Low-profile broadband high-gain array antenna

Abstract

The invention discloses a low-profile broadband high-gain array antenna which comprises a dielectric substrate, a microstrip array antenna arranged on the surface of the dielectric substrate and a grounding plate arranged on the bottom layer of the dielectric substrate, the microstrip array antenna comprises multiple sets of microstrip antenna linear arrays and a power division feed network, and the power division feed network is connected with the multiple sets of microstrip antenna linear arrays which are connected in parallel. The microstrip antenna linear array comprises a patch antenna unit group and an impedance converter, the patch antenna unit group comprises a plurality of patch antenna units which are connected in series in the vertical direction, the patch antenna unit group is connected with the power division feed network through the impedance converter, and slotting structures are symmetrically arranged in the patch antenna units; the slotting structures are symmetrically arranged at the edge positions of the patch antenna units, and the opening directions of the slotting structures are arranged outwards in the radial direction of the patch antenna units. The gaps are formed in the two sides of the patch antenna unit, so that the Q value of the antenna is reduced, and the bandwidth of the antenna is widened.

Description

Technical Field

[0001] The present application relates to the technical field of antenna design, and in particular to a low-profile, broadband, high-gain array antenna. Background Art

[0002] The combination of microstrip patch array antenna and digital beamforming technology can achieve excellent performance such as beam scanning. Microstrip array antennas can synthesize high-gain beams through array formation. They have the advantages of small size, low profile, light weight, and diverse superior electrical properties. In addition, this type of antenna is easy to integrate with the back-end circuit, suitable for mass production, and relatively low cost. However, microstrip array antennas also have some problems, such as narrow operating frequency band, high loss during radiation, complex feeding network, and large microstrip line transmission loss.

[0003] Some existing improvement schemes attempt to solve these problems, such as using a series of microstrip patch units and a feeding network to achieve low sidelobe characteristics of the antenna. However, since the air layer and parasitic patch units are added to the antenna structure in the prior art, the cross-sectional height of the antenna increases, which is not conducive to the integration of the antenna system.

[0004] Therefore, it is necessary to develop a new microstrip array antenna design to overcome the deficiencies in the prior art while maintaining or further improving the performance of the antenna. Summary of the invention

[0005] The purpose of this application is to provide a low-profile broadband high-gain array antenna in order to overcome the existing technical defects. By opening gaps on both sides of the patch antenna unit, the Q value of the antenna is reduced and the bandwidth of the antenna is widened.

[0006] The purpose of this application is achieved through the following technical solutions:

[0007] In a first aspect, the present application proposes a low-profile broadband high-gain array antenna, the array antenna comprising a dielectric substrate, a microstrip array antenna disposed on the surface of the dielectric substrate, and a ground plane disposed on the bottom layer of the dielectric substrate;

[0008] The microstrip array antenna includes a plurality of microstrip antenna linear arrays and a power division feeding network, wherein the power division feeding network connects the plurality of microstrip antenna linear arrays in parallel;

[0009] The microstrip antenna linear array includes a patch antenna unit group and an impedance converter, the patch antenna unit group includes a plurality of patch antenna units connected in series along a vertical direction, and the patch antenna unit group is connected to a power division feeding network through the impedance converter;

[0010] The patch antenna unit is symmetrically provided with slot structures, the slot structures are symmetrically provided at the edge of the patch antenna unit, and the opening direction of the slot structures is provided outwardly along the radial direction of the patch antenna unit.

[0011] In a possible implementation manner, the spacing between every two groups of adjacent microstrip antenna arrays is the same.

[0012] In a possible implementation manner, the distance between each two groups of adjacent microstrip antenna arrays is one wavelength.

[0013] In a possible implementation manner, each patch antenna unit is arranged in sequence at the same interval.

[0014] In a possible implementation, the power division feeding network is a one-to-fourteen-way feeding structure, including a main section and branch sections, wherein the main section and the branch sections are installed in a T-shaped structure.

