Wide-angular-domain low-scattering omnidirectional microstrip antenna

Abstract

The invention relates to a wide-angular-domain low-scattering omnidirectional microstrip antenna, which comprises a first dielectric substrate, wherein an upper radiation patch and an annular wave-absorbing structure are etched on the upper surface of the first dielectric substrate, and a lower radiation patch is etched on the lower surface of the first dielectric substrate; the upper radiation patch is located on the inner side of the annular wave-absorbing structure and is connected with the lower radiation patch through the first metal via hole; a plurality of first chip resistors distributed along the circumference are arranged on the annular wave-absorbing structure; the second dielectric substrate is located below the lower radiation patch, and a metal floor is etched on the lower surface of the second dielectric substrate; the metal floor is connected with the upper radiation patch through the second metal via hole and is connected with the annular wave-absorbing structure through the third metal via hole; the upper surface of the metal floor is provided with a plurality of second chip resistors, and the upper radiation patch is connected with the second chip resistors through fourth metal through holes. The triple wave absorbing paths are directly integrated on the antenna body, the low scattering performance is achieved, the original profile height is kept, and the dual-polarization single-station and dual-station RCS in the upper half space of the antenna is effectively reduced.

Description

Technical Field

[0001] This invention belongs to the field of low-scattering omnidirectional microstrip antennas, and specifically relates to a wide-angle domain low-scattering omnidirectional microstrip antenna. Background Art

[0002] Omnidirectional microstrip antennas have been widely used in various communication systems due to their low-profile structure, ease of integration, and excellent omnidirectional radiation performance. With the emergence of diverse and advanced detection technologies such as wide-angle scanning of phased array radar and bistatic radar cooperative detection, antenna-centric communication systems are facing a severe threat from combined single- and dual-station detection over a wide angle. Therefore, wide-angle stealth design of antennas has extremely high application value. However, current research on omnidirectional microstrip antennas mainly focuses on radiation performance optimization, while research on wide-angle low-scattering design is still lacking.

[0003] Traditional wide-angle low-scattering antenna designs typically employ the technique of loading absorbing materials or structures. These methods achieve the goal of low scattering in the wide-angle domain by absorbing electromagnetic wave energy and converting it into heat. Zhang Pengfei et al., in their published paper "Compact UWB and Low-RCS Vivaldi Antenna Using Ultrathin Microwave-Absorbing Materials," IEEE Antennas Wireless Propag. Lett. A low-scattering Vivaldi antenna design based on an ultrathin absorbing structure was proposed in [vol. 16, pp. 1965-1968, Apr. 2017]. The core concept of this design is to load ultrathin absorbing material onto the edge region and feed section of a traditional Vivaldi antenna, significantly reducing the antenna's radar cross-section under wide-angle incident wave conditions. However, while absorbing incident wave energy and converting it into internal energy through the absorbing material can achieve wide-angle scattering reduction and thus the design goal of low scattering in the wide-angle domain, it inevitably affects the antenna's radiation performance, leading to deterioration and increasing the antenna profile.

[0004] Therefore, it is necessary to optimize the absorption capability of wide-angle low-scattering omnidirectional microstrip antennas while ensuring antenna radiation performance. Summary of the Invention

[0005] To address the aforementioned problems in the prior art, this invention provides a wide-angle-domain low-scattering omnidirectional microstrip antenna. This invention provides a wide-angle, low-scattering omnidirectional microstrip antenna, comprising: a first dielectric substrate, the upper surface of which is etched with an upper radiating patch and a ring-shaped absorbing structure, and the lower surface of which is etched with a lower radiating patch; the upper radiating patch is located inside the ring-shaped absorbing structure and is connected to the lower radiating patch through a first metal via; the ring-shaped absorbing structure has a plurality of first patch resistors distributed circumferentially; a second dielectric substrate is located below the lower radiating patch, and the lower surface of the second dielectric substrate is etched with a metal ground plane; the metal ground plane is connected to the upper radiating patch through a second metal via and to the ring-shaped absorbing structure through a third metal via; the upper surface of the metal ground plane has a plurality of second patch resistors, and the upper radiating patch is connected to a plurality of second patch resistors one-to-one through a plurality of fourth metal vias.

