Broadband low-scattering grating lobe conformal array antenna based on characteristic mode analysis
By controlling the scattering grating lobes of the conformal array antenna through characteristic mode analysis and dielectric substrate structure design, the problem of significant radar cross section of the conformal array antenna in the wide-angle domain is solved, thereby achieving a reduction in radar cross section and an increase in bandwidth.
Patent Information
- Application Number
- CN202423170779.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-23
- Publication Date
- 2026-01-02
- Estimated Expiration
- 2034-12-23
AI Technical Summary
Existing conformal array antennas exhibit significant grating lobe phenomena in their radar cross-sections over a wide angular range, and there is a lack of effective research on low-scattering grating lobe design, which affects stealth performance.
A broadband low-scattering grating lobe conformal array antenna design based on characteristic mode analysis is adopted. By making targeted slots in the antenna radiating patch and the metal ground plane, the scattering mode current that contributes more to the scattering grating lobe is controlled. Combined with a two-layer dielectric substrate structure, the number of complex three-dimensional structures to be fabricated is reduced.
While ensuring antenna radiation performance, the conformal array antenna achieved a reduction in radar cross section both inside and outside the C-band, increasing bandwidth and simplifying the manufacturing process.
Smart Images
Figure CN223757680U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The utility model belongs to antenna technical field relates to a kind of wideband low lobe conformal array antenna based on eigenmode analysis, it can be used to radar detection platform with conformal demand and stealth demand. BACKGROUND
[0002] For the current high-tech information war, the importance of electronic countermeasure in combat is increasing, and the stealth capability of combat platform is also more and more important. Stealth technology is a technology for effectively controlling or suppressing the characteristic signals of a target, also known as low observable technology. The fundamental purpose of stealth is to reduce the detectability of the target and avoid being perceived by the opponent to improve the survivability of the target, thereby improving the overall combat effectiveness of the target. With the rapid development of modern radar detection technology, stealth capability is one of the important features of the new generation of combat aircraft. Low RCS means low radar detectability, i.e. high stealth performance, so the key to stealth technology is the RCS reduction technology of the target. Communication system is the key to information transmission of aircraft platform. With the development of aircraft towards high speed and stealth, the development trend of communication antenna is conformal, stealth, active, etc. Among them, phased array antenna has been widely used in aircraft platform due to its low profile, high gain, quick and convenient advantages. After years of development, the combat platform itself has reduced its radar cross section to a very low level by using shape stealth technology and coating radar absorbing material. The RCS of the planar phased array antenna used for communication has gradually become one of the key factors restricting the stealth performance of the platform. It is difficult to find a large flat surface on the aircraft platform to place a planar antenna, so the use of conformal antenna is also more and more widespread. Most of the researches are aimed at reducing the normal radar scattering cross section of array antenna. In the wide angle domain, the antenna radar scattering cross section grating lobe phenomenon is obvious and lacks research, so the low scattering lobe design of conformal array antenna is worth studying.
[0003] Eigenmode theory as a new way of antenna design and research not only has great advantages in antenna radiation analysis and design, but also has unique guidance in scattering analysis and control. By using eigenmode theory, the influence of antenna structure on radiation and scattering can be studied, and the low scattering lobe design of conformal array antenna can be realized under the premise of ensuring that the antenna radiation performance does not change as much as possible. UTILITY MODEL CONTENTS
[0004] The utility model discloses a purpose lies in the problem of lacking research in low scattering grating lobe of conformal array antenna, propose a wideband low scattering grating lobe conformal array antenna based on eigenmode analysis, on the basis of radiation mode and scattering mode analysis of traditional microstrip patch antenna, through the antenna radiation patch and antenna floor targeted slot, thereby control scattering mode current that scattering grating lobe contributes more to reduce the scattering grating lobe of conformal array antenna, simulation results show that, while guaranteeing the antenna radiation performance, realize the radar scattering surface reduction of conformal array antenna in C band in-band and out-of-band.
