Dual-polarized antenna and radar device

Abstract

The invention relates to the field of antennas, and particularly discloses a dual-polarized antenna, which comprises a slot antenna layer for radiating a first polarized wave and a microstrip antenna layer for radiating a second polarized wave, wherein the slot antenna layer comprises a waveguide structure, the waveguide structure comprises a plurality of radiation units arranged along a first direction, and each radiation unit comprises a plurality of radiation slots extending along a second direction; the micro-strip antenna layer comprises a plurality of micro-strip oscillator units arranged along a first direction, and each micro-strip oscillator unit comprises a plurality of micro-strip oscillators arranged along a second direction; the microstrip antenna layer is arranged on the slot antenna layer, at least one microstrip array unit is arranged between the radiation units, and projections of the microstrip arrays and the radiation slots on the waveguide structure are not overlapped; the antenna is simple in structure, has the characteristics of low profile, miniaturization and light weight, can obtain the electromagnetic scattering characteristics of a target in different polarization directions, and is suitable for a high-frequency dual-polarized antenna.

Description

Technical Field

[0001] This invention relates to the field of antennas, and more particularly to a dual-polarized antenna and radar device. Background Technology

[0002] Dual-polarized antennas, as core electromagnetic devices capable of simultaneously transmitting and receiving two orthogonally polarized electromagnetic waves (horizontal / vertical linear polarization, ±45° linear polarization, or orthogonal circular polarization, etc.), leverage their advantage of simultaneously capturing target polarization scattering characteristics and spatial propagation information. Through dual-channel signal collaborative analysis, they achieve accurate characterization of target attributes and environmental conditions, playing an irreplaceable role in fields such as meteorological detection, target classification, and object surface smoothness detection. They are gradually replacing traditional single-polarized antennas as key components for improving detection and observation efficiency.

[0003] Existing dual-polarized antennas mainly include reflector antennas, microstrip antennas, and waveguide slot antennas. Reflector antennas usually rely on mechanical scanning to operate, which makes the overall radar structure large and limits the placement scenarios. Microstrip antennas and waveguide slot antennas, on the other hand, have the characteristics of low profile, small size, and light weight.

[0004] For example, prior art document 1 discloses a case of dual-polarization application of waveguide slot antennas in CN113178708A. This dual-polarization waveguide slot array antenna includes multiple horizontally polarized antennas, vertically polarized antennas, and multiple feed lines, with each horizontally polarized antenna and vertically polarized antenna arranged alternately at equal intervals. Both types of polarized antennas include a radiating cavity, a base cavity, a waveguide-to-coaxial converter, and a matching load, implemented on the same flat waveguide and the same single-ridge waveguide, respectively, with a total cross-sectional area only 45% of a standard waveguide. One end of each feed line connects to the waveguide-to-coaxial converter via its first bend, and the other end connects to the feed source via its second bend. This invention has a small volume and array spacing, requires less space for feed line wiring, and has a larger scanning range for both horizontal and vertical polarized beams, making it suitable for weather radar. However, the dual-polarization of prior art 1 is composed of multiple waveguide slot arrays, which are simply stacked together. Furthermore, to achieve dual polarization, a certain degree of compromise is made in structural complexity, resulting in a more complex manufacturing process and preventing mass production of the entire array.

[0005] Reference document 2 is CN106058475B, which discloses a waveguide-microstrip common-aperture antenna. The waveguide-microstrip common-aperture antenna element includes a waveguide antenna, a microstrip antenna, and a reflective substrate. The microstrip antenna and the waveguide antenna are respectively fixed to the upper and lower sides of the reflective substrate. The reflective substrate has waveguide antenna radiation slots. The reflective substrate is elongated. The microstrip antennas are arranged in two rows along the length of the reflective substrate. The dielectric substrate of each microstrip antenna is perpendicular to the surface of the reflective substrate and parallel to the length of the reflective substrate. The radiators of the two rows of microstrip antennas are arranged opposite to each other. When viewed perpendicular to the reflective substrate, the waveguide antenna and the waveguide antenna radiation slots are both located in the middle of the two rows of microstrip antennas.

[0006] However, the common-aperture antenna in Comparative Document 2 uses a ridge waveguide slot antenna and a microstrip antenna to form a common-aperture antenna. The dielectric substrate of the microstrip antenna is perpendicular to the surface of the reflector plate and parallel to the length direction of the reflector plate. Furthermore, the radiators of the two rows of microstrip antennas are arranged back-to-back with each other. The technical problem it solves is eliminating the adverse effects between the waveguide antenna and the microstrip antenna, solving the integrated feeding problem, and achieving wideband and wide-angle scanning capability. However, its structure is complex, with a high profile and large volume, and the manufacturing process is also relatively complex, making it difficult to mass-produce.

[0007] Reference document 3 is invention patent CN112993538B, which discloses a dual-polarized antenna, including: a first dielectric layer; multiple radiating patches connected in series on the upper surface of the first dielectric layer, with each pair of adjacent radiating patches connected by a vertically polarized feed line; the vertically polarized feed line feeds the radiating patches in series, and after receiving electromagnetic energy from the feed source, the vertically polarized feed line generates a current in the vertical direction on the radiating patch, thereby causing the radiating patch to radiate vertically polarized electromagnetic wave energy outward; a substrate integrated waveguide structure is disposed at the lower end of the first dielectric layer, and the substrate integrated waveguide structure has multiple coupling slots, which are used to couple electromagnetic waves to the radiating patches through the coupling slots, so that the radiating patches radiate horizontally polarized electromagnetic waves.

[0008] First, in comparison document 3, the substrate-integrated waveguide structure couples electromagnetic waves to the radiating patch via a coupling slot, and then radiates them into space. Therefore, the coupling slot and the radiating patch interact, resulting in low vertical polarization isolation and potential signal leakage between the two polarization ports, thus affecting its anti-interference capability.

[0009] Secondly, it requires that the waveguide wavelength of the Substrate Integrated Waveguide (SIW) / 2 = the waveguide wavelength of the series-fed microstrip antenna. The waveguide wavelength of the SIW antenna and the waveguide wavelength of the series-fed antenna are related to the dielectric constant of the dielectric layer. Under normal conditions, it is necessary to select two dielectrics with different dielectric constants for mixed use, and special customized boards are required to achieve the desired effect.

[0010] Moreover, its application range is relatively narrow, only applicable to dual-polarized antennas with substrate integrated waveguide structure and series-fed microstrip antenna, and not applicable to dual-polarized antennas with metal waveguide and series-fed microstrip antenna. Summary of the Invention

[0011] The problem to be solved by the present invention is to provide a dual-polarized antenna with a simple structure, low profile, miniaturization and lightweight, which can obtain the electromagnetic scattering characteristics of a target in different polarization directions and is suitable for high-frequency dual-polarized antennas.

[0012] The problem to be solved by this invention is to provide a dual-polarized antenna that can be manufactured using a multilayer lamination process, facilitating mass production.

[0013] To address the aforementioned technical problems, this invention provides a dual-polarized antenna, comprising a slot antenna layer for radiating a first polarized wave and a microstrip antenna layer for radiating a second polarized wave. The slot antenna layer includes a waveguide structure comprising a plurality of radiating elements arranged along a first direction, each radiating element comprising a plurality of radiating slots extending along a second direction. The microstrip antenna layer comprises a plurality of microstrip array elements arranged along the first direction, each microstrip array element comprising a plurality of microstrip arrays arranged along the second direction. The microstrip antenna layer is disposed on the slot antenna layer, with at least one microstrip array element positioned between the radiating elements. The projections of the microstrip arrays and the radiating slots onto the waveguide structure do not overlap. The waveguide structure radiates electromagnetic wave energy in the first polarization direction into space through the radiating slots; the microstrip arrays of the microstrip antenna layer radiate electromagnetic wave energy in the second polarization direction into space. The microstrip arrays and radiating slots operate independently, both radiating directly into space.

