An airborne low profile broadband stealth antenna
By directly mounting a low-profile broadband stealth antenna on the aircraft skin and using metallized through-holes to form a metal wall, the problem of antenna installation disrupting the conductive continuity of the skin was solved, achieving a low-profile, wide-band stealth effect while maintaining the aircraft's stealth performance.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- THE 20TH RESEARCH INSTITUTE OF CHINA ELECTRONICS TECHNOLOGY GROUP CORP
- Filing Date
- 2023-03-14
- Publication Date
- 2026-05-19
AI Technical Summary
When existing airborne antennas are installed on stealth aircraft, they can easily disrupt the conductive continuity of the skin, leading to a decrease in stealth performance, especially when detection radar waves are grazing incident on the surface, resulting in a significant increase in traveling wave scattering.
Design an airborne low-profile broadband stealth antenna with a two-layer dielectric substrate and a metal ground plane structure. Metal walls are formed through metallized through-holes, which are directly mounted on the aircraft skin to maintain the conductive continuity of the skin. Radiation is achieved through radiating slots and feed metal lines, eliminating the need for an antenna radome.
Within the radar wave grazing angle of incidence domain, the antenna's RCS value is below -38.5 dBsm, maintaining the aircraft's stealth performance while possessing low profile and wide bandwidth characteristics, meeting the requirements for stealth aircraft.
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Figure CN116365225B_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of antenna technology, and in particular to an airborne low-profile broadband stealth antenna. Background Technology
[0002] Stealth technology generally refers to radar stealth technology, which mainly reduces the signal characteristics of detection radar waves through clever structural and shape design or the application of radar-absorbing materials, thereby shortening the detection range of the radar. RCS (Radar crosssection) is a parameter that measures the stealth performance of a target, with dimensions of square meters or dBsm (dBm). 2 Airborne avionics equipment requires a large number of airborne antennas, and the airborne antennas equipped on stealth aircraft are called airborne stealth antennas.
[0003] When a stealth aircraft conducts a penetration operation, the horizontal distance between the aircraft and the detection radar is much greater than the height difference between them, causing the radar waves to glide at the aircraft. In this situation, the radar's threat area is limited to a range within the forward angular region of the aircraft's nose, typically azimuth [-45°, +45°] and pitch [-10°, +10°] (azimuth is...). Figure 1 The angle between the XOY plane and the X-axis, and the pitch angle are... Figure 1 (The angle between the center and the Z-axis). When the radar wave is grazing-incidence, the scattered waves generated by various components of the aircraft are mainly scattering by traveling surface waves, while the scattered waves caused by other mechanisms such as specular scattering have little impact.
[0004] Conventional airborne antennas often employ microstrip patch antennas or disc-cone antennas. To ensure that these antennas appear seamless and without protrusions or depressions on the aircraft skin, a conformal radome is typically placed over the antenna radiator. Since the radome is transmissive but non-conductive, this disrupts the conductive continuity of the skin at the antenna mounting point. According to the principle of surface wave scattering, when a radar wave grazes and strikes the aircraft skin, the resulting surface current scattering at discontinuities can compromise the stealth capabilities of stealth aircraft.
[0005] Another type of airborne antenna is the microstrip patch antenna or the disc-cone antenna. This type of antenna has poor stealth performance after being installed on the aircraft and does not meet the requirements for use by stealth aircraft. Summary of the Invention
[0006] This application provides an airborne low-profile broadband stealth antenna, proposing a stealth antenna that can be directly installed on the aircraft skin without the need for an radome and replace part of the skin. After installation, the exposed surface of the antenna is entirely a flat metal surface except for narrow gaps, with no protrusions, thus maintaining the electrical continuity of the aircraft skin.
[0007] This application provides an airborne low-profile broadband stealth antenna, including: an upper metal ground plane 1, a radiating slot 3, a feed metal line 4, an upper dielectric substrate 5, a lower dielectric substrate 6, a lower metal ground plane 7, and a feed port 8.
[0008] The upper metal floor 1 is printed on the upper side of the upper dielectric substrate 5, and the lower metal floor 7 is printed on the lower side of the lower dielectric substrate 6. The two dielectric substrates are bonded together. Multiple metallized through holes 2 are provided between the upper metal floor 1 and the lower metal floor 7, and the multiple metallized through holes 2 are arranged according to the regular polygonal arrangement rule.
[0009] The upper metal floor 1 has radial slits 3 etched on it;
[0010] The lower dielectric substrate 6 has a power supply metal line 4 printed on it, which is connected to the power supply port 8. The power supply metal line 4 is perpendicular to the radiation gap 3.
