A wide-angle scanning antenna array with metal-bound decoupling structure

Abstract

The application relates to a wide-angle scanning antenna array with a metal edge covering decoupling structure and belongs to the technical field of antennas. The application comprises a first dipole antenna unit, a second dipole antenna unit and a ground plate; the first dipole antenna unit and the second dipole antenna unit are placed at +45 degrees on the ground plate and are connected with the feeding structure of each antenna unit through coaxial probes on the ground plate; metal edge covering is arranged on the side surface of the first dipole antenna unit and the second dipole antenna unit to realize decoupling. The decoupling structure is simple, the decoupling effect is obvious, the active standing wave in the working frequency band is good, and the design requirements of the wide-angle scanning antenna unit are met.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of antennas, and relates to a wide-angle scanning antenna, in particular to a wide-angle scanning antenna array with a metal edge covering decoupling structure. BACKGROUND

[0002] At present, there are extensive studies on the coupling suppression of antennas at home and abroad, and many methods have been found to reduce the coupling effect between antennas, such as adding a periodic structure above the antenna to realize path phase cancellation, such as Wu K.L. et al. in 2017 proposed ADS (array-antenna decoupling surface) by introducing a periodic decoupling circuit on the array antenna, using the decoupling circuit to introduce a second coupling path, which cancels out the original coupling path, thereby realizing the decoupling between the array elements; introducing a special structure between the antennas to realize the cancellation of the induced current between the two antennas, such as Xiumei Shen et al. in 2019 proposed a miniaturized two-element microstrip antenna array. The surface of the electromagnetic bandgap structure (EBG) is applied as the ground plane of two closely arranged patch antennas operating in the 5G new radio frequency band (26 500-29 500 MHz); the coupling energy of the additional branches of the feed network and the antenna is neutralized at the antenna port, such as Shuai Zhang et al. in 2016 proposed a broadband neutralization line to reduce the coupling of compact ultra-wideband (UWB) antennas; using antenna common mode and differential mode for coupling suppression, such as Libi Sun et al.

[19] in 2021 used a mode cancellation method on the spatially dense microstrip antenna to achieve high isolation, and proposed a mode cancellation method based on common mode (CM) and differential mode (DM) synthesis.

[0003] The above decoupling methods applied to the antenna array have problems such as complex decoupling structure design, too many decoupling structures, and increased difficulty in antenna assembly process. Therefore, it is very meaningful to simplify the decoupling structure of the antenna to save the overall work of the antenna. SUMMARY

[0004] Technical problems to be solved

[0005] The above existing decoupling method applied in the antenna array has the problems of complex decoupling structure design, too many decoupling structures, and increased difficulty in antenna assembly process.

[0006] In order to overcome the shortcomings of the above-mentioned prior art, the application provides an antenna with simple decoupling structure, easy to assemble, easy to assemble, and wide-angle scanning.

[0007] Technical scheme

[0008] The application discloses a wide-angle scanning antenna array with a metal edge covering decoupling structure, which is characterized by comprising a first dipole antenna unit, a second dipole antenna unit and a ground plate; the first dipole antenna unit and the second dipole antenna unit are arranged at ±45 degrees on the ground plate and are connected with a feed structure of each antenna unit through a coaxial probe on the ground plate; the top end of the first dipole antenna unit is provided with a slot, and the front surface is provided with an antenna unit, symmetrically printed metal patches and a metal via; the back surface is provided with a feed structure and metal patches, and the metal via is located directly below the top end slot and penetrates through the metal patches from the front surface to the back surface; the bottom end of the second dipole antenna unit is provided with a slot, and the front surface is provided with an antenna unit and symmetrically printed metal patches; the side surfaces of the first dipole antenna unit and the second dipole antenna unit are provided with metal edge covering.

[0009] The application further provides a technical scheme that the antenna unit is a two-arm inclined dipole structure.

[0010] The application further provides a technical scheme that the metal patches on the front surface are in a rectangular structure and are parallel to the inclined arms of the antenna unit.

[0011] The application further provides a technical scheme that the feed structure is an inverted L structure, which comprises three sections with different widths and is used for adjusting impedance matching by changing the line width.

