A multi-directional radiation leak coaxial cable

Abstract

The application provides a multi-directional radiation leakage coaxial cable, which comprises an inner conductor, an insulating layer, an outer conductor and a sheath which are coaxially nested in sequence from inside to outside, and at least two rows of slot groups are arranged on the outer conductor, the at least two rows of slot groups are distributed at different angles in the circumferential direction of the outer conductor, each row of slot groups comprises a plurality of slot arrays arranged periodically along the axial direction of the outer conductor, each slot array comprises a plurality of slots, the pitches of the slot groups are the same, the periodic arrangement of the two adjacent slot groups in the circumferential direction is different by half a pitch, and the phases of the respective excited electric fields are different by 180 degrees. The application can realize source separation in space by arranging the plurality of slot groups and making the two adjacent slot groups in the circumferential direction different by half a pitch and the phases of the excited electric fields different by 180 degrees, so that the sources are independent and do not interfere with each other, thereby increasing the number of radiation directions of all frequency points in the working frequency band of the leakage cable and making the leakage cable have stronger application scene applicability.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of leaky coaxial cable design, in particular to a multi-directional radiation leaky coaxial cable. BACKGROUND

[0002] The radiation of the radiation type leaky cable has directionality, and the strongest signal can be received at a position directly opposite the slot hole of the leaky cable. As the included angle with the slot hole increases, the received signal strength gradually decreases. The radiation lobe width can also be used to measure this characteristic. Generally, for a frequency band higher than 2000MHz, the 3dB lobe width is ±45° (i.e. 90°), and the 5dB lobe width is ±60° (i.e. 120°). (Note: Here, the lobe width is considered from the application perspective, and is based on the 95% coupling loss at the 2m circumference of the leaky cable. From the far field pattern of the leaky cable, the 3dB lobe width is about 120°).

[0003] This characteristic of the leaky cable is not a problem for traditional tunnel applications, because the tunnel scene is distributed in a strip shape, and the receiving end is fixed, so the conventional leaky cable can meet the requirements of the lateral radiation lobe of the leaky cable. However, with the development of leaky cable technology, leaky cables are becoming more and more diversified like antennas, and the application field of leaky cables is expanding. In the fields of 5G indoor coverage and industrial Internet of Things, wireless coverage leaky cable solutions are increasingly favored by people because of their support for wide frequency bands, uniform radiation, high stability and reliability. However, due to different requirements for the radiation lobe width of the leaky cable in different scenarios, for example, industrial applications may require the leaky cable to have multiple optimal radiation directions that do not interfere with each other or require the leaky cable to have omnidirectional radiation characteristics. These special requirements cannot be met by conventional leaky cables. SUMMARY

[0004] The present application relates to the technical field of leaky coaxial cable design, in particular to a multi-directional radiation leaky coaxial cable.

[0005] The following presents a simplified summary of one or more aspects in order to provide a basic understanding of such aspects. This summary is not an extensive overview of all contemplated aspects, and is intended to neither identify key or critical elements of all aspects nor delineate the scope of any or all aspects. Its sole purpose is to present some concepts of one or more aspects in a simplified form as a prelude to the more detailed description that is presented later.

[0006] According to an aspect of the present application, a multi-directional radiation leak coaxial cable is provided, comprising an inner conductor, an insulating layer, an outer conductor and a sheath coaxially nested in sequence from inside to outside, at least two groups of slot holes are formed on the outer conductor, the at least two groups of slot holes are distributed at different angles in the circumferential direction of the outer conductor, each group of slot holes comprises a plurality of slot hole arrays arranged periodically in the axial direction of the outer conductor, each slot hole array comprises a plurality of slot holes, the pitches of each group of slot holes are the same, and the periodic arrangement of two adjacent groups of slot holes in the circumferential direction is different by half a pitch, so that the phases of the respective excited electric fields are different by 180°.

[0007] In an embodiment, the slot holes of the multi-directional radiation leak coaxial cable are non-centrally symmetric patterns or centrally symmetric patterns inclined to the axial direction, and two adjacent slot holes in the circumferential direction are arranged axially symmetrically.

[0008] In an embodiment, the slot holes of the multi-directional radiation leak coaxial cable are L-shaped slots, U-shaped slots, T-shaped slots, E-shaped slots or triangular slots, and two adjacent slot holes in the circumferential direction are oppositely directed.

[0009] In an embodiment, the slot holes of the multi-directional radiation leak coaxial cable are rectangular slots, rhombic slots or elliptical slots inclined to the axial direction, and the inclination angles of two adjacent slot holes in the circumferential direction are opposite.

[0010] In an embodiment, the slot holes of the multi-directional radiation leak coaxial cable are linear slots, and two adjacent groups of slot holes in the circumferential direction are arranged in a staggered manner and differ by half a pitch.

[0011] In an embodiment, the included angle α between two adjacent groups of slot holes of the multi-directional radiation leak coaxial cable is δ, where δ is the required added radiation direction included angle.

