Leaky coaxial cable for indoor distribution and design method and system thereof

Abstract

The invention discloses a leaky coaxial cable for indoor distribution and a design method and system thereof, and belongs to the technical field of communication cables. The design method comprises the following steps: designing different electromagnetic wave radiation direction angles along the leaky coaxial cable according to the position of an electromagnetic wave target coverage area of a target scene space; according to different electromagnetic wave radiation direction angles along the designed leaky coaxial cable, calculating different periodic pitches of slotted holes corresponding to the different electromagnetic wave radiation direction angles of the leaky coaxial cable; and according to the designed different electromagnetic wave radiation direction angles and the calculated different periodic pitches of the corresponding slot holes, the slot length of the slot holes in each section of pitch of the leaky coaxial cable is calculated in combination with the requirement that the electromagnetic wave radiation intensity of the target coverage area is consistent. According to the invention, the leakage coaxial cable can be ensured not to have an obvious weak coverage area on a target coverage area, and not to be overlapped with an outdoor signal too much, so that the purpose of optimizing the indoor coverage effect of the leakage coaxial cable is achieved.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of communication cable, in particular to a leaky coaxial cable for indoor distribution and a design method and system thereof. BACKGROUND

[0002] The leaky coaxial cable is a kind of communication cable which can be used for signal transmission and signal transceiving, and is widely used in indoor distribution system. Figure 1 As shown in the figure, the leaky coaxial cable is composed of an inner conductor 1, a foamed insulation layer 2, an outer conductor 4 provided with a slot hole 3, and a sheath layer 5, wherein the signal transceiving is realized through the slot hole 3 on the outer conductor. In the indoor distribution system, the leaky cable is covered in the center of the target coverage area, and the leaky coaxial cable along the line area can obtain good signal coverage effect.

[0003] In the current wireless communication system coverage scheme, the outdoor space is basically covered by the external base station. However, due to the influence of floor shielding and other environmental factors, many indoor places cannot be covered by outdoor signals. The existing indoor signal coverage is mainly completed by indoor distribution leaky coaxial cable or indoor distribution antenna, and the signal is introduced from the machine room, and the leaky coaxial cable or antenna completes the wireless signal coverage in the indoor area. The leaky coaxial cable is widely used in indoor distribution system, as shown in the figure, the commonly used leaky coaxial cable has a consistent radiation direction (same angle θ) on a specific frequency band, and there is still a strong outdoor signal coverage on the area of about one meter in the window sill of various buildings, which leads to the existence of indoor and outdoor signal cross coverage in the area near the window sill, and the signal near the corner is weak. Figure 2

[0004] Based on this, the present application provides a design method of leaky coaxial cable for indoor distribution, which can ensure more sufficient indoor signal coverage and avoid cross coverage or weak coverage of signals. SUMMARY

[0005] The main purpose of the present application is to provide a leaky coaxial cable for indoor distribution and a design method and system thereof, by designing the combination of different slot hole sizes and different slot hole pitches of the leaky coaxial cable outer conductor radiation unit, the electromagnetic wave radiation direction of the radiation unit with different slot hole sizes and pitch sizes can be aligned with the target coverage area, and the level of radiation signal (i.e. coupling loss) in the target coverage area tends to be consistent, so as to optimize the use effect of the indoor target coverage area of the leaky coaxial cable.

[0006] In order to achieve the above purpose, the present application provides a design method of leaky coaxial cable for indoor distribution, comprising the following steps: Step S1, according to the position of the electromagnetic wave target coverage area of the target scene space, design different electromagnetic wave radiation direction angles of the leaky coaxial cable along the line;​ Step S2, according to the different electromagnetic wave radiation direction angle of the leaky coaxial cable along the line designed in step S1, the different pitch of the slot hole periodicity corresponding to the different electromagnetic wave radiation direction angle of the leaky coaxial cable is calculated; Step S3, according to the different electromagnetic wave radiation direction angle designed in step S1 and the different pitch of the slot hole periodicity corresponding to the different electromagnetic wave radiation direction angle calculated in step S2, and combining the requirement that the electromagnetic wave radiation intensity of the target coverage area is consistent, the slot length of the slot hole in each segment pitch of the leaky coaxial cable is calculated.