[0005] In order to realize the above-mentioned purpose, the technical scheme that the utility model adopts is:
[0006] A wideband low scattering grating lobe conformal array antenna based on eigenmode analysis, including coaxial feed, still including first dielectric substrate 2, second dielectric substrate 4 and metal floor 5 from top to bottom are stacked in proper order;
[0007] The upper surface of first dielectric substrate 2 is printed with radiation patch 1, and each radiation patch 1 is composed of two groups of symmetrical metal patches;
[0008] The metal floor is provided with floor center gap 7 and two circular arc-shaped gaps 6;The floor center gap 7 is located between the two circular arc-shaped gaps 6;
[0009] Microstrip feed line 3 is further arranged between the first dielectric substrate and the second dielectric substrate;The inner core 8 of the coaxial feed penetrates the second dielectric substrate 4 and is connected with the microstrip feed line 3;
[0010] The microstrip feed line 3, the second dielectric substrate 4, the metal floor 5, the circular arc-shaped gap 6 and the floor center gap 7 jointly constitute a feed layer.
[0011] Further, the geometric centers of the first dielectric substrate 2, the second dielectric substrate 4, the metal floor 5, the circular arc-shaped gap 6 and the floor center gap 7 coincide in the projection on the normal of the conformal surface.
[0012] Further, the two groups of metal patches constitute the radiation patch;Among them, metal patch A and metal patch B are a group, metal patch C and metal patch D are a group;The arrangement direction of metal patch A and metal patch B is perpendicular to the arrangement direction of metal patch C and metal patch D;The metal patch C and the metal patch D are located between the metal patch A and the metal patch B.
[0013] Further, the floor center gap 7 includes a circular defect and two long defects;The two long defects are respectively connected on both sides of the circular defect and are located on the straight line of the same diameter of the circular defect.
[0014] The two long defects are opposite to the circular arc-shaped gap on the same side.
[0015] Further, the projections of the metal patch A and the metal patch B on the metal floor are divided by their corresponding long strip defects.
[0016] Further, the projection of the microstrip feed line on the upper surface of the first dielectric substrate crosses the metal patch C and abuts the edge of the metal patch D.
[0017] Compared with the prior art, the technical scheme of the utility model has the following beneficial effects:
[0018] 1. The utility model discloses a specific slotting in the antenna radiation patch part and the metal floor part, which controls the mode current of the specific angle scattering grating lobe, increases the bandwidth, and reduces the radar scattering cross section of the conformal array antenna scattering grating lobe.
[0019] 2. The utility model discloses a two-layer dielectric substrate structure, the first layer dielectric substrate and the upper surface radiation patch part constitute a radiation layer, and the second layer dielectric substrate and the upper surface feed microstrip and the lower metal floor constitute a feed layer, which reduces the number of complex three-dimensional structures during processing, and facilitates the processing of each layer of dielectric substrate. BRIEF DESCRIPTION OF DRAWINGS
[0020] Figure 1 It is the overall structure schematic diagram of the utility model;
[0021] Figure 2 It is the side view of Figure 1
[0022] Figure 3 It is the unit structure schematic diagram in the utility model;
[0023] Figure 4 It is the top view of Figure 3
[0024] Figure 5 It is the bottom view of Figure 3
[0025] Figure 6 It is the S 11 Simulation result drawing of reference antenna and design antenna;
[0026] Figure 7 It is the single station RCS simulation result drawing of reference antenna in the x polarization under the angle domain in 5~8GHz frequency band;
[0027] Figure 8 It is the single station RCS simulation result drawing of the wideband low scattering grating conformal array antenna in the x polarization under the angle domain in 5~8GHz frequency band;
[0028] Figure 9 Compared with the traditional microstrip patch conformal array antenna, the single-station RCS of the low-scattering-lattice conformal array antenna of the utility model is reduced at the maximum scattering-lattice position under the x polarization incident wave in the 5~8GHz frequency band.
[0029] Figure 10 is the single-station RCS simulation result diagram of the low-lattice conformal array antenna of the utility model when the y polarization incident wave vertically irradiates in the 4~8GHz frequency band. DETAILED DESCRIPTION
[0030] The utility model will be further described below in combination with the drawings.
[0031] In order to facilitate the understanding of the technical solution of the patent for the person skilled in the art, at the same time, in order to make the technical purpose, technical scheme and beneficial effect of the patent more clear, and make the protection scope of the claim fully supported, the technical solution of the patent will be further described in the form of specific cases.
