A choke structure and a choke antenna

Abstract

The application provides a choke structure and a choke antenna. The choke structure comprises a top plate and a first cylinder arranged below the top plate, and the parts are coaxially arranged. The upper surface edge of the top plate is provided with a side plate to form a reflection cavity on the top plate for mounting an antenna unit. The top edge of the side plate is provided with a wave structure to reduce the generation of circumferential circulating current, reduce backward radiation and improve the front-to-back ratio of the antenna. The top plate is further provided with a first branch and a second branch arranged alternately upwards and downwards to respectively inhibit the propagation and scattering of low-frequency surface waves and high-frequency surface waves, and the surface wave inhibition effect is further improved through the differential coupling of the two branches. The choke structure provided by the application can effectively inhibit the propagation and scattering of high-frequency surface waves and low-frequency surface waves, reduce the need for setting other multipath inhibition structures in the vertical direction, reduce the height of the choke structure and facilitate the miniaturization design of the choke antenna.

Description

Technical Field

[0001] The present invention relates to the technical field of antennas, and in particular to a choke coil structure and a choke coil antenna. Background Art

[0002] In satellite communications, multipath refers to the reflections or scattered signals generated by satellite signals as they encounter obstacles such as buildings and trees during propagation. These signals mix with the direct signal and are received by the receiver antenna. Compared to the direct signal, multipath signals have a longer path, resulting in phase lag and amplitude attenuation or enhancement, thereby reducing the receiver's ranging accuracy. While improvements in satellite navigation systems and antennas have improved the accuracy of satellite positioning antennas, multipath interference remains a significant factor affecting antenna positioning accuracy.

[0003] In the existing technology, choke technology is often used to suppress the multipath effect of the antenna. The traditional choke structure usually consists of a base structure composed of multiple concentric circular grooves as the antenna ground plate. The number of these grooves is usually between three and five, and the groove depth is about one-quarter of the wavelength. This design ensures the axial ratio of the antenna. At the same time, the surface of the choke exhibits high impedance characteristics, which effectively prevents the propagation of reflected signals on its surface.

[0004] Although the existing choke structure has excellent performance, for general 2D or 3D chokes, in order to enhance the propagation suppression effect of surface reflection signals and ensure the multipath effect suppression effect, it is necessary to set up multiple concentric metal slots, which makes the diameter of the choke antenna used for satellite communication generally exceed 300 mm. The overall structure is large in size and high in cost, which is not conducive to installation, transportation and production. Summary of the Invention

[0005] Based on this, the purpose of the present invention is to provide a choke coil structure and a choke coil antenna to solve the problems in the prior art that the choke coil antenna is large in size, high in cost, and difficult to install, transport and produce.

[0006] In one aspect, the present invention provides a choke structure, which is made of a conductive material and includes a top plate and a first cylinder disposed below the top plate, wherein:

[0007] The top plate is circular and is coaxially arranged with the first cylinder. A side plate is further provided on the upper surface of the top plate. The side plate is arranged around the edge of the top plate to form a reflection cavity on the top plate for mounting the antenna unit. The top edge of the side plate has a sinusoidal wave structure.

[0008] The lower surface of the top plate is further provided with a first branch node, the first branch node being a square vertical plate structure, the outer side of the first branch node being coplanar with the inner side surface of the side plate, the inner side edge being spaced apart from the outer side surface of the first cylinder, and a plurality of the first branch nodes being evenly spaced apart along the circumference of the top plate;

[0009] A second branch node is also provided on the outer surface of the first cylinder. The second branch node is a square vertical plate structure, and multiple second branches are evenly spaced along the circumference of the first cylinder. The bottom edge of the second branch node is coplanar with the bottom edge of the first cylinder, and the outer edge of the second branch node is coplanar with the inner surface of the side plate. The circumferential positions of the first branch node and the second branch node are staggered.

[0010] Optionally, the reference depth of the wave structure is one-eighth of a wavelength, the reference height of the first cylinder is three-eighths of a wavelength, the reference heights of the first branch node and the second branch node are both one-eighth of a wavelength, and the total reference height of the choke structure is one-half wavelength.

