An improved structure of an array antenna radiator with wide bandwidth angle characteristic

Abstract

The application provides an array antenna radiator improved structure with a wide bandwidth angle characteristic, which comprises a metal floor, a feed layer dielectric substrate, a coupling slot layer dielectric substrate, a first radiation layer dielectric substrate, a second radiation layer dielectric substrate and a protective layer dielectric substrate. By adding the improved radiation patch on the radiation layer dielectric substrate, a new resonant frequency point is introduced, and the technical problem that the scanning blind spot effect of the microstrip phased array antenna in the prior art influences the working frequency band and the scanning angle domain is solved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of phased array radar antenna, and particularly relates to an array antenna radiator improved structure with wide bandwidth and wide angle characteristics. BACKGROUND

[0002] With the rapid development of aerospace technology, the performance requirements of modern airborne radar phased array antenna are also increasing. Whether it is a radar or an electronic countermeasure system, it is expected that the phased array antenna can save the occupied resources of the space platform, reduce its own weight, provide more redundancy for the space and weight of other electronic devices and weapon equipment; at the same time, it is also expected to improve its combat capability, discover targets in a larger airspace, and provide fast and accurate information for search, detection, identification, capture and tracking. Therefore, higher requirements are put forward for the miniaturization, light weight, wide bandwidth and wide angle scanning performance of the phased array antenna.

[0003] The traditional active phased array radiating unit mostly adopts Vivaldi end-fire antenna form. This type of antenna can obtain a wider working bandwidth and a larger beam scanning angle, but has the following problems:

[0004] (1) Large volume and large weight restrict the large-area application of the antenna on the airborne platform;

[0005] (2) The high profile characteristic makes the structural strength weaken with the increase of the antenna height;

[0006] (3) The mounting structure of the antenna is complex, and the assembly workload is large.

[0007] Microstrip antenna has many advantages such as low profile, small size, light weight, easy to conform to the surface of the carrier, easy to integrate with active devices, and becomes an important research form of new phased array radar antenna. However, on the one hand, compared with the vivaldi antenna commonly used in radar antenna, the bandwidth and scanning angle of microstrip antenna are narrow. On the other hand, due to the existence of mutual coupling between antenna units, when the array is scanned to a certain angle in space, a sharp and deep notch will appear, at this time the reflection coefficient of the array is large, which causes the energy to be totally reflected and a scanning blind spot appears, and the antenna will not be able to radiate or receive energy. Microstrip antenna is easy to excite the propagation of surface wave on the open microstrip substrate, which leads to more complex and strong mutual coupling effect between the units of the microstrip array than the traditional active phased array radiation units, resulting in performance deterioration such as array impedance mismatch and radiation pattern distortion. At large angle scanning, this mutual coupling effect is more intense, making the scanning blind spot phenomenon more serious. Blind spot effect is one of the serious problems affecting the wide bandwidth and wide angle scanning performance of microstrip phased array antenna. Since it appears before the grating lobe, and even appears at an angle not far from the broadside direction, it will inevitably greatly reduce the scanning area of the microstrip phased array antenna, leading to the decline of the scanning performance of the whole array, so that the microstrip antenna is difficult to realize wide angle scanning while ensuring wide bandwidth operation.

[0008] Scanning blind spot is one of the important factors restricting the realization of wide bandwidth and wide angle scanning of microstrip phased array antenna, therefore, overcoming the limitations of microstrip antenna in wide bandwidth and wide angle scanning performance has become a key problem to be solved. SUMMARY

[0009] Therefore, the present application provides an array antenna radiator improved structure with wide bandwidth and wide angle characteristics, which solves the technical problem of scanning blind spot effect of microstrip phased array antenna in the prior art affecting the antenna operating frequency band and scanning angle domain.

[0010] The embodiment of the present specification provides the following technical scheme: an improved structure of an array antenna radiator with wide bandwidth angle characteristics, characterized in that the components of the improved structure are tightly compacted and connected, and the improved structure comprises: a metal floor, a coaxial connector embedded in the metal floor; a feed layer dielectric substrate, the feed layer dielectric substrate is located on the upper layer of the metal floor; a coupling slot layer dielectric substrate, the coupling slot layer dielectric substrate is located on the upper layer of the feed layer dielectric substrate; a first radiation layer dielectric substrate, the first radiation layer dielectric substrate is located on the upper layer of the coupling slot layer dielectric substrate, and the upper surface of the radiation layer dielectric substrate has a first radiation patch, the first radiation patch is composed of a rectangular patch and a metal branch, and the metal branch is located at a preset position of the side edge of the rectangular patch; a second radiation layer dielectric substrate, the second radiation layer dielectric substrate is located on the upper layer of the first radiation layer dielectric substrate, and the upper surface of the second radiation layer dielectric substrate has a second radiation patch, the second radiation patch is composed of an inner rectangular patch and an outer L-shaped patch, the outer L-shaped patch is arranged around the four top corners of the inner rectangular patch, and there is a certain gap between the inner rectangular patch and the outer L-shaped patch; a protective layer dielectric substrate, the protective layer dielectric substrate is located on the upper layer of the second radiation layer dielectric substrate.