[0014] As an improvement to the above scheme, the slot antenna layer is a waveguide slot antenna layer or a substrate integrated waveguide slot antenna layer.

[0015] As an improvement to the above scheme, the waveguide structure is configured as a rectangular waveguide or a ridge waveguide.

[0016] As an improvement to the above scheme, the radiating element and the microstrip array element are arranged alternately along the first direction; the surface of the microstrip array element is parallel to the surface of the waveguide structure.

[0017] As an improvement to the above solution, the radiation unit includes a plurality of first radiation slots and second radiation slots extending along a second direction, wherein the first radiation slots and the second radiation slots are staggered in a first direction.

[0018] As an improvement to the above scheme, the radiating unit has a waveguide centerline arranged along the second direction, and the first radiating slot and the second radiating slot are respectively located on both sides of the waveguide centerline.

[0019] As an improvement to the above scheme, along the first direction, the offset distance between the centerlines of the first and second radiating slots and the waveguide centerline is... The width of the waveguide structure is .

[0020] As an improvement to the above scheme, along the second direction, each of the radiating elements of the waveguide slot antenna layer includes N1 radiating slots, and each of the microstrip array elements includes N2 microstrip arrays, wherein the number of microstrip arrays N2 is greater than or equal to the number of radiating slots N1.

[0021] As an improvement to the above scheme, along the second direction, each of the radiating elements of the substrate integrated waveguide slot antenna layer includes N1 radiating slots, and each of the microstrip array elements includes N2 microstrip arrays, wherein the number of microstrip arrays N2 is less than or equal to the number of radiating slots N1.

[0022] As an improvement to the above scheme, the number of radiation slots N1 is 1-32, and the number of microstrip arrays N2 is 1-48.

[0023] As an improvement to the above scheme, the microstrip antenna layer includes a grounding substrate, a dielectric substrate, a microstrip feed network, microstrip elements, and microstrip feed lines. The dielectric substrate is disposed on the grounding substrate, and a plurality of the microstrip elements are disposed on the dielectric substrate and connected to the microstrip feed network through the microstrip feed lines.

[0024] As an improvement to the above solution, the grounding substrate of the microstrip antenna layer is fixed to the waveguide structure of the slot antenna layer by a conductive connector or conductive adhesive.

[0025] As an improvement to the above solution, the surface of the waveguide structure is provided with a plurality of grooves arranged along a first direction, the grooves being adapted to the microstrip array unit, and the microstrip array unit being disposed within the grooves; As an improvement to the above scheme, the surface of the microstrip array is flush with the surface of the waveguide structure, or the surface of the microstrip array is higher than the surface of the waveguide structure.

[0026] As an improvement to the above scheme, along the first direction, the width of the waveguide structure is... The free space wavelength is , Along the first direction, the narrow side length of the waveguide structure is , .

[0027] As an improvement to the above scheme, along the first direction, the width of the radial slit is... , The diameter is 0.1-4 mm; along the second direction, the length of the radial slit is... The waveguide wavelength is , Along the first direction, in adjacent radiating elements, the spacing between the radiating slots is d1, where d1 satisfies... .

[0028] As an improvement to the above scheme, along the first direction, the width of the microstrip array is... , Along the second direction, the length of the microstrip array is , Along the first direction, in adjacent microstrip array elements, the spacing between the microstrip elements is d2, where d2 satisfies... .

[0029] As an improvement to the above scheme, the diameter of the metallized via in the substrate integrated waveguide slot antenna layer is [missing information]. , ; and / or the spacing between adjacent metallized vias is , .

[0030] As an improvement to the above scheme, the diameter of the metallized via in the substrate integrated waveguide slot antenna layer is d, where d is 0.1-1mm; and / or the spacing between adjacent metallized vias is d3, where d3 is 0.2-4mm.

[0031] As an improvement to the above scheme, the polarization directions of the first polarized wave and the second polarized wave are orthogonal; the first polarized wave is a horizontally polarized wave and the second polarized wave is a vertically polarized wave; or, the first polarized wave is a vertically polarized wave and the second polarized wave is a horizontally polarized wave; or, the first polarized wave is +45° obliquely polarized and the second polarized wave is -45° obliquely polarized; or, the first polarized wave is -45° obliquely polarized and the second polarized wave is +45° obliquely polarized.

[0032] Accordingly, the present invention provides a radar device, characterized in that it includes a dual-polarized antenna as described in any one of the above technical solutions.

[0033] Implementing this invention has the following beneficial effects: This invention discloses a dual-polarized antenna comprising a slot antenna layer for radiating a first polarized wave and a microstrip antenna layer for radiating a second polarized wave. The slot antenna layer includes a plurality of radiating elements arranged along a first direction, and the microstrip antenna layer includes a plurality of microstrip array elements arranged along the first direction. The microstrip antenna layer is disposed on the surface of the slot antenna layer, and at least one microstrip array element is disposed between the radiating elements. The projections of the microstrip array and the radiating slot onto the waveguide structure do not overlap. Therefore, this invention designs the slot antenna layer into a single-piece, multi-layered, press-fit structure. This structure is simple, features a low profile, miniaturization, and lightweight characteristics, and can acquire the electromagnetic scattering characteristics of a target in different polarization directions. It can be applied to high-frequency dual-polarized antennas. This invention abandons the traditional method of mechanically assembling multiple independent waveguide channels, fundamentally solving the problems of phase inconsistency and performance degradation between elements caused by assembly errors. It can provide richer target information, including polarization phase, amplitude, and polarization ratio.

[0034] The present invention, through the sequential arrangement of radiating elements and microstrip array elements, with at least one microstrip array element disposed between the radiating elements, ensures that the geometric position and electrical phase of all radiating slots have extremely high repeatability and consistency, thereby guaranteeing the stability and reliability of the beam pattern of the large-scale array antenna.

[0035] Meanwhile, the present invention designs the slot antenna layer into a multi-layer press-fit structure that can be integrally formed. It can use multi-layer press-fit manufacturing process, which is suitable for large-scale and mass production. While improving performance consistency, it significantly reduces the manufacturing cost and assembly complexity of complex waveguide arrays, making the large-scale application of high-performance planar slot array antennas possible.

[0036] Furthermore, this invention arranges the microstrip radiating patch array and the waveguide radiating slot array in a staggered manner (such as a quincunx pattern) along the lateral direction, which can make greater use of the limited aperture area and improve the integration density. This compact staggered layout ensures electromagnetic isolation between the two polarization units while allowing more radiating units to be arranged within the same aperture size, or significantly reducing the lateral size of the antenna while achieving the same radiation performance.