[0011] Optionally, a second cylinder is further provided on the upper surface of the top plate, and the first branch is further extended and arranged on the upper surface of the top plate, wherein:

[0012] The top edge height of the first branch node is smaller than the valley height of the wave structure, the second cylinder is coaxially arranged with the top plate, the radius of the second cylinder is larger than the radius of the first cylinder, the height of the second cylinder is smaller than the height of the side plate and larger than the valley height of the wave structure, and the outer side surface of the second cylinder is also spaced apart from the inner side edge of the first branch node.

[0013] Optionally, the number of the first branches is greater than the number of the second branches.

[0014] Optionally, the number of the first branches is 20, the number of the second branches is 16, and the number of waves in the wave structure is 10.

[0015] Optionally, the reference height of the first cylinder is less than a quarter wavelength, the reference height of the side panel is a quarter wavelength, the reference depth of the wave structure is one eighth wavelength, and the reference heights of the first branch node and the second branch node are both one eighth wavelength.

[0016] Optionally, edges of various parts of the choke structure are chamfered structures.

[0017] The present invention also provides a choke coil antenna, which includes the above-mentioned choke coil structure and an antenna unit fixed on the top plate through a support column, and the bottom edge of the antenna unit is arranged flush with the top point of the side plate.

[0018] Optionally, the antenna unit includes a main dielectric board and a patch radiation array arranged on the main dielectric board.

[0019] Optionally, the antenna unit further includes a second dielectric plate, which is stacked on the main dielectric plate and the patch radiation array.

[0020] The choke coil structure provided by the present invention is composed of a conductive material, including a top plate and a first cylinder arranged below the top plate, wherein the top plate is circular and coaxially arranged with the first cylinder, and a side plate is further provided on the upper surface of the top plate, and the side plate is arranged around the edge of the top plate to form a reflection cavity for installing the antenna unit on the top plate, and the top edge of the side plate is a sinusoidal wave structure, which can reduce the generation of circumferential circulating current, reduce backward radiation, and improve the front-to-back ratio of the antenna; a first branch and a second branch arranged up and down are also provided under the top plate, and the size of the first branch is smaller than that of the second branch, which can respectively suppress the propagation and scattering of low-frequency surface waves and high-frequency surface waves, and the first branch and the second branch are vertical plate structures, and the circumferential arrangement positions are staggered from each other, and the propagation and scattering of high-frequency surface waves and low-frequency surface waves can be further suppressed through asymmetric coupling therebetween. The choke structure provided by the present invention is a vertical structure, which can effectively reduce its diameter and suppress high-frequency surface waves and low-frequency surface waves through the first branch and the second branch. The first branch and the second branch are vertical plate structures and are staggered in the circumferential direction, which can reduce the coupling effect between the first branch and the second branch, further suppress the propagation and scattering of high-frequency surface waves and low-frequency surface waves, thereby reducing the need to set other multipath suppression structures in the vertical direction, reducing the height of the choke structure, and facilitating the miniaturization design of the choke antenna.

[0021] The choke ring antenna provided by the present invention includes the above-mentioned choke ring structure, which can effectively reduce the height of the choke ring antenna and realize the miniaturized design of the choke ring antenna. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 Schematic diagram of the structure of the choke ring antenna in the first embodiment of the present invention;

[0023] Figure 2 is the passive radiation pattern of the choke ring antenna in the first embodiment of the present invention at the first frequency;

[0024] Figure 3 is the passive radiation pattern of the choke ring antenna in the first embodiment of the present invention at the second frequency;

[0025] Figure 4 2 is a schematic structural diagram of a choke ring antenna in a second embodiment of the present invention;

[0026] Figure 5is the passive radiation pattern of the choke ring antenna in the second embodiment of the present invention at the first frequency;

[0027] Figure 6 1 is the passive radiation pattern of the choke ring antenna in the second embodiment of the present invention at the second frequency.

[0028] The following specific embodiments will further illustrate the present invention in conjunction with the above-mentioned drawings. DETAILED DESCRIPTION

[0029] To facilitate understanding of the present invention, the present invention will be described more fully below with reference to the accompanying drawings. The drawings illustrate several embodiments of the present invention. However, the present invention may be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a more thorough and comprehensive understanding of the present invention.