[0011] Further, the first radiation patch and the second radiation patch constitute a wide-angle matching structure of the microstrip antenna structure.

[0012] Further, a slotted floor layer is arranged above the coupling slot layer dielectric substrate.

[0013] Preferably, the slotted floor layer is slotted into a I-shaped groove.

[0014] Further, a strip-shaped feed line is fixed to the upper surface of the feed layer dielectric substrate, and the strip-shaped feed line is in feed connection with the inner conductor of the coaxial connector.

[0015] Preferably, the strip-shaped feed line adopts a width-gradually-changing shape.

[0016] Further, the dielectric substrate and the dielectric substrate have metal isolation walls inside, the metal isolation walls penetrate through the dielectric substrate and the dielectric substrate, and connect the metal floor and the slotted floor layer.

[0017] Preferably, the metal isolation walls are arranged around the I-shaped groove in the slotted floor layer and the strip-shaped feed line, and have a "convex" shape.

[0018] Compared with the prior art, the at least one technical scheme adopted by the embodiment of the present application can achieve the beneficial effects at least including: the present application provides an improved structure of an array antenna radiator with wide bandwidth and angle characteristics, which comprises a metal floor, a feed layer dielectric substrate, a coupling slot layer dielectric substrate, a first radiation layer dielectric substrate, a second radiation layer dielectric substrate and a protective layer dielectric substrate. By increasing the radiation patch, a new resonant frequency point is introduced, which can effectively adjust the bandwidth and scanning angle, so as to realize good wide bandwidth and angle scanning performance under the microstrip antenna structure. BRIEF DESCRIPTION OF DRAWINGS

[0019] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings needed in the embodiments will be briefly introduced as follows. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can also be obtained by those skilled in the art without creative labor.

[0020] Figure 1 is a structure schematic diagram of an improved structure of an array antenna radiator with wide bandwidth and angle characteristics according to an embodiment of the present application;

[0021] Figure 2 is a structure side view of an improved structure of an array antenna radiator with wide bandwidth and angle characteristics according to an embodiment of the present application;

[0022] Figure 3 is a structure schematic diagram of a radiation layer according to an embodiment of the present application;

[0023] Figure 4 is a structure schematic diagram of a radiation patch according to an embodiment of the present application;

[0024] Figure 5 is an active standing wave curve diagram of an improved structure of an array antenna radiator with wide bandwidth and angle characteristics according to an embodiment of the present application;

[0025] Figure 6 is an active standing wave curve diagram of a radiation structure of a microstrip antenna with only two rectangular patches according to an embodiment of the present application.

[0026] In the drawings, the reference signs are as follows: 1, metal floor; 2, feed layer dielectric substrate; 3, coupling slot layer dielectric substrate; 4, first radiation layer dielectric substrate; 5, second radiation layer dielectric substrate; 6, protective layer dielectric substrate; 7, second radiation patch; 8, first radiation patch; 9, slotted floor layer; 10, strip feed line; 11, metal isolation wall; 12, coaxial connector. DETAILED DESCRIPTION

[0027] The embodiments of the present application will be described in detail below with reference to the drawings.

[0028] The following specific examples illustrate the implementation of this application. Those skilled in the art can easily understand other advantages and effects of this application from the content disclosed in this specification. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. This application can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of this application. It should be noted that, in the absence of conflict, the following embodiments and features in the embodiments can be combined with each other. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0029] like Figure 1 As shown, this embodiment of the invention provides an improved structure for an array antenna radiator with wide bandwidth and angle characteristics. The improved structure is characterized by tightly compacted connections between its components. The improved structure includes: a metal ground plane 1 with a coaxial connector 12 embedded inside; a feed layer dielectric substrate 2 located above the metal ground plane 1; a coupling slot layer dielectric substrate 3 located above the feed layer dielectric substrate 2; and a first radiating layer dielectric substrate 4 located above the coupling slot layer dielectric substrate 3. The upper surface of the radiating layer dielectric substrate has a first radiating patch 8. A radiating patch 8 is composed of a rectangular patch and metal branches, the metal branches being located at a predetermined position on the side of the rectangular patch; a second radiating layer dielectric substrate 5 is located on top of the first radiating layer dielectric substrate 4, and the upper surface of the second radiating layer dielectric substrate 5 has a second radiating patch 7, which is composed of an inner rectangular patch and an outer L-shaped patch, the outer L-shaped patch being arranged around the four apex corners of the inner rectangular patch, and there is a certain gap between the inner rectangular patch and the outer L-shaped patch; a protective layer dielectric substrate 6 is located on top of the second radiating layer dielectric substrate 5.

