A wideband wide-angle scanning matching structure based on a tightly coupled antenna

Abstract

The application belongs to the technical field of microwave antennas, and particularly relates to a wideband wide-angle scanning matching structure based on a tightly coupled antenna, which comprises a plurality of antenna units, each of which comprises a metal floor, a feed layer dielectric substrate located on the upper layer of the metal floor, a copper layer etched on the lower surface of the feed layer dielectric substrate, a copper layer feed patch and a short circuit patch etched on the upper surface of the feed layer dielectric substrate, and a coaxial connector mounted in the metal floor; a feed probe is arranged in the feed layer dielectric substrate and is connected with the radiation patch and the coaxial connector, and a short circuit through hole is arranged in the feed layer dielectric substrate and is connected with the short circuit patch and the copper layer; wherein a first dielectric substrate is arranged at a certain height position above the copper layer feed patch and the short circuit patch, so that the working performance of the tightly coupled array antenna can be greatly improved, and the scanning angle domain in the 94.1% working bandwidth can reach ±60°.

Description

Technical Field

[0001] This application belongs to the field of microwave antenna technology, and specifically relates to a wide bandwidth angle scanning matching structure based on a tightly coupled antenna. Background Technology

[0002] With the continuous development of modern electronic warfare and the strong demand for radio frequency integration, airborne phased array radars are increasingly demanding wide-bandwidth, large-angle detection capabilities. However, the wide-bandwidth operation and large-angle scanning requirements of phased array radars present a performance contradiction: the radar beam's operating bandwidth is limited and narrowed when scanning in the large angle; conversely, achieving large-angle beam scanning is difficult for radar antennas operating in the wide band. Addressing the new demands and directions in current planar microstrip array antenna research, wide-bandwidth, large-angle scanning matching methods have become a crucial bottleneck technology.

[0003] Tightly coupled antennas are a novel type of planar microstrip array antenna that utilizes the strong mutual coupling effect between radiating arrays to extend bandwidth. Some tightly coupled antenna designs can use coaxial feeding, eliminating the need for complex feeding structures such as additional baluns, thus enabling low-profile antenna designs. However, due to the influence of surface waves and common-mode resonance, when a tightly coupled antenna scans to a large angle, the active standing wave rises, resulting in a lack of wide-angle scanning characteristics. Summary of the Invention

[0004] To address the aforementioned issues, this application provides a wide bandwidth angle scanning matching structure based on tightly coupled antennas, comprising multiple antennas, each antenna including: The metal floor, the power supply layer dielectric substrate located on the upper layer of the metal floor, the copper layer etched on the lower surface of the power supply layer dielectric substrate, and the copper layer power supply patch and short-circuit patch etched on the upper surface of the power supply layer dielectric substrate, the coaxial connector installed in the metal floor, the power supply probe disposed in the power supply layer dielectric substrate and connecting the coaxial connector and the copper layer power supply patch, and the short-circuit via disposed in the power supply layer dielectric substrate and connecting the short-circuit patch and the copper layer. A first dielectric substrate is disposed at a certain height above the copper layer feed patch and the short-circuit patch.

[0005] Preferably, a plurality of through holes or notches are provided on the feed layer dielectric substrate to reduce the number of through holes in the feed layer dielectric substrate.

[0006] Preferably, the copper layer feed patch has a raised section forming a connector that connects to the feed probe, and the short-circuit patch has a notch that surrounds but does not contact the connector.

[0007] Preferably, multiple short-circuit vias are added around the notch of the short-circuit patch, and multiple short-circuit vias are added circumferentially to the power supply probe. One end of each of the multiple short-circuit vias is connected to the short-circuit patch, and the other end is connected to the copper layer.

[0008] Preferably, the feed layer dielectric substrate is provided with a plurality of isolation vias with metal layers plated on the inner wall surface. The isolation vias are located inside the feed layer dielectric substrate and are evenly distributed along the two edges of the antenna H-plane, connecting the short-circuit patch and the copper layer.

[0009] Preferably, the first dielectric substrate and the feed layer dielectric substrate are kept at a certain distance by padding with a second dielectric substrate.

[0010] Preferably, the second dielectric substrate is a foam board.

[0011] Preferably, the first dielectric substrate is an integral structure and is positioned at a certain height above all the antennas via dielectric support pillars.

[0012] Preferably, the copper layer feed patch is funnel-shaped, including a large end and a small end, the small end being connected to the feed probe, and the short-circuit patch including two semi-elliptical patches disposed at both ends of the copper layer feed patch, the semi-elliptical patch located at the small end having a notch surrounding the small end.

[0013] Preferably, the perforation or notch is located at the end face of the parallel antenna E-plane near the feed layer dielectric substrate.

[0014] The advantages of this application include: (1) It can significantly improve the working performance of tightly coupled array antennas, and achieve a scanning angle range of ±60° within 94.1% of the working bandwidth.