[0007] Further, in step S2, the formula for calculating the different pitch of the slot hole periodicity corresponding to the different electromagnetic wave radiation direction angle is as follows: Formula 1; Wherein, ε is the equivalent dielectric constant of the insulating medium of the leaky coaxial cable; λ is the wavelength corresponding to the frequency of the electromagnetic wave; P is the pitch between the slot holes of the leaky coaxial cable; θ is the included angle between the electromagnetic wave radiation direction of the leaky coaxial cable and the transmission direction of the leaky coaxial cable.

[0008] Further, in step S3, the formula for calculating the slot length of the slot hole in each segment pitch of the leaky coaxial cable is as follows: Formula 2; Wherein, A is the radiation attenuation of the leaky coaxial cable of the n-th segment pitch length, which is a constant value; B is a fixed coefficient, which is a constant value; P n is the n-th segment pitch length between the slot holes of the leaky coaxial cable; θ n is the included angle between the electromagnetic wave radiation direction of the leaky coaxial cable of the n-th segment pitch length and the transmission direction of the leaky coaxial cable; L n is the slot length of the slot hole in the leaky coaxial cable of the n-th segment pitch length.

[0009] Further, in step S1, the different electromagnetic wave radiation direction angles of the leaky coaxial cable along the line are θ1 to θ n , and all intermediate values of θ1 to θ n should satisfy or (1≤x≤n); Wherein, θ1 is the electromagnetic wave radiation angle of the leaky coaxial cable along the initial segment pitch in the transmission direction, and θ n is the electromagnetic wave radiation angle of the leaky coaxial cable along the last segment pitch in the transmission direction; When the length of the leaky coaxial cable is greater than the length of the coverage area, θ1≤θ nWhen the length of the leaky coaxial cable is less than the first and last length of the coverage area, θ1≥θ n ; The electromagnetic wave radiation direction angle is defined as the included angle between the direction with the strongest electromagnetic wave amplitude in the electromagnetic wave radiation lobe diagram of the leaky coaxial cable and the transmission direction of the leaky coaxial cable.

[0010] Further, in step S1, according to the position of the electromagnetic wave target coverage area of the target scene space, different electromagnetic wave radiation direction angles of the leaky coaxial cable along the line are designed, including: According to the initial end and the last end boundary of the electromagnetic wave target coverage area of the target scene space and the initial segment and the last segment boundary position of the leaky coaxial cable, the slot hole radiation angle boundary values θ1 and θ n ; The angles of the electromagnetic wave radiation direction of the middle segment of the leaky coaxial cable are processed as an arithmetic sequence, that is, θ1 to θ n is an arithmetic sequence, wherein θ1 to θ n gradually increases or decreases, and the selection of the structure number n of the leaky coaxial cable is determined according to the tolerance of θ1 to θ n . n -θ n-1 |≥3°.

[0011] The application further provides a leaky coaxial cable for indoor distribution, which is designed by the design method of the leaky coaxial cable.

[0012] Further, the slot width W of the leaky coaxial cable is consistent, and the slot width is 1 / 8 to 1 / 10 of the average length of the slot holes of the multiple pitch structure slot holes.

[0013] The application further provides a design system of a leaky coaxial cable for indoor distribution, comprising: An electromagnetic wave radiation direction design module configured to design different electromagnetic wave radiation direction angles of the leaky coaxial cable along the line according to the position of the electromagnetic wave target coverage area of the target scene space; A slot hole pitch calculation module configured to calculate different pitches of the slot hole periodicity corresponding to different electromagnetic wave radiation direction angles of the leaky coaxial cable according to the different electromagnetic wave radiation direction angles of the leaky coaxial cable along the line designed by the electromagnetic wave radiation direction design module. The slot length calculation module is configured to calculate the slot length of the slots in each section of the leaky coaxial cable according to different electromagnetic wave radiation direction angles designed by the electromagnetic wave radiation direction design module and different slot pitches of the corresponding slot periodicity calculated by the slot pitch calculation module, and in combination with the requirement that the electromagnetic wave radiation intensity of the target coverage area is consistent.

[0014] The application further provides an electronic device, including a memory, a processor and a computer program stored in the memory and executable on the processor, wherein the processor implements the steps of the design method of the leaky coaxial cable for indoor distribution when executing the program.