[0011] Optionally, the ratio of the diameter d of the metallized via 2 to the free space wavelength λ corresponding to the operating frequency, d / λ, is not greater than 0.1, and the ratio of the diameter d to the center-to-center distance s of the adjacent metallized via, d / s, is not less than 0.5.
[0012] Multiple metallized vias 2 are arranged according to a regular polygonal pattern, and the circumcircle diameter D of the regular polygons, the free space wavelength λ corresponding to the operating frequency, and the dielectric constant ε of the substrate satisfy the following:
[0013] Optionally, multiple metallized vias 2 are arranged according to a regular octagonal arrangement rule.
[0014] Optionally, the radial slit 3 is rectangular in shape, etched on the upper metal floor, with a width of 0.01λ to 0.05λ and a length L1 of 0.3λ to 0.6λ. The long side of the radial slit is parallel to one side of the trajectory of the regular polygon.
[0015] Optionally, the width of the feeding metal line 4 is 0.01λ to 0.05λ, one end is attached to the metal core of the feeding port 8, and the other end extends to the midpoint of the long side of the radiation slit 3.
[0016] Optionally, the two dielectric substrates have the same thickness, ranging from 0.01λ to 0.05λ, where λ is the free space wavelength, and the two dielectric substrates have the same dielectric constant, ranging from 2.2 to 16.
[0017] Optionally, the two dielectric substrates can be bonded together using a multilayer board process.
[0018] This application proposes a stealth antenna that can be directly installed on the aircraft skin without a radome and replace part of the skin. After installation, the exposed surface of the antenna is entirely a flat metal surface except for narrow gaps, with no protrusions, thus maintaining the electrical continuity of the aircraft skin.
[0019] The above description is only an overview of the technical solution of this application. In order to better understand the technical means of this application and to implement it in accordance with the contents of the specification, and to make the above and other objects, features and advantages of this application more obvious and understandable, the following are specific embodiments of this application. Attached Figure Description
[0020] Various other advantages and benefits will become apparent to those skilled in the art upon reading the following detailed description of preferred embodiments. The accompanying drawings are for illustrative purposes only and are not intended to limit the scope of this application. Furthermore, the same reference numerals denote the same parts throughout the drawings. In the drawings:
[0021] Figure 1 This is a top view of the airborne low-profile broadband stealth antenna according to an embodiment of this application.
[0022] Figure 2 This is a schematic side cross-sectional view of an airborne low-profile broadband stealth antenna according to an embodiment of this application.
[0023] Figure 3 This is an example of the VSWR simulation results for an airborne low-profile broadband stealth antenna according to an embodiment of this application;
[0024] Figure 4 This is an example of the simulation results of the radiation pattern of the airborne low-profile broadband stealth antenna at a frequency of 4.3 GHz, according to an embodiment of this application.
[0025] Figure 5 The embodiments of this application show the simulated RCS curves of an airborne low-profile broadband stealth antenna when the radar detection wave frequencies are 2GHz, 6GHz, 10GHz, 14GHz, and 18GHz, with azimuth angles of [-90°, +90°] and elevation angles of 0°.
[0026] Figure 6 The simulated RCS curves of the airborne low-profile broadband stealth antenna in this application embodiment are obtained when the radar detection wave frequency is 2GHz, 6GHz, 10GHz, 14GHz, and 18GHz, with azimuth angles of [-90°, +90°] and elevation angles of 5°.
[0027] Figure 7The embodiment of this application shows the simulated RCS curves of an airborne low-profile broadband stealth antenna when the radar detection wave frequency is 2GHz, 6GHz, 10GHz, 14GHz, and 18GHz, with an azimuth angle of [-90°, +90°] and an elevation angle of -5°. Detailed Implementation
[0028] Exemplary embodiments of the present disclosure will now be described in more detail with reference to the accompanying drawings. While exemplary embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure may be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art.
[0029] This application provides an airborne low-profile broadband stealth antenna, such as... Figure 1 , Figure 2 The diagram shows: an upper metal floor 1, a radiating slot 3, a feeding metal line 4, an upper dielectric substrate 5, a lower dielectric substrate 6, a lower metal floor 7, and a feeding port 8.
[0030] The upper metal ground plane 1 is printed on the upper side of the upper dielectric substrate 5, and the lower metal ground plane 7 is printed on the lower side of the lower dielectric substrate 6. The two dielectric substrates are bonded together. For example, the two dielectric substrates can be bonded together using a multilayer board process.
[0031] Multiple metallized through holes 2 are provided between the upper metal floor 1 and the lower metal floor 7, and the multiple metallized through holes 2 are arranged according to the arrangement rule of regular polygons.
[0032] The upper metal floor 1 has radial slits 3 etched on it;
[0033] The lower dielectric substrate 6 has a power supply metal line 4 printed on it, which is connected to the power supply port 8. The power supply metal line 4 is perpendicular to the radiation gap 3.