[0030] It should be noted that when an element is referred to as being "fixed to" another element, it may be directly on the other element or there may be an intermediate element. When an element is referred to as being "connected to" another element, it may be directly connected to the other element or there may be an intermediate element. The terms "vertical," "horizontal," "left," "right," and similar expressions used herein are for illustrative purposes only.

[0031] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one skilled in the art to which this invention pertains. The terms used in this specification of the present invention are for the purpose of describing specific embodiments only and are not intended to limit the present invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0032] In order to solve the problems of the existing choke coil antenna being large in size, high in cost, and inconvenient for installation, transportation and production, the present invention provides a choke coil structure, which is made of conductive material and includes a top plate and a first cylinder arranged below the top plate, wherein the top plate is circular and coaxially arranged with the first cylinder, and a side plate is further provided on the upper surface of the top plate, and the side plate is arranged around the edge of the top plate to form a reflection cavity on the top plate for installing the antenna unit, and the top edge of the side plate is a sinusoidal wave structure, which can reduce the generation of circumferential circulating current, reduce backward radiation, and improve the front-to-back ratio of the antenna; below the top plate, a choke coil structure is further provided. There are first branches and second branches arranged up and down, and multiple first branches and second branches are arranged evenly spaced along the circumference of the top plate. The size of the first branch is smaller than that of the second branch, which can respectively suppress the propagation and scattering of low-frequency surface waves and high-frequency surface waves. The first branch and the second branch are vertical plate structures, and their circumferential arrangement positions are staggered with each other. The propagation and scattering of high-frequency surface waves and low-frequency surface waves can be further suppressed through the asymmetric coupling therebetween, thereby reducing the need to set other multipath suppression structures in the vertical direction, reducing the height of the choke structure, and providing convenience for the miniaturization design of the choke antenna.

[0033] First embodiment

[0034] like Figure 1 As shown, it is a schematic diagram of the structure of the choke antenna in the first embodiment of the present invention. The space above the top plate 10 is mainly used for the installation of the antenna unit 01, and the space below is arranged with the first cylinder 20, the first branch 31 and the second branch 32, which are used to suppress the propagation of low-frequency surface waves and high-frequency surface waves. The top plate 10 is circular and coaxially matched with each part.

[0035] A circle of side panels 11 is provided on the edge of the upper surface of the top plate 10 to form a reflection cavity on the top plate 10 for installing the antenna unit 01. The side panels 11 are provided with slots extending downward from the top edge, so that the top edge of the side panels 11 is a wave structure, and the wave structure is a sinusoidal wave. The top plate 10 is circular, and the antenna unit 01 is circular and is fixed to the top plate 10 by a support column 011. An opening is provided in the middle of the top plate 10 for arranging the feeding cable of the antenna unit 01.

[0036] The wavy structure of the side plate 11 can cut off the circumferential circulating current, increase the electromagnetic impedance of the surface, inhibit the electromagnetic wave from propagating downward, and thus improve the front-to-back ratio of radiation. In an optional embodiment, the wavy structure of the side plate 11 can also be a triangular wave or other waveform.

[0037] The first cylinder 20 can further improve the circular polarization performance of the antenna through its reflection and diffraction effects, and is also used for the arrangement of the second branch 32 .

[0038] Both the first branch 31 and the second branch 32 are square vertical plate structures that suppress the propagation of transverse electromagnetic waves. The first branch 31 is smaller than the second branch 32, and is used to suppress the propagation and scattering of low-frequency and high-frequency surface waves, respectively. The first branch 31 is located close to the antenna unit 01. For low-frequency electromagnetic waves that easily pass through the reflector cavity, the first branch 31 can promptly suppress the propagation of low-frequency electromagnetic waves. For high-frequency electromagnetic waves, the second branch 32 effectively increases the surface electromagnetic impedance of the choke structure, making the propagation path of high-frequency surface waves more tortuous, thereby reducing the propagation and scattering of high-frequency surface waves.