[0012] The application further provides a technical scheme that the first dipole antenna unit and the second dipole antenna unit are printed on a Rogers430 dielectric plate, and the dielectric constant of the Rogers430 dielectric plate is 4.38.

[0013] The application further provides a technical scheme that the coaxial probe is filled with Teflon medium, and the relative dielectric constant of the Teflon medium is 2.08.

[0014] The application further provides a technical scheme that the metal vias are arranged at equal intervals.

[0015] Beneficial effects

[0016] The wide-angle scanning antenna array with the metal edge covering decoupling structure provided by the application is provided with four metal edge coverings on both sides of two dipole antenna units, so that the antenna coupling is reduced in a simple structure, and the function of wide-angle scanning is realized.

[0017] 1. The decoupling structure is simple and has obvious decoupling effect.

[0018] 2. The active standing wave in the working frequency band is good, and the design requirement of the wide-angle scanning antenna unit is met. DETAILED DESCRIPTION

[0019] The accompanying drawings are included to provide a further understanding of the embodiments and are incorporated in and constitute a part of this specification. The drawings are not intended to be restrictive in any way.

[0020] Figure 1 The overall structure of the antenna of the present application;

[0021] Figure 2 The front structure of the first dipole antenna of the present application;

[0022] Figure 3 The back structure of the first dipole antenna of the present application;

[0023] Figure 4 The side edge wrapping structure of the second dipole antenna of the present application;

[0024] Figure 5 The front structure of the second dipole antenna of the present application;

[0025] Figure 6 The back structure of the second dipole antenna of the present application;

[0026] Figure 7 The side edge wrapping structure of the second dipole antenna of the present application;

[0027] Figure 8 The floor plan of the present application;

[0028] Figure 9 The antenna current path of the present application;

[0029] Figure 10 The decoupling structure of the present application and the key parameter analysis;

[0030] Figure 11 Active standing wave of the antenna with or without loading decoupling structure under periodic boundary under angle scanning;

[0031] Figure 12 Active S parameter of the antenna with loading decoupling structure under different scanning angles under periodic boundary.

[0032] 1 - first dipole antenna unit, 2 - second dipole antenna unit, 3 - floor, 101 - top end slot, 102 - metal patch, 103 - front printed antenna unit, 104 - metalized via, 105 - first section feeding structure, 106 - back feeding structure, 107 - second section feeding structure, 108 - third section feeding structure, 109 - metal edge wrapping, 201 - bottom end slot, 202 - front printed antenna unit, 203 - metal patch, 204 - first section feeding structure, 205 - second section feeding structure, 206 - third section feeding structure, 207 - metal edge wrapping, 301 - first opening, 302 - second opening. DETAILED DESCRIPTION

[0033] In order to make the purpose, technical scheme and advantages of the present application more clear, the present application is further described in detail below with reference to the drawings and examples. It should be understood that the specific examples described herein are only used to explain the present application and not to limit the present application. In addition, the technical features involved in each embodiment of the present application described below can be combined with each other as long as they do not conflict with each other.

[0034] The present application provides a decoupling structure with simple structure, which meets the design of high-isolation dual-polarized antenna unit with metal edge wrapping structure of wide-angle scanning antenna. The decoupling structure is simple in form, i.e. metal edge wrapping is performed on four sides of the antenna to form a metal strip perpendicular to the floor, and the metal strips of different polarizations of two antennas are closest. When one polarization of the antenna is excited, through space radiation and induced current, the metal edge wrapping of the antenna and the metal edge wrapping of the closest antenna unit form a reverse current, thereby concentrating the energy coupled to the adjacent antenna unit on the two metal edge wrappings and eliminating it.

[0035] The overall structure is shown in Figure 1 It includes a first dipole antenna unit 1, a second dipole antenna unit 2, and a floor 3, and is composed of three parts. The two antenna units are placed at ±45° on the floor and connected to the feed structure of the antenna unit through the coaxial probe on the floor.

