Large-aperture millimeter wave infrared common-aperture antenna based on optical synthetic aperture

Abstract

The invention provides a large-aperture millimeter wave infrared common-aperture antenna based on an optical synthetic aperture, and relates to the crossing field of optical and microwave detection technologies. According to the invention, the large-aperture millimeter wave infrared common-aperture antenna based on the optical synthetic aperture is adopted, so that the functions of infrared large-range search detection and precise tracking, fine identification and striking guiding of a millimeter wave array can be realized; the large-aperture optical design is adopted, so that the light collecting capacity and the resolution ratio of the optical system are improved, and the penetrating capacity of the optical system in dense fog, dense smoke, dust and cloud layers is enhanced; a large-aperture millimeter wave array design is adopted, so that the power of the millimeter wave array antenna is effectively improved; a frequency selective surface primary and secondary mirror technology is adopted, an infrared imaging system and a millimeter wave array antenna are effectively compatible, and the requirement for optical and microwave cooperative long-distance detection in the space-based field is met.

Description

Technical Field

[0001] The present invention relates to the intersection of optical and microwave detection technologies, and in particular to a large-aperture millimeter-wave infrared common-aperture antenna based on optical synthetic aperture. Background Art

[0002] In millimeter-wave infrared common aperture detection, the infrared imaging system can realize large-scale search and detection, provide guidance and indication information to the millimeter-wave array radar, and the millimeter-wave array can complete precise tracking, fine identification, guided strikes, etc. Millimeter-wave radar has good all-weather combat capabilities, and under the condition of large aperture design, it is relatively easy to detect moving targets, and can obtain accurate pointing beam synthesis, tracking, identification, guided strikes and large detection power; optical imaging adopts passive detection mode and is not easily affected by electronic interference, but the automatic target recognition of optical images with complex ground backgrounds is difficult and is easily affected by adverse environments such as fog, smoke, dust or snow.

[0003] The use of optical synthetic aperture design helps to improve the light-gathering ability and resolution of the optical system, and solves the problem of weak penetration in fog, smoke, dust and clouds. At present, the millimeter-wave infrared common aperture at home and abroad uses Cassegrain optical imaging system compatible with microwave parabolic antenna, and uses mechanical deflection to achieve tracking, but the detection fields of the two block each other and the deflection structure occupies too many load resources. In addition, the solution is limited in scale, which in turn affects the performance of the millimeter-wave array. Summary of the invention

[0004] 1. Technical issues to be resolved

[0005] In view of the shortcomings of the prior art, the present invention provides a large-aperture millimeter-wave infrared common-aperture antenna based on optical synthetic aperture, which solves the technical problems of traditional common-aperture design schemes such as mutual obstruction of detection fields of view, excessive load resources occupied by mechanical deflection structures and limited applicability.

[0006] (II) Technical solution

[0007] To achieve the above objectives, the present invention is implemented through the following technical solutions:

[0008] A large-aperture millimeter-wave infrared common-aperture antenna based on optical synthetic aperture, the front end of which includes several sub-aperture Cassegrain systems and a millimeter-wave array antenna, and the back end includes a sub-aperture beam combining device and an infrared imaging system;

[0009] The plurality of sub-aperture Cassegrain systems include a first sub-aperture Cassegrain system coaxially arranged with the millimeter wave array antenna and a plurality of second sub-aperture Cassegrain systems symmetrical about the center of the first sub-aperture Cassegrain system; any of the sub-aperture Cassegrain systems is a frequency selective surface primary and secondary mirror, and the frequency selective surface primary and secondary mirrors adopt a reverse optical millimeter wave transmission design for secondary reflection of infrared information and transmission of millimeter waves;

[0010] The millimeter wave array antenna is provided with a light-clearing aperture for providing infrared information to pass through, and is used to receive the millimeter wave; wherein the number of the light-clearing apertures corresponds one-to-one to the number of the sub-aperture Cassegrain systems;

[0011] The sub-aperture beam combining device is located on one side of the Cassegrain system behind the clear aperture and is coaxially arranged with the millimeter wave array antenna to receive each infrared information and combine the information;

[0012] The infrared imaging system is located on a side of the sub-aperture beam combining device away from the millimeter wave array antenna, and is coaxially arranged with the sub-aperture beam combining device to receive the infrared information after beam combining.