[0015] The application further provides a computer readable storage medium, which stores a computer program, wherein the computer readable storage medium stores the computer program, and the computer program executes the steps of the design method of the leaky coaxial cable when executed by a processor.

[0016] Compared with the prior art, the application has the following beneficial effects: (1) According to the radiation theory of the radiation type leaky coaxial cable, different radiation directions are designed for the leaky coaxial cable along the line according to the coverage area position of different scene spaces, and the outer conductor slot pitch is configured according to the radiation direction, so that the electromagnetic wave signals radiated by the leaky coaxial cable can fully cover the target coverage area in the indoor scene and can be concentrated in a certain specific area.

[0017] (2) According to the specific formula relationship, the matching slot leaky radiation amount is set according to the slot pitch between the slots and the preset electromagnetic wave radiation direction of the slots, so that the slot length of the leaky coaxial cable along the line satisfies formula 2, so that the leaky coaxial cable along the line has consistent coupling loss.

[0018] (3) After the design and calculation of the leaky coaxial cable, the same type of outer conductor slot combination is adopted, and the designed length is processed, and finally a customized product with several different slot pitches and slot lengths of the slots in a section of the leaky coaxial cable is produced, and the performance can ensure that the leaky coaxial cable does not have obvious weak coverage area in the target coverage area, and does not overlap with the outdoor signal too much, and the radiated signal is concentrated in a certain area in the target coverage area to a certain extent, so as to optimize the indoor coverage effect of the leaky coaxial cable. BRIEF DESCRIPTION OF DRAWINGS

[0019] Figure 1 It is a structural schematic diagram of the existing leaky coaxial cable; Figure 2 It is a schematic diagram of electromagnetic wave radiation to the target radiation area under the general situation of the existing leaky coaxial cable; Figure 3 Figure is a schematic diagram of the outer conductor slot structure of a commonly used leaky coaxial cable; Figure 4 Figure is a schematic diagram of the flow of the design method of the leaky coaxial cable for indoor distribution of the present application; Figure 5 Figure is a schematic diagram of the slot radiation direction of the leaky coaxial cable; Figure 6 Figure is a schematic diagram of the adjustment of the electromagnetic wave radiation direction of the leaky coaxial cable designed by the present application to the target area; Figure 7 Figure is a leaky coaxial cable radiation lobe diagram; Figure 8 Figure is a schematic diagram of the outer conductor slot structure of an exemplary leaky coaxial cable of the present application.

[0020] In the above figures, the following reference signs are included: 1, inner conductor; 2, foamed insulation layer; 3, slot; 4, outer conductor; 5, sheath layer. DETAILED DESCRIPTION

[0021] In order to make the purpose, technical solutions and advantages of the present application clearer and more apparent, the present application will be further described in detail below with reference to the embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and do not limit the present application. In addition, the technical features involved in each embodiment of the present application described below can be combined with each other as long as they do not conflict with each other.

[0022] The radiation type leaky coaxial cable is a coaxial cable with periodic slots on the outer conductor. The commonly used slot arrangement structure is shown in Figure 3 Based on these arrangements, the slots of the leaky coaxial cable can emit radiation waves with a wide frequency range. The radiation type leaky coaxial cable couples a part of the energy inside the leaky coaxial cable out through the slots to radiate outward. When the slot pitch of the leaky coaxial cable and the signal frequency meet certain conditions, the leaky coaxial cable emits radiation waves at a specific angle. The conventional leaky coaxial cable adopts a completely consistent outer conductor slot structure, so that the leaky coaxial cable has a completely consistent electromagnetic wave radiation direction and radiation intensity at a specific frequency band, resulting in the problem of signal cross coverage or weak coverage.