[0036] As shown in Figure 2 , 3 , 4, the first dipole antenna unit 1 is an antenna printed on a Rogers 430 dielectric board, and the dielectric constant of the dielectric board is 4.38. 103 is a front printed antenna unit. The present application adopts a two-arm inclined dipole structure to meet the plug-in adaptation of ±45° dual-polarized antenna. A slot 101 is opened at the top to meet the plug-in requirement. 101 is a top slot to meet the plug-in requirement. 102 is a pair of symmetrically printed metal patches to further widen the beam bandwidth of the antenna. The metallized via hole 104 and the back printed metal patch 106 ensure that the dipole antenna unit 2 can radiate (since the dipole unit 2 is slotted at the bottom, it will cause the metal patch of the radiating part 202 of the dipole antenna 2 to be disconnected, so the two structures of 106 and 104 are needed to provide a complete current loop for the dipole antenna 2 to ensure that the dipole antenna unit 2 can radiate); 105, 107, and 108 are feed structures printed on the back, and the impedance matching is adjusted by changing the line width of 107 and 108, which are connected to the 50Ω coaxial line on the floor 301. And 109 is the metal edge wrapping on both sides of the dielectric board to realize decoupling.

[0037] In order to prevent the current discontinuity of the two arms of the second dipole antenna unit 2, resulting in the zero line of the middle dip of the directional diagram, a path is constructed at the intersection of the second dipole antenna unit 2 for the radiation current of the second dipole antenna unit 2 to pass through, that is Figure 2 A row of metallized vias shown in 104 and Figure 3 The back metal patch shown in 106.

[0038] As shown in Figure 5 , 6 , 7, the dipole antenna unit 2 is printed on the Rogers 430 medium plate, and the dielectric constant of the medium plate is 4.38; 202 is the front printed antenna unit, the present application adopts the two-arm inclined dipole structure, 201 is the bottom slot to meet the plug-in requirements, 203 is a pair of symmetrically printed metal patches to further expand the beam width of the antenna; 204, 205, 205 are printed on the back of the feed structure, and the impedance matching is adjusted by changing the line width of 205 and 206, and is connected with the 50Ω coaxial line on the floor 302. And 207 is the metal edge of the two sides of the medium plate to realize decoupling.

[0039] Due to the design of the metallized via on the first dipole antenna unit 1, the current path of the second dipole antenna unit 2 is: from the right end of the second dipole antenna unit 2 to the right end of the floor, from the front of the first dipole antenna unit 1 to the back of the first dipole antenna unit 1 through the metallized via to contact the left end of the floor, and from the left end of the floor to the left end of the second dipole antenna unit 2. The current path is guided in a way that does not allow the current to enter the second dipole antenna unit 2 orthogonal to the radiation body; and the metal edge 207 is used on both sides of the medium plate.

[0040] As shown in Figure 8 , the floor is provided with holes 301 and 302, and a 50Ω coaxial line is connected to the first dipole antenna unit 1 and the second dipole antenna unit 2 for feeding.

[0041] The specific embodiment analysis is as follows

[0042] Using HFSS simulation software, simulation analysis is carried out before and after the antenna is loaded with decoupling structure, and the simulation results are shown in Figures 9-12 .

[0043] The decoupling edge structure is described as follows, the working current distribution of the decoupling structure is shown in Figure 9 , which refers to the metal edge of the two medium plates, forming a metal strip perpendicular to the floor, and the metal edges closest to the two antennas interact to decouple. Figure 9The text details the current flow path. When the left antenna is excited at the +45° port, the current flows downward through the decoupling structure at the antenna edge. At this time, the metal cladding at the edge of the nearby -45° polarized antenna generates an upward current in the opposite direction, which cancels out the induced electric field of the excited antenna. This significantly reduces the induced current transmitted by the same polarization, achieving the effect of decoupling by the same polarization.

[0044] Figure 10 As shown, the metal cladding height affects the coupling between ports of the two antenna array elements. As the metal cladding height increases, the coupling effect between the antennas gradually weakens, that is, the isolation between the two antenna elements of the array is optimized. When h = 15mm, the isolation is above 20dB. However, when h exceeds a certain value, this decoupling effect weakens and the port isolation decreases.

