An electromagnetic resonator for eliminating multipath interference of localizer

Abstract

The present application relates to the field of aviation navigation technology, and in particular to an electromagnetic resonator for eliminating multipath interference of heading beacons. The electromagnetic resonator includes a first glass, a first PVB film, an electromagnetic resonant body, a third PVB film and a third glass connected in sequence along the direction of electromagnetic wave incidence; the electromagnetic resonant body includes a copper-clad resonant absorption layer, a second glass, a second PVB film and a fully covered metal shielding layer connected in sequence along the direction of electromagnetic wave incidence; the size of the copper-clad resonant absorption layer is smaller than the size of the fully covered metal shielding layer. The electromagnetic resonant body of the present invention is the main structure of the electromagnetic resonator. When the electromagnetic wave irradiates the electromagnetic resonator, the electromagnetic resonator body can resonate, thereby achieving the purpose of absorbing electromagnetic waves; moreover, the dielectric substrate used in the present invention is ordinary glass, and the electromagnetic resonator body is encapsulated between two layers of glass using a mature lamination process, which can effectively withstand the outdoor wind and sun environment conditions.

Description

Technical Field

[0001] The invention relates to the technical field of aviation navigation, and in particular to an electromagnetic resonator for eliminating multipath interference of a heading beacon. Background Art

[0002] In modern civil transport airports, localizers (LOCs) are important devices for providing precise route guidance. However, with the development of urban construction, there are more and more large buildings near airport runways. When large buildings are located in specific locations, the facades of these buildings will cause multipath interference to the signals of the localizers, causing the channel structure to jitter. This jitter not only affects the navigation accuracy of the aircraft, but may also pose a threat to flight safety. At present, although some methods have been tried to reduce this interference, the effect is not ideal.

[0003] Existing methods for reducing multipath interference mainly include optimizing the installation location of localizers, adjusting localizer antenna parameters, lowering or even demolishing existing buildings, etc. However, these methods often require large-scale renovation or upgrading of airport facilities, which is costly and difficult to implement. These methods have limited effects on suppressing multipath interference and cannot completely solve the problem of channel jitter. In addition, foreign countries have adopted the method of installing grating structures on the facades of buildings to reduce multipath interference, but the grating structure is large in size, the overall structure is bulky, and the installation position needs to be reserved during the building design stage, which is not universally applicable.

[0004] Laying electromagnetic metamaterials on the surface of buildings is also a solution. However, since the operating frequency band of the heading beacon is 108.10-111.95MHz, the corresponding operating wavelength is relatively long. There are very few absorbing materials designed in this frequency band, and they are usually thick. If you want to reduce the thickness, you often use the method of loading lumped electronic components in the absorbing layer, which has a complex structure and is not conducive to large-scale mass production. At the same time, since the substrates used are usually flame-resistant glass fiber reinforced epoxy resin laminates (FR4) and polytetrafluoroethylene (PTFE) and other traditional dielectric materials, they cannot pass heat resistance, moisture resistance, and radiation resistance tests in outdoor environments. Summary of the invention

[0005] The object of the present invention is to provide an electromagnetic resonator for eliminating the multipath interference of a localizer, so as to eliminate the multipath interference of a localizer.

[0006] According to the present invention, an electromagnetic resonator for eliminating multipath interference of a heading beacon is provided, wherein the electromagnetic resonator comprises a first glass, a first PVB film, an electromagnetic resonant body, a third PVB film and a third glass which are sequentially connected along the direction of incident electromagnetic waves; the electromagnetic resonant body comprises a copper-clad resonant absorption layer, a second glass, a second PVB film and a fully covered metal shielding layer which are sequentially connected along the direction of incident electromagnetic waves; the size of the copper-clad resonant absorption layer is smaller than the size of the fully covered metal shielding layer, and PVB is polyvinyl butyral.

[0007] Furthermore, the electromagnetic resonator is a symmetrical structure, the size of the electromagnetic resonator is 800 mm×800 mm, and the thickness of the electromagnetic resonator body is 12-13 mm.