[0023] In view of the above problems, the present application proposes a design method of a leaky coaxial cable for indoor distribution, as shown in Figure 4 The method comprises the following steps: Step S1, designing different electromagnetic wave radiation direction angles of the leaky coaxial cable along the line according to the position of the electromagnetic wave target coverage area of the target scene space; Step S2, according to the different electromagnetic wave radiation direction angle of the leaky coaxial cable along the line designed in step S1, the different pitch of the slot hole periodicity corresponding to the different electromagnetic wave radiation direction angle of the leaky coaxial cable is calculated; Step S3, according to the different electromagnetic wave radiation direction angle designed in step S1 and the different pitch of the slot hole periodicity corresponding to the different electromagnetic wave radiation direction angle calculated in step S2, and combining the requirement that the electromagnetic wave radiation intensity of the target coverage area is consistent, the slot length of the slot hole in each pitch of the leaky coaxial cable is calculated.

[0024] Generally, the radiation type leaky coaxial cable works in the case of the best use frequency band (that is, without considering the radiation of high order mode electromagnetic wave, the radiation type leaky coaxial cable usually uses single mode radiation for wireless communication in engineering for transmission quality), the angle θ (such as Figure 5 ) between the electromagnetic wave radiation direction and the transmission direction of the leaky coaxial cable can be obtained from the relationship , wherein, is the propagation constant of the electric wave along the longitudinal direction of the leaky coaxial cable, is the propagation constant of the space electromagnetic wave. is the equivalent dielectric constant of the insulating medium of the leaky coaxial cable; is the wavelength of the corresponding frequency of the electromagnetic wave; is the pitch between the slot holes of the leaky coaxial cable. Based on the above relationship, the different pitch of the slot hole gap periodicity of the leaky coaxial cable can be calculated by the following formula 1.

[0025] Formula 1; , wherein, is the equivalent dielectric constant of the insulating medium of the leaky coaxial cable; is the wavelength of the corresponding frequency of the electromagnetic wave; is the pitch between the slot holes of the leaky coaxial cable; is the included angle between the electromagnetic wave radiation direction of the leaky coaxial cable and the transmission direction of the leaky coaxial cable.

[0026] Exemplarily, as shown in Figure 6 , the electromagnetic wave of the leaky cable radiated to the target coverage area is defined as the direction with the strongest electromagnetic wave amplitude in the electromagnetic wave radiation lobe diagram, and there is still a certain amount of weak signal in other directions (when the radiation type leaky coaxial cable works in the best use frequency band, the multi-mode signal, that is, the electromagnetic wave in other directions, is suppressed by the effect of the slot hole arrangement, so that the leaky coaxial cable radiates a certain direction with strong electromagnetic wave in single mode), and the electromagnetic wave lobe diagram is as shown in Figure 7 , wherein Figure 7 the layer by layer lobe structure is the electromagnetic wave of each mode of the leaky coaxial cable. The electromagnetic wave radiation direction of the leaky coaxial cable of the present application only considers the strongest direction, and the electromagnetic wave radiation direction changes from θ1 to θn The selected leaky cable can have a size ranging from 1 / 2" to 1-5 / 8", and a medium equivalent dielectric constant Generally between 1.2 and 1.4.

[0027] The electromagnetic wave radiation range (θ1, θ n ) of the leaky coaxial cable can be calculated according to the actual size and requirements of the site. By substituting the value of θ into formula 1, the range value of the periodic pitch P of the outer conductor slot of the leaky coaxial cable at a specific frequency wavelength λ can be calculated, and all intermediate values of θ1 to θ n should satisfy θ1≤θ x ≤θ n or θ1≥θ x ≥θ n (1≤x≤n) to avoid weak coverage areas in the coverage space of the leaky coaxial cable. For example For a 1-1 / 4" leaky cable with a medium equivalent dielectric constant of 1.23, the main electromagnetic wave radiation direction is set to 88° to 104° at a usage frequency of 2100Mhz, and the pitch value range of the leaky coaxial cable is designed to be 105.6mm to 132.7mm. Figure 5

[0028] For example, the different electromagnetic wave radiation direction angles of the leaky coaxial cable along the line are designed as follows: according to the initial end and the last end boundary of the electromagnetic wave coverage area of the target scene space and the initial segment and the last segment boundary position of the leaky coaxial cable, the slot hole radiation angle boundary values θ1 and θ n at the start and end positions of the leaky coaxial cable are calculated; the radiation direction of the middle segment of the leaky coaxial cable should be uniformly directed to the coverage area, so for θ1 to θ n , the angle of each segment slot hole is processed as an arithmetic progression, i.e. θ1 to θ n is an arithmetic sequence, and θ1 to θ n gradually increases or decreases, which can better ensure that the electromagnetic coverage of the leaky coaxial cable is relatively uniform and does not exist weak coverage. The number n of the leaky coaxial cable structure is selected according to the tolerance of θ1 to θ n , and the tolerance |θ n -θ n-1 |≥3°.