[0013] Preferably, any of the frequency selective surface primary and secondary mirrors comprises a frequency selective surface primary mirror and a frequency selective surface secondary mirror;

[0014] The frequency selective surface primary mirror is provided with a hole, and is used for first reflection of infrared information;

[0015] The frequency selective surface secondary mirror is used for reflecting the infrared information reflected by the frequency selective surface primary mirror for a second time, so that the infrared information passes through the corresponding holes and the clear aperture in sequence.

[0016] Preferably, the surfaces of the primary and secondary frequency selective surface mirrors are formed of a plurality of identical units arranged in a two-dimensional periodic manner to form a single-layer or multi-layer planar structure.

[0017] Preferably, the unit is a cross gap, a Y-shaped gap, a cross fractal or a Y-shaped fractal.

[0018] Preferably, the substrate of the primary and secondary frequency selective surface mirrors is Rogers 5880 or silicon dioxide.

[0019] Preferably, the number of the sub-aperture Cassegrain systems is five.

[0020] Preferably, the antenna unit of the millimeter wave array antenna is in the form of a microstrip patch antenna unit, which is coaxially fed, and the coaxial line below passes through the dielectric substrate and the microstrip patch welding dielectric on the top surface.

[0021] Preferably, the dielectric substrate is Rogers 6002.

[0022] Preferably, the working mode of the millimeter wave array antenna is active detection.

[0023] Preferably, the infrared imaging system adopts passive staring focal plane detection.

[0024] (III) Beneficial effects

[0025] The present invention provides a large-aperture millimeter-wave infrared common aperture antenna based on optical synthetic aperture. Compared with the prior art, it has the following beneficial effects:

[0026] The present invention adopts a large-aperture millimeter-wave infrared common-aperture antenna based on optical synthetic aperture, which can realize infrared large-range search and detection and millimeter-wave array to complete precise tracking, fine identification, and guided strike functions; the large-aperture optical design is adopted to improve the light collecting ability and resolution of the optical system, and enhance its penetration ability in heavy fog, thick smoke, dust and clouds; the large-aperture millimeter-wave array design is adopted to effectively enhance the power of the millimeter-wave array antenna; the frequency selective surface primary and secondary mirror technology is adopted to effectively make the infrared imaging system and the millimeter-wave array antenna compatible, meeting the needs of optical and microwave collaborative long-distance detection in the space-based field. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0028] Figure 1 A schematic structural diagram of a large-aperture millimeter-wave infrared common-aperture antenna based on optical synthetic aperture provided in an embodiment of the present invention;

[0029] Figure 2 A schematic diagram of a central transverse section of a large-aperture millimeter-wave infrared common-aperture antenna based on optical synthetic aperture provided by an embodiment of the present invention;

[0030] Figure 3 A schematic diagram of the structure of a frequency selective surface primary and secondary mirror provided by an embodiment of the present invention;

[0031] Figure 4 A schematic diagram of the structure of a millimeter wave array antenna provided in an embodiment of the present invention (the millimeter wave array antenna only gives the central light aperture as an example). DETAILED DESCRIPTION

[0032] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention are clearly and completely described. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0033] Millimeter-wave radar has good all-weather combat capability and is relatively easy to detect moving targets. However, its detection accuracy is lower than that of optics, and it is susceptible to complex ground clutter and electromagnetic interference imposed by the enemy in air-to-ground combat situations. Optical imaging uses passive detection and is not easily affected by electronic interference, but automatic target recognition of optical images with complex ground backgrounds is difficult and is easily affected by adverse environments such as fog, smoke, dust or snow. "Millimeter wave + infrared" dual-mode collaborative detection helps to improve the system's anti-interference ability and multi-task combat capability under different natural environmental conditions, realize accurate detection, identification and continuous tracking of moving targets, and break through the wide-area distributed panoramic and wide-spectrum detection system architecture.

[0034] Based on this understanding, the embodiment of the present application innovatively provides a large-aperture millimeter-wave infrared common-aperture antenna based on optical synthetic aperture, which uses the synthetic aperture method to expand the overall scale. At the same time, it solves the technical problems of traditional common-aperture design schemes such as mutual obstruction of detection fields of view, excessive load resources occupied by mechanical deflection structures, and limited applicability.