[0037] In summary, the dual-polarized antenna of this invention can simultaneously transmit and receive two orthogonal polarization modes, increasing channel capacity, enhancing anti-interference capabilities, improving radar target identification capabilities, and achieving more accurate identification and measurement. This meets the needs of high-end radar systems (high-precision weather radar, high-precision FOD radar, high-precision marine radar, etc.), scientific remote sensing and imaging, and next-generation communication equipment. Attached Figure Description

[0038] Figure 1This is a schematic diagram of an embodiment of a dual-polarized antenna according to the present invention; Figure 2 yes Figure 1 The diagram shows an exploded view of a dual-polarized antenna. Figure 3 yes Figure 1 The diagram shows a schematic of the structure of a microstrip antenna layer for a dual-polarized antenna. Figure 4 yes Figure 1 The diagram shows a schematic of the slot antenna layer structure of a dual-polarized antenna. Figure 5 yes Figure 1 A partial schematic diagram of a dual-polarized antenna is shown. Figure 6 This is a schematic diagram of another embodiment of a dual-polarized antenna according to the present invention; Figure 7 yes Figure 6 The diagram shows a schematic of the slot antenna layer structure of a dual-polarized antenna. Figure 8 This is a schematic diagram of the ridge waveguide structure of a dual-polarized antenna according to the present invention; Figure 9 This is the vertical polarization radiation pattern of a dual-polarized antenna embodiment 1 of the present invention; Figure 10 This is the radiation pattern of the horizontal polarization of a dual-polarized antenna embodiment 1 of the present invention; Figure 11 This is the vertical polarization radiation pattern of a dual-polarized antenna embodiment 2 of the present invention; Figure 12 This is the radiation pattern of the horizontal polarization of a dual-polarized antenna embodiment 2 of the present invention; Figure 13 This is the vertical polarization radiation pattern of a dual-polarized antenna embodiment 3 of the present invention; Figure 14 This is the radiation pattern of the horizontal polarization of a dual-polarized antenna embodiment 3 of the present invention; Figure 15 This is the vertical polarization pattern of a dual-polarized antenna embodiment 4 of the present invention; Figure 16 This is the radiation pattern of the horizontal polarization of a dual-polarized antenna embodiment 4 of the present invention; Figure 17 This is a structural schematic diagram of a dual-polarized antenna according to Comparative Example 1 of the present invention; Figure 18 This is a schematic diagram of the combined structure of a dual-polarized antenna, Comparative Example 1, of the present invention; Figure 19 This is the vertical polarization pattern of a dual-polarized antenna, Comparative Example 1 of the present invention; Figure 20This is the radiation pattern of the horizontal polarization of a dual-polarized antenna according to Example 1 of the present invention. Detailed Implementation

[0039] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings. It is hereby declared that the directional terms such as up, down, left, right, front, back, inside, and outside used in this text are based solely on the accompanying drawings and are not intended to specifically limit the invention.

[0040] like Figures 1-4 As shown, Figures 1-4 An embodiment of a dual-polarized antenna of the present invention is shown, which includes a slot antenna layer 1 for radiating a first polarized wave and a microstrip antenna layer 2 for radiating a second polarized wave. The slot antenna layer 1 includes a waveguide structure 11, which includes a plurality of radiating elements 10 arranged along a first direction. Each radiating element includes a plurality of radiating slots 12 extending along a second direction. The slot antenna layer 1 transmits electromagnetic energy to the slots through the waveguide structure 11 and radiates it into free space through the slots to form the desired radiating beam. Further planning the arrangement of the waveguide slot antenna array can control the direction and shape of the beam.

[0041] The microstrip antenna layer 2 includes a plurality of microstrip array sub-units 20 arranged along a first direction, and the microstrip array sub-units 20 include a plurality of microstrip arrays 21 arranged along a second direction. The microstrip antenna layer 2 is disposed on the slot antenna layer 1, and at least one microstrip array element 20 is disposed between the radiating elements 10. The projections of the microstrip array element 21 and the radiating slot 12 onto the waveguide structure 11 do not overlap. The slot antenna layer 1 radiates electromagnetic wave energy in a first polarization direction into space through the radiating slot 12; the microstrip array element 21 of the microstrip antenna layer 2 radiates electromagnetic wave energy in a second polarization direction into space.

[0042] The radiation slot 12 and microstrip array 21 of the present invention operate independently and radiate directly into space. They have high vertical polarization isolation, which avoids possible signal leakage between polarization ports, improves their anti-interference ability, and enables radar to identify multiple targets with high precision.

[0043] It should be noted that, in this embodiment, the second direction is located on the plane of the waveguide structure 11 and is parallel to the direction of the microstrip feed, while the first direction is located on the plane of the waveguide structure 11 and is perpendicular to the first direction.

[0044] In some embodiments, the radiating slit 12 radiates electromagnetic wave energy in the horizontal polarization direction into space, and the microstrip array 21 radiates electromagnetic wave energy in the vertical polarization direction into space.

[0045] In this invention, the slot antenna layer 1 includes a waveguide structure 11, which includes a plurality of radiating elements 10 arranged along a first direction. That is, this invention designs the slot antenna layer 1 as a multi-layer press-fit structure that can be integrally formed. This invention integrates a microstrip antenna layer 2 into the structure of the slot antenna layer 1 on the basis of the slot antenna layer 1, making full use of the gaps between the radiating elements 10, and placing at least one microstrip array sub-unit 20 between the radiating elements 10.

[0046] This dual-polarized antenna features a simple structure, low profile, miniaturization, and lightweight design. It can acquire the electromagnetic scattering characteristics of a target in different polarization directions and can be applied to high-frequency dual-polarized antennas. This invention abandons the traditional method of mechanically assembling multiple independent waveguide channels, fundamentally solving the problems of phase inconsistency and performance degradation between elements caused by assembly errors. It can provide richer target information (polarization phase, amplitude, polarization ratio, etc.).

[0047] The radiating slot 12 and microstrip array 21 of this invention operate independently, both radiating directly in space. They exhibit high vertical polarization isolation, preventing signal leakage between polarization ports and improving anti-interference capabilities, thus enabling high-precision multi-target radar identification. Furthermore, this invention is applicable to dual-polarized antennas using metal waveguides / SIW and series-fed microstrip antennas, offering broad applicability and eliminating the need for a custom dielectric layer.

[0048] The present invention, through the sequential arrangement of radiating elements 10 and microstrip array elements 20, with at least one microstrip array element 20 disposed between the radiating elements 10, ensures that the geometric position and electrical phase of all radiating slots have extremely high repeatability and consistency, thereby guaranteeing the stability and reliability of the beam pattern of the large-scale array antenna.

[0049] Meanwhile, the slot antenna layer 1 is a multi-layer press-fit structure that can be integrally molded. It can use multi-layer press-fit manufacturing process, which is suitable for large-scale and mass production. While improving performance consistency, it significantly reduces the manufacturing cost and assembly complexity of complex waveguide arrays, making it possible for the large-scale application of high-performance planar slot array antennas.

[0050] In some embodiments, the slot antenna layer 1 may be a waveguide slot antenna layer or a substrate integrated waveguide slot antenna layer; both the waveguide slot antenna layer and the substrate integrated waveguide slot antenna layer radiate electromagnetic waves by opening slots in the waveguide structure 11. However, the waveguide slot antenna layer radiates electromagnetic waves outward by setting a metal cavity waveguide wall and opening slots in the wall to interrupt the surface current of the inner wall of the waveguide; while the substrate integrated waveguide slot antenna layer radiates electromagnetic waves outward by forming a "virtual" waveguide cavity on the PCB board using upper and lower metal layers and two rows of metallized via arrays, and etching slots in the top metal layer.

[0051] The slot antenna layer 1 of this invention can be a waveguide slot antenna layer or a substrate integrated waveguide slot antenna layer, depending on cost and production requirements. For high-frequency applications (such as millimeter-wave bands), a substrate integrated waveguide (SIW) slot antenna layer is preferred to simplify the process; for high-power scenarios, a waveguide slot antenna layer (metal waveguide) is selected to ensure heat dissipation and reliability.

[0052] It should be noted that, Figure 1-5 The dual-polarized antenna shown has a waveguide slot antenna layer 1 as its slot antenna layer. Figure 6-7 The dual-polarized antenna shown has a slot antenna layer 1 made of substrate integrated waveguide slot antenna layer.