[0006] In one embodiment of the present invention, both the upper radiating patch and the lower radiating patch are circular patches and are concentrically arranged.

[0007] In one embodiment of the present invention, the first dielectric substrate and the second dielectric substrate are bonded together by a semi-cured layer.

[0008] In one embodiment of the present invention, eight first patch resistors are provided, and the eight first patch resistors are evenly distributed along the circumference at the edge of the slot of the annular absorbing structure.

[0009] In one embodiment of the present invention, two second surface mount resistors are provided, and the two second surface mount resistors are spaced 90° apart.

[0010] In one embodiment of the present invention, the resistance value of each of the first surface mount resistor and the second surface mount resistor is 50Ω.

[0011] In one embodiment of the present invention, the surface of each of the first metal via, the second metal via, the third metal via, and the fourth metal via is coated with a metal layer.

[0012] In one embodiment of the present invention, the wide-angle low-scattering omnidirectional microstrip antenna is center-fed via an SSMA RF connector.

[0013] In one embodiment of the present invention, the upper radiating patch is connected to two second patch resistors on the metal floor via the fourth metal via, respectively, to serve as a first absorbing path and a second absorbing path, wherein the first absorbing path is used to absorb... The second absorbing path is used to absorb the small-angle incident wave. The polarized small-angle incident wave; the eight first patch resistors on the annular absorbing structure are respectively connected to the metal ground plane through the third metal via to form a third absorbing path, which is used to absorb the small-angle incident wave. Polarized large-angle incident wave.

[0014] In one embodiment of the present invention, the scattering current of the wide-angle low-scattering omnidirectional microstrip antenna is orthogonal to the direction of its radiated current.

[0015] Compared with the prior art, the beneficial effects of the present invention are as follows: The wide-angle-domain low-scattering omnidirectional microstrip antenna of this invention achieves effective absorption of wide-angle-domain dual-polarized incident waves by forming a triple absorption path through a ring-shaped absorbing structure and a coordinated arrangement of a first patch resistor and a second patch resistor, thereby realizing wide-angle-domain low-scattering characteristics. Since the absorbing path is directly integrated into the antenna body, while achieving low-scattering performance, the original antenna profile height is maintained, and the RCS of both dual-polarized monostatic and bistatic antennas in the upper half-space of the antenna is effectively reduced.

[0016] The wide-angle low-scattering omnidirectional microstrip antenna of the present invention absorbs light through a first absorbing path. Polarized small-angle incident waves are absorbed through the second absorption path. Polarized small-angle incident waves are absorbed through the third absorption path. Large-angle incident polarized waves. Furthermore, according to the equivalence principle, the radiated current corresponding to the vertically polarized omnidirectional radiation characteristics can be equivalently represented as a dipole current distributed along the z-axis. The absorbed scattered current is distributed only within the xoy plane and is orthogonal to the radiated current. Therefore, loading multiple absorbing paths will not significantly affect the antenna's radiation characteristics, making it a promising candidate for various applications.

[0017] The above description is merely an overview of the technical solution of the present invention. In order to better understand the technical means of the present invention and to implement it in accordance with the contents of the specification, and to make the above and other objects, features and advantages of the present invention more apparent and understandable, preferred embodiments are described in detail below with reference to the accompanying drawings. Attached Figure Description

[0018] Figure 1 This is an exploded structural diagram of a wide-angle domain low-scattering omnidirectional microstrip antenna provided in an embodiment of the present invention; Figure 2 This is a schematic diagram of the structure of the wide-angle domain low-scattering omnidirectional microstrip antenna provided in an embodiment of the present invention; Figure 3 This is a schematic diagram of the equivalent radiated current and equivalent scattered current of the wide-angle domain low-scattering omnidirectional microstrip antenna provided in an embodiment of the present invention; Figure 4 This is a monostation RCS result diagram of the present invention when the dual-polarized incident wave is incident in the range of 0~90°. Figure 5This is a result diagram of the three-dimensional scattering pattern of the present invention when the dual-polarized incident wave is incident at 0°, 45° and 90° respectively; Figure 6 This is a simulation result of the antenna radiation performance of the present invention.