[0039] Specifically, the first branch node 31 is fixed on the lower surface of the top plate 10, with its inner edge spaced apart from the first cylinder 20 and its outer edge coplanar with the inner surface of the side plate 11; the second branch node 32 is fixed on the outer surface of the first cylinder 20, and the bottom edge of the second branch node 32 is flush with the bottom surface of the first cylinder 20, which can increase the bottom surface size of the choke structure and improve the stability of the overall placement.

[0040] There are multiple first branches 31 and second branches 32 evenly spaced along the circumference of the top plate 10 and the first cylinder 20, and the number of first branches 31 is greater than the number of second branches 32. At the same time, the first branches 31 and the second branches 32 are staggered in the circumferential direction to improve the asymmetric coupling effect of the first branches 31 and the second branches 32, increase the tortuosity of the surface wave propagation path, and improve the suppression effect on the propagation and scattering of high-frequency surface waves and low-frequency surface waves.

[0041] The dimensions of each part are determined according to the wavelength of the center frequency. In this first embodiment, the reference depth of the wave structure is one-eighth of a wavelength, and the height of the side panel 11 is slightly greater than the reference depth of the wave structure, so that the valley bottom of the wave structure is slightly higher than the top surface of the top panel 10; the reference height of the first cylinder 20 is three-eighths of a wavelength, and the reference heights of the first branch 31 and the second branch 32 are both one-eighth of a wavelength, and the actual height of the first branch 31 is slightly less than one-eighth of a wavelength; on the whole, the total reference height of the choke structure is one-half wavelength, and there will be certain differences depending on the actual processing tolerance. Compared with the height of more than three-quarters of a wavelength in the prior art, the overall height of the choke antenna can be effectively reduced.

[0042] In a specific example, the number of first branches 21 is 20, the number of second branches 32 is 16, the number of waves in the wave structure is 10, and the arrangement position of the first branches 31 corresponds to the zero point position of the sinusoidal waveform of the wave structure, that is, each first branch 31 is located in the middle position of adjacent peaks and valleys of the wave structure.

[0043] like Figure 2 and Figure 3As shown, the passive radiation pattern of the choke antenna of the first embodiment at the first frequency and the second frequency, wherein the first frequency is 1.227 GHz and the second frequency is 1.575 GHz, which are the center frequencies of the two frequency bands of satellite communication respectively. The design wavelength is 200 mm, the top plate diameter is 135 mm, the first branch length is 15 mm and the thickness is 3 mm, the second branch length is 37.5 mm and the thickness is 4 mm, and the diameter of the first cylinder is 60 mm. The sidelobe suppression at the frequency of 1.227 GHz reaches -35 dB, and the sidelobe suppression at the frequency of 1.575 GHz reaches -30 dB. The overall sidelobe suppression effect is significant, and the front-to-back ratio is considerable.

[0044] Second embodiment

[0045] like Figure 4 FIG. 1 is a schematic diagram of the structure of the choke antenna in the second embodiment of the present invention. Part of the structure thereof is the same as that of the first embodiment, and the same parts will not be described again.

[0046] In the second embodiment, a second cylinder 40 is further provided on the upper surface of the top plate 10, and the first branch 31 is also extended and arranged on the upper surface of the top plate 10, and the height of the portion of the first branch 31 located above the top plate 10 is greater than the height of the portion located below the top plate 10, which can enhance the effect of suppressing surface waves in the reflection cavity, thereby preferentially suppressing the propagation of surface waves upstream of their propagation, enhancing the effect of suppressing multipath effects, and improving the front-to-back ratio in the low-frequency band.

[0047] Among them, the top edge height of the first branch node 31 is less than the valley height of the wave structure, the second cylinder 40 is coaxially arranged with the top plate 10, the radius of the second cylinder 40 is greater than the radius of the first cylinder 20, the height of the second cylinder 40 is less than the height of the side plate 11 and greater than the valley height of the wave structure, and the outer side surface of the second cylinder 40 is also spaced apart from the inner side edge of the first branch node 31.

[0048] In this embodiment, the first cylinder 20 is a hollow cylinder, which mainly uses its surface characteristics to suppress surface waves. The hollow structure can reduce the overall weight while ensuring its performance requirements. The second cylinder 40 is a solid cylinder, which can enhance the concentration effect of electromagnetic energy, provide a stronger electric field, improve the reflection effect, effectively enhance low-frequency radiation, and improve the low-frequency gain of the antenna.

