CN115458889A

CN115458889A - Leaky cable with MIMO (multiple input multiple output) function

Info

Publication number: CN115458889A
Application number: CN202211150627.6A
Authority: CN
Inventors: 查昊; 杨军; 李俊达; 王耀民; 李昀
Original assignee: China Information Consulting and Designing Institute Co Ltd
Current assignee: China Information Consulting and Designing Institute Co Ltd
Priority date: 2022-09-21
Filing date: 2022-09-21
Publication date: 2022-12-09
Anticipated expiration: 2042-09-21
Also published as: CN115458889B

Abstract

The invention discloses a leaky cable for improving MIMO function, which comprises a leaky cable body, wherein the leaky cable body comprises a first leaky cable and a second leaky cable, the first leaky cable comprises an inner conductor, an insulating medium and a first outer conductor from inside to outside, an inclined slotted hole unit is arranged on the first outer conductor, the inclined slotted hole unit comprises more than two inclined slotted hole groups, the inclined slotted hole groups are vertically arranged, and each inclined slotted hole group comprises more than one group of splayed slotted holes; the second leakage cable sequentially comprises an inner conductor, an insulating medium and a second outer conductor from inside to outside, a forked groove hole unit is arranged on the second outer conductor and comprises more than two forked groove hole groups, the forked groove hole groups are vertically arranged, and each forked groove hole group is centrosymmetric and comprises more than two forked groove holes. The leaky cable innovatively improves the slotted hole form of the combined leaky cable, improves the coupling loss, further improves the communication quality, simultaneously realizes more uniform spatial field distribution and enlarges the radiation area.

Description

Leaky cable with MIMO (multiple input multiple output) function

Technical Field

The invention belongs to the technical field of mobile communication, and particularly relates to a leaky cable for improving the MIMO function.

Background

The leaky coaxial cable integrates the functions of signal transmission, transmission and reception, has the dual functions of a coaxial cable and an antenna, and is mainly suitable for covering long and narrow area scenes such as tunnels, roadways, subways and the like. When the 5G era is entered, the 5G terminal mainly uses 1T4R and 2T4R, and at this time, the network side needs to deploy at least a radio frequency medium more than 2T/R, so as to fully embody the improvement of capacity and coverage brought by 5G, and the prior art mainly includes two types: the A-type mode utilizes a single leaky cable to construct a multipath effect, wherein radio frequency signals are fed in from a forward end and a reverse end of the same leaky cable at the same time, and because two paths of signals are opposite in radiation and have lower correlation in a transmission path inside the leaky cable, the MIMO (multiple-in multiple-out) characteristic can be realized. Therefore, the method has great discount on the feasibility and the universality of scenes; the B-type mode realizes the MIMO characteristic by combining a plurality of leaky cables, and has the advantages that the equipment and the implementation do not need to be considered too much, the requirement on the wireless environment does not need to be strict, different polarization is realized by adopting different slotting modes in different environments, and better MIMO characteristic can be obtained in the same polarization mode and the cross polarization mode. In addition, in order to expand the application scenes of the leaky cable (such as building scenes), a C-type wide-angle leaky cable is also developed, the slot design of the C-type wide-angle leaky cable is improved, the radial radiation distance and the performance of the C-type wide-angle leaky cable exceed those of a common leaky cable, and the application scene width of the leaky cable is enhanced. The type C is also a single cable mode, it is more difficult to implement MIMO in a building type scene with the type a mode, and the above-mentioned type 3 modes all face several common problems: the cable has no universality, the radiation of the existing cable is directional, the radiation area is narrow, if the bidirectional radiation is realized, the construction process of the leaky cable is high, the coverage effect is influenced because the installation cannot be carried out, and therefore, the technical level of implementing personnel is higher.

Disclosure of Invention

The purpose of the invention is as follows: the invention aims to solve the technical problem of providing a leaky cable for improving the MIMO function aiming at the defects of the prior art.