[0035] The improvement ideas of the embodiments of the present invention are as follows: a large aperture can improve the efficiency and resolution of the optical system and the millimeter wave array. Although it is not difficult to expand the millimeter wave array, if the optical aperture is only expanded, on the one hand, the processing difficulty will increase. On the other hand, the large-aperture lens surface changes greatly, which will lead to the deterioration of the frequency selective surface, thereby affecting the efficiency of the millimeter wave array. Based on this, the embodiments of the present invention propose a method of using a synthetic aperture to reduce the impact.

[0036] In order to better understand the above technical solution, the above technical solution will be described in detail below in conjunction with the accompanying drawings and specific implementation methods.

[0037] Example:

[0038] like Figures 1-2 As shown, an embodiment of the present invention provides a large-aperture millimeter-wave infrared common-aperture antenna based on optical synthetic aperture, the front end of which includes several sub-aperture Cassegrain systems 1 and a millimeter-wave array antenna 2, and the back end includes a sub-aperture beam combining device 3 and an infrared imaging system 4.

[0039] The several sub-aperture Cassegrain systems 1 include a first sub-aperture Cassegrain system coaxially arranged with the millimeter-wave array antenna 2 and a plurality of second sub-aperture Cassegrain systems symmetrical about the center of the first sub-aperture Cassegrain system; any of the sub-aperture Cassegrain systems 1 is a frequency selective surface primary and secondary mirror, and the frequency selective surface primary and secondary mirrors adopt a reflective optical millimeter-wave transparent design for secondary reflection of infrared information and transmission of millimeter waves.

[0040] The millimeter wave array antenna 2 is provided with a clear aperture 5 for allowing infrared information to pass through, and is used to receive the millimeter wave; wherein the number of the clear apertures 5 corresponds one-to-one to the number of the sub-aperture Cassegrain systems 1 .

[0041] The sub-aperture beam combining device 3 is located on the side of the clear aperture 5 back to the ion aperture Cassegrain system 1 and is coaxially arranged with the millimeter wave array antenna 2 to receive each of the infrared information and combine the information.

[0042] The infrared imaging system 4 is located on the side of the sub-aperture beam combining device 3 away from the millimeter wave array antenna 2, and is coaxially arranged with the sub-aperture beam combining device 3 to receive the infrared information after combining.

[0043] It is to be supplemented that the sub-aperture Cassegrain system 1 defined in the scheme includes a first sub-aperture Cassegrain system coaxially arranged with the millimeter-wave array antenna 2 and a plurality of second sub-aperture Cassegrain systems symmetrical about the center of the first sub-aperture Cassegrain system, specifically, in the same plane, the first sub-aperture Cassegrain system is located at the center, and the remaining plurality of second sub-aperture Cassegrain systems correspond to the center of the first sub-aperture Cassegrain system; and, thus, it can be determined that the overall light aperture corresponding to each sub-aperture Cassegrain system 1 of the millimeter-wave array antenna 2 also presents a similar circularly symmetrical distribution, which can be specifically referred to. Figure 1 (Assume that the number of subaperture Cassegrain systems is 5).

[0044] On the one hand, the embodiment of the present invention adopts the frequency selective surface primary and secondary mirror technology, which effectively makes the infrared imaging system and the millimeter wave array antenna compatible, avoiding the mutual obstruction of the detection fields of the two and the deflection structure occupying too many load resources.

[0045] On the other hand, the embodiment of the present invention adopts a large-aperture millimeter-wave infrared common-aperture antenna based on optical synthetic aperture, which can realize infrared large-range search and detection and millimeter-wave array to complete the functions of precise tracking, fine identification, and guided strike; the large-aperture optical design is adopted to improve the light gathering ability and resolution of the optical system, and enhance its penetration ability in heavy fog, thick smoke, dust and clouds; the large-aperture millimeter-wave array design is adopted to effectively enhance the power of the millimeter-wave array antenna.