[0019] Reference numerals: 1-Upper radiating patch; 2-Annular absorbing structure; 3-First dielectric substrate; 4-Lower radiating patch; 5-Second dielectric substrate; 6-Metal ground plane; 7-First metal via; 8-Second metal via; 9-Third metal via; 10-Fourth metal via. DETAILED DESCRIPTION

[0020] To further illustrate the technical means and effects adopted by the present invention to achieve the intended purpose, the following detailed description of a wide-angle domain low-scattering omnidirectional microstrip antenna based on the present invention is provided in conjunction with the accompanying drawings and specific embodiments.

[0021] The foregoing and other technical contents, features, and effects of the present invention will be clearly presented in the following detailed description of specific embodiments in conjunction with the accompanying drawings. Through the description of the specific embodiments, a more in-depth and concrete understanding can be gained of the technical means and effects adopted by the present invention to achieve its intended purpose. However, the accompanying drawings are for reference and illustration only and are not intended to limit the technical solutions of the present invention.

[0022] Example 1 like Figure 1 and Figure 2 As shown, Figure 1 This is an exploded structural diagram of a wide-angle domain low-scattering omnidirectional microstrip antenna provided in an embodiment of the present invention; Figure 2 This is a schematic diagram of the structure of a wide-angle domain low-scattering omnidirectional microstrip antenna provided in an embodiment of the present invention. The antenna plane is placed on the xoy plane, such that the x-axis and y-axis directions are both parallel to the antenna plane, and the +z-axis direction is along the antenna normal direction.

[0023] In this embodiment, the wide-angle low-scattering omnidirectional microstrip antenna includes: an upper radiating patch 1, a ring-shaped absorbing structure 2, a first dielectric substrate 3, a lower radiating patch 4, a second dielectric substrate 5, and a metal ground plane 6.

[0024] Specifically, the upper surface of the first dielectric substrate 3 is etched with an upper radiating patch 1 and an annular absorbing structure 2, and the lower surface is etched with a lower radiating patch 4. The upper radiating patch 1 is located inside the annular absorbing structure 2, and the upper radiating patch 1 is connected to the lower radiating patch 4 through a first metal via 7. The annular absorbing structure 2 is provided with a plurality of first chip resistors distributed circumferentially. The second dielectric substrate 5 is located below the lower radiating patch 4, and the lower surface of the second dielectric substrate 5 is etched with a metal ground plane 6. The metal ground plane 6 is connected to the upper radiating patch 1 through a second metal via 8, and the metal ground plane 6 is also connected to the annular absorbing structure 2 through a third metal via 9. At the same time, a plurality of first chip resistors on the annular absorbing structure 2 are connected one-to-one through a plurality of third metal vias 9. A plurality of second chip resistors are provided on the upper surface of the metal ground plane 6, and the upper radiating patch 1 is connected one-to-one through a plurality of fourth metal vias 10 to a plurality of second chip resistors on the metal ground plane 6.

[0025] The wide-angle-domain low-scattering omnidirectional microstrip antenna of this invention achieves effective absorption of wide-angle-domain dual-polarized incident waves by forming a triple absorption path through a ring-shaped absorbing structure 2, a first patch resistor, and a second patch resistor in a coordinated arrangement, thereby realizing wide-angle-domain low-scattering characteristics. Since the absorbing path is directly integrated into the antenna body, while achieving low-scattering performance, the original antenna profile height is maintained, and the RCS of both dual-polarized monostatic and bistatic antennas in the upper half-space is effectively reduced. It is understood that traditionally, the thickness of the absorbing material is very thick, which increases the profile height; however, the patch resistor in this embodiment is very thin, so its impact on the profile height is negligible.

