A complementary source metasurface antenna with wide lobe radiation characteristics

Abstract

The present application belongs to the technical field of microwave antennas, and specifically provides a complementary source metasurface antenna with wide lobe radiation characteristics, to meet the requirements of communication antennas in mobile satellite communication systems, i.e., wide lobe radiation performance, high gain and low profile. The present application changes the omnidirectional radiation mode of the floor to double-beam radiation on the two sides of the ±48° direction by introducing a large-size floor, and then realizes mode synthesis with the omnidirectional side radiation mode of the metasurface structure, thus achieving a metasurface antenna with wide lobe radiation characteristics. Meanwhile, the introduction of a metal microstrip line in the middle of the metasurface structure makes the half-power lobe of the radiation mode more flat and the lobe width larger. Finally, the present application changes the radiation pattern of the feed gap radiation mode by large-size floor design without introducing a monopole antenna, to realize pattern complementation and wide lobe radiation characteristics, while having high gain, lower profile and simple structure.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of microwave antennas, and specifically provides a complementary source metasurface antenna with wide lobe radiation characteristics, which has high gain and is easy to design. BACKGROUND

[0002] With the rapid development of wireless communication technology and demand, people's requirements for communication speed, stability and communication bandwidth of communication system are increasingly improved, especially for mobile satellite communication. The architecture of mobile satellite communication system contains space part, user part and ground part, which supplements and expands the ground mobile communication system by integrating satellite communication and mobile communication. Mobile satellite communication system has many advantages, such as large coverage, no coverage blind area, no geographical limitation, etc. These advantages make mobile satellite communication play a crucial role in broadcasting and emergency communication in the case of serious damage to ground communication. Because the satellites of navigation system are usually operated in the middle orbit of the earth, the angle range of the receiving antenna for positioning service is very wide, usually between the zenith with θ (zenith angle) of 0° and the ground low elevation angle with θ of 70°; at the same time, the antenna needs to have a certain gain in this angle range; therefore, the mobile communication satellite system puts forward strict requirements on the antenna gain at the beam width and low elevation angle.

[0003] Generally, wide-beam radiation antennas will form a complementary source antenna by means of a set of orthogonal magnetic current source and electric current source, thereby realizing the wide-beam radiation characteristics; however, the traditional complementary source antenna needs to introduce a monopole antenna to realize the equivalent current source, resulting in a large profile of the antenna. Therefore, it is of great significance and value to realize the wide lobe radiation performance while making the antenna have a small profile by other methods. SUMMARY

[0004] The present application aims to solve the problems existing in the prior art, and provides a complementary source metasurface antenna with wide lobe radiation characteristics, so as to meet the requirements of communication antenna in mobile satellite communication system, which has wide lobe radiation performance, high gain and low profile.

[0005] To achieve the above-mentioned purpose, the technical scheme adopted by the present application is as follows:

[0006] The complementary source metasurface antenna with wide lobe radiation characteristics comprises, from bottom to top, a lower metal layer 1, a lower dielectric substrate 2, an intermediate metal layer 3, an upper dielectric substrate 4 and an upper metal layer 5 which are sequentially stacked; characterized in that the lower metal layer is a metal feed line, the metal feed line is located on the center line of the lower dielectric substrate; the intermediate metal layer is a metal ground plate, the metal ground plate is provided with a coupling feed slot 6 in the center, and the slot direction of the coupling feed slot is perpendicular to the metal feed line; the upper metal layer is composed of a rectangular metal patch array 5-1 and a metal microstrip line 5-2, and the rectangular metal patch array and the metal microstrip line are both located in the center of the upper dielectric substrate, and the metal microstrip line is arranged in parallel to the metal feed line and divides the rectangular metal patch array into two symmetrical rectangular metal patch sub-arrays.

[0007] Further, the metal ground plate should be square and have a large size, and the side length should be at least 150 mm or more, so that the designed antenna can have stable wide lobe radiation characteristics; at the same time, after the size of the metal ground plate meets the above condition, the 3dB lobe width increases with the increase of the side length of the metal ground plate, and the wide lobe radiation characteristics can be strengthened.