[0012] In an embodiment, the number of groups of slot holes n of the multi-directional radiation leak coaxial cable is m, where m is the required number of radiation lobes.

[0013] In an embodiment, when n=3 or 5, the slot hole group located in the middle position coincides with the midline of the narrow side of the outer conductor of the multi-directional radiation leak coaxial cable.

[0014] In an embodiment, the pitch D of the slot hole groups on the expanded outer conductor of the multi-directional radiation leak coaxial cable is D 绝缘 / 360°, where D 绝缘 is the outer diameter of the insulating layer.

[0015] The beneficial effects of the embodiment of the present application are: by setting multiple groove hole groups, and making the adjacent two groove hole groups in the circumferential direction differ by half a pitch, the phase of the excitation electric field differs by 180 degrees, source separation can be achieved in space, so that the excitation sources are independent of each other and do not interfere with each other, thereby increasing the number of radiation directions of all frequency points in the leakage cable working frequency band, and making the leakage cable have stronger application scene applicability. BRIEF DESCRIPTION OF DRAWINGS

[0016] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following will briefly introduce the drawings needed to be used in the embodiments. It should be understood that the following drawings only show some embodiments of the present application, and should not be regarded as limiting the scope. For those skilled in the art, other related drawings can also be obtained without creative labor.

[0017] The above features and advantages of the present application can be better understood after reading the detailed description of the embodiments of the present application in conjunction with the following drawings. In the drawings, the components are not necessarily drawn to scale, and the components having similar related properties or features can have the same or similar reference numerals.

[0018] Figure 1 is a perspective structural schematic diagram of the embodiment of the present application;

[0019] Figure 2 is an external conductor development schematic diagram of the embodiment of the present application (the groove hole is a U-shaped groove);

[0020] Figure 3 is an external conductor development schematic diagram of the embodiment of the present application (the groove hole is a U-shaped groove);

[0021] Figure 4 is an external conductor development schematic diagram of the embodiment of the present application (the groove hole is a U-shaped groove);

[0022] Figure 5 is a cross-sectional schematic diagram of the embodiment of the present application;

[0023] Wherein: Wherein: 1-internal conductor; 2-insulation layer; 3-external conductor; 4-sheath; 31-groove hole group; 311-first groove hole group; 312-second groove hole group; 313-third groove hole group; 32-groove hole array; 33-groove hole; 34-center line; 35-lap edge. DETAILED DESCRIPTION

[0024] The present application will be described in detail below in conjunction with the drawings and specific embodiments. It should be noted that the aspects described below in conjunction with the drawings and specific embodiments are only exemplary and should not be understood as limiting the scope of the present application.

[0025] As Figure 1 and asFigure 2 As shown in the drawings, the present application provides a multi-directional radiation leakage coaxial cable, which comprises an inner conductor 1, an insulating layer 2, an outer conductor 3 and a sheath 4 coaxially nested in sequence from inside to outside. The outer conductor 3 is provided with at least two rows of slot groups 31, which are distributed at different angles in the circumferential direction of the outer conductor 3. Each row of slot groups 31 comprises a plurality of slot arrays 32 arranged periodically in the axial direction of the outer conductor 3, and each slot array 32 comprises a plurality of slots 33. The pitches P of the slot groups 31 are the same, and the direction of the slots 33 changes every half pitch P. The periodic arrangement of the two adjacent slot groups 31 in the circumferential direction is different by half a pitch, so that the phases of the respective excitation electric fields are different by 180°.

[0026] The radiation excitation of the leakage cable is derived from the change in the current distribution of the outer conductor caused by the slotting of the outer conductor. Taking the V-shaped slot and the U-shaped slot as examples, usually, the “ / ” and “\”, the positive U and the inverted U each occupy half a pitch P, and the excitation electric field generated by the cutting current has two directions with a phase difference of 180°. By making the phase difference of the excitation electric field between the two adjacent slot groups 31 be 180°, the source separation can be achieved in space, so that the two excitation sources are independent of each other and do not interfere with each other (relatively), achieving the purpose of increasing the number of radiation directions.

[0027] The slots 33 can be non-centrally symmetric patterns or centrally symmetric patterns inclined to the axial direction. Common non-centrally symmetric pattern slots include L-shaped slots, U-shaped slots, T-shaped slots, E-shaped slots, triangular slots, etc. When the slots are in these shapes, the circumferential directions of the two adjacent slots 33 are opposite. Taking the U-shaped slot as an example, as shown in Figure 3 each row of slot groups 31 is periodically arranged in the axial direction with a fixed pitch P, and the positive U-shaped slot and the inverted U-shaped slot in one slot array 32 are arranged according to half a pitch. Therefore, the two adjacent slot groups 31 only need to be staggered by P / 2 to achieve a phase difference of 180° between the excitation electric fields of the two adjacent slot groups 31 in the circumferential direction.