[0053] In some embodiments, the radiating element 10 and the microstrip array element 20 can be arranged in an alternating manner along a first direction; the surface of the microstrip array 21 is parallel to the surface of the waveguide structure 11, giving it the characteristics of low profile, miniaturization, and lightweight, which not only improves space utilization and realizes the function of dual polarization, but also ensures the efficiency of large-scale production of the overall structure, that is, only an appropriate slot antenna layer 1 needs to be constructed, and then the microstrip antenna layer 2 can be installed on the slot antenna layer 1. The installation method can be adhesive bonding, or a connector can be used to fix it to the slot antenna layer 1.

[0054] In some embodiments, the radiating elements 10 and microstrip array elements 20 can be arranged in an alternating manner along a first direction, with a microstrip array element 20 positioned between every two adjacent radiating elements 10. This embodiment arranges the radiating elements 10 and microstrip array elements 20 in an alternating manner (such as a staggered arrangement) along the first direction, which can maximize the utilization of the limited aperture area and improve integration. This compact, alternating layout ensures electromagnetic isolation between the two polarization elements while allowing for the arrangement of more radiating elements within the same aperture size, or significantly reducing the lateral size of the antenna while achieving the same radiation performance.

[0055] In some embodiments, such as Figure 5As shown, the radiation unit includes a plurality of first radiation slots 12A and second radiation slots 12B extending along a second direction, and the first radiation slots 12A and second radiation slots 12B are staggered in the first direction.

[0056] To achieve better dual polarization, in some preferred embodiments, the radiating unit includes a waveguide centerline L1 arranged along a second direction, with the first radiating slot 12A and the second radiating slot 12B respectively located on both sides of the waveguide centerline.

[0057] It should be noted that the waveguide centerline L1 is the centerline of each radiating element along the second direction.

[0058] In some embodiments, along a first direction, the offset distance between the centerlines of the first and second radiating slots and the waveguide centerline is [missing information]. The width of the waveguide structure is The offset distance between the centerlines of the first and second radiating slots and the waveguide centerline is... This enables more accurate identification and measurement, ensuring its application in high-frequency dual-polarized antennas, especially meeting the requirements of the W-band, and satisfying extremely high performance and resolution demands. It should be noted that the W-band refers to the 75-110 GHz millimeter-wave frequency band.

[0059] In some embodiments, along the second direction, each radiating element of the waveguide slot antenna layer includes N1 radiating slots 12, and each microstrip sub-element includes N2 microstrip elements 21, wherein the number of microstrip elements 21 N2 is greater than or equal to the number of radiating slots 12 N1. This invention, through a specific arrangement of the radiating elements and microstrip sub-element, with at least one microstrip sub-element positioned between the radiating elements and parallel to them, ensures extremely high repeatability and consistency in the geometric position and electrical phase of all radiating slots 12. The fact that the number of microstrip elements 21 N2 is greater than or equal to the number of radiating slots 12 N1 further ensures more consistent beam pointing of the two antennas, improving identification accuracy.

[0060] Along the second direction, each radiating element of the substrate integrated waveguide slot antenna layer includes N1 radiating slots 12, and each microstrip array element includes N2 microstrip arrays 21. The number of microstrip arrays 21, N2, is less than or equal to the number of radiating slots 12, N1. Furthermore, the dielectric constant of a general dielectric substrate is higher than that of air. To address the technical problem of a shortened waveguide wavelength due to the change in dielectric constant, the number of microstrip arrays 21, N2, in the substrate integrated waveguide slot antenna layer is less than or equal to the number of radiating slots 12, N1. By increasing the number of radiating slots 12, the beam pointing of the two antennas is more consistent, improving the accuracy of identification.

[0061] Preferably, the number of radiating slots 12, N1, is 1-32, and the number of microstrip arrays 21, N2, is 1-48, with the specific values ​​determined according to the application frequency band. For example, in low-frequency bands (such as below 6 GHz), larger N1 and N2 can be selected to enhance gain; in high-frequency bands (such as above 24 GHz), the number can be reduced to reduce loss. In specific implementations, parametric design software (such as HFSS) can be used to optimize the number configuration.

[0062] Regarding the microstrip antenna layer 2, the microstrip antenna layer 2 includes a plurality of microstrip array sub-units 20 arranged along a first direction, and the microstrip array sub-units 20 include a plurality of microstrip arrays 21 arranged along a second direction; like Figure 2 As shown, in some embodiments, the microstrip antenna layer 2 includes a ground substrate 23, a dielectric substrate 22, a microstrip feed network 24, microstrip elements 21, and microstrip feed lines 25. The dielectric substrate 22 is disposed on the ground substrate 23, and several microstrip elements 21 are disposed on the dielectric substrate 22 and connected to the microstrip feed network 24 through the microstrip feed lines 25. The ground substrate 23 provides a return path for the radiated current on the microstrip elements 21, forming a complete resonant structure with the microstrip elements 21. The dielectric substrate 22 provides mechanical support for the entire structure. Furthermore, different dielectric substrates 22 have different dielectric constants. Selecting a suitable dielectric substrate based on its dielectric constant reduces the physical size of the antenna, achieving the design goals of low profile and miniaturization. The microstrip feed lines 25 and the microstrip feed network 24 distribute the input signal to each microstrip element 20 according to a specific amplitude and phase.

[0063] In some embodiments, the grounding substrate 23 of the microstrip antenna layer 2 can be fixed to the waveguide structure 11 of the slot antenna layer 1 by adhesive bonding or by using connectors. Preferably, the grounding substrate 23 of the microstrip antenna layer 2 is fixed to the waveguide structure 11 of the slot antenna layer 1 by mechanical connectors (such as screws or solder joints) or adhesive. In implementation, the connectors need to be evenly distributed to maintain mechanical stability; adhesive is suitable for flexible installation and reduces stress.

[0064] In some embodiments, the surface of the waveguide structure 11 may also be provided with a plurality of grooves arranged along a first direction, the shape of which is adapted to the microstrip array unit 20, so that the microstrip array unit 20 is embedded in the groove. This design can reduce the overall profile height, facilitating transportation and installation.

[0065] In some embodiments, the surface of the microstrip array 21 is flush with, slightly lower than, or slightly higher than the surface of the waveguide structure 11. Having the surface of the microstrip array 21 flush with the surface of the waveguide structure 11 ensures planar consistency and avoids edge diffraction. Having the surface of the microstrip array 21 lower than the surface of the waveguide structure 11 protects the microstrip array from mechanical damage. Having the surface of the microstrip array 21 higher than the surface of the waveguide structure 11 ensures polarization and reduces the number of groove processing steps. Preferably, the surface of the microstrip array 21 is flush with or slightly higher than the surface of the waveguide structure 11.

[0066] Preferably, the depth of the groove is slightly greater than the thickness of the microstrip array subunit 20, with a tolerance reserved to compensate for thermal expansion.

[0067] Furthermore, this invention, through the slot antenna layer 1 and the microstrip antenna layer 2, can simultaneously transmit and receive two orthogonal polarization modes. To enhance anti-interference capabilities and improve radar target identification capabilities, the waveguide structure 11, the radiating slot 12, and the microstrip array 21 can be implemented in various ways to meet the needs of different products and scenarios.

[0068] For example, in the field of foreign object detection (FOD) equipment for airport runways, dual-polarized antennas operating in the 92-94 GHz frequency band can have their waveguide structure and microstrip array dimensions set and adjusted according to detection requirements.

[0069] In the field of weather radar, dual-polarized antennas operating in the 9.1-9.5GHz frequency band can have their waveguide structure and microstrip array dimensions set and adjusted according to detection requirements.

[0070] In some embodiments, along the first direction, the width of the waveguide structure 11 is... The free space wavelength is , Along the first direction, the narrow side length of the waveguide structure 11 is , This ensures that electromagnetic waves can propagate in the TE10 dominant mode within the waveguide.