[0008] Based on the above technical solution, the beneficial effects of the present application are:

[0009] The present application provides a complementary source metasurface antenna with wide lobe radiation characteristics, which has very significant wide lobe radiation characteristics, high gain and low profile, and is simple in structure and easy to implement; in particular:

[0010] 1) The present application changes the original ground plate radiation mode by introducing a large size ground plate (metal ground plate), from the original omnidirectional radiation mode to the double beam radiation on both sides of the ±48° direction; at the same time, the double beam radiation mode caused by the large size ground plate and the omnidirectional side radiation mode of the metasurface structure realize mode synthesis, and finally realize the metasurface antenna with wide lobe radiation characteristics; and compared with the traditional complementary source antenna, the present application has lower profile; in addition, the large size ground plate can be well integrated into various communication platforms with large metal surfaces such as vehicle-mounted, ship-mounted and airborne, effectively avoiding the influence of the size of the metal ground plate on the radiation performance of the conventional antenna;

[0011] 2) The present application introduces a narrow band metal structure (metal microstrip line) in the middle of the metasurface structure (rectangular metal patch array), without changing the omnidirectional side radiation pattern of the metasurface structure, so that the field distribution of the metasurface is more concentrated on the newly introduced narrow band metal structure and the central metasurface patch, so that the half-power lobe of this radiation mode is more flat, and the lobe width is larger;

[0012] In conclusion, the application realizes the complementary of the radiation pattern by changing the radiation pattern of the feed gap radiation mode through the large size floor design without introducing monopole antenna (increasing the antenna profile) to realize the complementary of the radiation pattern, and then realizing the wide lobe radiation characteristics. BRIEF DESCRIPTION OF DRAWINGS

[0013] Figure 1 Figure 1 is a three-dimensional structure schematic diagram of a complementary source metasurface antenna with wide lobe radiation characteristics in the application; wherein, 1 is a lower metal layer, 2 is a lower dielectric substrate, 3 is an intermediate metal layer, 4 is an upper dielectric substrate, 5 is an upper metal layer, 5-1 is a rectangular metal patch array, 5-2 is a metal microstrip line, and 6 is a coupling feed gap.

[0014] Figure 2 Figure 2 is a top view structure schematic diagram of a complementary source metasurface antenna with wide lobe radiation characteristics in the application.

[0015] Figure 3 Figure 3 is a port S 11 curve.

[0016] Figure 4 Figure 4 is the E-plane pattern and H-plane pattern of a complementary source metasurface antenna with wide lobe radiation characteristics in the embodiment of the application at a frequency point of 4.2 GHz; wherein, (a) is the E-plane pattern, and (b) is the H-plane pattern.

[0017] Figure 5 Figure 5 is a comparison result diagram of the E-plane pattern of a complementary source metasurface antenna with wide lobe radiation characteristics in the embodiment of the application and that of a comparative example at a frequency point of 4.2 GHz. DETAILED DESCRIPTION

[0018] In order to make the purpose, technical scheme and beneficial effects of the application more clear and explicit, the application is further described in detail below in combination with the drawings and examples.

[0019] The embodiment provides a complementary source metasurface antenna with wide lobe radiation characteristics, and the structure thereof is as shown in Figure 1 、 Figure 2As shown, specifically includes: from bottom to top sequentially stacked lower metal layer 1, lower layer dielectric substrate 2, intermediate metal layer 3, upper layer dielectric substrate 4 and upper metal layer 5; wherein, the lower metal layer 1 is a metal feed line, the metal feed line is located in the lower layer dielectric substrate on the center line; the intermediate metal layer 3 is a metal ground plate, the metal ground plate is provided with a coupling feed gap 6 in the center, and the opening direction of the coupling feed gap 6 is perpendicular to the metal feed line; the upper metal layer 5 is composed of a rectangular metal patch array 5-1 and a metal microstrip line 5-2, and the rectangular metal patch array and the metal microstrip line are located in the center of the upper layer dielectric substrate 4, and the metal microstrip line is parallel to the metal feed line and divides the rectangular metal patch array into two symmetrical (symmetrical about the metal microstrip line) rectangular metal patch subarrays.