In order to solve the technical problem, the invention discloses a leaky cable for improving the MIMO function, which comprises a leaky cable body and a sheath layer wrapping the leaky cable body, wherein the leaky cable body comprises a first leaky cable and a second leaky cable, the first leaky cable sequentially comprises an inner conductor, an insulating medium and a first outer conductor from inside to outside, the first outer conductor is provided with an inclined slotted hole unit, the inclined slotted hole unit is used for realizing vertical polarization and comprises more than two inclined slotted hole groups, the inclined slotted hole groups are vertically arranged, and each inclined slotted hole group comprises more than one group of splayed slotted holes; the second leaky cable sequentially comprises an inner conductor, an insulating medium and a second outer conductor from inside to outside, a forked groove hole unit is arranged on the second outer conductor and used for realizing horizontal polarization and comprises more than two forked groove hole groups, the forked groove hole groups are vertically arranged, and each forked groove hole group is centrosymmetric and comprises more than two forked groove holes.

Furthermore, the first outer conductor is provided with inclined slot hole units in a double-sided staggered manner, the second outer conductor is provided with forked slot hole units in a double-sided staggered manner, and the pitch of the two inclined slot hole units is the same as that of the two forked slot hole units and is marked as P.

Further, the forked groove hole unit comprises two forked groove hole groups, the two forked groove hole groups are vertically arranged, each forked groove hole group comprises six forked groove holes which are respectively marked as a first forked groove hole, a second forked groove hole, a third forked groove hole, a fourth forked groove hole, a fifth forked groove hole and a sixth forked groove hole, the first forked groove hole, the third forked groove hole, the fourth forked groove hole, the fifth forked groove hole and the sixth forked groove hole are on the same horizontal line, the fourth forked groove hole, the sixth forked groove hole, the fourth forked groove hole, the fifth forked groove hole and the sixth forked groove hole are on the same horizontal line, and the distance between the two horizontal lines is d1 _x (ii) a The distance between two fork-shaped slot hole groups is d2 _x The total length of the two rows of forked-shaped slot holes is L _x (ii) a The inclination angle of the forked groove hole is theta _x Width of w _x 。

Further, the inclined slot unit includes two inclined slot groups which are vertically arranged, and each inclined slot group includes three groups and eight groupsThe slotted holes are marked as a first splayed slotted hole, a second splayed slotted hole and a third splayed slotted hole, the first splayed slotted hole comprises a first inclined slotted hole and a second inclined slotted hole, the second splayed slotted hole comprises a third inclined slotted hole and a fourth inclined slotted hole, the third splayed slotted hole comprises a fifth inclined slotted hole and a sixth inclined slotted hole, and the inclination angles of the two inclined slotted holes in each group of splayed slotted holes are theta respectively _o And 180 DEG-theta _o ，θ _o Is an included angle between one inclined slotted hole and the axial direction of the leakage cable, and the width of the two inclined slotted holes is w _o The vertical distance between the two inclined slotted holes is d1 _o (ii) a Each inclined slot hole group is sequentially provided with a first inclined slot hole, a third inclined slot hole, a fifth inclined slot hole, a sixth inclined slot hole, a fourth inclined slot hole and a second inclined slot hole; the distance between two inclined groove hole groups is d2 _o The total length of two rows of inclined slot holes is L _o 。

Further, the inclination angle theta of the fork-shaped slotted hole _x The angle of inclination theta of one inclined slot hole in the splayed slot hole _o And setting theta in the same way, wherein the value range of theta is 26-34 degrees.

Further, the distance d1 in the set of fork-shaped slots _x The vertical distance d1 between the two inclined slotted holes of each group of splayed slotted holes in the inclined slotted hole group _o And setting d1, wherein the value range of d1 is 2-4 mm.

Further, the distance d2 between two fork-shaped slot hole groups _x Distance d2 from two inclined groove hole groups _o And setting d2, wherein the value range of d2 is 2-4 mm.

Further, the total length L of the two rows of forked slotted holes _x Total length L of two rows of inclined slot holes _o And setting the L value as L, wherein the L value range is 25-33 mm.