[0008] Furthermore, the thickness of the third glass and the first glass is 6 mm, the thickness of the second glass is 12 mm, and the thickness of the third PVB film, the second PVB film and the first PVB film is 0.38 mm.

[0009] Furthermore, the copper-clad resonant absorption layer is provided with straight grooves of equal size at positions corresponding to the four corners of the electromagnetic resonator, and the copper-clad resonant absorption layer is provided with a square hole on the line connecting the center of any straight groove and the center of the copper-clad resonant absorption layer.

[0010] Furthermore, the side length of any square hole is a millimeters, where a is determined according to the thickness of the electromagnetic resonance body, the incident angle of the electromagnetic wave, and the frequency value of the electromagnetic wave to be absorbed by the electromagnetic resonator.

[0011] Furthermore, when the thickness of the electromagnetic resonant body is 12-13 mm and the incident angle of the electromagnetic wave is 70°, a satisfies the following relationship: f=108+k / a, wherein k is a preset coefficient and f is the frequency value of the electromagnetic wave that the electromagnetic resonator is intended to absorb.

[0012] Furthermore, when f belongs to [108.10,111.95], k=80.

[0013] The present invention has at least the following beneficial effects:

[0014] The copper-clad resonance absorption layer, the second glass, the second PVB film and the fully covered metal shielding layer of the electromagnetic resonator of the present invention are the main structures of the electromagnetic resonator, and together constitute the electromagnetic resonance body; when the electromagnetic wave irradiates the electromagnetic resonator, the electromagnetic resonance body can generate resonance, thereby achieving the purpose of absorbing the electromagnetic wave; moreover, the dielectric substrate adopted by the present invention is ordinary glass, and the electromagnetic resonance body is encapsulated between two layers of glass by a mature lamination process to form a three-layer laminated glass structure, thereby realizing the protection of the electromagnetic resonance body, effectively withstanding the outdoor environmental conditions of wind and sun, solving the problem that conventional absorbing materials cannot be used outdoors for a long time, and can be installed on the facade of a large building as a glass curtain wall, without the need for large-scale transformation of the facade of the large building. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. 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 creative work.

[0016] Figure 1 A cross-sectional schematic diagram of an electromagnetic resonator for eliminating multipath interference of a localizer provided by an embodiment of the present invention;

[0017] Figure 2 A schematic plan view of a copper-clad resonant absorption layer of a single electromagnetic resonator for eliminating multipath interference of a heading beacon provided by an embodiment of the present invention;

[0018] Figure 3 A schematic plan view of a copper-clad resonant absorption layer of a periodically arranged electromagnetic resonator for eliminating multipath interference of a heading beacon provided in an embodiment of the present invention;

[0019] Figure 4 A schematic diagram of absorptivity curves of an electromagnetic resonator for eliminating multipath interference of a localizer corresponding to multiple incident angles provided by an embodiment of the present invention;

[0020] In the figure: 1 is the first glass, 2 is the first PVB film, 3 is the copper-clad resonance absorption layer, 4 is the second glass, 5 is the second PVB film, 6 is the metal shielding layer, 7 is the third PVB film, 8 is the third glass, 9 is the straight groove, and 10 is the square hole. DETAILED DESCRIPTION

[0021] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only 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 those skilled in the art without creative work are within the scope of protection of the present invention.

[0022] According to the present invention, an electromagnetic resonator for eliminating multipath interference of a localizer is provided, such as Figure 1 As shown, the electromagnetic resonator comprises a first glass 1, a first PVB film 2, an electromagnetic resonant body, a third PVB film 7 and a third glass 8 connected in sequence along the incident direction of the electromagnetic wave; the electromagnetic resonant body comprises a copper-clad resonant absorption layer 3, a second glass 4, a second PVB film 5 and a fully covered metal shielding layer 6 connected in sequence along the incident direction of the electromagnetic wave; the size of the copper-clad resonant absorption layer 3 is smaller than the size of the fully covered metal shielding layer 6. Wherein, PVB is polyvinyl butyral.