[0032] A kind of wideband low scattering-lattice conformal array antenna based on eigenmode analysis, including radiating patch, first dielectric substrate, microstrip feed line, second dielectric substrate, metal floor, circular arc slit, floor center slit, coaxial feed inner core.The radiating patch is located on the upper surface of first dielectric substrate;The microstrip feed line is located on the upper surface of second dielectric substrate;The circular arc slit and floor center slit are located on the lower surface of second dielectric substrate;The coaxial feed inner core penetrates second dielectric substrate and is connected with microstrip feed line.It is characterized in that:
[0033] 3*5 periodic arrangement of radiating patch is printed on the upper surface of the first dielectric substrate, and the radiating patch is composed of two groups of symmetrical small metal patches;The coaxial feed inner core is connected with microstrip feed line by second dielectric substrate;Two groups of metal patches constitute radiating patch;Among them, metal patch A1-1 and metal patch B1-4 are a group, metal patch C1-3 and metal patch D1-4 are a group;The arrangement direction of metal patch A and metal patch B is perpendicular to the arrangement direction of metal patch C and metal patch D;The metal patch C and metal patch D are both located between metal patch A and metal patch B.
[0034] The lower surface of the second dielectric substrate has a defective structure, i.e. the circular arc slit and the floor center slit;The microstrip feed line is located on the upper surface of the second dielectric substrate, and together with the second dielectric substrate, the metal floor, the circular arc slit and the floor center slit forms a feed layer.
[0035] The geometric centers of the first dielectric substrate, the second dielectric substrate, the metal floor, the circular arc slit and the floor center slit coincide in the projection of the normal direction of the conformal surface
[0036] The interval of the radiation patches arranged alternately is d, and d is 27mm.
[0037] The first dielectric substrate has a thickness of h1, and h1 is 3.2-3.4mm; the second dielectric substrate has a thickness of h2, and h2 is 1.9-2.1mm.
[0038] The radiation patch is composed of two groups of symmetrical small radiation patches, the first group of small patches has a size of L1*W1, L1 is 9.4-9.6mm, W1 is 2-2.2mm, and the geometric center of the two patches is offset from the projection center by q1, which is 4.05mm; the second group of small patches has a size of L2*W2, L2 is 5.2-5.3mm, W2 is 5.9-6.1mm, and the geometric center of the two patches is offset from the projection center by q2, which is 3.375mm.
[0039] The microstrip feed line is located on the upper surface of the second dielectric substrate, has a length of F1, and F1 is 8.5-8.6mm; the microstrip feed line has a width of F2, and F2 is 1.2-1.4mm.
[0040] The circular-arc-shaped gap has an inner diameter of R1, and R1 is 11.4-11.6mm; the circular-arc-shaped gap has an outer diameter of R2, and R2 is 12.4-12.6mm.
[0041] The floor center gap is composed of a rectangular gap and a circular hole with the same geometric center, the rectangular gap has a length of S1, and S1 is 14.8-15.2mm; the rectangular gap has a width of S2, and S2 is 0.5-0.7mm; the circular hole has a radius of R3, and R3 is 2.4-2.6mm.
[0042] Referring to Figure 1 and Figure 2 , the utility model discloses radiation patch 1, first dielectric substrate 2, microstrip feed line 3, second dielectric substrate 4, metal floor 5, circular-arc-shaped gap 6, floor center gap 7, coaxial feeding inner core 8. Antenna whole conforming is on the cylindrical surface with the diameter of 100mm.
[0043] Referring to Figure 1 , the first dielectric substrate 2 upper surface is printed with 3*5 periodic arrangement radiation patch 1, and the interval of periodic arrangement is 27mm;Radiation patch 1 is located on the upper surface of the first dielectric substrate 2;The microstrip feed line 3 is located on the upper surface of the second dielectric substrate 4;The metal floor 5, the circular-arc-shaped gap 6 and the floor center gap 7 are located on the lower surface of the second dielectric substrate 4;The coaxial feeding inner core 8 is connected with the microstrip feed line by penetrating the second dielectric substrate.