[0026] In one optional embodiment, the upper radiating patch 1 and the lower radiating patch 4 are both circular patches and are concentrically arranged, and are connected by a first metal via 7. The first dielectric substrate 3 and the second dielectric substrate 5 are bonded together by a semi-cured layer, which is beneficial for miniaturizing the antenna.

[0027] For example, there are eight first surface mount resistors, which are evenly distributed along the circumference at the edge of the slot in the annular absorbing structure 2. It is understood that the number of third metal vias 9 is the same as the number of first surface mount resistors, and the positions of the third metal vias 9 also correspond to the positions of the first surface mount resistors.

[0028] For example, there are two second surface mount resistors, spaced 90° apart, meaning one second surface mount resistor is positioned along the x-axis and the other along the y-axis. It is understood that the number of fourth metal vias 10 is the same as the number of second surface mount resistors, and the positions of the fourth metal vias 10 correspond to the positions of the second surface mount resistors.

[0029] Preferably, the resistance value of each first surface mount resistor and each second surface mount resistor is 50Ω. Further, the surface mounts of both the first and second surface mount resistors can be 0201 type surface mount resistors with a resistance value of 50Ω.

[0030] In an optional embodiment, the surface of each of the first metal via 7, the second metal via 8, the third metal via 9, and the fourth metal via 10 is coated with a metal layer. Preferably, the metal layer can be applied using an immersion tin process.

[0031] In an optional implementation, the wide-angle, low-scattering omnidirectional microstrip antenna is center-fed via an SSMA RF connector. Preferably, the SSMA RF connector is an SSMA-KFD10 RF connector.

[0032] Preferably, both the first dielectric substrate 3 and the second dielectric substrate 5 can be made of non-metallic materials with a dielectric constant of 2.65, which can reduce material costs and simplify the design process; the upper radiating patch 1, the annular absorbing structure 2, the lower radiating patch 4 and the metal ground plate 6 can all be made of copper.

[0033] In this embodiment, the scattering current of the wide-angle low-scattering omnidirectional microstrip antenna is orthogonal to the direction of its radiated current. This orthogonality avoids the adverse effects of the absorption path on the antenna's radiation performance, thus maintaining the antenna's radiation performance unchanged.

[0034] The working principle of the wide-angle low-scatter omnidirectional microstrip antenna in this embodiment is as follows: the upper radiating patch 1 is connected to the metal ground plane 6 through the second metal via 8 to achieve the antenna's vertically polarized omnidirectional radiation performance. Based on this, a triple absorbing structure is integrated into the antenna structure. Specifically, the upper radiating patch 1 is connected to two second patch resistors on the metal ground plane 6 through the fourth metal via 10, serving as the first and second absorbing paths. The angles of the two second patch resistors differ by 90°. Therefore, the first absorbing path is used to absorb vertically polarized small-angle incident waves, and the second absorbing path is used to absorb horizontally polarized small-angle incident waves. The eight first patch resistors on the ring absorbing structure 2 are respectively connected to the metal ground plane 6 through the third metal via 9, serving as the third absorbing path, which is used to absorb... Polarized large-angle incident waves. Additionally, Large-angle polarized incident waves can be absorbed in the scattering state by terminating a 50Ω load at the radiation port.

[0035] The following example uses a specific structure to illustrate the wide-angle domain low-scattering omnidirectional microstrip antenna of this embodiment.