[0023] In this embodiment, the metal shielding layer 6 is fully covered, and the size of the copper-clad resonant absorption layer 3 is smaller than the size of the fully covered metal shielding layer 6, that is, the copper-clad resonant absorption layer 3 is not fully covered, which is beneficial to improve the absorption effect of electromagnetic waves.

[0024] In this embodiment, the electromagnetic resonator absorbs electromagnetic waves by a periodic arrangement; as a preferred specific implementation, the size of a single electromagnetic resonator is 800 mm × 800 mm, and the thickness of the electromagnetic resonance body is 12-13 mm; the thickness of the electromagnetic resonator is 25 mm (about 0.009 wavelength), wherein the thickness of the third glass 8 and the first glass 1 are both 6 mm, the thickness of the second glass is 12 mm, and the thickness of the third PVB film 7, the second PVB film 5 and the first PVB film 2 are all 0.38 mm.

[0025] In this embodiment, Figure 2 Shown and Figure 3As shown, the copper-clad resonant absorption layer 3 is provided with straight grooves of equal size at the positions corresponding to the four corners of the electromagnetic resonator, and the copper-clad resonant absorption layer 3 is provided with a square hole 10 on the line connecting the center of any straight groove 9 and the center of the copper-clad resonant absorption layer 3, which can improve the absorption effect of electromagnetic waves. The absorption frequency point can be moved by adjusting the side length of the square hole 10. As a specific implementation, the side length of any square hole 10 is a millimeters, and a is determined according to the thickness of the electromagnetic resonance body, the incident angle of the electromagnetic wave, and the frequency value of the electromagnetic wave to be absorbed by the electromagnetic resonator. When the incident angle of the electromagnetic wave is 70°, a satisfies the following relationship: f=108+k / a, where k is a preset coefficient, f is the frequency value of the electromagnetic wave to be absorbed by the electromagnetic resonator, and the unit of f is MHz; when f belongs to [108.10,111.95], k=80.

[0026] In this embodiment, the electromagnetic response of each electromagnetic resonator is similar to that of an LC oscillation circuit, which can store and convert the energy of electric and magnetic fields. When electromagnetic waves are irradiated onto the electromagnetic resonator, the electric and magnetic fields interact with these structures, and the current induced in the metal structure converts energy between the characteristics of its inductance and capacitance, similar to the energy conversion in the LC oscillation circuit. If the resonant frequency of the electromagnetic resonator is designed to be around 110 MHz, then when the frequency of the electromagnetic wave is 110 MHz, the electromagnetic resonator can produce a strong resonance, which is externally manifested as the absorption of electromagnetic waves. At the same time, since the electromagnetic resonator of this embodiment is a symmetrical structure, the absorption effect of horizontally polarized and vertically polarized electromagnetic waves is consistent.

[0027] like Figure 4 As shown, when the size of the electromagnetic resonator is 800 mm × 800 mm, the thickness of the electromagnetic resonator body is 12-13 mm, the side length of the square hole 10 is set according to f=108+80 / a and the incident angle of the electromagnetic wave is 70°, the electromagnetic resonator of this embodiment has an absorption rate of less than -10 dB for electromagnetic waves in the frequency band of [110.38, 110.87], that is, an absorption rate of more than 90% is achieved.

[0028] like Figure 4As shown, when the size of the electromagnetic resonator is 800 mm×800 mm, the thickness of the electromagnetic resonator body is 12-13 mm and the side length of the square hole is set to 10 according to f=108+80 / a, the electromagnetic resonator of this embodiment has different absorption rates for electromagnetic waves at different incident angles of the electromagnetic wave, wherein the absorption rate curves arranged in order of absorption rate from small to large correspond to the incident angles of the electromagnetic wave of 80°, 30°, 40°, 50°, 70° and 60°, respectively. It can be seen that the electromagnetic resonator of this embodiment has a certain absorption effect on electromagnetic waves with incident angles of 80°, 30°, 40°, 50°, 70° and 60°, and the electromagnetic resonator of this embodiment has a better absorption effect on electromagnetic waves with incident angles of 60°, 70°, 50° and 40°, and the absorption rate can reach below -10dB.