[0045] Figure 11 Comparison of active |S| antenna scanning angle before and after decoupling antenna design 11 The parameters clearly show that without a decoupling structure, when the scanning angle is 20° and 40°, the antenna is active in the 5.5-6.5GHz frequency band. 11 |Parameter greater than -10dB, active within the operating frequency band|S 11 The parameter is greater than -5dB, meaning the antenna cannot meet basic operational requirements at this point. However, after applying the decoupling structure, with scanning angles of 20° and 40°, the active |S 11 The parameters are mostly below -15dB, fully meeting the matching requirements of antenna array scanning. Compared to active antennas with and without a loaded decoupling structure, the scanning parameters are significantly higher. 11 |Parameters, decoupling structure for active|S 11 The parameter improvement effect is obvious.

[0046] The above analysis describes the active |S| of the antenna before and after loading the decoupling structure. 11 |Parameter details, in addition to considering the decoupling structure loaded under the periodic boundary, also need to pay attention to the active|S|S under different antenna scanning angles. 11 |Parameter performance, such as Figure 12 As shown, the active |S| is in the scanning angle range of 0°-80°. 11 The parameters generally maintain good performance across the operating frequency band, remaining mostly below -10dB. At a scanning angle of 60°-80°, the active |S 11 The parameter exhibits a slight bulge at 5.8 GHz, which may be related to resonance between antenna structures. Overall, the antenna element with this decoupling structure can achieve a wide-angle scan of 70° under periodic boundary conditions.

[0047] Overall, the decoupling structure of the design is simple, the effect is obvious, and it is easy to integrate, easy to array and can realize wide-angle scanning function.

[0048] The above merely illustrates the specific embodiments of the present application, but the protection scope of the present application is not limited thereto, and any skilled person in the art can easily think of various equivalent modifications or replacements within the technical range disclosed by the present application, and these modifications or replacements shall be covered within the protection scope of the present application.

Claims

1. A wide-angle scanning antenna array with metal-bound decoupling structure, characterized in that The antenna comprises a first dipole antenna unit (1), a second dipole antenna unit (2) and a floor (3). The first dipole antenna unit (1) and the second dipole antenna unit (2) are placed on the floor at ±45° and are connected to the feeding structure of each antenna unit through a coaxial probe on the floor (3). The top end of the first dipole antenna unit (1) is slotted, and the front side is provided with an antenna unit, symmetrically printed metal patches and metal vias. The back side is provided with a feeding structure and metal patches, and the metal vias are located directly below the top end slot and pass through the metal patches from the front side to the back side. The bottom end of the second dipole antenna unit (2) is slotted, and the front side is provided with an antenna unit and symmetrically printed metal patches. The back side is provided with a feeding structure. The first dipole antenna unit (1) and the second dipole antenna unit (2) are both provided with metal edges on the side surfaces. The metal edges are provided on the four side edges of the antenna to form a metal strip perpendicular to the floor, and the metal strips of different polarizations of the two antennas are closest to each other. When one of the antennas is excited, through space radiation and induced current, the metal edge of the antenna forms a reverse current with the metal edge of the antenna unit closest to it, thereby concentrating the energy of the excited antenna unit to the adjacent antenna surface and eliminating it.

2. The wide-angle scanning antenna array with metal-bound decoupling structure according to claim 1, characterized in that The antenna unit is a two-arm inclined dipole structure.

3. A wide-angle scanning antenna array with metal-bound decoupling structure according to claim 2, characterized in that The metal patches on the front side are rectangular structures and are parallel to the inclined arms of the antenna unit.

4. The wide angle scanning antenna array with metal-bound decoupling structure according to claim 1, characterized in that The feeding structure is an inverted L structure, which comprises three sections of different widths, and the impedance matching is adjusted by changing the line width.

5. The wide angle scanning antenna array with metal-bound decoupling structure according to claim 1, characterized in that The first dipole antenna unit (1) and the second dipole antenna unit (2) are printed on a Rogers430 dielectric plate, and the dielectric constant thereof is 4.

38.

6. A wide-angle scanning antenna array with metal-bound decoupling structure according to claim 1, characterized in that The coaxial probe is filled with Teflon medium, and the relative dielectric constant thereof is 2.

08.

7. The wide angle scanning antenna array with metal-bound decoupling structure according to claim 1, characterized in that The metal vias are arranged at equal intervals.

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