[0015] In a possible implementation manner, the signal amplitude at the output port of the power division feeding network satisfies the Chebyshev distribution.

[0016] In a possible implementation manner, the dielectric substrate has a thickness of 0.254 mm.

[0017] In a possible implementation manner, the structural cross-sectional height of the array antenna is the sum of the thicknesses of the microstrip array antenna, the dielectric substrate, and the ground plane.

[0018] In a possible implementation manner, the number of patch antenna units is ten.

[0019] In a possible implementation manner, the number of microstrip antenna arrays is 14 groups.

[0020] The above-mentioned main scheme of the present application and its further options can be freely combined to form multiple schemes, all of which are schemes that can be adopted and claimed for protection in the present application; and in the present application, (non-conflicting options) options and other options can also be freely combined. After understanding the scheme of the present application, those skilled in the art can understand that there are multiple combinations based on the prior art and common knowledge, all of which are technical schemes to be protected by the present application, and they are not exhaustively listed here.

[0021] The present application discloses a low-profile broadband high-gain array antenna, the array antenna includes a dielectric substrate, a microstrip array antenna arranged on the surface of the dielectric substrate, and a ground plane arranged on the bottom layer of the dielectric substrate. The microstrip array antenna includes multiple groups of microstrip antenna arrays and a power division feeding network. The power division feeding network connects multiple groups of microstrip antenna arrays in parallel. The microstrip antenna array includes a patch antenna unit group and an impedance converter. The patch antenna unit group includes multiple patch antenna units in a vertical direction and connected in series. The patch antenna unit group is connected to the power division feeding network through an impedance converter. The patch antenna unit is symmetrically provided with a slotted structure, which is symmetrically arranged at the edge position of the patch antenna unit, and the opening direction of the slotted structure is arranged radially outward of the patch antenna unit. By opening gaps on both sides of the patch antenna unit, the Q value of the antenna is reduced and the bandwidth of the antenna is widened. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0023] Figure 1 A schematic diagram of a low-profile, broadband, high-gain array antenna proposed in an embodiment of the present application is shown.

[0024] Figure 2 A side view of the overall structure of the low-profile, broadband, high-gain array antenna proposed in an embodiment of the present application.

[0025] Figure 3 This is a schematic diagram of the patch antenna unit structure proposed in an embodiment of the present application.

[0026] Figure 4 This is a diagram of the -10dB bandwidth simulation results proposed in the embodiment of the present application.

[0027] Figure 5 These are the simulated E-plane and H-plane directional diagrams proposed in the embodiments of the present application.

[0028] Figure numerals: 1 - dielectric substrate; 2 - ground plane; 3 - patch antenna unit; 4 - impedance converter; 5 - microstrip antenna array; 6 - power division feeding network; 7 - slotted structure. DETAILED DESCRIPTION

[0029] The following describes the embodiments of the present application through specific examples, and those skilled in the art can easily understand other advantages and effects of the present application from the contents disclosed in this specification. The present application can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present application. It should be noted that the following embodiments and features in the embodiments can be combined with each other without conflict.

[0030] Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making any creative work shall fall within the scope of protection of this application.

[0031] In the prior art, in order to achieve low side lobes, microstrip antennas usually use a series microstrip patch unit and a feeding network. Compared with the traditional antenna structure, the antenna structure adds an air layer and a parasitic patch unit, and the antenna cross-sectional height increases.

[0032] In order to solve the problems of narrow impedance bandwidth and high profile of existing low sidelobe microstrip antennas, an embodiment of the present application proposes a low-profile, broadband, high-gain array antenna. By opening gaps on both sides of the patch antenna unit, the Q value of the antenna is reduced and the bandwidth of the antenna is widened, which is described below.