[0071] Preferably, the width of the waveguide structure 11 is... The narrow side length of waveguide structure 11 is 0.6λ-0.95λ. It is 0.01λ-0.45λ.

[0072] In some embodiments, the width of the radial slit 12 is , The length is 0.1-4 mm; along the second direction, the length of the radial slit 12 is... The waveguide wavelength is , Along the first direction, in adjacent waveguide radiating elements, the spacing between the radiating slots 12 is d1, where d1 satisfies... This ensures that all gaps radiate in phase and suppresses the appearance of grid lobes.

[0073] By controlling the width and length of the radiation slit 12, the radiation efficiency can be improved.

[0074] Preferably, the width of the radial slit 12 for Specifically, it can be 2mm, but is not limited to this. The length of the radial slit 12... for Specifically, it can be 14.5mm, but is not limited to this. The spacing d1 between the radial slits 12 is... Specifically, it can be 22.15mm, but it is not limited to this.

[0075] In some embodiments, the width of the microstrip antenna layer along the first direction is e. Along the second direction, the length of the microstrip array is , Along the first direction, in adjacent microstrip array elements, the spacing between the microstrip elements is d2, where d2 satisfies... This results in in-phase radiation and grating lobe suppression.

[0076] In some embodiments, when the slot antenna layer 1 is a substrate integrated waveguide slot antenna layer, the diameter of the metallized via 31 of the substrate integrated waveguide slot antenna layer is [missing information]. , ; and / or the spacing between adjacent metallized vias 31 is , This ensures that the metallized vias can effectively simulate a continuous metal wall, preventing electromagnetic energy from leaking from the via gaps, while also avoiding unnecessary electromagnetic resonance caused by excessively large via diameters.

[0077] Preferably, the diameter of the metallized via 31 in the substrate integrated waveguide slot antenna layer is d, where d is 0.1-1mm, specifically 0.3mm, 0.4mm, 0.5mm, 0.6mm, 0.7mm, 0.8mm, 0.9mm, or 1mm, but is not limited to these values. This size ensures fabrication feasibility (e.g., the limits of PCB drilling processes), avoids incomplete metallization of the hole wall due to excessively small diameters, and prevents excessively large via diameters from causing high-order mode excitation or weakening the sealing of the waveguide cavity.

[0078] Preferably, the spacing between adjacent metallized vias 31 is d3, where d3 is 0.2-4 mm, specifically 0.2 mm, 0.5 mm, 1.0 mm, 1.5 mm, 2.0 mm, 2.5 mm, 3 mm, 3.5 mm, or 4.0 mm, but is not limited to these values. This dimension ensures a sufficiently high via density, forming a continuous "virtual" waveguide wall to prevent electromagnetic field diffusion.

[0079] In some embodiments, the waveguide structure of the slot antenna may be configured as a rectangular waveguide or a ridge waveguide (e.g., Figure 8 As shown, the rectangular waveguide has higher power capacity and lower transmission loss, while the ridge waveguide can achieve a smaller size at the same operating frequency. The appropriate waveguide shape can be selected according to the actual situation. Furthermore, based on the requirement that the polarization directions of the first polarized wave and the second polarized wave are orthogonal, this invention also proposes: the first polarized wave is a horizontally polarized wave and the second polarized wave is a vertically polarized wave; or, the first polarized wave is a vertically polarized wave and the second polarized wave is a horizontally polarized wave; or the first polarized wave is +45° slanted polarization and the second polarized wave is -45° slanted polarization; or the first polarized wave is -45° slanted polarization and the second polarized wave is +45° slanted polarization. In practice, various combinations can be achieved by adjusting the slot and array element orientation. For example, when the slot antenna layer 1 radiates a horizontally polarized wave, the microstrip array element 20 rotates 90° to radiate a vertically polarized wave; or slanted polarization can be achieved by adjusting the phase of the feed network.

[0080] Accordingly, the present invention also provides a radar device including any of the aforementioned dual-polarized antennas. In implementation, the dual-polarized antenna serves as the radar front-end, integrated with a signal processing module (such as an FPGA), and is used in meteorological detection or communication systems. The antenna is connected via a standard interface (such as a WR-90 waveguide port), and the overall packaging takes into account heat dissipation and environmental protection.

[0081] This invention provides a dual-polarized antenna that can simultaneously transmit and receive two orthogonal polarization modes, enhancing anti-interference capabilities, improving radar target identification capabilities, and achieving more accurate identification and measurement. This meets the needs of high-end radar systems (high-precision weather radar, automotive radar, marine radar, etc.), scientific remote sensing and imaging, and next-generation communication equipment.

[0082] The present invention will be further illustrated below with specific embodiments. Example 1 I. Dual-polarized antenna: It includes a waveguide slot antenna layer and a microstrip antenna layer. The waveguide slot antenna layer is a four-slot standing wave waveguide wide-side longitudinal slot antenna with an operating frequency of 9.3~9.5Hz, and the microstrip antenna layer is a six-element microstrip antenna layer.

[0083] (1) Core design parameters of waveguide slot antenna layer: Operating frequency band: 9.3~9.5GHz (center frequency f=9.4GHz) Gap type: Wide-side longitudinal seam gap Number of gaps: 4 Waveguide dimensions: wide side a = 21 mm, narrow side b = 2 mm Longitudinal distance of the gap: 24.5mm Antenna lateral distance: 22mm Gap dimensions: Length = 16mm, Width = 1mm The horizontal scanning angle is ±20°. Polarization mode: horizontal polarization (E plane along the wide side a direction).

[0084] (2) Core design specifications of the microstrip antenna layer 2: Frequency band: 9.3~9.5GHz (center frequency f=9.4GHz) Array size: 6-element linear array (arranged along the microstrip transmission direction) Dielectric substrate 22: Rogers 4350 ( =3.66) Substrate parameters: Thickness h = 0.254 mm The copper foil thickness t = 35um (0.035mm) Microstrip connector width: W=0.55mm Interval spacing: d=16.6mm.

[0085] II. Verification process: The key design constraint for a wide-side longitudinal slot antenna with a four-slot standing wave wave guide operating at 9.3~9.5Hz is to ensure TE 10 Using single-mode transmission, slot resonant radiation, and array in-phase excitation, with a wide side length a = 21 mm and a narrow side length b = 2 mm, verify whether the length of the wide side meets the requirements.

[0086] in, TE 10 The cutoff frequency of the mode, Indicates the length of the wide side. It represents the speed of light.

[0087] Therefore, the lower operating frequency limit of the designed waveguide structure 11 is 9.3 GHz. >1.2 , satisfy TE 10 The single-mode transmission condition can satisfy the requirement that electromagnetic waves are transmitted at the waveguide wavelength in the waveguide and at the spatial wavelength in the air.

[0088] In this embodiment, the slot size of the slotted antenna layer 1 is calculated to satisfy the wide-side longitudinal slot resonance (electrical length satisfies λ / 2), while also needing to be corrected in conjunction with the electromagnetic environment within the waveguide:

[0089] in, Represents the center wavelength of free space (at a center frequency of 9.4 GHz). ≈31.91mm). Substituting these values ​​into the calculation, we get:

[0090] The slot width of the slot in the slot antenna layer 1 is required to be less than 1 / 10 of the free space center wavelength. Therefore, the slot width of the slot in the slot antenna layer 1 is designed to be 1 mm.

[0091] Regarding the first and second radiating slots distributed along the second direction mentioned above, the distance between the slots is half the waveguide wavelength, and the calculation formula is as follows:

[0092]

[0093] in, This indicates the waveguide wavelength of the slot antenna layer. Represents the wavelength in free space. This indicates the length of the wide side of the rectangular waveguide. Indicates the distance between gaps.

