Miniaturized ultra-wideband conformal antenna and array

Abstract

The utility model belongs to the technical field of antennas, and particularly discloses a miniaturized ultra-wideband conformal antenna and array, comprising an outer radiation layer, a base layer, an inner radiation layer, a support layer and a conformal mounting layer which are sequentially stacked and connected, a low-frequency oscillator of the log-periodic antenna structure is bent; and a feed cable is accommodated in the supporting layer and is connected with the log-periodic antenna structures in the outer radiation layer and the inner radiation layer. The antenna has the advantages of being small in size, wide in frequency band and capable of being well installed on the surface of an aircraft carrier in a conformal mode.

Description

Technical Field

[0001] This application belongs to the technical field of antennas, and more specifically, relates to a miniaturized ultra-wideband conformal antenna and array. Background Art

[0002] In modern aerospace, the seeker of an aircraft usually relies on high-performance antennas to achieve precise navigation and communication functions. These antennas not only need to maintain stable performance under various environmental conditions, but also must have good directivity and gain to ensure that the aircraft can effectively receive and transmit signals.

[0003] With the development of the ultra-wideband and miniaturization of aircraft, the installation space for antennas in the aircraft is gradually shrinking. Due to reasons such as large volume and short frequency band of traditional antennas, it is difficult to adapt to the development needs, especially difficult to be conformally installed on the surface of the aircraft carrier, and there is an urgent need for improvement. Summary of the Utility Model

[0004] In view of the defects or improvement requirements of the prior art, this application provides a miniaturized ultra-wideband conformal antenna and array, aiming to solve the problems that existing antennas are large in volume, short in frequency band, and difficult to be conformally installed on the surface of the aircraft carrier.

[0005] A miniaturized ultra-wideband conformal antenna provided in the first aspect of this application adopts the following technical solution:

[0006] A miniaturized ultra-wideband conformal antenna includes an outer radiation layer, a base layer, an inner radiation layer, a support layer, and a conformal installation layer that are sequentially laminated and connected, where:

[0007] Log-periodic antenna structures are provided on both the outer radiation layer and the inner radiation layer, and the low-frequency oscillators of the log-periodic antenna structure are bent;

[0008] A feeding cable is accommodated in the support layer, and the feeding cable connects the log-periodic antenna structures in the outer radiation layer and the inner radiation layer.

[0009] Through the above technical solution conceived by this application, compared with the prior art, since this antenna is composed of multiple laminated structures, the structure of the antenna is relatively compact and the size is relatively small. The antenna under the laminated structure design can be well conformally installed with the aircraft carrier through the conformal installation layer; in addition, since log-periodic antenna structures are printed on both the inner and outer radiation layers, the antenna has a good bandwidth and is extremely suitable for meeting the radar detection requirements on the aircraft carrier platform; after the low-frequency oscillators in the log-periodic antenna structure are bent, the length dimension of the log-periodic antenna structure can be greatly reduced, which is beneficial to improving the miniaturization of the antenna.

[0010] As a further preference, the bending spacing of the low-frequency oscillator is 7.2 mm to 7.8 mm, and the longitudinal width is 2 mm to 8 mm.

[0011] As a further preference, an absorbing layer is provided between the support layer and the conformal mounting layer.

[0012] As a further preference, the thickness of the absorbing layer is 1 mm - 2 mm.

[0013] As a further preference, the outer radiation layer and the inner radiation layer are made of polyimide film.

[0014] As a further preference, the log-periodic antenna structure is a printed copper-plated pattern.

[0015] As a further preference, the base layer is composed of a polytetrafluoroethylene fiberglass cloth layer.

[0016] As a further preference, the support layer is composed of polymethacrylimide foam.

[0017] As a further preference, the antenna is in the shape of a curved panel body.

[0018] A technical solution adopted by an antenna array provided in the second aspect of the present application is as follows:

[0019] An antenna array includes multiple small-sized ultra-wideband conformal antennas described in any one of the first aspect, and the multiple small-sized ultra-wideband conformal antennas are used to be evenly arranged around the aircraft carrier.