[0033] Please refer to Figure 1 and Figure 2 , Figure 1 A schematic diagram of a low-profile, broadband, high-gain array antenna proposed in an embodiment of the present application is shown. Figure 2 This is a side view of the overall structure of a low-profile broadband high-gain array antenna proposed in an embodiment of the present application, wherein the array antenna comprises a dielectric substrate 1, a microstrip array antenna disposed on the surface of the dielectric substrate 1, and a ground plane 2 disposed on the bottom layer of the dielectric substrate 1;

[0034] The microstrip array antenna comprises a plurality of microstrip antenna linear arrays 5 and a power division feeding network 6, wherein the power division feeding network 6 connects the plurality of microstrip antenna linear arrays 5 in parallel;

[0035] The microstrip antenna array 5 includes 3 groups of patch antenna units and an impedance converter 4. The 3 groups of patch antenna units include a plurality of patch antenna units 3 connected in series along a vertical direction. The 3 groups of patch antenna units are connected to a power division feeding network 6 through the impedance converter 4.

[0036] The patch antenna unit 3 is symmetrically provided with slot structures 7 , which are symmetrically arranged at the edge of the patch antenna unit 3 , and the opening direction of the slot structures 7 is arranged radially outwards of the patch antenna unit 3 .

[0037] The dielectric substrate 1 is the basic material of the entire antenna and is arranged with the main antenna components. The microstrip array antenna is installed on one side of the dielectric substrate 1 and includes a plurality of patch antenna units 3 connected in series. These units are arranged in a specific way to achieve the required performance indicators. The ground plane 2 is located on the other side of the dielectric substrate 1, opposite to the microstrip array antenna, and is used to improve the overall efficiency and performance of the antenna. The power division feeding network 6 is responsible for evenly distributing the input signal to each microstrip antenna array and ensuring that all units can work synchronously to achieve the best effect. The impedance transformer 4 is placed between the microstrip antenna array 5 and the power division feeding network 6 to optimize the matching state of the two, thereby improving the energy transmission efficiency of the entire system.

[0038] Figure 3 This is a schematic diagram of the structure of the patch antenna unit 3 proposed in the embodiment of the present application. The slotted structure 7 is provided with symmetrically distributed small holes or notches on the edge of each patch antenna unit 3. The design purpose of these structures is to increase the effective electrical length of the antenna without changing the physical size, thereby reducing the quality factor (Q value) and expanding the operating frequency band.

[0039] It is worth noting that the slotting technology used in this application is particularly critical for improving antenna performance. By introducing the slotted structure 7 into the patch antenna unit 3, the electrical path length can be effectively extended without significantly increasing the volume, which helps to reduce the loss near the antenna resonant frequency and also broaden the working bandwidth of the antenna. In addition, appropriately adjusting the distance between adjacent microstrip antenna arrays 5 can further optimize the antenna's directional pattern characteristics, such as reducing the sidelobe level.

[0040] The microstrip antenna array 5 is connected in parallel through a power division feeding network 6. The power division feeding network 6 is a one-to-fourteen feeding structure, and the feeding network includes a main section and a branch section, and the main section and the branch section are installed in a "T" shape. The output port signal amplitude of the power division feeding network 6 satisfies the Chebyshev distribution.

[0041] This embodiment adopts the Chebyshev amplitude division method to set the power division feeding network 6 structure so that the antenna obtains a lower sidelobe level. In the embodiment, the power division feeding network 6 divides the input signal into fourteen paths, and the power division feeding network 6 structure is symmetrically arranged.

[0042] In the embodiment, the main section of the power division feeding network 6 is a main branch, and the branch sections are multiple branches. The multiple branch sections are connected to the main section in a "T"-shaped structure, so that the patch antenna unit 3 is connected to the main section through each branch section, forming a T-shaped power division feeding network 6, which has a simple design and a small size, and is more conducive to the miniaturization of the microstrip antenna.

[0043] The thickness of the dielectric substrate of this embodiment is 0.254 mm. The entire device of this embodiment includes a microstrip array antenna, a dielectric substrate and a ground plane 2, and the sum of the three structures is 0.254 mm. Compared with the traditional microstrip antenna, this device can achieve a wider bandwidth and a lower profile height while ensuring a small volume, which promotes the use of microstrip array antennas in vehicle-mounted radar systems, helps microstrip antennas further expand their application fields and improve performance.