[0094] Furthermore, the slotted antenna layer 1 also includes multiple radiating elements arranged along the first direction. When the actual spacing is greater than the maximum allowable spacing, a harmful pseudo-beam with an intensity comparable to the main lobe will be generated on the antenna pattern, called a "grating lobe". The grating lobe will disperse the radiated energy, causing the radar or communication system to misjudge and interfere in the non-target direction. When the actual spacing is less than or equal to the maximum allowable spacing, it can be ensured that no grating lobe is generated within the specified scanning angle range, thereby ensuring that the antenna energy is concentrated and the beam is "pure".

[0095] The maximum permissible spacing between the radiating elements is calculated as follows:

[0096] in, Indicates the maximum permissible spacing between radiating elements. Represents the wavelength in free space. Indicates the scanning angle. Indicates the number of array elements.

[0097] In this embodiment, the scanning angle is 20°, and the number of array elements represents the number of radiating units, which is 16. Therefore, substituting these values, we can determine the maximum allowable spacing between the radiating units. The maximum allowable spacing between the geometric center points of two adjacent radiating elements, perpendicular to the waveguide extension direction, is set to 22 mm.

[0098] The microstrip antenna layer 2 operates in the frequency band of 9.3~9.5GHz, therefore its center frequency free space wavelength is 31.91mm. The method for calculating the microstrip waveguide wavelength based on the center frequency free space wavelength is as follows: The width of the microstrip array 21 of the microstrip antenna layer 2 is determined by the free space wavelength of the center frequency and the relative permittivity of the dielectric substrate 22. The specific calculation method is as follows:

[0099]

[0100] in, This indicates the width of the microstrip array. Represents the wavelength in free space. The relative permittivity of the dielectric substrate is represented by 10.45 mm, and the width of the microstrip array is 10.45 mm.

[0101] The formula for calculating the effective dielectric constant is shown below:

[0102] in, Indicates the effective dielectric constant. This represents the relative permittivity of the dielectric substrate. Indicates the thickness of the dielectric substrate. This indicates the width of the microstrip array.

[0103] The length L of microstrip 21:

[0104] The formula for calculating the wavelength of the microstrip waveguide based on the center frequency, free-space wavelength, and effective dielectric constant is as follows:

[0105] in, This indicates the waveguide wavelength of the microstrip antenna layer. Represents the wavelength in free space. This represents the effective dielectric constant.

[0106] Calculations show that the wavelength of the microstrip waveguide in the microstrip antenna layer 2 is approximately 17 mm.

[0107] Regarding the spacing between the microstrip array elements 21, in this embodiment, an end-feed method is considered, with the feed line length between array elements being approximately 0.5 mm. The length of microstrip array 21 is less than 0.5. Based on manufacturing process precision and performance, in practical applications, depending on the substrate, the center-to-center spacing of the rectangular microstrip patch is approximately... This ensures that all array elements are in phase and achieves side-firing characteristics. Specifically, the spacing between the microstrip array elements 21 is half the waveguide wavelength, and the length of the microstrip array element 21 in the feeding direction is half the waveguide wavelength. The design of the microstrip antenna layer 2 is not limited by this. In actual use, the optimal size configuration can be calculated according to actual needs.

[0108] Furthermore, based on the distance between the microstrip elements 21 of the microstrip antenna layer 2 ( ) and the distance between the slots in the slotted antenna layer 1 ( It can be seen that the number of microstrip arrays 21 should be greater than or equal to the number of slots.

[0109] III. Performance Testing The dual-polarized antenna of Example 1 was simulated and tested. The dual-polarized antenna was parallel to the ground along the edge of the first direction and perpendicular to the ground along the edge of the second direction. Figure 9 The radiation patterns of a wide-side longitudinal slot antenna and a microstrip antenna with vertical polarization at a center frequency f=9.4GHz. Figure 10 The radiation pattern of the wide-side longitudinal slot and the horizontal polarization of the microstrip antenna at the center frequency f=9.4GHz. Figure 9 , Figure 10 It can be seen that the main polarization direction of the wide-side longitudinal slot antenna is horizontal, with a main polarization gain of 25.3 dBi and sidelobes below -25 dB. The main polarization direction of the microstrip antenna is vertical, with a main polarization gain of 22.9 dBi and sidelobes below -25 dB. The vertical polarization isolation between the two antennas is about 50 dB, and the horizontal polarization isolation is about 54 dB. It has the advantages of high gain, low sidelobes, and high dual polarization isolation.

[0110] Example 2 I. Dual-polarized antenna: It includes a waveguide slot antenna layer and a microstrip antenna layer. Unlike Embodiment 1, the waveguide slot antenna layer is a substrate-integrated waveguide slot antenna layer.

[0111] Integrated waveguide slot antenna layer: Operating frequency band: 92~94GHz (center frequency (f=93GHz), slot type: substrate integrated waveguide antenna, number of slots: 8, waveguide dimensions: width a=1.6mm, longitudinal spacing of slots: 1.2mm, transverse spacing of antennas: 2.8mm, slot dimensions: length=1.6mm, width=0.1mm, substrate parameters: model: RO3003G2 ( =3), thickness h=0.127mm, copper foil thickness t=35um (0.035mm), via diameter d=0.2mm, via spacing: d3=0.35mm.

[0112] II. Verification process: Compared to the waveguide slot antenna layer, the main difference of the substrate integrated waveguide slot antenna layer is that it constructs a "virtual" waveguide cavity through metallized vias 31, thereby achieving the same function as the waveguide slot antenna layer. Therefore, for the integrated waveguide slot antenna layer, the verification methods for parameters other than the metallized vias and waveguide wavelength of the slot antenna layer are the same as in Embodiment 1, and will not be repeated here. The width 'a' of the equivalent rectangular waveguide of SIW eff It can be derived from the following formula:

[0113] The wavelength of a SIW waveguide can be obtained from the following formula:

[0114] The dimensions of the metallized vias and waveguide wavelengths are calculated as follows:

[0115]

[0116]

[0117] in, This indicates the diameter of the metallized via. This indicates the via spacing of the metallized vias. This indicates the waveguide wavelength of the slot antenna layer. Represents the wavelength in free space. Indicates the dielectric constant of the dielectric layer. Indicates the distance between gaps.

[0118] III. Performance Testing The dual-polarized antenna of Example 2 was simulated and tested. The dual-polarized antenna was parallel to the ground along the edge of the first direction and perpendicular to the ground along the edge of the second direction. Figure 11 The radiation pattern of the vertical polarization of the eight-slot substrate integrated waveguide antenna and microstrip antenna with a center frequency f=93GHz. Figure 12 The radiation pattern of the horizontal polarization of the eight-slot substrate integrated waveguide antenna and microstrip antenna with a center frequency f=93GHz. Figure 11 , Figure 12 It can be seen that the main polarization direction of the eight-slot substrate integrated waveguide antenna is horizontal, with a main polarization gain of 24.3 dBi and sidelobes below -25 dB. The main polarization direction of the microstrip antenna is vertical, with a main polarization gain of 26.5 dBi and sidelobes below -25 dB. The vertical polarization isolation between the two antennas is about 31 dB, and the horizontal polarization isolation is about 40 dB. It has the advantages of high gain, low sidelobes, and high dual polarization isolation.