[0046] Since the first sub-aperture Cassegrain system, the millimeter wave array antenna 2, the aperture beam combining device 3 and the infrared imaging system 4 are coaxially arranged, Figure 2 The light-clearance aperture corresponding to the first sub-aperture Cassegrain system on the millimeter-wave array antenna shown adopts a central light-clearance design, so that the corresponding infrared information can smoothly enter the aperture beam combining device 3 through the millimeter-wave array antenna, and then enter the infrared imaging system 4 for processing to ensure the performance of the infrared imaging system.

[0047] like Figures 1 to 3 As shown, in an optional embodiment, the frequency selective surface primary and secondary mirrors include a frequency selective surface primary mirror 11 and a frequency selective surface secondary mirror 12 (actually, a primary mirror using a concave reflector and a secondary mirror using a convex reflector, the two together form a classic Cassegrain system), wherein:

[0048] The frequency selective surface primary mirror 11 is provided with holes and is used for first reflecting infrared information;

[0049] The frequency selective surface secondary mirror 12 is used for reflecting the infrared information reflected by the frequency selective surface primary mirror 11 for a second time, so that the infrared information passes through the corresponding holes and the clear aperture 5 in sequence.

[0050] The substrates of the primary and secondary frequency selective surface mirrors are made of millimeter wave transparent materials, and the substrates of the primary and secondary frequency selective surface mirrors are Rogers 5880 or silicon dioxide to ensure the performance of the millimeter wave array antenna.

[0051] like Figure 3 As shown, in an optional embodiment, the surface of the primary and secondary mirrors of the frequency selective surface uses a number of identical units, which are arranged in a two-dimensional periodic manner to form a single-layer or multi-layer planar structure, and the millimeter-wave passband bandwidth is expanded by multi-layer cascading and changing the coupling between unit layers.

[0052] Exemplarily, the unit here may be a cross gap, a Y-shaped gap, a cross fractal, a Y-shaped fractal, or the like.

[0053] It can be understood that since the frequency selective surface itself does not absorb energy, its main feature is that it can present filtering characteristics for electromagnetic waves at different frequencies, incident angles and polarization states. The embodiment of the present invention can set the passband of the primary and secondary mirrors in the millimeter wave frequency band through design, and the unit can use gold-plated materials and increase its occupancy rate on the primary and secondary mirror surfaces to achieve high efficiency reflection of infrared information.

[0054] like Figure 4 As shown, in an optional embodiment, the antenna unit 21 of the millimeter wave array antenna adopts a microstrip patch antenna unit, coaxial feeding, and the coaxial below passes through the dielectric substrate 21 and the microstrip patch welding dielectric on the top surface ( Figure 4The medium millimeter wave array antenna 2 only gives the central light aperture as an example).

[0055] Furthermore, the dielectric substrate 22 is Rogers 6002, and the dielectric substrate integrates power division, power distribution and other networks.

[0056] It should be noted that this is only an example, and other antenna unit forms, dielectric substrates and feeding methods may also be used.

[0057] In addition, it should be understood that the array arrangement of the millimeter wave array antenna 2 is a basic array design, which can be a one-dimensional or two-dimensional periodic arrangement, and the grid can be rectangular and triangular, which is determined by the specific design requirements and is not limited to uniqueness here.

[0058] In an optional embodiment, the working mode of the millimeter wave array antenna 2 is active detection, so that it can form a directional beam according to infrared information, provide information such as distance, position, radial length, and continue tracking.

[0059] In particular, in an optional implementation, the embodiment of the present invention further defines that the infrared imaging system 4 adopts passive staring focal plane detection, thereby being able to obtain information such as position and target contour features and provide it to the millimeter wave array antenna.

[0060] In summary, compared with the prior art, the present invention has the following beneficial effects:

[0061] 1. The embodiment of the present invention adopts the frequency selective surface primary and secondary mirror technology, which effectively makes the infrared imaging system and the millimeter wave array antenna compatible, avoids the mutual obstruction of the detection field of view of the two and the deflection structure taking up too many load resources, realizes the infrared large-scale search detection and the millimeter wave array to complete the functions of pointing beam synthesis, precise tracking, fine identification, and guided strike, and provides a new means for the collaborative detection of space-based optics and microwave common aperture.