[0030] Furthermore, the second radiating patch 7 and the first radiating patch 8 constitute the wide-angle matching structure of the microstrip antenna structure.

[0031] Specifically, the second radiating patch 7 is located at a predetermined position on the upper surface of the radiating layer dielectric substrate 5, and consists of an inner rectangular patch and L-shaped patches surrounding the four vertices of the rectangular patch. The radiating patch 7 can introduce new resonant frequencies and effectively adjust the bandwidth and scanning angle. The first radiating patch 8 is located at a predetermined position on the lower surface of the radiating layer dielectric substrate 4, and consists of a rectangular patch and a tail metal stub, wherein the tail metal stub has a significant effect on improving bandwidth and impedance matching. The second radiating patch 7 and the first radiating patch 8 constitute the wide-angle matching structure of this microstrip antenna structure.

[0032] Further, the coupling slot layer medium substrate 3 is provided with a slotted floor layer 9.

[0033] Further, the upper surface of the feed layer medium substrate 2 is fixed with a strip feed line 10, which is in feed connection with the inner conductor of the coaxial connector 12.

[0034] Further, the medium substrate 2 and the medium substrate 3 have a metal isolation wall 11 inside, which penetrates the medium substrate 2 and the medium substrate 3, and connects the metal floor 1 and the slotted floor layer 9.

[0035] Preferably, the metal isolation wall 11 is arranged around the I-shaped groove in the slotted floor layer 9 and the strip feed line 10, and is in the shape of a "convex" character. The metal isolation wall 11 penetrates the medium substrate 2 and the medium substrate 3, and connects the metal floor 1 and the slotted floor layer 9. The metal isolation wall 11 can confine the energy in the metal cavity, reduce energy leakage, and improve the isolation between units.

[0036] Preferably, the slotted floor layer 9 is slotted into an I-shaped groove.

[0037] Preferably, the strip feed line 10 adopts a width-graduated profile to achieve good matching between the feed and radiation parts.

[0038] Embodiment one

[0039] An improved structure of an array antenna radiator with wide bandwidth and wide angle characteristics is shown in Figure 1 The improved structure includes a metal floor 1, a feed layer medium substrate 2, a coupling slot layer medium substrate 3, a radiation layer medium substrate 4, a radiation layer medium substrate 5, a protective layer medium substrate 6, a radiation patch 7, a radiation patch 8, a slotted floor layer 9, a strip feed line 10, a metal isolation wall 11, and a feed coaxial 12.

[0040] The metal floor 1 with a thickness of h1=3mm is located on the lower surface of the feed layer medium substrate 2 with a thickness of h2=0.508mm, the coupling slot layer medium substrate 3 is located on the upper surface of the feed layer medium substrate 2, with a thickness of h3=0.127mm, the radiation layer medium substrate 4 with a thickness of h4=1.397mm is located on the upper surface of the coupling slot layer medium substrate 3, the radiation layer medium substrate 5 is located on the upper surface of the radiation layer medium substrate 4, the protective layer medium substrate 6 is located on the upper surface of the radiation layer medium substrate 5, for protecting the metal patch 7 and the radiation patch 8 from being eroded and damaged by the external environment. The thickness of the radiation layer medium substrate 5 is h5=1.146mm, and the thickness of the protective layer medium substrate 6 is h6=0.4mm.

[0041] Radiation patch 7 is located on the upper surface of dielectric substrate 5, which is composed of an inner rectangular patch and an outer L-shaped patch surrounding the four corners of the rectangular patch, the length of the L-shaped patch is w1=3.35mm, the width is w3=0.2mm, the distance between the L-shaped patches is w4=0.7mm, and the side length of the inner rectangular patch is w2=6.6mm. Radiation patch 8 is located on the upper surface of dielectric substrate 4, which is composed of a rectangular patch and a tail metal branch, the width of the rectangular patch is w5=6mm, the length is w6=6mm, and the size of the tail metal branch is w7=1mm and w8=1mm, as shown in Figure 4

[0042] The coupling slot groove is located on the slotted floor layer 9, which is fed by the strip feed line 10 to excite the above-mentioned radiation patch 7 and radiation patch 8. The strip feed line 10 adopts a tapered shape to avoid the occurrence of impedance mismatch due to structural mutation. The metal isolation wall 11 is located in the feed layer dielectric substrate 2 and the coupling slot layer dielectric substrate 3, which surrounds the coaxial and coupling slot of the antenna unit, forms a coaxial structure to achieve good matching of the vertical transition of the coaxial and strip line, and realizes it in the form of a metal wall connected to the metal floor 1 and the slotted floor layer 9.