[0034] This application proposes a stealth antenna that can be directly installed on the aircraft skin without a radome and replace part of the skin. After installation, the exposed surface of the antenna is entirely a flat metal surface except for narrow gaps, with no protrusions, thus maintaining the electrical continuity of the aircraft skin.
[0035] In some embodiments, the ratio of the diameter d of the metallized via 2 to the free space wavelength λ corresponding to the operating frequency, d / λ, is not greater than 0.1, and the ratio of the diameter d to the center-to-center distance s of the adjacent metallized via 2, d / s, is not less than 0.5.
[0036] Multiple metallized vias 2 are arranged according to a regular polygonal pattern, and the circumcircle diameter D of the regular polygons, the free space wavelength λ corresponding to the operating frequency, and the dielectric constant ε of the substrate satisfy the following: Current dielectric substrate fabrication processes make it difficult to form through-metal walls between two or more dielectric substrates. This application's embodiments utilize a method of arranging multiple metallized vias in a row to simulate the formation of a metal wall; this method is simple and low-cost. The multiple metallized vias 2 can be arranged according to regular polygonal rules, such as squares, hexagons, octagons, and dodecagons. In some embodiments, the multiple metallized vias 2 are arranged according to a regular octagonal rule. Subsequent embodiments will describe specific examples of the stealth antenna of this application using a regular octagonal arrangement; other regular polygonal structures will not be elaborated upon here.
[0037] In some embodiments, the radial slit 3 is rectangular in shape, etched on the upper metal floor, with a width of 0.01λ to 0.05λ and a length L1 of 0.3λ to 0.6λ. The long side of the radial slit is parallel to one side of the trajectory of the regular polygon.
[0038] In some embodiments, the width of the feeding metal line 4 is 0.01λ to 0.05λ, one end is attached to the metal core of the feeding port 8, and the other end extends to the midpoint of the long side of the radiation slit 3.
[0039] In some embodiments, the two dielectric substrates have the same thickness, ranging from 0.01λ to 0.05λ, where λ is the free space wavelength, and the two dielectric substrates have the same dielectric constant, ranging from 2.2 to 16.
[0040] This application also proposes an implementation example of an airborne low-profile broadband stealth antenna:
[0041] like Figure 1 As shown, the airborne low-profile broadband stealth antenna includes: an upper metal ground plane 1, a metallized via 2, a radiating slot 3, a feed metal line 4, an upper dielectric substrate 5, a lower dielectric substrate 6, a lower metal ground plane 7, and a feed port 8. The upper metal ground plane 1 is printed on the upper side of the upper dielectric substrate 5, and the lower metal ground plane 7 is printed on the lower side of the lower dielectric substrate 6. The two dielectric substrates have the same thickness and are bonded together using a multilayer board process.
[0042] The upper dielectric substrate 5 and the lower dielectric substrate 6 have the same dielectric constant ε, both being 4.5, and a total thickness H of 2 mm (approximately 0.028λ). Each metallized via 2 has a diameter d of 1 mm, and the center-to-center distance s between adjacent metallized vias is 2.5 mm. Multiple vias are arranged along a regular octagonal trajectory, with a circumcircle diameter D of 32.8 mm. The radial slot 3 is rectangular in shape, etched onto the upper metal substrate, with a width W1 of 1.4 mm and a length L1 of 25 mm. The long side of the radial slot is parallel to one side of the regular octagonal trajectory. The feed metal line 4 is printed on the upper side of the lower dielectric substrate, with a width W2 of 0.96 mm. One end overlaps the metal core of the feed port 8, and the other end extends to the midpoint of the long side of the radial slot 3, perpendicular to the long side of the radial slot 3.
[0043] Figure 3 The simulation results of the VSWR of an airborne low-profile broadband stealth antenna according to this embodiment are shown. The horizontal axis represents frequency, and the vertical axis represents VSWR. It can be seen that the VSWR of the antenna is less than 2 in the frequency range of 4.285 GHz to 4.325 GHz.
[0044] Figure 4 The simulation results of the radiation pattern of an airborne integrated broadband stealth antenna in this embodiment at a frequency of 4.3 GHz are shown. The horizontal axis represents the azimuth angle, and the vertical axis represents the elevation angle. It can be seen that the maximum gain of the antenna reaches 5.2 dBi.
[0045] Figure 5 This embodiment shows an airborne integrated broadband stealth antenna mounted on a simulated stealth aircraft. The simulated RCS curves of the antenna are shown when radar detection waves illuminate the antenna at frequencies of 2GHz, 6GHz, 10GHz, 14GHz, and 18GHz, with azimuth angles of [-90°, +90°] and elevation angles of 0°. The horizontal axis represents the azimuth angle, and the vertical axis represents the RCS value.