[0015] (2) It has a wide range of applications and can be applied to most existing planar microstrip array antennas to solve the contradiction between the two functional requirements of wide-band operation and large-angle scanning of planar microstrip array antennas. It has significant application value, especially for phased array antennas with wide-band operation and large-angle scanning requirements.

[0016] (3) The wideband large-angle scanning matching structure has a small external size, simple three-dimensional structure, low process implementation difficulty, easy engineering implementation, and low requirements for equipment mass production. Attached Figure Description Figure 1 This is a schematic diagram of the stacked structure of the improved antenna using the present application.

[0017] Figure 2 This is a schematic diagram of the original antenna structure stack.

[0018] Figure 3 This is a comparison diagram of the active standing waves of the original antenna and the improved antenna when they are not scanning.

[0019] Figure 4This is a comparison diagram of active standing waves during E-plane scanning of the original antenna and the improved antenna.

[0020] Figure 5 This is a comparison diagram of active standing waves during H-plane scanning of the original antenna and the improved antenna. Detailed Implementation

[0021] To make the technical solution and advantages of this application clearer, the technical solution of this application will be described in a clearer and more complete manner below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are only some embodiments of this application, and are only used to explain this application, not to limit this application. It should be noted that, for ease of description, only the parts related to this application are shown in the accompanying drawings. Other related parts can be referred to the general design. In the absence of conflict, the embodiments and technical features in the embodiments of this application can be combined with each other to obtain new embodiments.

[0022] Furthermore, unless otherwise defined, the technical or scientific terms used in this application description shall have the ordinary meaning understood by one of ordinary skill in the art to which this application pertains. The terms "upper," "lower," "left," "right," "center," "vertical," "horizontal," "inner," and "outer," etc., used in this application description to indicate relative direction or positional relationship are used only to indicate relative orientation or positional relationship, and do not imply that the device or component must have a specific orientation, or be constructed and operated in a specific orientation. When the absolute position of the described object changes, its relative positional relationship may also change accordingly, and therefore should not be construed as a limitation on this application. The terms "first," "second," "third," and similar terms used in this application description are used only for descriptive purposes to distinguish different components, and should not be construed as indicating or implying relative importance. The terms "a," "one," or "the," etc., used in this application description should not be construed as an absolute limitation on quantity, but should be construed as indicating the existence of at least one. The terms "including," "comprising," etc., used in this application description mean that the element or object preceding the word covers the element or object listed after the word and its equivalents, without excluding other elements or objects.

[0023] Furthermore, it should be noted that, unless otherwise explicitly specified and limited, terms such as “installation,” “connection,” and “linkage” used in the description of this application should be interpreted broadly. For example, a connection can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; or it can be a connection within two components. Those skilled in the art can understand its specific meaning in this application according to the specific circumstances.

[0024] like Figure 1As shown, this application provides a wide bandwidth angle scanning matching structure based on tightly coupled antennas, including multiple antennas, each antenna including: The metal floor 5, the power supply layer dielectric substrate 3 located on the upper layer of the metal floor 5, the copper layer etched on the lower surface of the power supply layer dielectric substrate 3, and the copper layer power supply patch 7 and short-circuit patch 6 etched on the upper surface of the power supply layer dielectric substrate 3, the coaxial connector 11 installed in the metal floor 5, the power supply probe 10 disposed in the power supply layer dielectric substrate 3 and connecting the coaxial connector 11 and the copper layer power supply patch 7 in parallel, and the short-circuit through hole 8 disposed in the power supply layer dielectric substrate 3 and connecting the short-circuit patch 6 and the copper layer 4 in parallel. A first dielectric substrate 1 is disposed at a certain height above the copper layer feeding patch 7 and the short-circuit patch 6.

[0025] Based on the above technical features, its technical effects include: The short-circuit via 8 improves the impedance matching of the feed section from the coaxial connector 11 to the copper layer feed patch 7; the feed layer dielectric substrate 3 has internal holes, which reduces the equivalent dielectric constant of the feed layer dielectric substrate 3 and shifts the resonance caused by the surface wave inside the dielectric to a higher frequency, effectively expanding the working bandwidth of the antenna; the addition of the first dielectric substrate 1 and the second dielectric substrate 2 requires detailed optimization of the thickness of the two dielectric substrates, which can improve the matching between the radiating structure and free space on the one hand, and effectively suppress the generation of surface waves on the periodic structure during antenna scanning on the other hand, thereby increasing the scanning range of the antenna.

[0026] In some alternative embodiments, a plurality of through holes or notches are provided on the feed layer dielectric substrate 3 to reduce the number of holes in the feed layer dielectric substrate 3.

[0027] In some alternative embodiments, a copper layer feed patch 7 protrudes at one location to form a connector that connects to the feed probe 10, and a short-circuit patch 6 has a notch that surrounds but does not contact the connector.