[0029] The slot holes of the conventional radiation type leaky coaxial cable have the same radiation intensity and electromagnetic wave radiation direction at the same pitch P and slot hole size and shape. For the leaky coaxial cable of the present application, the pitch P is different in the length direction, so the slot holes at different pitch intervals along the line of the leaky coaxial cable need to be designed to be of different sizes, so that the radiation electromagnetic wave intensity on the coverage area is substantially consistent.

[0030] ​The common structure of the radiation type leaky coaxial cable is "one" type slot hole and "eight" type slot hole, and the radiation amount of the slot hole is mainly related to the frequency band and the slot hole area per unit length. Generally, the shape and arrangement of the slot holes in the same leaky coaxial cable are basically consistent, and only the slot length, slot width and angle are adjusted to control the size of the slot hole radiation amount; the main reason is that adjusting the shape and arrangement of the slot hole (including the number of slot holes in one pitch and the arrangement mode) will change the pattern of the electromagnetic wave lobe radiated by the slot hole, so that the electromagnetic wave lobes of the leaky coaxial cable at each pitch period are inconsistent, thereby destroying the superposition characteristics of the electromagnetic radiation periodic structure of the leaky coaxial cable, and the electromagnetic signal at the place where the shape of the slot hole changes will fluctuate sharply, resulting in poor strength and uniformity of the coverage field intensity.

[0031] Since the surface current of the leaky coaxial cable is parallel to the axial direction of the leaky coaxial cable, and the slot width W of the leaky coaxial cable is small and much smaller than the slot length L, and the slot length direction is directly opposite to the surface current direction, therefore the slot length L of the general leaky coaxial cable has more significant influence on the coupling loss. Based on this, in order to control the electromagnetic wave radiation direction of the leaky coaxial cable, the leaky coaxial cable of the present application adopts periodic slot holes with different pitch intervals P distributed along the axial direction, and mainly adjusts the slot length L to control the intensity of the leaky coaxial cable radiation level, that is, different pitches P and corresponding slot lengths L are set to make the coupling loss along the line equivalent and the radiation direction face the target coverage area, and the arrangement mode of the slot hole is designed to remain consistent.

[0032] For the coupling loss of the radiation type leaky coaxial cable, the approximate formula is: wherein A is a fixed coefficient, λ is the electromagnetic wavelength, r is the distance from the receiving antenna to the front of the leaky coaxial cable (generally, the coupling loss value at 2 meters is taken as the standard, that is, r=2 meters), a r is the radiation attenuation of the leaky coaxial cable.

[0033] wherein the radiation amount a rn to the target coverage area is related to the slot length L n , the number of pitches per unit length 1 / P n , the radiation direction θ n , and the calculation formula is: Formula 2; wherein, is the radiation attenuation of the leaky coaxial cable of the nth pitch length, and is a constant value; B is a fixed coefficient, and is a constant value; P n is the nth pitch length between the slot holes of the leaky coaxial cable; θ n is the angle between the electromagnetic wave radiation direction of the leaky coaxial cable of the nth pitch length and the transmission direction of the leaky coaxial cable; L n is the slot length of the slot hole in the leaky coaxial cable of the nth pitch length.

[0034] The leaky coaxial cable of the present invention radiates to the target area through slots at various points along the axis. It should be basically consistent, that is, for the entire leaky coaxial cable, If both B and B are constants, then the parameters of a certain slot in the coaxial cable can be leaked ( It can be determined The definite value. When the electrical performance parameters of a certain slot structure at a specific wavelength band λ are obtained through testing, then for the same performance parameters... The pitch P and slot length L corresponding to the value of B can be calculated by substituting the preset θ range into Formula 1 to obtain the range of P values, and then deriving L through Formula 2.