[0046] Figure 6 This embodiment shows an airborne integrated broadband stealth antenna mounted on a simulated stealth aircraft. The simulated RCS curves of the antenna are shown when radar detection waves illuminate the antenna at frequencies of 2GHz, 6GHz, 10GHz, 14GHz, and 18GHz, with azimuth angles of [-90°, +90°] and elevation angles of 5°. The horizontal axis represents the azimuth angle, and the vertical axis represents the RCS value.
[0047] Figure 7This embodiment shows an airborne integrated broadband stealth antenna mounted on a simulated stealth aircraft. The simulated RCS curves of the antenna are shown when radar detection waves illuminate the antenna at frequencies of 2GHz, 6GHz, 10GHz, 14GHz, and 18GHz, with azimuth angles of [-90°, +90°] and elevation angles of -5°. The horizontal axis represents the azimuth angle, and the vertical axis represents the RCS value.
[0048] from Figures 5-7 It can be seen that when the radar detection wave illuminates the stealth aircraft in a grazing incidence manner, the RCS value of this antenna is less than -38.5 dBsm in the range of azimuth [-45°, +45°] and pitch [-5°, +5°].
[0049] The airborne low-profile broadband stealth antenna proposed in this embodiment does not require a radome and can be directly mounted on the aircraft skin, replacing a portion of it. After installation, the exposed surface of the antenna, except for narrow gaps, is entirely a flat metal surface, eliminating protrusions and maintaining the conductive continuity of the aircraft skin, thus preserving the stealth capability of the aircraft. The antenna's RCS value is below -38.5 dBsm in the radar detection angle and wide bandwidth, while its thickness is 0.02λ to 0.1λ. Therefore, the antenna of this embodiment possesses both low profile and wide bandwidth stealth advantages.
[0050] It should be noted that, in this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element.
[0051] The sequence numbers of the embodiments in this application are for descriptive purposes only and do not represent the superiority or inferiority of the embodiments.
[0052] The embodiments of this application have been described above with reference to the accompanying drawings. However, this application is not limited to the specific embodiments described above. The specific embodiments described above are merely illustrative and not restrictive. Those skilled in the art can make many other forms under the guidance of this application without departing from the spirit and scope of the claims. All of these forms are within the protection scope of this application.
Claims
1. An airborne low-profile broadband stealth antenna, characterized in that, include: Upper metal floor (1), radiation gap (3), feed metal line (4), upper dielectric substrate (5), lower dielectric substrate (6), lower metal floor (7), feed port (8); The upper metal floor (1) is printed on the upper side of the upper dielectric substrate (5), and the lower metal floor (7) is printed on the lower side of the lower dielectric substrate (6). The two dielectric substrates are bonded together. Multiple metallized through holes (2) are provided between the upper metal floor (1) and the lower metal floor (7), and the multiple metallized through holes (2) are arranged according to the regular octagonal arrangement rule. The upper metal floor (1) has radial slits (3) etched on it; The lower dielectric substrate (6) has a feed metal line (4) printed on it, which is connected to the feed port (8). The feed metal line (4) is perpendicular to the radiation gap (3). Multiple metallized vias (2) are arranged according to the arrangement rules of regular polygons, and the circumcircle diameter D of the regular polygons, the free space wavelength λ corresponding to the operating frequency, and the dielectric constant ε of the dielectric substrate satisfy: ; The radial slit (3) is rectangular in shape, etched on the upper metal floor, with a width of 0.01λ to 0.05λ and a length L1 of 0.3λ to 0.6λ. The long side of the radial slit is parallel to one side of the trajectory of the regular polygon. The feed metal wire (4) has a width of 0.01λ to 0.05λ, with one end attached to the metal core of the feed port (8) and the other end extending to the midpoint of the long side of the radiation slit (3).
2. The airborne low-profile broadband stealth antenna as described in claim 1, characterized in that, The ratio of the diameter d of the metallized via (2) to the free space wavelength λ corresponding to the working frequency, d / λ, is not greater than 0.1, and the ratio of the diameter d to the center distance s of the adjacent metallized via, d / s, is not less than 0.
5.
3. The airborne low-profile broadband stealth antenna as described in claim 1, characterized in that, The two dielectric substrates have the same thickness, ranging from 0.01λ to 0.05λ, where λ is the free space wavelength, and the two dielectric substrates have the same dielectric constant, ranging from 2.2 to 16.
4. The airborne low-profile broadband stealth antenna as described in claim 1, characterized in that, Two dielectric substrates are bonded together using a multilayer board process.