[0062] 2. The embodiment of the present invention adopts a large-aperture millimeter-wave infrared common-aperture antenna based on optical synthetic aperture, which can realize infrared large-range search and detection and millimeter-wave array to complete precise tracking, fine identification, and guided strike functions; the large-aperture optical design is adopted to improve the light gathering ability and resolution of the optical system, and enhance its penetration ability in heavy fog, thick smoke, dust and clouds; the large-aperture millimeter-wave array design is adopted to effectively enhance the power of the millimeter-wave array antenna.

[0063] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the existence of other identical elements in the process, method, article or device including the elements.

[0064] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A large-aperture millimeter-wave infrared common-aperture antenna based on optical synthetic aperture, characterized in that: The front end includes a plurality of sub-aperture Cassegrain systems (1) and a millimeter wave array antenna (2), and the back end includes a sub-aperture beam combining device (3) and an infrared imaging system (4); The plurality of sub-aperture Cassegrain systems (1) include a first sub-aperture Cassegrain system coaxially arranged with the millimeter wave array antenna (2) and a plurality of second sub-aperture Cassegrain systems symmetrical about the center of the first sub-aperture Cassegrain system; any of the sub-aperture Cassegrain systems (1) is a frequency selective surface primary and secondary mirror, and the frequency selective surface primary and secondary mirrors adopt a reflective optical millimeter wave transmission design for secondary reflection of infrared information and transmission of millimeter waves; The millimeter wave array antenna (2) is provided with a light-clearing aperture (5) for allowing infrared information to pass through, and is used to receive the millimeter wave; wherein the number of the light-clearing apertures (5) corresponds one-to-one to the number of the sub-aperture Cassegrain systems (1); The sub-aperture beam combining device (3) is located on a side of the clear aperture (5) behind the ion aperture Cassegrain system (1), and is coaxially arranged with the millimeter wave array antenna (2) to receive each of the infrared information and combine the information; The infrared imaging system (4) is located on a side of the sub-aperture beam combining device (3) away from the millimeter wave array antenna (2), and is coaxially arranged with the sub-aperture beam combining device (3) to receive infrared information after beam combining.

2. The large-aperture millimeter-wave infrared common-aperture antenna according to claim 1, characterized in that: Any of the frequency selective surface primary and secondary mirrors comprises a frequency selective surface primary mirror (11) and a frequency selective surface secondary mirror (12); The frequency selective surface primary mirror (11) is provided with a hole and is used for first reflecting infrared information; The frequency selective surface secondary mirror (12) is used for secondarily reflecting the infrared information reflected by the frequency selective surface primary mirror (11), so that the infrared information passes through corresponding holes and clear apertures (5) in sequence.

3. The large-aperture millimeter-wave infrared common-aperture antenna according to claim 1, characterized in that: The surfaces of the primary and secondary frequency selective surface mirrors are formed of a plurality of identical units arranged in a two-dimensional periodic manner to form a single-layer or multi-layer planar structure.

4. The large-aperture millimeter-wave infrared common-aperture antenna according to claim 3, characterized in that: The unit is a cross gap, a Y-shaped gap, a cross fractal or a Y-shaped fractal.

5. The large-aperture millimeter-wave infrared common-aperture antenna according to claim 1, characterized in that: The substrates of the primary and secondary frequency selective surface mirrors are Rogers 5880 or silicon dioxide.

6. The large-aperture millimeter-wave infrared common-aperture antenna according to claim 1, characterized in that: The number of the sub-aperture Cassegrain systems (1) is 5.

7. The large-aperture millimeter-wave infrared common-aperture antenna according to claim 1, characterized in that: The antenna unit (21) of the millimeter wave array antenna (2) is in the form of a microstrip patch antenna unit, which is coaxially fed, and the coaxial line at the bottom passes through the dielectric substrate (22) and the microstrip patch welding dielectric on the top surface.

8. The large-aperture millimeter-wave infrared common-aperture antenna according to claim 7, characterized in that: The dielectric substrate (22) is Rogers 6002.

9. The large-aperture millimeter-wave infrared common-aperture antenna according to claim 1, characterized in that: The working mode of the millimeter wave array antenna (2) is active detection.

10. The large-aperture millimeter-wave infrared common-aperture antenna according to claim 1, characterized in that: The infrared imaging system (4) adopts passive staring focal plane detection.

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