[0043] Figure 1 The active standing wave of the improved structure of the array antenna radiator with wideband wide-angle characteristics is shown in Figure 5 The standing wave of the phased array antenna composed of the microstrip antenna unit after removing the four L-shaped patches in the radiation patch 7 and the metal branch in the radiation patch 8 is shown in Figure 6 It can be seen that the antenna with a wideband wide-angle scanning matching structure can realize ±60° scanning in the E-plane (electric field plane) and ±45° scanning in the H-plane (magnetic field plane) within a working frequency band of 40%; the antenna without a wideband wide-angle scanning matching structure has a deteriorated standing wave at 11.5GHz, which cannot meet the working frequency band of 8GHz-12GHz. It can be seen that the improved structure of the array antenna radiator with wideband wide-angle characteristics can realize good wide-angle scanning performance within the 8-12GHz frequency band, and has the characteristics of simple implementation, which has important significance for the application research of wideband wide-angle microstrip phased array antenna.

[0044] In summary, the improved structure of the array antenna radiator with wideband wide-angle characteristics provided in the embodiments of the present application can achieve at least the following technical effects compared with the prior art:

[0045] ​1. This invention effectively expands the bandwidth of microstrip antennas, removes scanning blind spots from the operating bandwidth, and significantly improves the scanning angular domain of microstrip phased array antennas based on 40% operating bandwidth. The scanning angle of the E-plane (electric field) can reach ±60°, and the scanning angle of the H-plane (magnetic field) can reach ±45°. At the same time, it retains the advantages of microstrip antennas such as low profile, small size, light weight, easy conformal integration with carrier surface, and easy integration with active devices.

[0046] 2. The structure adopted in this invention has a low design and processing difficulty coefficient, is easy to implement, and has strong engineering practical significance.

[0047] 3. This invention can be used to achieve wide bandwidth and wide angle scanning of microstrip antennas, and can be used on various radars, electronic warfare and communication equipment on various shipborne, airborne and land-based platforms.

[0048] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. An improved structure for an array antenna radiator with wide bandwidth and wide angle characteristics, characterized in that, The improved structure comprises tightly compacted and connected components, and includes: Metal floor (1), with a coaxial connector (12) embedded inside the metal floor (1); The power supply layer dielectric substrate (2) is located on the upper layer of the metal floor (1). A strip feed wire (10) is fixed on the upper surface of the power supply layer dielectric substrate (2). The strip feed wire (10) is connected to the inner conductor of the coaxial connector (12) for power supply. The coupling gap layer dielectric substrate (3) is located on top of the feed layer dielectric substrate (2); The first radiating layer dielectric substrate (4) is located on the upper layer of the coupling gap layer dielectric substrate (3). The upper surface of the radiating layer dielectric substrate has a first radiating patch (8). The first radiating patch (8) is composed of a rectangular patch and a metal branch. The metal branch is located at a preset position on the side of the rectangular patch. The second radiating layer dielectric substrate (5) is located on top of the first radiating layer dielectric substrate (4). The upper surface of the second radiating layer dielectric substrate (5) has a second radiating patch (7). The second radiating patch (7) is composed of an inner rectangular patch and an outer L-shaped patch. The outer L-shaped patch is arranged around the four apex corners of the inner rectangular patch. There is a certain gap between the inner rectangular patch and the outer L-shaped patch. The protective layer dielectric substrate (6) is located on top of the second radiating layer dielectric substrate (5).

2. The improved structure of an array antenna radiator with wide bandwidth and wide angle characteristics according to claim 1, characterized in that, The second radiating patch (7) and the first radiating patch (8) constitute the wide-angle matching structure of the microstrip antenna structure of the array antenna radiator.

3. The improved structure of an array antenna radiator with wide bandwidth and angle characteristics according to claim 1, characterized in that, A slotted floor layer (9) is provided on the coupling gap layer dielectric substrate (3).

4. The improved structure of an array antenna radiator with wide bandwidth and wide angle characteristics according to claim 1, characterized in that, The grooves in the grooved floor layer (9) are I-shaped grooves.

5. An improved structure for an array antenna radiator with wide bandwidth and angle characteristics according to claim 1, characterized in that, The strip feeder (10) adopts a gradually changing width shape.

6. An improved structure for an array antenna radiator with wide bandwidth and wide angle characteristics according to claim 1, characterized in that, The feed layer dielectric substrate (2) and the coupling gap layer dielectric substrate (3) have metal isolation electric walls (11) inside. The metal isolation electric walls (11) penetrate the feed layer dielectric substrate (2) and the coupling gap layer dielectric substrate (3) and connect the metal floor (1) and the slotted floor layer (9).

7. An improved structure for an array antenna radiator with wide bandwidth and angle characteristics according to claim 6, characterized in that, The metal insulating electric wall (11) is arranged around the I-shaped groove and the strip feed line (10) in the slotted floor layer (9), in a "convex" shape.

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