[0020] Generally speaking, compared with the prior art through the above technical solutions conceived by the present application, the following technical advantages are mainly possessed:

[0021] 1. This antenna adopts a multi-layer structure laminated design, and can make the antenna into a curved panel body adapted to the aircraft carrier, so as to be well conformally mounted on the aircraft carrier. The log-periodic antenna structure is printed in both the inner and outer radiation layers, and the low-frequency oscillator in the log-periodic antenna structure is designed to be bent, so that while the antenna has a good bandwidth, it also has a small size, and is extremely suitable for meeting the radar detection requirements on the aircraft carrier platform.

[0022] 2. The polyimide film selected for the inner radiation layer and the outer radiation layer of this antenna is a flexible printed material, which is beneficial to conformal mounting with the curved surface of the mounting carrier.

[0023] 3. This antenna overcomes the influence of the metal nature of the aircraft platform and can achieve the characteristics of ultra-wideband and end-fire pattern under extremely low profile conditions. Description of the Drawings

[0024] Figure 1It is a schematic diagram of a miniaturized ultra-wideband conformal antenna structure provided by an embodiment of the present application;

[0025] Figure 2 It is an element diagram of a miniaturized ultra-wideband conformal antenna array provided by an embodiment of the present application;

[0026] Figure 3 It is an installation diagram of a miniaturized ultra-wideband conformal antenna array provided by an embodiment of the present application;

[0027] Figure 4 It is a voltage standing wave ratio curve of a miniaturized ultra-wideband conformal antenna provided by an embodiment of the present application;

[0028] Figure 5 It is a gain curve before and after arraying of a miniaturized ultra-wideband conformal antenna and array provided by an embodiment of the present application;

[0029] Figure 6 It is a gain pattern at 1 GHz of a miniaturized ultra-wideband conformal antenna provided by an embodiment of the present application;

[0030] Figure 7 It is a gain pattern at 2 GHz of a miniaturized ultra-wideband conformal antenna provided by an embodiment of the present application;

[0031] Figure 8 It is a gain pattern at 4 GHz of a miniaturized ultra-wideband conformal antenna provided by an embodiment of the present application;

[0032] Figure 9 It is a gain pattern at 8 GHz of a miniaturized ultra-wideband conformal antenna provided by an embodiment of the present application;

[0033] Figure 10 It is a gain pattern at 12 GHz of a miniaturized ultra-wideband conformal antenna provided by an embodiment of the present application;

[0034] Figure 11 It is a gain pattern at 1 GHz after arraying of a miniaturized ultra-wideband conformal antenna array provided by an embodiment of the present application;

[0035] Figure 12 It is a gain pattern at 2 GHz after arraying of a miniaturized ultra-wideband conformal antenna array provided by an embodiment of the present application;

[0036] Figure 13 It is a gain pattern at 4 GHz after arraying of a miniaturized ultra-wideband conformal antenna array provided by an embodiment of the present application;

[0037] Figure 14 It is a gain pattern at 8 GHz after arraying of a miniaturized ultra-wideband conformal antenna array provided by an embodiment of the present application;

[0038] Figure 15 This is the gain pattern at 12 GHz after the miniaturized ultra-wideband conformal antenna array provided by the embodiments of the present application.

[0039] In all the drawings, the same reference numerals are used to represent the same elements or structures, where:

[0040] 1. Outer radiation layer; 2. Base layer; 3. Inner radiation layer; 4. Feeding cable; 5. Support layer; 6. Absorbing layer; 7. Conformal mounting layer; 8. Radiation oscillator; 9. Feeding printed line. Specific embodiments

[0041] In order to make the objectives, technical solutions and advantages of the present application more clear and understandable, the present application will be further described in detail below with reference to the drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0042] The following is a further detailed description of the present application with reference to the attached Figures 1-15 The present application will be further described in detail.