[0020] More specifically: in the embodiment, the upper layer dielectric substrate adopts Taconic RF-35 plate material with a relative dielectric constant of 3.5, which is square with a side length of 300 mm and a height of 4 mm; the lower layer dielectric substrate adopts Neltec NY9260 plate material with a relative dielectric constant of 2.6, which is square with a side length of 300 mm and a height of 0.8 mm; accordingly, the intermediate metal layer (metal ground plate) is also square with a side length of 300 mm, that is, a large ground plate design; the size of the coupling feed gap is 2 mm wide and 10 mm long; the size of the metal feed line is 2.4 mm wide and 158 mm long; in the rectangular metal patch array, the long side of the rectangular metal patch unit (radiation unit) is parallel to the metal microstrip line, the size of the two rows of radiation units adjacent to the coupling feed gap in the rectangular metal patch array is 4.4 mm wide and 8 mm long, and the size of the two rows of radiation units away from the coupling feed gap is 4 mm wide and 8 mm long; the size of the metal microstrip line is 1 mm wide and 17.2 mm long. It should be noted that the above structure sizes are exemplary preferred values provided by the embodiment, and in actual application, under the complementary source metasurface antenna structure design with wide lobe radiation characteristics of the application, the specific structure size can be adaptively optimized and adjusted according to application requirements, for example, the size of the metal ground plate can be changed according to different application scenarios.

[0021] Meanwhile, the application also provides a comparative example, which is only different from the embodiment in that the upper metal layer 5 is only composed of a rectangular metal patch array 5-1.

[0022] The simulation test results of the complementary source metasurface antenna with wide lobe radiation characteristics in the embodiment and the comparative example are as shown in Figures 3-5 , and are as follows:

[0023] As shown in Figure 3 , the S 11The curve shows a good reflection coefficient, and the antenna has a 10dB matching frequency band of 4.10-4.33GHz, and a relative bandwidth of 5.6%.

[0024] As shown in Figure 4 Fig. 4 is an E-plane radiation pattern and an H-plane radiation pattern of the complementary source metasurface antenna at a frequency of 4.2GHz in the embodiment; as shown in the figure, the gain of the antenna at the frequency of 4.2GHz is 5.92dBi, and the 3dB beam width is 150°; in combination Figure 3 With Figure 4 It can be seen that the complementary source metasurface antenna in the embodiment has a wide-beam radiation characteristic and a high gain.

[0025] As shown in Figure 5 Fig. 5 is a comparison result of the E-plane radiation pattern of the complementary source metasurface antenna and the comparative example at a frequency of 4.2GHz in the embodiment; as can be seen from the comparison of the two E-plane radiation patterns, the 3dB beam width of the comparative example at the frequency of 4.2GHz is reduced to 132°; thus, it can be seen that the structure design of the metal microstrip line effectively widens the beam of the antenna radiation pattern, and makes the antenna radiation pattern more flat.

[0026] The above is only a specific embodiment of the present application, any feature disclosed in the specification can be replaced by other equivalent or similar purpose features unless specifically described; all features disclosed, or steps in all methods or processes, except for mutually exclusive features and / or steps, can be combined in any way.

Claims

1. A complementary source metasurface antenna with wide-lobe radiation characteristics, comprising: The following layers are stacked sequentially from bottom to top: a lower metal layer (1), a lower dielectric substrate (2), an intermediate metal layer (3), an upper dielectric substrate (4), and an upper metal layer (5); characterized in that the lower metal layer is a metal feed line, which is located on the center line of the lower dielectric substrate; the intermediate metal layer is a metal ground plane, and a coupling feed gap (6) is opened in the center of the metal ground plane, the opening direction of the coupling feed gap being perpendicular to the metal feed line; the upper metal layer is composed of a rectangular metal patch array (5-1) and a metal microstrip line (5-2), both the rectangular metal patch array and the metal microstrip line being located at the center of the upper dielectric substrate, the metal microstrip line being parallel to the metal feed line and dividing the rectangular metal patch array into two symmetrical rectangular metal patch sub-arrays; the metal ground plane is square, and the side length should be more than 150 mm.

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