[0044] Referring to Figure 3 The geometric centers of the first dielectric substrate 2, the second dielectric substrate 4, the metal floor 5, the circular-arc-shaped gap 6 and the floor center gap 7 coincide in the projection on the normal of the conformal surface.
[0045] Referring to Figure 4 The radiation patch 1 is composed of two groups of symmetrical small radiation patches, the first group of small patches has a size of L1, L1 is in the range of 9.4-9.6 mm, a width of W1, W1 is in the range of 2-2.2 mm, and the geometric centers of the two patches are offset from the projection center by q1, q1 is 4.05 mm; the second group of small patches has a size of L2, L2 is in the range of 5.2-5.3 mm, a width of W2, W2 is in the range of 5.9-6.1 mm, and the geometric centers of the two patches are offset from the projection center by q2, q2 is 3.375 mm. In this example, but not limited to, L1=9.5 mm, W1=2.1 mm, L2=5.25 mm, and W2=6 mm.
[0046] Referring to Figure 4 The first dielectric substrate 2 has a thickness of h1, h1 is in the range of 3.2-3.4 mm, and the second dielectric substrate 4 has a thickness of h2, h2 is in the range of 1.9-2.1 mm. In this example, but not limited to, h1=3.302 mm and h2=2.032 mm.
[0047] Referring to Figure 4 The microstrip feed line 3 is located on the upper surface of the second dielectric substrate 4, has a length of F1, F1 is in the range of 8.5-8.6 mm, and has a width of F2, F2 is in the range of 1.2-1.4 mm. In this example, but not limited to, F1=8.55 mm and F2=1.3 mm.
[0048] Referring to Figure 5 The circular-arc-shaped gap 6 has an inner diameter of R1, R1 is in the range of 11.4-11.6 mm, and has an outer diameter of R2, R2 is in the range of 12.4-12.6 mm; the floor center gap 7 is composed of a rectangular gap and a circular hole with the same geometric center, the rectangular gap has a length of S1, S1 is in the range of 14.8-15.2 mm, and has a width of S2, S2 is in the range of 0.5-0.7 mm; the circular hole has a radius of R3, R3 is in the range of 2.4-2.6 mm. In this example, but not limited to, R1=11.5 mm, R2=12.5 mm, R3=2.5 mm, S1=15 mm, and S2=0.6 mm.
[0049] The technical effects of the utility model can be further illustrated by the following simulation experiment:
[0050] 1. Simulation software:
[0051] HFSS_19.0, commercial simulation software Feko2021
[0052] 2. Simulation content:
[0053] Simulation 1: The return loss of the wideband low-scattering-lobe conformal array antenna of the above embodiment in the frequency band of 4-8 GHz is simulated by using the simulation software, and the result is shown in Figure 6 .
[0054] As can be seen from Figure 6 , the S 11 of the reference unit is less than -10 dB in the frequency band of 5.06-5.85 GHz, and the S 11 of the design unit is less than -10 dB in the frequency band of 5.06-6.78 GHz, which indicates that the design unit has better radiation performance in the wideband range compared with the reference unit.
[0055] Simulation 2: The monostatic RCS of the antenna when the x-polarized incident wave is incident from different angles in the frequency band of 5-8 GHz is simulated by using the simulation software, and the result is shown in Figure 7 .
[0056] As can be seen from Figure 7 , the scattering lobe phenomenon becomes more and more obvious with the increase of frequency, and even the scattering lobe is the same as or higher than the main lobe at a higher frequency such as 7.5 GHz, with a lobe peak of -4.6 dB, which indicates that the scattering lobe phenomenon of the traditional microstrip patch conformal array is obvious.
[0057] Simulation 3: The monostatic RCS of the antenna when the x-polarized incident wave is incident from different angles in the frequency band of 5-8 GHz is simulated by using the simulation software, and the result is shown in Figure 8 .