[0028] The centrally symmetric pattern inclined to the axial direction can be a rectangular slot (i.e. a V-shaped slot), a rhombic slot or an elliptical slot. As shown in Figure 2 the front half pitch and the rear half pitch of the V-shaped slot are arranged axially symmetrically, and when they are staggered by P / 2, the inclination angles of the two adjacent slots 33 in the circumferential direction are just opposite. At this time, the phases of the excitation electric fields of the two adjacent slot groups 31 in the circumferential direction are different by 180°.

[0029] In addition, the slots 33 can also be vertical one-slot slots, as shown in Figure 4 When the pitches of the two adjacent slot groups 31 are staggered by P / 2, the phases of the excitation electric fields of the two adjacent slot groups 31 in the circumferential direction are different by 180°.

[0030] The radiation direction and quantity can be controlled by setting the included angle between slot groups 31 and the number of columns of slot groups 31. The included angle α = δ between two adjacent columns of slot groups 31 can be set, where δ is the required angle for the new radiation direction. The number of columns of slot groups can be set, n = m, where m is the required number of radiation lobes.

[0031] For example: A 13 / 8-inch leaky cable with an insulation outer diameter of 42.0mm needs to have two additional radial directions added. The angle between the added radial directions and the original directions must be 90°. Therefore, n = m = 2 + 1 = 3, meaning a total of 3 rows of slot groups (31) are required; α = δ = 90°. Figure 5 As shown, the newly added first slot group 311 and third slot group 313 form an angle of ±90° (minimum angle) with the original second slot group 312 on the cross-section of the leaky cable; D = απD insulation / 360° = 32.97mm, and the spacing between each row of slot groups 31 on the outer conductor surface is 32.97mm; therefore, two rows of slot groups, differing from the original slot sequence by half a pitch P, need to be added on the basis of the original slotting, arranged at ±90° with the original slot rows, and set on the outer conductor before longitudinal wrapping, with a designed spacing of 32.97mm. It should be noted that the spacing D and the included angle α in this application are calculated with respect to the geometric center of slot 33.

[0032] Furthermore, it should be noted that when the number of slot group columns n = 3 or 5, which is an odd number, the slot group 31 located in the middle position should be centered. Figure 2 As shown, the slot group 31 in the middle position coincides with the center line 34 of the narrow side of the outer conductor, so that when the outer conductor is wrapped vertically, the overlapping edge 35 will not block the slot.

[0033] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0034] The prior description of this disclosure is provided to enable any person skilled in the art to make or use this disclosure. Various modifications to this disclosure will be apparent to those skilled in the art, and the general principles defined herein may be applied to other variations without departing from the spirit or scope of this disclosure. Therefore, this disclosure is not intended to be limited to the examples and designs described herein, but should be accorded the widest scope consistent with the principles and novel features disclosed herein.

[0035] The above description is merely a preferred example of this application and is not intended to limit this application. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application shall be included within the scope of protection of this application.

Claims

1. A multi-directional radiating leaky coaxial cable comprising, in order from the inside out, an inner conductor, an insulating layer, an outer conductor and a sheath, characterized in that: At least two groups of slot holes are arranged on the outer conductor, and the at least two groups of slot holes are distributed at different angles in the circumferential direction of the outer conductor. Each group of slot holes includes a plurality of slot hole arrays arranged periodically in the axial direction of the outer conductor. Each slot hole array includes a plurality of slot holes. The pitches of the slot hole groups are the same, and the periodic arrangement of two adjacent slot hole groups in the circumferential direction is different by half a pitch, so that the phases of the respective excitation electric fields are different by 180°. The included angle α between two adjacent slot hole groups is δ, where δ is the required new radiation direction included angle. The number of slot hole groups n is m, where m is the required number of radiation lobes. When n=3 or 5, the slot hole group located in the middle position coincides with the middle line of the narrow edge of the outer conductor. The pitch D = aπD of the slot group on the expanded outer conductor 绝缘 / 360°, where D 绝缘 is the outer diameter of the insulation layer; The slot hole is a non-central symmetric figure or a central symmetric figure inclined to the axial direction, and two adjacent slot holes in the circumferential direction are arranged symmetrically with respect to the axis.

2. The multi-directional radiating leaky coaxial cable according to claim 1, characterized by: The slot hole is an L-shaped slot, a U-shaped slot, a T-shaped slot, an E-shaped slot or a triangular slot, and two adjacent slot holes in the circumferential direction are oppositely directed.

3. The multi-directional radiating leaky coaxial cable of claim 1, wherein: The slot hole is a rectangular slot, a rhombic slot or an elliptical slot inclined to the axial direction, and the inclination angles of two adjacent slot holes in the circumferential direction are opposite.

4. The multi-directional radiating leaky coaxial cable of claim 1, wherein: The slot hole is a straight slot, and two adjacent slot hole groups in the circumferential direction are arranged with a half-pitch difference.

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