[0029] The copper-clad resonance absorption layer 3, the second glass 4, the second PVB film 5 and the fully covered metal shielding layer 6 of the electromagnetic resonator of this embodiment are the main structures of the electromagnetic resonator, and together constitute the electromagnetic resonance body. When electromagnetic waves irradiate the electromagnetic resonator, the electromagnetic resonance body can resonate, thereby achieving the purpose of absorbing electromagnetic waves.

[0030] The overall thickness of the electromagnetic resonator of this embodiment is only 25 mm, ie, 0.009 wavelength, and has the advantage of a low profile.

[0031] The structure of the electromagnetic resonator of this embodiment does not need to use lumped electronic components to improve the wave absorption performance, and the printing of the absorption layer can be completed by screen printing copper paste.

[0032] Moreover, the dielectric substrate used in this embodiment is ordinary glass, and the electromagnetic resonance body is encapsulated between two layers of glass using a mature lamination process to form a three-layer laminated glass structure, thereby protecting the electromagnetic resonance body and effectively withstanding outdoor wind and sun conditions. This solves the problem that conventional absorbing materials cannot be used outdoors for a long time, and can be installed as a glass curtain wall on the facade of a large building without the need for large-scale renovation of the facade of the large building.

[0033] Although some specific embodiments of the present invention have been described in detail by way of example, it will be appreciated by those skilled in the art that the above examples are for illustration only and are not intended to limit the scope of the present invention. It will also be appreciated by those skilled in the art that various modifications may be made to the embodiments without departing from the scope and spirit of the present invention. The scope of the present invention is defined by the appended claims.

Claims

1. An electromagnetic resonator for eliminating multipath interference of a localizer, characterized in that: The electromagnetic resonator comprises a first glass (1), a first PVB film (2), an electromagnetic resonant body, a third PVB film (7) and a third glass (8) which are connected in sequence along the direction of electromagnetic wave incidence; the electromagnetic resonant body comprises a copper-clad resonant absorption layer (3), a second glass (4), a second PVB film (5) and a fully covered metal shielding layer (6) which are connected in sequence along the direction of electromagnetic wave incidence; the size of the copper-clad resonant absorption layer (3) is smaller than the size of the fully covered metal shielding layer (6), and the PVB is polyvinyl butyral; the copper-clad resonant absorption layer (3) is provided with straight grooves of equal size at positions corresponding to the four corners of the electromagnetic resonator, and the copper-clad resonant absorption layer (3) is provided with a square hole (10) on a line connecting the center of any straight groove (9) and the center of the copper-clad resonant absorption layer (3).

2. The electromagnetic resonator for eliminating multipath interference of a localizer according to claim 1, characterized in that: The electromagnetic resonator is a symmetrical structure, the size of the electromagnetic resonator is 800 mm×800 mm, and the thickness of the electromagnetic resonance body is 12-13 mm.

3. The electromagnetic resonator for eliminating multipath interference of a heading beacon according to claim 2, characterized in that: The thickness of the third glass (8) and the first glass (1) is 6 mm, the thickness of the second glass is 12 mm, and the thickness of the third PVB film (7), the second PVB film (5) and the first PVB film (2) is 0.38 mm.

4. The electromagnetic resonator for eliminating multipath interference of a localizer according to claim 1, characterized in that: The side length of any square hole (10) is a millimeters, where a is determined according to the thickness of the electromagnetic resonance body, the incident angle of the electromagnetic wave, and the frequency value of the electromagnetic wave to be absorbed by the electromagnetic resonator.

5. The electromagnetic resonator for eliminating multipath interference of a localizer according to claim 4, characterized in that: When the thickness of the electromagnetic resonant body is 12-13 mm and the incident angle of the electromagnetic wave is 70°, a satisfies the following relationship: f=108+k / a, wherein k is a preset coefficient and f is the frequency value of the electromagnetic wave that the electromagnetic resonator is intended to absorb.

6. The electromagnetic resonator for eliminating multipath interference of a localizer according to claim 5, characterized in that: When f belongs to [108.10,111.95], k=80.

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