[0119] Example 3 I. Dual-polarized antenna: It includes a waveguide slot antenna layer and a microstrip antenna layer. Unlike Embodiment 1, the waveguide slot antenna layer and microstrip antenna layer operate in the 92-94 GHz frequency band (high frequency, center frequency f=93 GHz). Slot type: wide-side longitudinal slot; number of slots: 4; waveguide dimensions: wide side a=1.92 mm, narrow side b=1.2 mm; longitudinal spacing between slots: 2.97 mm; transverse spacing between antennas: 2.38 mm; slot dimensions: length=1.7 mm, width=0.4 mm; substrate parameters: Rogers 4350 (…). =3.66), thickness h=0.127mm, copper foil thickness t=35um (0.035mm), microstrip linewidth: W=0.1mm, element spacing: d=1.81mm.

[0120] II. Verification Process Same as Example 1 III. Performance Testing The dual-polarized antenna of Example 3 was simulated and tested. The dual-polarized antenna was parallel to the ground along the edge of the first direction and perpendicular to the ground along the edge of the second direction. Figure 13 The radiation patterns of a wide-side longitudinal slot antenna and a microstrip antenna with vertical polarization at a center frequency f=93GHz. Figure 14 The radiation patterns of a wide-side longitudinal slot antenna and a microstrip antenna with horizontal polarization at a center frequency f=93GHz. Figure 13 , Figure 14 It can be seen that the main polarization direction of the wide-side longitudinal slot antenna is horizontal, with a main polarization gain of 28dBi and sidelobes below -30dB. The main polarization direction of the microstrip antenna is vertical, with a main polarization gain of 25.2dBi and sidelobes below -27dB. The vertical polarization isolation between the two antennas is about 49dB, and the horizontal polarization isolation is about 46dB. It has the advantages of high gain, low sidelobes, and high dual polarization isolation.

[0121] Example 4 I. Dual-polarized antenna: It includes a waveguide slot antenna layer and a microstrip antenna layer. Unlike Embodiment 1, the waveguide slot antenna layer uses a ridge waveguide as the transmission waveguide, operating in the 9.3-9.5GHz frequency band (center frequency f=9.4GHz). Slot type: wide-side longitudinal slot; number of slots: 5; waveguide dimensions: wide side a=15mm, narrow side b=5.5mm, ridge height d=4mm, ridge width=6mm; longitudinal slot distance: 19mm; transverse antenna distance: 22mm; slot dimensions: length=16mm, width=1mm; substrate parameters: model: RO3003G2 (…). =3), thickness h=0.254mm, copper foil thickness t=35um (0.035mm), microstrip connection line width: W=0.55mm, element spacing: d=16.6mm.

[0122] II. Verification Process Simulation results show that the waveguide wavelength of this ridge waveguide is 39.12 mm, and the longitudinal distance of the slot is slightly greater than or slightly less than [the specified value]. / 2, put the waveguide antenna in traveling wave mode, and take 19mm.

[0123] III. Performance Testing The dual-polarized antenna of Example 4 was simulated and tested. The dual-polarized antenna was parallel to the ground along the edge of the first direction and perpendicular to the ground along the edge of the second direction. Figure 15 The radiation patterns of the ridge waveguide longitudinal slot antenna and the microstrip antenna with a center frequency f=9.4GHz and vertical polarization. Figure 16 The radiation patterns of the ridge waveguide longitudinal slot antenna and the microstrip antenna with a center frequency f=9.4GHz and horizontal polarization. Figure 15 , Figure 16 It can be seen that the main polarization direction of the ridge waveguide longitudinal slot antenna is horizontal, with a main polarization gain of 25.3 dBi and sidelobes below -27 dB. The main polarization direction of the microstrip antenna is vertical, with a main polarization gain of 23.7 dBi and sidelobes below -26 dB. The vertical polarization isolation between the two antennas is about 42 dB, and the horizontal polarization isolation is about 42 dB. It has the advantages of high gain, low sidelobes, and high dual polarization isolation.

[0124] Application Example 1 The dual-polarized antennas of Examples 1 and 4 are used in a weather radar. The radar transmits H and V polarized waves and receives echo signals of H→H, V→V (same polarization) and H→V, V→H (cross polarization). The dual-polarized antenna utilizes the significant difference in the characteristics of the dual-polarized echoes to accurately measure the shape, size, and orientation of precipitation particles (raindrops, snowflakes, hail, etc.), distinguish precipitation types (rain / snow / hail / graupel), correct precipitation intensity measurement errors, and identify non-meteorological targets (such as birds and insects).

[0125] Application Example 2 The dual-polarized antennas of Examples 2 and 3 are used in airport runway foreign object detection (FOD) radar. The radar emits H and V polarized waves and receives echo signals of H→H, V→V (same polarization) and H→V, V→H (cross polarization). By utilizing the significant difference in the characteristics of the dual-polarized echoes, it is possible to accurately separate FOD targets from background clutter such as runway surface, pavement markings, water accumulation, and gravel. It effectively suppresses strong ground clutter and environmental interference such as rain and fog, distinguishes the material (metal and non-metal) and approximate size of FOD targets, and achieves accurate identification, location, and classification of FOD targets.

[0126] Application Example 3 The dual-polarized antennas of Examples 1 and 4 are used in marine radar. The radar transmits H and V polarized waves and receives echo signals of H→H, V→V (same polarization) and H→V, V→H (cross polarization). By utilizing the significant differences in the characteristics of the dual-polarized echoes, it is possible to distinguish oil spills on the sea surface, seawater, islands and reefs, and maritime navigation targets.

[0127] Comparative Example 1 I. Dual-polarized antenna like Figure 17 As shown, it includes a first dielectric layer, multiple interconnected radiating patches 200 and a substrate integrated waveguide structure, a converter 412, and an impedance transformer 500.

[0128] The radiating patch 200 is disposed on the upper surface of the first dielectric layer. Each pair of adjacent radiating patches 200 is connected by a vertically polarized feed line 300. There is a row of metallized holes 421 on each of the left and right sides of the radiating patch 200. The substrate integrated waveguide structure is disposed at the lower end of the first dielectric layer. Multiple coupling slots 411 are opened on the substrate integrated waveguide structure. The substrate integrated waveguide structure is used to couple electromagnetic waves to the radiating patch 200 through the coupling slots 411 so that the radiating patch 200 radiates horizontally polarized electromagnetic waves.

[0129] Multiple coupling gaps 411 are arranged alternately on both sides of the axis of symmetry of the multiple radiating patches 200 along the arrangement direction of the multiple radiating patches 200. Each radiating patch 200 corresponds to a coupling gap 411, and the radiating patch 200 at least partially covers the coupling gap 411.

[0130] The substrate integrated waveguide structure 400 and the radiating patch 200 are arranged and designed according to the following parameters to obtain a dual-polarized antenna: Substrate Integrated Waveguide Structure 400: Number of slots: 4, Dielectric parameters: Dielectric constant =1.8, thickness h=0.127mm, strip waveguide dimensions: wide side a=1.6mm, longitudinal distance of slot: 1.86mm, slot dimensions: length=1.65mm, width=0.1mm, copper foil thickness t=35um (0.035mm), via diameter d=0.2mm, via spacing: d3=0.35mm.

[0131] Radiation patch 200: Array size: 4, Dielectric parameter: Dielectric constant =3, thickness h=0.127mm, copper foil thickness t=35um (0.035mm), microstrip linewidth: W=1mm, element spacing: d=1.81mm.

[0132] like Figure 18 As shown, the number of substrate integrated waveguide structures 400 and radiating patches 200 arranged along the first direction is the same as in Examples 1-4, which is 16.