[0035] This invention also provides a leaky coaxial cable for indoor distribution, designed using the aforementioned design method for leaky coaxial cables for indoor distribution. Specifically, the leaky coaxial cable of this invention comprises, from the inside out, an inner conductor, an insulation layer, an outer conductor, and a sheath layer. The outer conductor has periodic slots with different pitch intervals distributed along its axis. Each pitch of the leaky coaxial cable has the same coupling loss. The slot width W of the leaky coaxial cable is consistent, and the slot width is 1 / 8 to 1 / 10 of the average slot length of the multiple pitch structures. The slots are figure-eight shaped, and the slot inclination angle α varies from 15° to 30°.

[0036] Once the attenuation and coupling loss values ​​of a certain slot type are determined through testing under known parameters such as slot length L, slot width W, slot inclination angle α, and pitch P, the slot length L and pitch P values ​​corresponding to the radiation angle θ of other slots of the same series of slot types under the same attenuation, coupling, slot width W, and slot inclination angle α can be calculated using Formula 2. For a slot parameter of a certain pitch P, industry technicians can select a suitable slot for testing based on experience to determine whether the attenuation and coupling loss of the leaky coaxial cable structure with a given pitch P and slot parameters meet the usage requirements. Based on the parameters of this structure, the slot length of other leaky coaxial cables with the same attenuation and coupling loss requirements can be further calculated.

[0037] For example, Figure 8The outer groove hole of the leaky coaxial cable is arranged in an "eight" shape, the coupling loss thereof is about 70 dB under a 2100 MHz frequency band, the attenuation thereof is about 5 dB per hundred meters, the pitch thereof is 250 mm, the groove length of the groove hole of the leaky coaxial cable is about 20 mm, and the radiation direction of the leaky coaxial cable is 55°; under the same wavelength, attenuation and coupling loss performance conditions of the frequency band, and under the condition that the groove width and the groove skew angle are unchanged, the pitch of the groove hole with a radiation angle of 70° of the leaky coaxial cable is calculated as 180 mm by formula 1, and the groove length is calculated as 17.8 mm by formula 2, which is equivalent to the actual groove length of 18.0 mm.

[0038] The application further provides a design system of the leaky coaxial cable for indoor distribution, comprising: The electromagnetic wave radiation direction design module is configured to design different electromagnetic wave radiation direction angles of the leaky coaxial cable along a line according to the position of the electromagnetic wave target coverage area of the target scene space. The groove pitch calculation module is configured to calculate different pitches of groove holes corresponding to different electromagnetic wave radiation direction angles of the leaky coaxial cable according to the different electromagnetic wave radiation direction angles of the leaky coaxial cable along a line designed by the electromagnetic wave radiation direction design module. The groove length calculation module is configured to calculate the groove length of the groove holes in each pitch of the leaky coaxial cable according to the different electromagnetic wave radiation direction angles designed by the electromagnetic wave radiation direction design module and the different pitches of the corresponding groove holes calculated by the groove pitch calculation module, and in combination with the requirement that the electromagnetic wave radiation intensity of the target coverage area is consistent.

[0039] In addition, the application further provides an electronic device, which comprises at least one processor and at least one memory, the memory is in data connection with the processor, wherein the memory stores instructions executable by the at least one processor, and the instructions are executed by the at least one processor to enable the at least one processor to execute the steps of the design method of the leaky coaxial cable for indoor distribution.

[0040] The processor can be a central processing unit (CPU), and can also be other general-purpose processors, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field-programmable gate array (FPGA) or other programmable logic device, discrete gate or transistor logic, discrete hardware components, etc. The general-purpose processor can be a microprocessor or the processor can also be any conventional processor.

[0041] Finally, the present application also provides a computer readable storage medium, and the computer readable storage medium stores a computer program. When the computer program is run by a processor, the steps of the design method of the leaky coaxial cable for indoor distribution are executed.

[0042] Those skilled in the art can understand that all or part of the processes in the above-mentioned embodiment methods can be completed by a computer program instructing related hardware. The computer program can be stored in a non-volatile computer readable storage medium, and when the computer program is executed, the processes of the above-mentioned embodiments can be included. Any reference to memory, storage, database or other medium used in the embodiments provided by the present application can include at least one of non-volatile and volatile memory. The non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory or optical memory, etc. The volatile memory can include random access memory (RAM) or external cache memory. As an illustration but not limitation, the RAM can be in various forms, such as static random access memory (SRAM) or dynamic random access memory (DRAM), etc.