[0028] In some alternative embodiments, a plurality of short-circuit vias 8 are added around the notch of the short-circuit patch 6, and a plurality of short-circuit vias 8 are added circumferentially to the power supply probe 10. One end of the plurality of short-circuit vias 8 is connected to the short-circuit patch 6, and the other end is connected to the copper layer 4.

[0029] In some alternative embodiments, the feed layer dielectric substrate 3 is provided with a plurality of isolation vias 9 whose inner wall surfaces are plated with metal layers. The isolation vias 9 are located inside the feed layer dielectric substrate 3 and are evenly distributed along the two edges of the antenna H-plane, connecting the short-circuit patch 6 and the copper layer 4.

[0030] In some alternative embodiments, the first dielectric substrate 1 and the feed layer dielectric substrate 3 are kept at a certain distance by a second dielectric substrate 2.

[0031] In some alternative embodiments, the second dielectric substrate 2 is a foam board.

[0032] In some alternative embodiments, the first dielectric substrate 1 is an integral structure and is disposed at a certain height above all the antennas via dielectric pillars.

[0033] In some alternative embodiments, the copper layer feed patch 7 is funnel-shaped, including a large end and a small end. The small end is connected to the feed probe 10. The short-circuit patch 6 includes two semi-elliptical patches disposed at both ends of the copper layer feed patch 7. The semi-elliptical patch located at the small end has a notch surrounding the small end.

[0034] In some alternative embodiments, the perforation or notch is located at the end face of the parallel antenna E surface near the feed layer dielectric substrate 3.

[0035] Figures 3-5 The original antenna is given as follows: Figure 2 The figure shows a comparison of the active standing wave ratio (VSWR) of the improved antenna and the antenna without scanning. As can be seen from the figure, without scanning, the VSWR resonant peak of the improved antenna shifts to higher frequencies, and the in-band active VSWR is smoother, resulting in a wider antenna bandwidth. During E-plane and H-plane scanning, the active VSWR of the improved antenna is significantly improved, especially during large-angle H-plane scanning, where the active VSWR is significantly reduced from around 3.5 to below 2.5. The improved tightly coupled antenna can achieve ±60° scanning (VSWR < 2.5) in the E-plane and H-plane within the frequency band of 7.2–20 GHz (relative bandwidth 94.1%). Therefore, the matching design technology proposed in this invention can effectively extend the operating bandwidth and scanning angular domain of the planar microstrip array antenna.

[0036] 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. A wide bandwidth angle scanning matching structure based on a tightly coupled antenna, characterized in that, include: Metal floor (5), power supply layer dielectric substrate (3) located on the upper layer of metal floor (5), copper layer etched on the lower surface of power supply layer dielectric substrate (3), copper layer power supply patch (7) and short-circuit patch (6) etched on the upper surface of power supply layer dielectric substrate (3), coaxial connector (11) installed in metal floor (5); power supply probe (10) provided in power supply layer dielectric substrate (3) connecting coaxial connector (11) and copper layer power supply patch (7) in parallel, and short-circuit via (8) provided in power supply layer dielectric substrate (3) connecting short-circuit patch (6) and copper layer (4) in parallel; Among them, a first dielectric substrate (1) is provided at a certain height above the copper layer feeding patch (7) and the short-circuit patch (6). Multiple perforations or notches are provided on the feed layer dielectric substrate (3) to reduce the number of perforations or notches on the feed layer dielectric substrate (3); A copper layer feed patch (7) has a raised section forming a connector that connects to the feed probe (10), and a short-circuit patch (6) has a notch that surrounds but does not contact the connector; Multiple short-circuit vias (8) are added around the notch of the short-circuit patch (6), and multiple short-circuit vias (8) are added circumferentially to the power supply probe (10). One end of the multiple short-circuit vias (8) is connected to the short-circuit patch (6), and the other end is connected to the copper layer (4). The feed layer dielectric substrate (3) is provided with multiple isolation vias (9) with metal layers plated on the inner wall surface. The isolation vias (9) are located inside the feed layer dielectric substrate (3) and are evenly distributed along the two edges of the antenna H surface, connecting the short-circuit patch (6) and the copper layer (4). The first dielectric substrate (1) and the feed layer dielectric substrate (3) are kept at a certain distance by a second dielectric substrate (2) being placed between them. The perforation or notch is located at the end face of the parallel antenna E surface near the feed layer dielectric substrate (3); The copper layer feed patch (7) is funnel-shaped, including a large end and a small end. The small end is connected to the feed probe (10). The short-circuit patch (6) includes two semi-elliptical patches disposed at both ends of the copper layer feed patch (7). The semi-elliptical patch located at the small end has a notch surrounding the small end.

2. The wide bandwidth angle scanning matching structure based on a tightly coupled antenna as described in claim 1, characterized in that, The second dielectric substrate (2) is made of foam board.

3. The wide bandwidth angle scanning matching structure based on a tightly coupled antenna as described in claim 1, characterized in that, The first dielectric substrate (1) is an integral structure and is set at a certain height above all antennas by dielectric support pillars.

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