Further, the pitch P ranges from 210 mm to 250mm.

Further, the width w of the forked groove hole _x Width w of inclined slot hole _o And setting the value of w to be 3-5 mm.

Has the advantages that: the utility model provides a leak cable that promotes MIMO function improves the slotted hole form that merges leak cable innovatively, including slotted hole shape, size, range, angle, not only has the characteristic of C class, and realizes that the scene of general adaptation is suitable for the MIMO characteristic, improves the coupling loss and makes communication quality further improve. The two-sided slotting mode changes cable directional coverage into bidirectional (approximately omnidirectional) coverage, realizes more uniform spatial field distribution, enlarges the radiation area, and meets the requirements of more potential scenes (for example, leaky cables vertically cover opposite building scenes). The technical requirements of constructors are reduced, and the labor cost is reduced; merging the leaky cable also reduces the CAPEX (Capital Expenditure) Cost, saves the installation space, reduces the installation difficulty, and further reduces the Total Cost of Ownership (Total Cost of Ownership).

Drawings

The foregoing and/or other advantages of the invention will become more apparent from the following detailed description of the invention when taken in conjunction with the accompanying drawings.

Fig. 1 is a schematic structural diagram of a leaky cable for improving a MIMO function according to an embodiment of the present application.

Fig. 2 is an exploded schematic view of an outer conductor current line of an inclined slotted leaky cable in a leaky cable for improving the MIMO function according to the embodiment of the present application.

Fig. 3 is an exploded view of a current line of an outer conductor of a vertically symmetric slot in a leaky cable for improving MIMO function according to an embodiment of the present application.

Fig. 4 is a schematic diagram illustrating a design of an inclined slot on a first outer conductor in a leaky cable for improving MIMO function according to an embodiment of the present application.

Fig. 5 is a schematic diagram illustrating staggered arrangement of the first outer conductor copper strip spreading inclined slots in the leaky cable for improving MIMO provided in the embodiment of the present application.

Fig. 6 is a schematic diagram illustrating superposition of a cross-shaped slot radiation field on a second outer conductor in a leaky cable for improving the MIMO function according to an embodiment of the present application.

Fig. 7 is a schematic design diagram of a forked slot hole on a second outer conductor in a leaky cable for improving the MIMO function according to the embodiment of the application.

Fig. 8 is a schematic diagram illustrating staggered arrangement of second outer conductor copper strips in a leaky cable for improving the MIMO function according to the embodiment of the present application.

Fig. 9 is a schematic diagram of a simulation result of an operating frequency band and a voltage standing wave ratio of a leaky cable when a vertical distance d1=0 between two oblique slots of each group of splayed slots in a leaky cable middle oblique slot group for improving the MIMO function according to the embodiment of the present application.

Fig. 10 is a schematic diagram of a simulation result of an operating frequency band and a voltage standing-wave ratio of a leaky cable when a vertical distance d1=4mm between two inclined slots of each group of splayed slots in a leaky cable for improving the MIMO function provided by the embodiment of the present application.

Detailed Description

Embodiments of the present invention will be described below with reference to the accompanying drawings.

The leaky cable with the MIMO function can be applied to a closed long and narrow scene with limited indoor installation space, such as a subway, a tunnel and a mine, to realize the MIMO characteristic, and can also be applied to indoor building type scenes, such as a corridor, a single-side office building, a double-side office building and a hotel; dense shopping areas with simple materials such as glass, wood plates or gypsum boards and the like at intervals; an elongated underground parking lot; an elevator to realize MIMO characteristics; meanwhile, cables can be vertically and horizontally arranged outdoors to cover opposite buildings, and the MIMO characteristic can be realized.