[0133] II. Performance Testing The dual-polarized antenna in Comparative Example 1 is simulated and tested. The dual-polarized antenna is parallel to the ground along the edge of the first direction and perpendicular to the ground along the edge of the second direction. The results are... Figure 19 The radiation patterns of the substrate integrated waveguide antenna and the microstrip antenna with a center frequency of f=93GHz and vertical polarization. Figure 20 The radiation patterns of the substrate integrated waveguide antenna and microstrip antenna with a center frequency f=93GHz and horizontal polarization. Figure 19 , Figure 20 It can be seen that the substrate integrated waveguide antenna has a main polarization direction of horizontal polarization, a main polarization gain of 24.2 dBi, and sidelobes below -25 dB. The microstrip antenna has a main polarization direction of vertical polarization, a main polarization gain of 25.9 dBi, and sidelobes below -25 dB. The vertical polarization isolation between the two antennas is about 18.5 dB, and the horizontal polarization isolation is about 30 dB.

[0134] However, Embodiments 1-4 of the present invention all exhibited a vertical polarization isolation greater than 40 dB, while Comparative Example 1, without any outstanding performance in other aspects, showed a significant difference in vertical polarization isolation compared to the present invention.

[0135] In summary, the present invention provides a waveguide and microstrip hybrid dual-polarized antenna and radar device, which successfully solves the inherent contradiction between performance, size and manufacturability of traditional dual-polarized antennas.

[0136] This invention creatively proposes a vertical hybrid stacking layout of slotted antenna layer 1 and microstrip antenna layer 2. The core of this layout lies in the fact that the two polarization radiating elements do not overlap in spatial projection, achieving true aperture sharing. This not only ensures that the horizontal and vertical polarized beams have highly consistent phase centers, thus achieving excellent beam matching characteristics and high isolation, laying the foundation for high-precision dual-polarization measurements, but also fundamentally realizes low profile and compact antenna design.

[0137] Furthermore, the integrated structure described in this invention (especially multilayer laminated metal waveguides or SIW) greatly simplifies the assembly process of traditional complex waveguide arrays, making it highly suitable for large-scale, mass production. This significantly reduces manufacturing costs while ensuring high performance and high consistency, enabling the widespread application of such high-performance planar array antennas in fields such as weather radar and modern communication systems.

[0138] The above-disclosed embodiments are merely preferred embodiments of the present invention and should not be construed as limiting the scope of the present invention. Therefore, any equivalent variations made in accordance with the claims of the present invention are still within the scope of the present invention.

Claims

1. A dual-polarized antenna, characterized in that, It includes a slot antenna layer for radiating a first polarized wave and a microstrip antenna layer for radiating a second polarized wave. The slot antenna layer includes a waveguide structure, the waveguide structure includes a plurality of radiating elements arranged along a first direction, and the radiating elements include a plurality of radiating slots extending along a second direction. The microstrip antenna layer includes a plurality of microstrip array elements arranged along a first direction, and the microstrip array elements include a plurality of microstrip array elements arranged along a second direction. The microstrip antenna layer is disposed on the slot antenna layer, and at least one microstrip array element is disposed between the radiating elements. The projections of the microstrip array element and the radiating slot on the waveguide structure do not overlap.

2. A dual-polarized antenna as described in claim 1, characterized in that, The slot antenna layer is a waveguide slot antenna layer or a substrate-integrated waveguide slot antenna layer.

3. A dual-polarized antenna as described in claim 1, characterized in that, The waveguide structure is configured as a rectangular waveguide or a ridge waveguide.

4. A dual-polarized antenna as described in claim 1, characterized in that, The radiating elements and microstrip array elements are arranged alternately along the first direction; the surface of the microstrip array is parallel to the surface of the waveguide structure.

5. A dual-polarized antenna as described in claim 1, characterized in that, The radiation unit includes a plurality of first radiation slots and second radiation slots extending along a second direction, the first radiation slots and the second radiation slots being staggered in the first direction.

6. A dual-polarized antenna as described in claim 4, characterized in that, The radiating unit has a waveguide centerline arranged along a second direction, and the first radiating slot and the second radiating slot are respectively located on both sides of the waveguide centerline.

7. A dual-polarized antenna as described in claim 5, characterized in that, Along the first direction, the offset distance between the centerlines of the first and second radiating slots and the waveguide centerline is... The width of the waveguide structure is .

8. A dual-polarized antenna as described in claim 2, characterized in that, Along the second direction, each of the radiating elements of the waveguide slot antenna layer includes N1 radiating slots, and each of the microstrip array elements includes N2 microstrip arrays, wherein the number of microstrip arrays N2 is greater than or equal to the number of radiating slots N1.

9. A dual-polarized antenna as described in claim 2, characterized in that, Along the second direction, each of the radiating elements of the substrate integrated waveguide slot antenna layer includes N1 radiating slots, and each of the microstrip array elements includes N2 microstrip arrays, wherein the number of microstrip arrays N2 is less than or equal to the number of radiating slots N1.

10. A dual-polarized antenna as described in claim 8, characterized in that, The number of radiation slots, N1, is 1-32, and the number of microstrip arrays, N2, is 1-48.

11. A dual-polarized antenna as described in claim 1, characterized in that, The microstrip antenna layer includes a grounding substrate, a dielectric substrate, a microstrip feed network, microstrip elements, and microstrip feed lines. The dielectric substrate is disposed on the grounding substrate, and a plurality of the microstrip elements are disposed on the dielectric substrate and connected to the microstrip feed network through the microstrip feed lines.

12. A dual-polarized antenna as described in claim 11, characterized in that, The grounding substrate of the microstrip antenna layer is fixed to the waveguide structure of the slot antenna layer by connectors or adhesive.

13. A dual-polarized antenna as described in claim 1, characterized in that, The surface of the waveguide structure is provided with a plurality of grooves arranged along a first direction, the grooves being adapted to the microstrip array unit, and the microstrip array unit being disposed within the groove.

14. A dual-polarized antenna as described in claim 13, characterized in that, The surface of the microstrip array is flush with the surface of the waveguide structure, or the surface of the microstrip array is higher than the surface of the waveguide structure.

15. A dual-polarized antenna as described in claim 1, characterized in that, Along the first direction, the width of the waveguide structure is... The free space wavelength is , ; Along the first direction, the narrow side length of the waveguide structure is , .

16. A dual-polarized antenna as described in claim 15, characterized in that, Along the first direction, the width of the radial slit is , It is 0.1-4mm; Along the second direction, the length of the radial slit is The waveguide wavelength is , ; Along the first direction, in adjacent radiating elements, the spacing between the radiating slots is d1, where d1 satisfies... .

17. A dual-polarized antenna as described in claim 1, characterized in that, Along the first direction, the width of the microstrip array is , ; Along the second direction, the length of the microstrip array is , ; Along the first direction, in adjacent microstrip array elements, the spacing between the microstrip array elements is d2, where d2 satisfies .

18. A dual-polarized antenna as described in claim 2, characterized in that, The diameter of the metallized via in the substrate integrated waveguide slot antenna layer is [missing information]. , ; And / or the spacing between adjacent metallized vias is , .

19. A dual-polarized antenna as described in claim 18, characterized in that, The diameter of the metallized via in the substrate integrated waveguide slot antenna layer is d, where d is 0.1-1 mm; And / or the spacing between adjacent metallized vias is d3, where d3 is 0.2-4 mm.

20. A dual-polarized antenna as described in claim 1, characterized in that, The polarization directions of the first polarized wave and the second polarized wave are orthogonal; The first polarized wave is a horizontally polarized wave, and the second polarized wave is a vertically polarized wave; Alternatively, the first polarized wave may be a vertically polarized wave, and the second polarized wave may be a horizontally polarized wave; Alternatively, the first polarization wave is +45° oblique polarization, and the second polarization wave is -45° oblique polarization; Alternatively, the first polarization wave can be -45° slant polarization, and the second polarization wave can be +45° slant polarization.

21. A radar device, characterized in that, Includes a dual-polarized antenna as described in any one of claims 1-20.

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