[0043] Embodiments For a certain place target coverage area about 9 meters wide, 1 meter from the window, the total length of the indoor distribution of the leaky coaxial cable of the application is 10 meters, wherein there are 5 pitch structures corresponding to the radiation angles θ1 to θ5, and the length of each section is 2 meters, 2 meters, 3 meters, 2 meters and 1 meter. The electromagnetic wave of θ1 angle covers the corner area of the wall, and when θ1 is 88°, the weak coverage area of the wall corner can be reduced to within 0.1 meters; the electromagnetic wave of θ5 angle avoids the window 1 meter away, and the angle is about 104°; the electromagnetic wave of θ2 to θ4 angle is adjusted to concentrate in the personnel concentration area, and the value is selected between 88° and 104°. Through actual test verification, the slot length L1=17mm, the radiation angle θ1=88°, and the 1-1 / 4"leaky coaxial cable with a pitch of 132.7mm can be obtained by actual test. The attenuation and coupling loss of this structure is about 4.9dB / 100m and 70Db, and the dielectric constant of the leaky coaxial cable is about 1.23. Therefore, a leaky coaxial cable with 5 different slot pitches is designed, and when the radiation angle range is (88°, 104°), the leaky coaxial cable signal radiation can be concentrated in the target coverage area, and the slot radiation direction adjustment to the target area is shown in Figure 6 The slot pitch and slot length required by other corresponding radiation angles are calculated by formula 1 and formula 2. The electrical performance and slot parameters of the leaky coaxial cable are shown in table 1.

[0044] Table 1 Slot electrical performance and slot parameters of target leaky coaxial cable

[0045] The above-described embodiments only represent the embodiments of the present application, which are described in detail and in detail, but cannot be understood as limiting the scope of the patent of the present application, and the present application can also be implemented in other specific ways or other specific forms without deviating from the spirit or essential characteristics of the present application. Therefore, the described embodiments should be regarded as illustrative rather than limiting in any aspect. The scope of the present application should be explained by the appended claims, and any changes equivalent to the intent and scope of the claims should also be included in the scope of the present application.

Claims

1. A method of designing a leaky coaxial cable for indoor distribution, characterized by, The method comprises the following steps: Step S1, according to the position of the target scene space electromagnetic wave target coverage area, design the different electromagnetic wave radiation direction angle of the leaky coaxial cable along the line; Step S2, according to the different electromagnetic wave radiation direction angle of the leaky coaxial cable along the line designed in step S1, calculate the different pitch of the slot hole periodicity corresponding to the different electromagnetic wave radiation direction angle of the leaky coaxial cable; Step S3, according to the different electromagnetic wave radiation direction angle designed in step S1 and the different pitch of the corresponding slot hole periodicity calculated in step S2, and combining the requirement that the electromagnetic wave radiation intensity of the target coverage area is consistent, calculate the slot length of the slot hole in each pitch of the leaky coaxial cable.

2. The design method of a leaky coaxial cable for indoor distribution according to claim 1, characterized by, In step S2, the formula for calculating the different pitch of the slot hole periodicity corresponding to the different electromagnetic wave radiation direction angle is as follows: Formula 1 ; wherein, is the equivalent dielectric constant of the dielectric medium of the leaky coaxial cable; is the wavelength of the electromagnetic wave corresponding to the frequency; is the pitch between the slots of the leaky coaxial cable; is the angle between the direction of electromagnetic wave radiation and the direction of transmission of the leaky coaxial cable.

3. The design method of a leaky coaxial cable for indoor distribution according to claim 1, characterized by, In step S3, the formula for calculating the slot length of the slot hole in each pitch of the leaky coaxial cable is as follows: Formula 2: wherein, is the leakage coaxial cable radiation attenuation of the n-th segment pitch length, and is a constant value; B is a fixed coefficient, and is a constant value; P n is the n-th segment pitch length of the leakage coaxial cable slot; θ n is the angle between the electromagnetic wave radiation direction of the n-th segment pitch length of the leakage coaxial cable and the transmission direction of the leakage coaxial cable; L n is the slot length of the slot in the n-th segment pitch length of the leakage coaxial cable.