MIMO technology is mainly classified into three categories: transmit diversity, spatial multiplexing, beamforming. For a 2T/R leaky-cable mode, transmission diversity and spatial multiplexing technologies can be mainly realized, and the transmission diversity and the spatial multiplexing both utilize weak correlation of spatial channels to improve the reliability of signal transmission and improve the peak rate of data transmission. The spatial latitude of the combined leaky-cable is not available, how to realize weak correlation can be realized through frequency, time and a polarization mode, or the uncorrelated channels are realized through a wireless multipath environment, the polarization mode is one of better modes, and the performance of the same polarization mode of the combined double-cable is better than that of a cross polarization mode because different antenna polarization modes cause different reflection coefficients of the inner wall of the tunnel. Because the inner wall of the tunnel is made of a conductor material and has a high dielectric constant, the transmitting end can generate higher reflected waves by adopting a same polarization mode, so that the power is smaller in relative cross polarization by adopting the same polarization mode, and the channel capacity is relatively higher. The prerequisite that the same polarization is higher than the cross polarization capacity is that in a tunnel with a multipath environment, if the same polarization is not in the multipath environment, the capacity improvement is only logarithmic grade, so that the universality is avoided, and the channel independence is realized by utilizing the difference of the polarization modes without depending on the environment change and the polarization orthogonal mode, so that the universality environment is adapted.

The embodiment of the application discloses promote leaky cable of MIMO function, as shown in fig. 1, including leaky cable body 100 and parcel the restrictive coating 200 of leaky cable body, leaky cable body 100 includes first leaky cable 110 and second leaky cable 120, first leaky cable 110 includes inner conductor 3, insulating medium 4 and first outer conductor 111 from interior to exterior in proper order, as shown in fig. 5, inclined slot unit 112 has been seted up on first outer conductor 111, inclined slot unit 112 is used for realizing vertical polarization, includes more than two inclined slot groups 113, and inclined slot group 113 is arranged perpendicularly, and every inclined slot group 113 includes more than a set of splayed slotted hole; the second leaky cable 120 sequentially comprises an inner conductor, an insulating medium and a second outer conductor 121 from inside to outside, as shown in fig. 8, a forked groove hole unit 122 is arranged on the second outer conductor 121, the forked groove hole unit 122 is used for realizing horizontal polarization and comprises more than two forked groove hole groups 123, the forked groove hole groups 123 are vertically arranged, and each forked groove hole group 123 is centrally symmetrical and comprises more than two forked groove holes.

Because the vertically polarized electromagnetic waves and the horizontally polarized electromagnetic waves are not interfered with each other to realize orthogonality, the MIMO characteristic is presented.

In this embodiment, as shown in fig. 5, the first outer conductor 111 is provided with inclined slot units 112 on both sides in a staggered manner, as shown in fig. 8, the second outer conductor 121 is provided with forked slot units 122 on both sides in a staggered manner, and the pitch of the two inclined slot units 112 is the same as the pitch of the two forked slot units 122, which is denoted as P.

In order to realize more scene coverage, the embodiment adopts a double-sided slotting mode,because the cable outer conductor copper strip adopts the overlap joint mode of indulging, two-sided symmetry fluting is realized more difficultly at the technology, and this embodiment adopts the staggered arrangement mode. Under the condition of single-mode radiation of the single-sided slot, the radiation direction of the leaky cable is mainly concentrated around the leaky cable, and the radiation angle theta of the leaky cable can be known according to the following formula (1) _m Mainly composed of pitch P, wavelength lambda, harmonic order m and dielectric constant epsilon _r To determine the position of the target object,

the frequency is 3.5GHz, the wavelength is lambda =0.08 m, and the dielectric constant epsilon of the insulating medium of the copper cable _r About 1.25, the pitch P is 240mm, when the harmonic frequency m is less than or equal to-1, the leakage cable can work in the radiation mode, and the maximum radiation direction (radiation angle theta) of the leakage cable can be realized _m ) In the vicinity of the 30 deg. direction of the side with the slotted hole.

Compared with a single-side slotted leaky cable, the double-side slotted leaky cable has more symmetrical directional diagrams, can avoid the problem of a dead zone on the back of a slotted hole of the single-side slotted cable, enables the signal to radiate more uniformly in space, increases the radiation area and improves the communication quality.