[0058] As can be seen from Figure 8 , the scattering lobe does not appear completely in the set angle domain at a lower frequency in the frequency band, and gradually appears completely with the increase of frequency, and the lobe peak also increases with the increase of frequency. The maximum value of the scattering lobe of the reference array appears at 7.7 GHz, at which time the lobe peak is -4.62 dB; the scattering lobe phenomenon of the design array does not change obviously with the frequency, and the maximum value of the scattering lobe appears at 8 GHz, at which time the lobe peak is -15.9 dB. Compared with the traditional microstrip patch conformal array in the frequency band, the monostatic RCS at the scattering lobe of the present embodiment is reduced.
[0059] Simulation 4, using simulation software, the above-mentioned embodiment of the wideband low-scattering grating conformal array antenna in the 5~8GHz frequency band under the x polarization incident wave, compared with the RCS reduction of the traditional microstrip patch conformal array antenna at the scattering grating peak, the results are shown in Figure 9
[0060] As can be seen from Figure 9 , compared with the reference conformal array, the design array has RCS reduction effect in the scattering grating of 5~8GHz frequency band, the average reduction is 13.4dB, the RCS reduction at the scattering grating of 7.2GHz is the largest, and the peak reduction is 35.8dB.
[0061] Simulation 5, using simulation software, the above-mentioned embodiment of the wideband low-scattering grating conformal array antenna in the 4~8GHz frequency band when the y polarization incident wave is normally incident, the single station RCS of the antenna, the results are shown in Figure 10
[0062] As can be seen from Figure 10 , when the y polarization incident wave is normally incident in the 4~8GHz frequency band, the embodiment has obvious RCS reduction effect, the RCS reduction at 6.5GHz is the largest, and the peak reduction is 11.5dB.
[0063] Although the embodiments of the present application have been shown and described, it can be understood by those skilled in the art that various modifications, changes, replacements and deformations can be made to these embodiments without departing from the principles and spirits of the present application, the scope of the present application is defined by the appended claims and their equivalents.
Claims
1. A wideband low-scattering grating lobe conformal array antenna based on eigenmode analysis, comprising a coaxial feed, characterized in that, It also includes from top to bottom in turn laminating first dielectric substrate (2), second dielectric substrate (4) and metal floor (5); The first dielectric substrate (2) upper surface is printed with radiation patch (1), and each radiation patch (1) is composed of two groups of symmetrical metal patches; The metal floor is provided with floor center gap (7) and two circular arc gaps (6); the floor center gap (7) is located between the two circular arc gaps (6); The first dielectric substrate and the second dielectric substrate are further provided with microstrip feed line (3); the coaxial feed inner core (8) penetrates the second dielectric substrate (4) and is connected with the microstrip feed line (3); The microstrip feed line (3), the second dielectric substrate (4), the metal floor (5), the circular arc gap (6) and the floor center gap (7) jointly constitute a feed layer.
2. The wideband low-scattering grating lobe conformal array antenna based on eigenmode analysis of claim 1, wherein, The geometric centers of the first dielectric substrate (2), the second dielectric substrate (4), the metal floor (5), the circular arc gap (6) and the floor center gap (7) coincide in the projection on the normal of the conformal surface.
3. The wideband low-scattering grating lobe conformal array antenna based on eigenmode analysis of claim 1, wherein, Two groups of metal patches constitute the radiation patch; wherein, metal patch A and metal patch B are a group, metal patch C and metal patch D are a group; the arrangement direction of metal patch A and metal patch B is perpendicular to the arrangement direction of metal patch C and metal patch D; the metal patch C and the metal patch D are both located between the metal patch A and the metal patch B.
4. The wideband low-scattering grating lobe conformal array antenna based on eigenmode analysis of claim 3, wherein, The floor center gap (7) includes a circular defect and two long defects; the two long defects are respectively connected on both sides of the circular defect and located on the straight line of the same diameter of the circular defect; The two long defects are opposite to the same side of the circular arc gap.
5. The wideband low-scattering grating lobe conformal array antenna based on eigenmode analysis of claim 4, wherein, The projection of the metal patch A and the metal patch B on the metal floor is divided by the corresponding long defect.
6. The wideband low-scattering grating lobe conformal array antenna based on eigenmode analysis of claim 5, wherein, The projection of the microstrip feed line on the upper surface of the first dielectric substrate crosses the metal patch C and abuts on the edge of the metal patch D.