[0036] Thickness of the first dielectric substrate 3 =0.762mm, the thickness of the second dielectric substrate 5 =0.254mm, both the first dielectric substrate 3 and the second dielectric substrate 5 are made of F4B material with a dielectric constant of 2.65, and are connected by a prepreg. The prepreg is Rogers RO4450F with a dielectric constant of 3.5 and a loss tangent of 0.004. The radius of the metal ground plane 6 is... =28.5mm, radius of the first dielectric substrate 3 =35mm, the distance from the outer metal structure of the ring-shaped absorbing structure 2 to the center point of the antenna. =33.5mm, the distance from the inner metal structure of the ring-shaped absorbing structure 2 to the center point of the antenna. =29.8mm, the distance of the third metal via 9 from the center point of the antenna. =28mm, radius of upper radiating patch 1 =24.2mm, the distance of the second metal via 8 from the center point of the antenna. =14mm, distance of the fourth metal via 10 from the center point of the antenna. =10mm, radius of lower radiating patch 4 =8.7mm, the distance from the first metal via 7 to the center point of the antenna. =5mm, the width of the inner metal structure of the annular absorbing structure 2 =2.6mm, width of the outer metal structure =1.5mm; Width of the metal branch of the annular absorbing structure 2 =0.24mm, length =3.8mm; Angular spacing of the first metal via 7 =60°, the angle interval of the fourth metal via 10 =72°, the angle interval of the inner metal structure of the annular absorbing structure 2 =30°, angular spacing of the outer metal structure =26°; radius of the third metal via 9 =0.15mm, radius of the second metal via 8 =0.45mm, radius of the first metal via 7 =0.35mm, radius of the fourth metal via 10 =0.5mm.

[0037] Based on the above structure, the radiation current corresponding to the vertically polarized omnidirectional radiation characteristics is equivalent to a dipole current distributed along the z-axis. Simultaneously, the absorbed scattered current is distributed only within the xoy plane and is orthogonal to the radiation current, such as... Figure 3 As shown, Figure 3This is a schematic diagram of the equivalent radiated current and equivalent scattered current of the wide-angle low-scattering omnidirectional microstrip antenna provided in an embodiment of the present invention. As can be seen from the figure, integrating multiple absorbing structures into the antenna does not affect the antenna's radiation characteristics.

[0038] Furthermore, the wide-angle domain low-scattering omnidirectional microstrip antenna of this embodiment was modeled and simulated using the simulation software ANSYS HFSS to analyze its electromagnetic characteristics.

[0039] like Figure 4 As shown, Figure 4 This is a monostatic RCS result diagram of the present invention when the dual-polarized incident wave is incident in the range of 0~90°. Figure 4 'a' is polarization direction, Figure 4 b is Polarization direction. As can be seen from the figure, the monostatic RCS of the wide-angle low-scattering omnidirectional microstrip antenna in this embodiment is significantly reduced in the wide-angle domain.

[0040] like Figure 5 As shown, Figure 5 This is a result of the three-dimensional scattering pattern of the dual-polarized incident wave when incident at 0°, 45°, and 90°. As can be seen from the figure, the RCS of the wide-angle low-scattering omnidirectional microstrip antenna of this embodiment is significantly reduced in the wide-angle domain.

[0041] like Figure 6 As shown, Figure 6 This is a simulation result diagram of the antenna radiation performance of the present invention, wherein, Figure 6 In the diagram, 'a' represents the reflection coefficient. Figure 6 In the diagram, b represents the 3GHz gain generation pattern in the xoz plane. Figure 6 In the diagram, c represents the 3GHz gain generation pattern in the yoz plane. Figure 6 In the figure, d represents the gain generation diagram at 3 GHz in the xoy plane. As can be seen from the figure, the radiation performance of the wide-angle low-scattering omnidirectional microstrip antenna in this embodiment has not deteriorated significantly, its operating frequency remains at 3 GHz, and it exhibits good omnidirectional radiation characteristics.

[0042] It is worth noting that the wide-angle domain low-scattering omnidirectional microstrip antenna in this embodiment achieves effective absorption of wide-angle domain dual-polarized incident waves without increasing the profile or affecting the radiation performance through a triple absorption path, and also achieves effective reduction of the wide-angle domain RCS of dual-polarized antennas.

[0043] The wide-angle low-scattering omnidirectional microstrip antenna of the present invention absorbs light through a first absorbing path. Polarized small-angle incident waves are absorbed through the second absorption path. Polarized small-angle incident waves are absorbed through the third absorption path. Large-angle incident polarized waves. Furthermore, according to the equivalence principle, the radiated current corresponding to the vertically polarized omnidirectional radiation characteristics can be equivalently represented as a dipole current distributed along the z-axis. The absorbed scattered current is distributed only within the xoy plane and is orthogonal to the radiated current. Therefore, loading multiple absorbing paths will not significantly affect the antenna's radiation characteristics, making it a promising candidate for various applications.