[0049] Corresponding to the design of the space above the top plate 10, in this embodiment, the reference height of the first cylinder 20 is one-quarter wavelength, and the actual height is slightly less than one-quarter wavelength. The reference height of the side plate 11 is one-quarter wavelength, and the actual height is slightly greater than one-quarter wavelength. The total reference height is one-half wavelength, and the reference depth of the wave structure is one-eighth wavelength. The sum of the reference heights of the first branch 31 located at the upper and lower portions of the top plate 10, as well as the reference height of the second branch 32, are both one-eighth wavelength. The actual dimensions of each component may vary depending on specific processing tolerances, and depending on specific requirements, the difference from the reference dimensions is generally less than 3 mm. This application does not impose any other specific restrictions on the actual dimensions.

[0050] In order to avoid tip discharge, in the present application, the edges of each part of the choke coil structure are chamfered structures.

[0051] The present invention also provides a choke antenna, which includes the above-mentioned choke structure and an antenna unit 01 fixed on the top plate by a support column. The bottom edge of the antenna unit 01 is set flush with the top of the side plate 11 to avoid plane reflection oscillation.

[0052] To achieve miniaturization requirements, the antenna unit 01 includes a main dielectric plate and a patch radiation array arranged on the main dielectric plate. The overall structure is a flat plate and occupies little space in the height direction.

[0053] To further improve antenna gain, in the first embodiment, antenna unit 01 also includes a second dielectric plate, which is stacked above the main dielectric plate and the patch radiator array. Adding this second dielectric plate above the antenna unit modulates the antenna's electromagnetic field distribution, increasing its effective radiation area. The interaction between the reflection effect of the reflective cavity and the electromagnetic field modulation of the second dielectric plate above significantly improves antenna gain.

[0054] The support columns and dielectric plates can be made of insulating plastic, which has no special interference with electromagnetic waves. The shape design and arrangement quantity are more flexible, which can reduce the design difficulty; the other parts are all made of conductive materials, which can be selected from copper or aluminum and other conductive materials with good conductivity and structural strength.

[0055] like Figure 5 and Figure 6 As shown, the passive radiation pattern of the choke ring antenna of the second embodiment at the first frequency and the second frequency is shown, wherein the first frequency is 1.227 GHz and the second frequency is 1.575 GHz, which are the center frequencies of the two frequency bands of satellite communication respectively. The design wavelength is 200 mm. The upper part of the first branch has a height of 18 mm and the lower part has a height of 8 mm. The diameter of the second cylinder is 80 mm and the height is 35 mm. The parameters of other parts that are the same as those of the first embodiment are also the same, such as Figure 5 and Figure 6As shown, the sidelobe suppression at a frequency of 1.227 GHz reaches -30 dB, and the sidelobe suppression at a frequency of 1.575 GHz reaches -30 dB. The overall sidelobe suppression effect is significant, and the first branch is extended to the upper surface of the top plate. A solid cylinder is also provided on the top plate, which can effectively improve the low-frequency gain. Although the overall front-to-back ratio is worse than that of the first embodiment, the gain consistency of the high-frequency band and the low-frequency band on the main lobe is better.

[0056] In satellite communications, the diameter of the top plate 10 of the above embodiment can be reduced to 135 mm, which can reduce the size in the horizontal direction and achieve an overall miniaturized design.

[0057] The choke structure and choke antenna provided by the present invention are provided with a top plate and a first cylinder located below the top plate, wherein the top plate is circular and coaxially arranged with the first cylinder, and the upper surface of the top plate is also provided with a side plate, which is arranged around the edge of the top plate to form a reflection cavity for installing the antenna unit on the top plate, and the top edge of the side plate is a sinusoidal wave structure, which can reduce the generation of circumferential circulating current, reduce backward radiation, and improve the front-to-back ratio of the antenna; a first branch and a second branch arranged up and down are also provided under the top plate, the size of the first branch is smaller than the size of the second branch, which can respectively suppress the propagation and scattering of low-frequency surface waves and high-frequency surface waves, and the first branch and the second branch are vertical plate structures, and the circumferential arrangement positions are staggered with each other, and the propagation and scattering of high-frequency surface waves and low-frequency surface waves can be further suppressed through the asymmetric coupling therebetween, thereby reducing the need to set other multipath suppression structures in the vertical direction, reducing the height of the choke structure, and facilitating the miniaturization design of the choke antenna.