In this embodiment, as shown in fig. 7 and 8, the forked-slot unit 122 includes two forked-slot groups 123, the two forked-slot groups 123 are vertically arranged, each forked-slot group 123 includes six forked slots, which are respectively denoted as a first forked slot 124, a second forked slot 125, a third forked slot 126, a fourth forked slot 127, a fifth forked slot 128 and a sixth forked slot 129, the first to third forked slots are on the same horizontal line, the fourth to sixth forked slots are on the same horizontal line, and the distance between the two horizontal lines is d1 _x (ii) a The distance between the two fork-shaped slot hole groups 123 is d2 _x The total length of the two rows of forked-shaped slot holes is L _x (ii) a The inclined angle of the forked slotted hole is theta _x Width of w _x 。

When the phase difference of the current lines passing through the two slotted holes is zero or integral multiple of 2 pi, the component directions of the radiation fields in the horizontal direction are the same and are mutually superposed; in the vertical direction, the radiation field components have opposite directions and cancel each other out, as shown in fig. 6, if the phase difference of the current lines passing through the two slots is zero or integral multiple of 2 pi, the distance between the slots should satisfy the condition that the phase difference is integral multiple of the working half-wavelength, and if the distance between the two slots is 0, that is, the geometric centers of the two slots coincide, the condition that the phase difference of the current lines is the same can be satisfied, and horizontal polarization can be realized.

In this embodiment, the inclined slot hole unit 112 includes two inclined slot hole groups 113, the two inclined slot hole groups 113 are vertically arranged, each inclined slot hole group 113 includes three groups of splayed slot holes, which are marked as a first splayed slot hole, a second splayed slot hole and a third splayed slot hole, the first splayed slot hole includes a first inclined slot hole 114 and a second inclined slot hole 115, the second splayed slot hole includes a third inclined slot hole 116 and a fourth inclined slot hole 117, the third splayed slot hole includes a fifth inclined slot hole 118 and a sixth inclined slot hole 119, and the inclined angles of the two inclined slot holes in each group of splayed slot holes are θ _o And 180 DEG-theta _o All width being w _o The vertical distance between the two inclined slotted holes is d1 _o (ii) a A first inclined slotted hole 114, a third inclined slotted hole 116, a fifth inclined slotted hole 118, a sixth inclined slotted hole 119, a fourth inclined slotted hole 117 and a second inclined slotted hole 115 are sequentially arranged in each inclined slotted hole group 113; the distance between two inclined groove hole groups 113 is d2 _o The total length of two rows of inclined slot holes is L _o 。

Each of the fork-shaped slot groups 123 includes six fork-shaped slots, and each of the inclined slot groups 113 includes three sets of splayed slots, which are intended to extend the leaky cable to a wider frequency band while suppressing higher harmonics. Table 1 shows a relationship between the number of slotted groups and the frequency band expansion multiple, and it can be known from table 1 that as the number of slotted groups increases, the multiple of the leaky cable frequency band expansion increases continuously, and if the number of slotted groups is too large, the electromagnetic coupling phenomenon is severe due to too close slot distance, which also affects energy transmission in the leaky cable communication process, so the leaky cable with the number of slotted groups being 3 is selected in this embodiment.

TABLE 1 slotted group number vs. band expansion multiple

Number of grooved groups in one period (pitch P)	Number of band expansion
		1	2
2	4
		3	6
4	8

In this embodiment, the inclination angle θ of the fork-shaped slot hole _x The angle of inclination theta of one inclined slot hole in the splayed slot hole _o And setting theta to be in a range of 26-34 degrees.