[0044] It should be noted that, in this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations are intended to cover non-exclusive inclusion, such that an article or apparatus comprising a list of elements includes not only those elements but also other elements not expressly listed. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the article or apparatus that includes said element. Terms such as "connected" or "linked" are not limited to physical or mechanical connections but can include electrical connections, whether direct or indirect. The orientations or positional relationships indicated by terms such as "upper," "lower," "left," and "right" are based on the orientations or positional relationships shown in the accompanying drawings and are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as limiting the invention.

[0045] The above description, in conjunction with specific preferred embodiments, provides a further detailed explanation of the present invention. It should not be construed that the specific implementation of the present invention is limited to these descriptions. For those skilled in the art, various simple deductions or substitutions can be made without departing from the concept of the present invention, and all such modifications and substitutions should be considered within the scope of protection of the present invention.

Claims

1. A wide-angle-domain low-scattering omnidirectional microstrip antenna, characterized in that, include: The first dielectric substrate has an upper radiating patch and a ring-shaped absorbing structure etched on its upper surface, and a lower radiating patch etched on its lower surface. The upper radiating patch is located inside the annular absorbing structure and is connected to the lower radiating patch through a first metal via; the annular absorbing structure is provided with a plurality of first patch resistors distributed along the circumference; The second dielectric substrate is located below the lower radiating patch, and a metal ground plane is etched on the lower surface of the second dielectric substrate. The metal floor is connected to the upper radiating patch through a second metal via and to the annular absorbing structure through a third metal via. The upper surface of the metal floor is provided with a plurality of second chip resistors, and the upper radiating patch is connected to the plurality of second chip resistors one by one through a plurality of fourth metal vias.

2. The wide-angle-domain low-scattering omnidirectional microstrip antenna according to claim 1, characterized in that, Both the upper and lower radiating patches are circular patches and are concentrically arranged.

3. The wide-angle-domain low-scattering omnidirectional microstrip antenna according to claim 1, characterized in that, The first dielectric substrate and the second dielectric substrate are bonded together by a semi-cured layer.

4. The wide-angle-domain low-scattering omnidirectional microstrip antenna according to claim 1, characterized in that, There are eight first surface mount resistors, which are evenly distributed along the circumference at the edge of the slot of the annular absorbing structure.

5. The wide-angle-domain low-scattering omnidirectional microstrip antenna according to claim 4, characterized in that, There are two second surface mount resistors, and the two second surface mount resistors are spaced 90° apart.

6. The wide-angle-domain low-scattering omnidirectional microstrip antenna according to claim 5, characterized in that, The resistance of each of the first and second surface mount resistors is 50Ω.

7. The wide-angle low-scattering omnidirectional microstrip antenna according to claim 1, characterized in that, The surface of each of the first, second, third, and fourth metal vias is coated with a metal layer.

8. The wide-angle-domain low-scattering omnidirectional microstrip antenna according to claim 1, characterized in that, The wide-angle, low-scattering omnidirectional microstrip antenna is center-fed via an SSMA RF connector.

9. The wide-angle-domain low-scattering omnidirectional microstrip antenna according to claim 5, characterized in that, The upper radiating patch is connected to two second surface-mount resistors on the metal floor via the fourth metal via, serving as a first absorption path and a second absorption path. The first absorption path is used to absorb... The second absorbing path is used to absorb the small-angle incident wave. Polarized small-angle incident wave; The eight first surface-mount resistors on the annular absorbing structure are respectively connected to the metal ground plane through the third metal vias to form a third absorbing path, which is used to absorb microwaves. Polarized large-angle incident wave.

10. The wide-angle-domain low-scattering omnidirectional microstrip antenna according to claim 9, characterized in that, The scattering current of the wide-angle low-scattering omnidirectional microstrip antenna is orthogonal to the direction of its radiated current.

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