[0043] The embodiments of the present application disclose a miniaturized ultra-wideband conformal antenna. Referring to Figures 1-2 , the antenna includes an outer radiation layer 1, a base layer 2, an inner radiation layer 3, a support layer 5, and a conformal mounting layer 7 that are sequentially laminated and connected. Among them, a log-periodic antenna structure is printed on the outer radiation layer 1 and the inner radiation layer 3, and the low-frequency oscillators of the log-periodic antenna structure are bent; and a feeding cable 4 is accommodated in the support layer 5. The outer conductor of the feeding cable 4 is electrically connected to the log-periodic antenna structure of the inner radiation layer 3, and the inner conductor of the feeding cable 4 is electrically connected to the log-periodic antenna structure of the outer radiation layer 1.

[0044] Furthermore, an absorbing layer 6 is further provided between the support layer 5 and the conformal mounting layer 7 to improve the low-frequency matching characteristics of the antenna.

[0045] Specifically, the outer radiation layer 1 and the inner radiation layer 3 are the main body parts of the antenna, preferably made of polyimide film material, with a thickness preferably of 0.05 mm and a dielectric constant of 3.5, for realizing the function of antenna electromagnetic signal conversion. Since the polyimide film is a flexible printed material that can be bent arbitrarily, on this basis, the consistency forming with the surface shape of the carrier can be realized. During specific installation, glue can be applied to the back of the polyimide film and pasted on the surface of the substrate 2.

[0046] In the outer radiation layer 1 and the inner radiation layer 3, the log-periodic antenna structure is a special copper-plated pattern printed on the polyimide film material, and this pattern is formed based on the principle of planar log-periodic antenna.

[0047] Specifically, as Figure 1 and Figure 2As shown, the log-periodic antenna structure includes a feeding printed line 9 and a plurality of radiation oscillators 8. The plurality of radiation oscillators 8 are staggered on both sides of the feeding printed line 9 and are all connected to the feeding printed line 9. The oscillator lengths and spacings of the plurality of radiation oscillators 8 vary in a logarithmic period, and the radiation oscillators 8 are fed through the feeding printed line 9. It can be understood that the plurality of radiation oscillators 8 include high-frequency oscillators and low-frequency oscillators.

[0048] Preferably, the printed pattern includes 16 radiation oscillators 8. The size of the longest radiation oscillator 8 is preferably 155 mm, and the length of the shortest radiation oscillator 8 is preferably 2 mm. The oscillator lengths vary according to the logarithmic periodic law, and the scaling factor is 0.75. To reduce the lateral size, the low-frequency oscillators (i.e., the first 6 longer radiation oscillators 8 in the pattern) are designed to be zigzagged, so that the longitudinal dimensions of each radiation oscillator 8 are reasonably lengthened, and the total length of the zigzagged oscillators remains unchanged. Preferably, the bending spacing is set to 7.2 mm to 7.8 mm, and the longitudinal width is set to 2 mm to 8 mm. To reduce the abrupt change in the surface current flowing through the antenna, a smooth transition design is carried out at the bending points, so that the low-frequency oscillators are in an earthworm shape.

[0049] Furthermore, the base layer 2 is preferably made of a polytetrafluoroethylene fiberglass cloth board, with a thickness preferably of 2 mm and a dielectric constant of 2.2. The polytetrafluoroethylene fiberglass cloth board can be processed into a shape consistent with the curvature of the carrier to achieve conformal mounting. In this design, the base layer 2 serves as the mounting carrier for the outer radiation layer 1 and the inner radiation layer 3, and together with the outer radiation layer 1 and the inner radiation layer 3, forms the radiation main body of the antenna, forming a curved log-periodic antenna unit.

[0050] Furthermore, the support layer 5 is preferably made of polymethacrylimide foam, with a thickness preferably of 7.5 mm, and is used to support the outer radiation layer 1, the base layer 2, and the inner radiation layer 3. The polymethacrylimide foam can be processed into a shape consistent with the curvature of the carrier to achieve conformal mounting. The dielectric constant of the polymethacrylimide foam is between 1.06 and 1.27, which does not affect the electromagnetic characteristics of the antenna.