The first outer conductor 111 is provided with an inclined slot, the current flowing through the inclined slot can be decomposed into two components parallel to the slot and perpendicular to the slot, as shown in fig. 2 and 3, for the current component perpendicular to the slot shown in fig. 2 (a) and 3 (a), when the width of the slot is sufficiently small, the displacement current generated by cutting the current line component parallel to the slot by the slot can be ignored, i.e. no radiation can be generated, while the current component perpendicular to the slot shown in fig. 2 (b) and 3 (b) is cut by the slot to generate a larger displacement current, electromagnetic energy is radiated, the component of the current line perpendicular to the slot can be divided into a horizontal component and a vertical component, the horizontal component current generates a field strength in the Z direction, and the current of the vertical component generates a field strength in the circumferential direction, i.e. phi-upward. Therefore, as shown in fig. 4, the design of symmetrical slots (splayed slots) is adopted, and the phases of the current lines of the symmetrical slots are opposite, so that the electric field vectors generated by the displacement current of the slots are opposite in the horizontal direction and are cancelled by superposition; in the vertical direction, the directions are the same, and the superposition and the addition are carried out; in the radial direction, the directions are opposite, and cancellation is superposed. Thereby achieving the effect of vertically polarized radiation. Meanwhile, the inclination angle of the slot hole can also influence the component size of the radiation field in the horizontal direction and the vertical direction, the inclination angle is increased to increase the component in the horizontal direction and reduce the component in the vertical direction, so that the angle of the slot hole is properly reduced, the purity of vertical polarization can be improved, and the angle of the slot hole is reduced without limitation, so that the coupling loss of the leaky cable is increased, the radial radiation performance is reduced, and the inclination angle cannot be reduced. The second outer conductor 121 is provided with a fork-shaped slot (X-shaped) which is also consistent with the splayed slot, the size of the inclination angle of the slot still causes the component size of the horizontal direction and the radiation field in the horizontal direction and the component size of the vertical direction to be different, because of the fork-shaped slotted cable, the phases of the coincident current lines of the slot are the same, the vertical component can be completely offset, and the splayed slot can not completely offset the horizontal component, therefore, the angle dependence of the horizontal polarization purity on the slot is smaller, the inclination angle of the slot is increased, the horizontal component can be increased, and the suggested value of the inclination angle is consistent with that of the first outer conductor 111.

In this embodiment, the distance d1 in the fork-shaped slot hole group 123 _x Perpendicular distance d1 from two inclined slots of each group of splayed slots in inclined slot group 113 _o And setting d1, wherein the value range of d1 is 2-4 mm.

Different from the reflection of ordinary coaxial cable, the equivalent transmission line of leaky cable is asymmetric, and its impedance value that distributes along the axle can change along with the difference of position, and every fluting hole on the outer conductor of leaky cable can both carry out periodic reflection to electromagnetic energy, and when this kind of reflection between the adjacent slotted hole satisfies certain condition, will produce the resonance under operating frequency, makes electromagnetic energy oscillation appear in the transmission process, influences communication. The working frequency point is called a resonant point of a leaky cable, and for better communication quality, part of the frequency points which cannot be used for communication needs to be converted into usable frequency points by adjustment, so that the suppression of the resonant point needs to be considered at the same time of the design of the slot, in this embodiment, the offset adjustment is performed on the slot and the cross-shaped slot of the three-splayed shape to suppress the resonant point, and the inclined slot in a half period is translated by d1 in the X direction.

Simulation analysis is performed by using HFSS (High Frequency Structure simulation) electromagnetic simulation software, the operating Frequency range is set to be 0 to 3500MHz, frequency sweeping is performed by using 500MHz as a step length, and Voltage Standing Wave Ratio (VSWR) of the leaky cable is obtained as shown in fig. 9, as can be seen from fig. 9, when the Frequency is 500MHz, the peak value of the Voltage Standing Wave Ratio of the leaky cable is 1.83, and the Voltage Standing Wave ratios of the other Frequency points are all less than 1.15. According to the electrical performance requirement of the standard YD/T2491-2013 in the communication industry, the standing-wave ratio is less than 1.30 under the condition of 500MHz, so that the position is a resonance point, the electromagnetic energy reflection is obvious, and the communication quality is influenced. In this embodiment, the slot is translated, the initial translation value d1=4mm, as shown in fig. 10, the operating frequency range of the simulation process is still set to 0 to 3500MHz, the frequency is still swept by taking 500MHz as the step length, and the voltage standing wave ratio of the leaky cable is as shown in fig. 10, it can be seen from fig. 10 that except for 0MHz, the voltage standing wave ratios of other operating frequencies are all less than 1.30, which meets the requirements of the industry standard, through the dislocation adjustment, the resonance point of the tri-splayed slot leaky cable at 1000MHz is obviously suppressed, that is, the leaky cable can normally operate within the operating frequency of 3500MHz, and meets the communication requirements.

