units differ by -90°, forming a right-handed circularly polarized beam.

[0035] Figure 5 (a) is the standing wave ratio curve of the antenna of the present invention. It can be seen that the operating frequency bands of the two ports of the antenna of the present invention are consistent, and the standing wave ratio thereof is lower than 2 in the range of 4-12 GHz, indicating that the impedance matching of the antenna of the present invention is good.

[0036] Figure 5 (b) is the gain and axial ratio curve of the antenna of the present invention. It can be seen that within the working frequency band, the simulated and measured gains of the antenna are both greater than 8dBi, and the axial ratio is less than 3dB in the range of 4-10.5GHz.

[0037] Figure 6 This is the directional diagram of the antenna of the present invention. It can be seen that the antenna of the present invention has good dual circular polarization characteristics, and the main lobe direction is basically radiated in the axial direction, where:

[0038] Figure 6 (a) is the left-hand circularly polarized beam of the antenna of the present invention at 5 GHz;

[0039] Figure 6 (b) is the right-hand circularly polarized beam of the antenna of the present invention at 5 GHz;

[0040] Figure 6 (c) is the left-hand circularly polarized beam of the antenna of the present invention at 7.5 GHz;

[0041] Figure 6 (d) is the right-hand circularly polarized beam of the antenna of the present invention at 7.5 GHz;

[0042] Figure 6 (e) is the left-hand circularly polarized beam of the antenna of the present invention at 10 GHz;

[0043] Figure 6 (f) is the right-hand circularly polarized beam of the antenna of the present invention at 10 GHz;

[0044] The present invention discloses a dual circularly polarized ultra-wideband conformal antenna, which belongs to the field of antenna technology. The antenna utilizes the relatively soft property of the F4B dielectric substrate to achieve complete conformality of the entire antenna, making it easy to conform to the conical platform. The compact structure of the entire antenna is achieved by utilizing the compactly designed feeding network and radiation unit, which greatly reduces the overall size and manufacturing cost of the antenna. The single pulse antenna of the present invention maintains complete conformality of the antenna while achieving ultra-wideband and dual circular polarization, and has the advantages of high gain, low axial ratio, etc., and can be applied to ultra-wideband conical conformal platform antenna systems.

[0045] Based on the same inventive concept, the present invention also provides a wireless communication device, including the above-mentioned dual circularly polarized ultra-wideband conformal antenna.

Claims

1. A dual circularly polarized ultra-wideband conformal antenna, characterized in that: The invention comprises a conical radiation array (1) and a cylindrical feeding network (2); the conical radiation array (1) comprises a coupled microstrip line (11), a hollow conical dielectric substrate (12) and a conical Vivaldi array (13); the coupled microstrip line (11) and the conical Vivaldi array (13) are respectively arranged on the outer wall and the inner wall of the hollow conical dielectric substrate (12); the cylindrical feeding network (2) comprises, from the outside to the inside, a first feeding network (21), a first cylindrical dielectric substrate (22), a cylindrical metal floor (23), a second cylindrical dielectric substrate (24) and a second feeding network (25); the first feeding network (21) and the second feeding network (25) are coupled and connected via a gap on the cylindrical metal floor (23); the first feeding network (21) is connected to the coupled microstrip line (11), and the cylindrical metal floor (23) is connected to the conical Vivaldi array (13); The first feeding port (212) in the first feeding network (21) is excited, and the first feeding network (21) and the second feeding network (25) are coupled and connected through the gaps on the cylindrical metal floor (23), and four currents are output to four sections of coupled microstrip lines in the coupled microstrip line (11), so that the phases of the four Vivaldi units of the conical Vivaldi array (13) differ by 90 degrees, respectively, to form a left-handed circularly polarized beam; The second feeding port (251) in the second feeding network (25) is excited, and the first feeding network (21) and the second feeding network (25) are coupled and connected via the gaps on the cylindrical metal floor (23), and four currents are output to four sections of coupled microstrip lines in the coupled microstrip line (11), so that the phases of the four Vivaldi units of the conical Vivaldi array (13) differ by -90 degrees, respectively, to form a right-handed circularly polarized beam.

2. The dual circularly polarized ultra-wideband conformal antenna according to claim 1, characterized in that: The coupled microstrip line (11) comprises a first coupled microstrip line (111), a second coupled microstrip line (112), a third coupled microstrip line (113) and a fourth coupled microstrip line (114); and the conical Vivaldi array (13) comprises a first Vivaldi unit (131), a second Vivaldi unit (132), a third Vivaldi unit (133) and a fourth Vivaldi unit (134).

3. The dual circularly polarized ultra-wideband conformal antenna according to claim 1, characterized in that: The first feeding network (21) comprises a first microstrip line (217), a second microstrip line (218) and a third microstrip line (219); the first microstrip line (217) is provided with a fourth output port (216); the second microstrip line (218) is provided with a first isolation port (211); the third microstrip line (219) is provided with a first feeding port (212) and a second output port (214); the first feeding network (21) further comprises a first output port (213) and a third output port (215); the first output port (213), the second output port (214), the third output port (215) and the fourth output port (216) are respectively connected to the first coupled microstrip line (111), the second coupled microstrip line (112), the third coupled microstrip line (113) and the fourth coupled microstrip line (114) of the coupled microstrip line (11).

4. The dual circularly polarized ultra-wideband conformal antenna according to claim 1, characterized in that: The cylindrical metal floor (23) comprises a first elliptical gap (233), a second elliptical gap (234), a third elliptical gap (235), a fourth elliptical gap (236), a fifth elliptical gap (237), a sixth elliptical gap (238), a first through hole (231) and a second through hole (232); the first feeding network (21) and the second feeding network (25) are connected respectively via the first to sixth elliptical gaps and the first through hole (231) and the second through hole (232).

5. The dual circularly polarized ultra-wideband conformal antenna according to claim 1, characterized in that: The second feeding network (25) comprises a fourth microstrip line (253), a fifth microstrip line (254) and a sixth microstrip line (255); the fourth microstrip line (253) is provided with a second feeding port (251) and a first metal through hole (256); the fifth microstrip line (254) is provided with a second metal through hole (257); and the sixth microstrip line (255) is provided with a second isolation port (252); the fourth microstrip line (253) is connected to the first metal through hole (25 6), passes through a first through hole (231) in the cylindrical metal floor (23), and is connected to a first output port (213) of the first feeding network (21); the fifth microstrip line (254) passes through a second metal through hole (257), passes through a second through hole (232) in the cylindrical metal floor (23), and is connected to a third output port (215) of the first feeding network (21); the first through hole (231) and the second through hole (232) are both insulating holes.

6. The dual circularly polarized ultra-wideband conformal antenna according to claim 1, characterized in that: The first isolation port (211) in the first feeding network (21) and the second isolation port (252) in the second feeding network (25) are connected to a 50-ohm matching load.

7. The dual circularly polarized ultra-wideband conformal antenna according to claim 1, characterized in that: The hollow cone dielectric substrate (12), the first cylindrical dielectric substrate (22) and the second cylindrical dielectric substrate (24) are all wound using F4B material with a thickness of 0.5 mm, a dielectric constant of 2.65 and a loss tangent of 0.

001.

8. The dual circularly polarized ultra-wideband conformal antenna according to claim 1, characterized in that: The coupled microstrip line (11), the conical Vivaldi array (13), the cylindrical metal floor (23), the first feeding network (21) and the second feeding network (25) are all made of metal copper with a thickness of 0.035 mm.

9. A wireless communication device, characterized in that: An ultra-wideband conformal antenna with dual circular polarization comprising the dual circular polarization described in any one of claims 1-8.

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