[0051] By providing the support layer 5, the radiation main body can be kept at a certain distance from the conformal mounting layer 7, reducing the influence of the antenna surface current by the mirror principle and achieving good antenna radiation characteristics. Among them, a square slot of 4 mm × 3.5 mm is opened in the middle of the support layer 5 for placing the feeding cable 4.

[0052] Furthermore, the outer conductor of the feeding cable 4 is connected to the feeding printed line 9 of the inner radiation layer 3. The inner conductor of the feeding cable 4 is welded to the feeding printed line 9 of the outer radiation layer 1 through the top vias of the inner radiation layer 3, the base layer 2, and the outer radiation layer 1. The feeding cable 4 can also be equipped with an SSMP or SMP type connector for docking with subsequent equipment.

[0053] Further, the specification of the absorbing layer 6 is preferably MCS / SS6M, which is made of an absorbing material, and its thickness is preferably 1-2 mm. The absorbing layer 6 is installed between the support layer 5 and the conformal mounting layer 7 to suppress the image current in the low-frequency radiation area and improve the low-frequency matching characteristics of the antenna. To achieve a better impedance matching effect and ensure the low-frequency radiation efficiency, the absorbing layer 6 is generally set to two layers, and the thickness of a single layer is preferably 1 mm.

[0054] In this design, the outer radiation layer 1, the base layer 2, the inner radiation layer 3, the support layer 5 with the feeding cable 4, and the absorbing layer 6 are stacked in sequence, and then fixed on the surface of the conformal mounting layer 7 to form the whole antenna. For easy understanding, Figure 2 the (a) in Figure 2 shows the front structure of the antenna,

[0055] In some specific implementation cases, the overall size of the antenna is 114 mm × 68 mm × 13 mm, that is, 0.380λ L × 0.227λ L × 0.043λ L where λ L represents the wavelength corresponding to the lowest operating frequency of the antenna. Through the reasonable loading of the absorbing material, the lowest operating frequency of the antenna is extended to 1 GHz, and the profile height of the antenna is only 13 mm, that is, the height electrical size is only 0.043λ L .

[0056] The embodiment of the present application also discloses an antenna array, which includes a plurality of miniaturized ultra-wideband conformal antennas. The plurality of miniaturized ultra-wideband conformal antennas are used to be evenly arranged around the aircraft carrier to form a passive broadband receiving antenna array.

[0057] As Figure 3 shown, the antenna array is installed on the surface of the aircraft platform, and the plurality of miniaturized ultra-wideband conformal antennas therein form a circular array, which does not affect the aerodynamic performance of the aircraft. Through the "earthworm-shaped" design of the logarithmic periodic antenna radiation oscillator 8, the lateral size is reduced, and the overall size of the antenna is 114 mm × 68 mm × 13 mm, that is, 0.380λ L × 0.227λ L × 0.043λ LBy reasonably loading the wave-absorbing material, the lowest operating frequency of the antenna is extended to 1 GHz, and the antenna profile height is only 13 mm, that is, the height electrical size is only 0.043λ L 。

[0058] For easy understanding, Figure 4 The voltage standing wave ratio curve of a miniaturized ultra-wideband conformal antenna is shown. The standing wave is less than 3 within the operating frequency band (1-12) GHz of the antenna. Figure 5 The gain curves before and after the formation of a miniaturized ultra-wideband conformal antenna and an array are shown. The maximum gain range of the antenna element is (0.4-6.2) dB. As Figures 6 to 10 shown, the antenna has good end-fire radiation pattern characteristics within the frequency range of (1-12) GHz. The radiation patterns of the E-plane (i.e., the electric field plane) and H-plane (i.e., the magnetic field plane) of the antenna element both maintain high symmetry.