In this embodiment, the distance d2 between the two fork-shaped slot hole sets 123 _x Distance d2 from two inclined groove hole groups 113 _o And setting d2, wherein the value range of d2 is 2-4 mm.

In this embodiment, the total length L of the two rows of fork-shaped slots _x Total length L of two rows of inclined slot holes _o And setting the L value as L, wherein the L value range is 25-33 mm.

The first outer conductor 111 splits a single-row inclined slot group in the prior art into double-row inclined slot groups (a row and b row), wherein the a row and the b row are symmetrically arranged, and the distance d2 is controlled to be 2-4 mm; the length of each split row of slotted holes is smaller than 1/4 wavelength of the highest service frequency supported by the leaky-cable, 3.5G frequency deployment can be met, meanwhile, the length L of the split double-row slotted holes is larger than the length of a single row in the prior art, the current intercepted by the slotted holes is increased, the radiation electromagnetic energy to the external space is increased, the coupling loss is correspondingly reduced, and the radial radiation performance is more excellent. The second outer conductor 121 also comprises two forked slot hole groups 123, the distance d2 and the length L are the same as those of the first outer conductor 111, and the overall length of the double-row slot group is increased compared with that of a conventional single slot hole, the length is increased, and the number of units after splitting is increased, so that the radiation angle and the coverage uniformity of the leakage cable can be effectively enlarged.

The slot pitch P also affects the coupling loss, which is affected by the phase superposition of different slot radiation fields, and the coupling loss becomes smaller when the slot pitch increases, but after the slot pitch increases to a certain value, the coupling loss becomes larger because the electromagnetic energy radiated per unit length decreases, so in this embodiment, the pitch P has a value ranging from 210 mm to 250mm.

In this embodiment, the width w of the fork-shaped slot _x Width w of inclined slot hole _o And setting the value of w to be 3-5 mm.

When the width of the slot hole is increased, the result of the same coupling loss is also improved, the width of the slot hole is increased, and the horizontal current lines are cut by the slot hole to generate displacement current, so that excitation is generated, electromagnetic waves are radiated to the space, and the effect is better.

The present invention provides a leaky cable for improving MIMO function, and there are many methods and ways for implementing the technical solution, and the above description is only a specific embodiment of the present invention, and it should be noted that, for those skilled in the art, a number of modifications and decorations can be made without departing from the principle of the present invention, and these modifications and decorations should also be regarded as the protection scope of the present invention. All the components not specified in the present embodiment can be realized by the prior art.

Claims

1. The leaky cable capable of improving the MIMO function is characterized by comprising a leaky cable body (100) and a sheath layer (200) wrapping the leaky cable body, wherein the leaky cable body (100) comprises a first leaky cable (110) and a second leaky cable (120), the first leaky cable (110) sequentially comprises an inner conductor (3), an insulating medium (4) and a first outer conductor (111) from inside to outside, an inclined slotted hole unit (112) is formed in the first outer conductor (111), the inclined slotted hole unit (112) is used for realizing vertical polarization and comprises more than two inclined slotted hole groups (113), the inclined slotted hole groups (113) are vertically arranged, and each inclined slotted hole group (113) comprises more than one group of splayed slotted holes; the second leaky cable (120) sequentially comprises an inner conductor, an insulating medium and a second outer conductor (121) from inside to outside, a forked groove hole unit (122) is formed in the second outer conductor (121), the forked groove hole unit (122) is used for achieving horizontal polarization and comprises more than two forked groove hole groups (123), the forked groove hole groups (123) are vertically arranged, and each forked groove hole group (123) is symmetrical in center and comprises more than two forked groove holes.