[0058] Throughout this specification, reference to terms such as "one embodiment," "some embodiments," "examples," "specific examples," or "some examples" means that a specific feature, structure, material, or characteristic described in conjunction with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, schematic representations of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

[0059] The above-described embodiments merely represent several specific implementations of the present invention. While the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that a person skilled in the art would be able to make various modifications and improvements without departing from the spirit of the present invention, all of which fall within the scope of protection of the present invention. Therefore, the scope of protection of the present invention shall be determined by the appended claims.

Claims

1. A choke coil structure, characterized in that: The choke coil structure is made of conductive material and includes a top plate and a first cylinder disposed below the top plate, wherein: The top plate is circular and is coaxially arranged with the first cylinder. A side plate is further provided on the upper surface of the top plate. The side plate is arranged around the edge of the top plate to form a reflection cavity on the top plate for mounting the antenna unit. The top edge of the side plate has a sinusoidal wave structure. The lower surface of the top plate is further provided with a first branch node, the first branch node being a square vertical plate structure, the outer side of the first branch node being coplanar with the inner side surface of the side plate, the inner side edge being spaced apart from the outer side surface of the first cylinder, and a plurality of the first branch nodes being evenly spaced apart along the circumference of the top plate; A second branch node is also provided on the outer surface of the first cylinder. The second branch node is a square vertical plate structure, and multiple second branches are evenly spaced along the circumference of the first cylinder. The bottom edge of the second branch node is coplanar with the bottom edge of the first cylinder, and the outer edge of the second branch node is coplanar with the inner surface of the side plate. The circumferential positions of the first branch node and the second branch node are staggered.

2. The choke coil structure according to claim 1, characterized in that The reference depth of the wave structure is one-eighth of a wavelength, the reference height of the first cylinder is three-eighths of a wavelength, the reference heights of the first branch node and the second branch node are both one-eighth of a wavelength, and the total reference height of the choke structure is one-half of a wavelength.

3. The choke coil structure according to claim 1, characterized in that The upper surface of the top plate is further provided with a second cylinder, and the first branch is further extended and arranged on the upper surface of the top plate, wherein, The top edge height of the first branch node is smaller than the valley height of the wave structure, the second cylinder is coaxially arranged with the top plate, the radius of the second cylinder is larger than the radius of the first cylinder, the height of the second cylinder is smaller than the height of the side plate and larger than the valley height of the wave structure, and the outer side surface of the second cylinder is also spaced apart from the inner side edge of the first branch node.

4. The choke coil structure according to claim 1 or 3, characterized in that: The number of the first branches is greater than the number of the second branches.

5. The choke coil structure according to claim 4, characterized in that: The number of the first branches is 20, the number of the second branches is 16, and the number of waves in the wave structure is 10.

6. The choke coil structure according to claim 3, characterized in that The reference height of the first cylinder is less than a quarter wavelength, the reference height of the side plate is a quarter wavelength, the reference depth of the wave structure is one eighth wavelength, and the reference heights of the first branch node and the second branch node are both one eighth wavelength.

7. The choke coil structure according to claim 1, characterized in that The edges of each part of the choke coil structure are chamfered structures.

8. A choke ring antenna, characterized in that: It comprises the choke coil structure according to any one of claims 1 to 7, and an antenna unit fixed on the top plate by a support column, wherein the bottom edge of the antenna unit is flush with the top point of the side plate.

9. The choke ring antenna according to claim 8, wherein The antenna unit includes a main dielectric plate and a patch radiation array arranged on the main dielectric plate.

10. The choke ring antenna according to claim 9, wherein The antenna unit further includes a second dielectric plate, which is stacked on the main dielectric plate and the patch radiation array.

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