[0044] like Figure 4 and Figure 5 As shown, Figure 4 This is a diagram of the -10dB bandwidth simulation results proposed in the embodiment of the present application. Figure 5 These are the simulated E-plane and H-plane directional diagrams proposed in the embodiments of the present application.

[0045] from Figure 4 It can be seen that the range of S11≤-10dB of the antenna covers the simulation frequency band of 60GHz-90GHz, that is, the absolute bandwidth is greater than 30GHz and the relative bandwidth is greater than 38.96%. Figure 5 It can be seen that the maximum gain of the antenna within the frequency band is 20.27dBi. On the E-plane radiation pattern, the sidelobe level of the antenna is -17.06dB, and the 3dB beam width is 12.85; on the H-plane radiation pattern, the sidelobe level of the antenna is -16.27dB, and the 3dB beam width is 7.25°. The above data show that the array antenna proposed in the embodiment of the present application has excellent performance and can meet the needs of high-performance antennas for applications such as vehicle-mounted and unmanned aerial vehicles.

[0046] Compared with the prior art, the embodiments of the present application have the following beneficial effects:

[0047] First, by opening gaps on both sides of the patch antenna unit, the electrical length of the antenna is increased, the Q value of the antenna is reduced, the antenna bandwidth is widened, and a -10dB bandwidth greater than 38.96% is achieved, solving the problem of narrow operating bandwidth of existing microstrip array antennas and limited application in electronic warfare systems.

[0048] Second, the cross-sectional height of the entire structure is only the sum of the thicknesses of the microstrip array antenna, the dielectric substrate and the ground plane 2. The entire structure has a relatively low cross-sectional height and is easy to integrate into the system.

[0049] The above description is only a preferred embodiment of the present application and is not intended to limit the present application. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present application should be included in the protection scope of the present application.

Claims

1. A low-profile broadband high-gain array antenna, characterized in that: The array antenna comprises a dielectric substrate, a microstrip array antenna arranged on the surface of the dielectric substrate, and a ground plane arranged on the bottom layer of the dielectric substrate; The microstrip array antenna includes a plurality of microstrip antenna linear arrays and a power division feeding network, wherein the power division feeding network connects the plurality of microstrip antenna linear arrays in parallel; The microstrip antenna linear array includes a patch antenna unit group and an impedance converter, the patch antenna unit group includes a plurality of patch antenna units connected in series along a vertical direction, and the patch antenna unit group is connected to a power division feeding network through the impedance converter; The patch antenna unit is symmetrically provided with slot structures, which are symmetrically arranged at the edge of the patch antenna unit, and the opening direction of the slot structures is arranged radially outwards of the patch antenna unit.

2. The array antenna according to claim 1, characterized in that: The spacing between every two adjacent microstrip antenna arrays is the same.

3. The array antenna according to claim 2, characterized in that: The distance between each two adjacent microstrip antenna arrays is one wavelength.

4. The array antenna according to claim 1, characterized in that: Each patch antenna unit is arranged in sequence at the same interval.

5. The array antenna according to claim 1, characterized in that: The power division feeding network is a one-to-fourteen-way feeding structure, including a main section and a branch section, wherein the main section and the branch section are installed in a T-shaped structure.

6. The array antenna according to claim 1, characterized in that: The signal amplitude at the output port of the power division feeding network satisfies the Chebyshev distribution.

7. The array antenna according to claim 1, characterized in that: The thickness of the dielectric substrate is 0.254 mm.

8. The array antenna according to claim 1, wherein: The structural cross-sectional height of the array antenna is the sum of the thicknesses of the microstrip array antenna, the dielectric substrate and the ground plane.

9. The array antenna according to claim 1, characterized in that: The number of patch antenna units is 10.

10. The array antenna according to claim 1, characterized in that: The number of microstrip antenna arrays is 14.

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