2. The leaky cable for improving the MIMO function as claimed in claim 1, wherein the first outer conductor (111) is provided with inclined slot units (112) on both sides in a staggered manner, the second outer conductor (121) is provided with fork-shaped slot units (122) on both sides in a staggered manner, and a pitch of the two inclined slot units (112) is the same as a pitch of the two fork-shaped slot units (122), which is denoted by P.

3. The leaky cable for improving MIMO function as claimed in claim 2, wherein said forked slot unit (122) comprises two forked slot groups (123), said two forked slot groups (123) are vertically arranged, each forked slot group (123) comprises six forked slots, respectively designated as a first forked slot (124), a second forked slot (125), a third forked slot (126), a fourth forked slot (127), a fifth forked slot (128) and a sixth forked slot (129), the first to third forked slots are on the same horizontal line, the fourth to sixth forked slots are on the same horizontal line, and the distance between the two horizontal lines is d1 _x (ii) a The distance between two fork-shaped slot hole groups (123) isd2 _x The total length of the two rows of forked-shaped slot holes is L _x (ii) a The inclined angle of the forked slotted hole is theta _x Width is w _x 。

4. A leaky cable for improving MIMO function according to claim 3, wherein said slanted slot units (112) include two slanted slot groups (113), said two slanted slot groups (113) are vertically arranged, each slanted slot group (113) includes three groups of splayed slots, denoted as a first splayed slot, a second splayed slot and a third splayed slot, said first splayed slot includes a first slanted slot (114) and a second slanted slot (115), said second splayed slot includes a third slanted slot (116) and a fourth slanted slot (117), said third splayed slot includes a fifth slanted slot (118) and a sixth slanted slot (119), and the slanted angles of the two slanted slots in each group are θ _o And 180 DEG-theta _o All width being w _o The vertical distance between the two inclined slotted holes is d1 _o (ii) a A first inclined slotted hole (114), a third inclined slotted hole (116), a fifth inclined slotted hole (118), a sixth inclined slotted hole (119), a fourth inclined slotted hole (117) and a second inclined slotted hole (115) are sequentially arranged in each inclined slotted hole group (113); the distance between two inclined groove hole groups (113) is d2 _o The total length of two rows of inclined slot holes is L _o 。

5. The leaky cable for improving MIMO function as claimed in claim 4, wherein the angle θ of inclination of the forked slot hole _x The angle of inclination theta of one inclined slot hole in the splayed slot hole _o And setting theta in the same way, wherein the value range of theta is 26-34 degrees.

6. Leaky cable for improving MIMO function according to claim 5, characterized in that the distance d1 in the fork-shaped slotted hole group (123) _x A vertical distance d1 from two inclined slotted holes of each group of splayed slotted holes in the inclined slotted hole group (113) _o And setting d1, wherein the value range of d1 is 2-4 mm.

7. Leaky cable for improving MIMO function according to claim 6, characterized in that the distance d2 between two fork-shaped slot hole groups (123) _x A distance d2 from the two inclined groove hole groups (113) _o And setting d2, wherein the value range of d2 is 2-4 mm.

8. The leaky cable for improving MIMO function as claimed in claim 7, wherein the total length L of the two rows of forked slots _x Total length L of two rows of inclined slot holes _o And setting the L value as L, wherein the L value range is 25-33 mm.

9. The leaky cable for improving the MIMO function as claimed in claim 8, wherein the pitch P is in a range of 210-250 mm.

10. Leaky cable for improving MIMO function as claimed in claim 9, wherein a width w of said forked slot hole _x Width w of inclined slot hole _o And setting the value of w to be 3-5 mm.