4. The design method of a leaky coaxial cable for indoor distribution according to claim 1, characterized by, In step S1, the angles of different electromagnetic wave radiation directions along the leaky coaxial cable are designed to be θ1 to θ2. n , and θ1 to θ n All intermediate values ​​should satisfy θ1≤θ x ≤θ n or θ1≥θ x ≥θ n (1≤x≤n); wherein θ1 is the electromagnetic wave radiation angle of the leaky coaxial cable at the initial segment pitch along the transmission direction, θ n is the electromagnetic wave radiation angle of the leaky coaxial cable at the final segment pitch along the transmission direction; When the length of the leaky coaxial cable is greater than the length of the coverage area, θ1≤θ n When the length of the leaky coaxial cable is less than the length of the coverage area, θ1≥θ n ; The electromagnetic wave radiation direction angle is defined as the included angle between the direction with the strongest electromagnetic wave amplitude in the electromagnetic wave radiation lobe diagram of the leaky coaxial cable and the transmission direction of the leaky coaxial cable.

5. The design method of a leaky coaxial cable for indoor distribution according to claim 1, characterized by, In step S1, according to the position of the target scene space electromagnetic wave target coverage area, design the different electromagnetic wave radiation direction angle of the leaky coaxial cable along the line, including: According to the initial end and the last end boundary of the electromagnetic wave target coverage area of the target scene space, and the initial segment and the last segment boundary position of the leaky coaxial cable, the slot hole radiation angle boundary values θ1 and θ2 of the initial end and the last end position of the leaky coaxial cable are calculated n ; The angles of the electromagnetic wave radiation direction of the intermediate section of the leaky coaxial cable are processed as an arithmetic progression, i.e. θ1 to θ n are an arithmetic progression, wherein θ1 to θ n gradually increase or decrease, and the selection of the number n of the leaky coaxial cable structure is determined according to the tolerance of θ1 to θ n , the tolerance of the arithmetic progression |θ n -θ n-1 |≥3°.

6. A leaky coaxial cable for indoor distribution designed by a design method of the leaky coaxial cable according to any one of claims 1 to 5, characterized by, The leaky coaxial cable comprises, from inside to outside, an inner conductor, an insulating layer, an outer conductor and a sheath layer, and the axis of the outer conductor is distributed with periodic slot holes at different pitch intervals along the line, and the leaky coaxial cable in each pitch has the same coupling loss.

7. The leaky coaxial cable for indoor distribution of claim 6, wherein, The slot width W of the leaky coaxial cable is consistent, and the slot width is 1 / 8 to 1 / 10 of the average of the slot lengths of the slot holes in the multiple pitch structure.

8. A design system for a leaky coaxial cable for indoor distribution, characterized by It comprises: An electromagnetic wave radiation direction design module configured to design the different electromagnetic wave radiation direction angle of the leaky coaxial cable along the line according to the position of the target scene space electromagnetic wave target coverage area; A slot hole pitch calculation module configured to calculate the different pitch of the slot hole periodicity corresponding to the different electromagnetic wave radiation direction angle of the leaky coaxial cable according to the different electromagnetic wave radiation direction angle of the leaky coaxial cable along the line designed by the electromagnetic wave radiation direction design module; A slot hole slot length calculation module configured to calculate the slot length of the slot hole in each pitch of the leaky coaxial cable according to the different electromagnetic wave radiation direction angle designed by the electromagnetic wave radiation direction design module and the different pitch of the corresponding slot hole periodicity calculated by the slot hole pitch calculation module, and combining the requirement that the electromagnetic wave radiation intensity of the target coverage area is consistent.

9. An electronic device, comprising: The electronic device comprises at least one processor and at least one memory, the memory is in data connection with the processor, wherein the memory stores instructions executable by the at least one processor, and the instructions are executed by the at least one processor to enable the at least one processor to perform the steps of the design method of the leaky coaxial cable for indoor distribution according to any one of claims 1 to 5.

10. A computer-readable storage medium, characterized in that, The computer program is stored on the computer readable storage medium, and when the computer program is run by the processor, the steps of the design method of the leaky coaxial cable for indoor distribution according to any one of claims 1 to 5 are executed.

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