[0059] Under this design scheme, the antenna array of this application adopts the form of a log-periodic antenna. After being installed on the surface of the aircraft platform, it can still achieve the end-fire radiation pattern characteristics. After the antenna is installed on the platform to form an array, the maximum gain range is (-1.8-11.0) dB. As Figures 11 to 15 shown, after the antenna is arrayed on the aircraft platform, the radiation pattern tilts upward. In the E-plane of the radiation pattern, the pointing angle of the main lobe deviates from the flight direction by no more than 30°; the H-plane of the radiation pattern has good symmetry and beam width values.

[0060] It should be understood that expressions such as "including" and "may include" used in this application indicate the existence of the disclosed functions, operations, or constituent elements, and do not limit the existence of one or more additional functions, operations, and constituent elements. In this application, terms such as "including" and / or "having" may be interpreted as indicating a specific characteristic, number, operation, constituent element, component, or a combination thereof, but do not exclude the existence or possibility of addition of one or more other characteristics, numbers, operations, constituent elements, components, or a combination thereof.

[0061] It should be understood that the orientation or positional relationship indicated by terms such as "center", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing this application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus cannot be understood as a limitation to this application.

[0062] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include one or more of such features. In the description of this application, "a plurality of" means two or more unless otherwise specifically defined.

[0063] In this application, unless otherwise clearly specified and defined, terms such as "installed", "connected", "coupled", "fixed", etc. shall be construed in a broad sense. For example, it may be a fixed connection, a detachable connection, or an integral connection; it may be a mechanical connection or an electrical connection; it may be directly connected or indirectly connected through an intermediate medium, and it may be the communication inside two components. For those of ordinary skill in the art, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0064] It is easy for those skilled in the art to understand that the above are only the preferred embodiments of this application and are not intended to limit this application. Any modifications, equivalent replacements, and improvements made within the spirit and principles of this application shall be included within the protection scope of this application.

Claims

1. A miniaturized ultra-wideband conformal antenna, characterized in that: The invention comprises an outer radiation layer (1), a base layer (2), an inner radiation layer (3), a support layer (5) and a conformal mounting layer (7) which are sequentially stacked and connected, wherein: The outer radiation layer (1) and the inner radiation layer (3) are both provided with a logarithmic periodic antenna structure, and the low-frequency oscillator of the logarithmic periodic antenna structure is in a curved shape; The support layer (5) contains a feeder cable (4), which connects the logarithmic periodic antenna structure in the outer radiation layer (1) and the inner radiation layer (3).

2. The miniaturized ultra-wideband conformal antenna according to claim 1, characterized in that: The bending interval of the low-frequency vibrator is 7.2 mm to 7.8 mm, and the longitudinal width is 2 mm to 8 mm.

3. The miniaturized ultra-wideband conformal antenna according to claim 1, characterized in that: A wave absorbing layer (6) is provided between the supporting layer (5) and the conformal mounting layer (7).

4. The miniaturized ultra-wideband conformal antenna according to claim 3, characterized in that: The thickness of the wave absorbing layer (6) is 1 mm to 2 mm.

5. The miniaturized ultra-wideband conformal antenna according to any one of claims 1 to 4, characterized in that: The outer radiation layer (1) and the inner radiation layer (3) are made of polyimide films.

6. The miniaturized ultra-wideband conformal antenna according to any one of claims 1 to 4, characterized in that: The log-periodic antenna structure is a printed copper-plated pattern.

7. The miniaturized ultra-wideband conformal antenna according to any one of claims 1 to 4, characterized in that: The base layer (2) is composed of a polytetrafluoroethylene glass fiber cloth layer.

8. The miniaturized ultra-wideband conformal antenna according to any one of claims 1 to 4, characterized in that: The support layer (5) is made of polymethacrylimide foam.

9. The miniaturized ultra-wideband conformal antenna according to any one of claims 1 to 4, characterized in that: The antenna is in the shape of a curved plate.

10. An antenna array, characterized in that: It comprises a plurality of miniaturized ultra-wideband conformal antennas as described in any one of claims 1 to 9, wherein the plurality of miniaturized ultra-wideband conformal antennas are used to be evenly spaced around an aircraft carrier.

Images