Leakage cable for suppressing high-order mode based on symmetric slotted holes

Abstract

The invention provides a leakage cable for suppressing a high-order mode based on symmetrical slotted holes, which comprises an inner conductor, an insulating layer, a conductor layer and an outer ring sleeve which are sequentially and coaxially nested from inside to outside, and is characterized in that a plurality of slotted hole groups are formed in the conductor layer and are distributed along the circumferential direction of the conductor layer; each slotted hole group comprises a plurality of slotted hole arrays which are arranged at intervals in the axial direction of the conductor layer, each slotted hole array comprises a plurality of >-shaped first slotted holes and a plurality of <-shaped second slotted holes, and each first slotted hole and each second slotted hole are respectively composed of two rectangular grooves. By applying the technical scheme of the invention, the problems of high-frequency attenuation and unstable signal transmission of a leaky cable in a high-frequency band in the prior art are solved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of leaky cable design, in particular to a leaky cable based on symmetrical slot holes for suppressing high-order modes. BACKGROUND

[0002] The design of conventional leaky cables is mainly aimed at low and medium frequency bands (such as 900MHz, 1800MHz, 2100MHz, 2600MHz, etc.), however, with the popularization of 5G communication technology, the demand for leaky cables suitable for high frequency bands (such as 3.5GHz, 4.9GHz, etc.) is increasing, and the conventional leaky cables will face serious high-frequency attenuation at high frequencies due to skin effect and dielectric loss, and when the operating frequency approaches the cutoff frequency of the leaky cable, the generation of high-order modes will cause unstable signal transmission, increase the fluctuation of coupling loss, and make it difficult for the leaky cable to meet the demand in terms of electrical performance.

[0003] Therefore, the existing leaky cable has the problems of high-frequency attenuation and unstable signal transmission at high frequencies, which needs to be improved. SUMMARY

[0004] The present application provides a leaky cable based on symmetrical slot holes for suppressing high-order modes to solve the problem of high-frequency attenuation and unstable signal transmission at high frequencies in the prior art.

[0005] According to one aspect of the present application, a leaky cable based on symmetrical slot holes for suppressing high-order modes is provided, which comprises an inner conductor, an insulating layer, a conductor layer and an outer ring sleeve coaxially nested in sequence from inside to outside, a plurality of slot hole groups are formed on the conductor layer, and the plurality of slot hole groups are distributed along the circumference of the conductor layer; each slot hole group comprises a plurality of slot hole arrays arranged axially along the conductor layer, each slot hole array comprises a plurality of first slot holes in the shape of ">" and a plurality of second slot holes in the shape of "<", and each first slot hole and second slot hole is composed of two rectangular slots.

[0006] Further, each slot hole array comprises a first slot hole unit and a second slot hole unit, the first slot hole unit comprises a plurality of first slot holes, the second slot hole unit comprises a plurality of second slot holes, and the number of first slot holes in the first slot hole unit is the same as that of second slot holes in the second slot hole unit.

[0007] Further, the number of first slot holes and second slot holes in each slot hole array is the same, and the total number of first slot holes and second slot holes is 4-12.

[0008] Further, the included angle between the two rectangular slots constituting the first slot hole or the second slot hole is α, the range of α is 15°-70°, and the included angle openings of the first slot holes and the second slot holes in the same slot hole array are mutually divergent in the axial direction of the conductor layer.

[0009] Further, the length of the rectangular slot constituting the first slot hole or the second slot hole is L, and L ranges from 0.18λ to 0.25λ, λ being the corresponding wavelength of the target high-order mode. m Further, the length of the rectangular slot constituting the first slot hole or the second slot hole is L, and L ranges from 0.18λ to 0.25λ, λ being the corresponding wavelength of the target high-order mode. m Further, the length of the rectangular slot constituting the first slot hole or the second slot hole is L, and L ranges from 0.18λ to 0.25λ, λ being the corresponding wavelength of the target high-order mode.

[0010] Further, the length of the rectangular slot constituting the first slot hole or the second slot hole is L, and L ranges from 0.18λ to 0.25λ, λ being the corresponding wavelength of the target high-order mode.

[0011] Further, the length of the rectangular slot constituting the first slot hole or the second slot hole is L, and L ranges from 0.18λ to 0.25λ, λ being the corresponding wavelength of the target high-order mode. m Further, the length of the rectangular slot constituting the first slot hole or the second slot hole is L, and L ranges from 0.18λ to 0.25λ, λ being the corresponding wavelength of the target high-order mode. m Further, the length of the rectangular slot constituting the first slot hole or the second slot hole is L, and L ranges from 0.18λ to 0.25λ, λ being the corresponding wavelength of the target high-order mode.

[0012] Further, the length of the rectangular slot constituting the first slot hole or the second slot hole is L, and L ranges from 0.18λ to 0.25λ, λ being the corresponding wavelength of the target high-order mode. m Further, the length of the rectangular slot constituting the first slot hole or the second slot hole is L, and L ranges from 0.18λ to 0.25λ, λ being the corresponding wavelength of the target high-order mode. m Further, the length of the rectangular slot constituting the first slot hole or the second slot hole is L, and L ranges from 0.18λ to 0.25λ, λ being the corresponding wavelength of the target high-order mode.

[0013] Further, L=0.3[1+kln(1+f / f m )][λ / (e) 1 / 2 ], where 0.2

[0014] Further, D=c[1.2-0.15ln(αf m / f)] 1 / α [2 / (e+1)] 1 / 2 / π(f+f m ), where α is the number of slot hole groups, e is the relative dielectric constant of the conductor layer, and f is the lowest frequency of the working frequency of the leakage cable based on the symmetric slot hole to suppress the high-order mode.

[0015] By applying the technical solution of this invention, a first slot in the shape of ">" and a second slot in the shape of "<" are set on the conductor layer, which disrupts the propagation path of higher-order modes, preventing them from propagating stably in the leaky cable based on symmetrical slot suppression of higher-order modes. This reduces fluctuations in signal attenuation and coupling loss. Especially when the operating frequency is close to or exceeds the cutoff frequency of the leaky cable, this setting can optimize the electromagnetic field distribution and radiation characteristics of the leaky cable based on symmetrical slot suppression of higher-order modes in the target frequency band, effectively suppressing higher-order modes, ensuring stable signal propagation, maintaining the communication quality of the leaky cable based on symmetrical slot suppression of higher-order modes in the high-frequency band, improving the reliability and applicability of the leaky cable based on symmetrical slot suppression of higher-order modes in high-frequency application scenarios, and solving the problems of high-frequency attenuation and unstable signal transmission in the high-frequency band of existing leaky cables. Attached Figure Description

[0016] The accompanying drawings, which form part of this application, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings:

[0017] Figure 1 A top view of a leakage cable based on symmetrical slots for suppressing higher-order modes, according to an embodiment of the present invention, is shown.

[0018] Figure 2 A partial cross-sectional view of a leakage cable based on symmetrical slots suppressing higher-order modes is shown.

[0019] Figure 3 A schematic diagram showing the dimensions of the first and second slots in the slot group is shown;

[0020] Figure 4 The simulation diagram of attenuation obtained by optimizing a conventional leaky cable in the 0-6GHz range is shown.

[0021] Figure 5 It shows Figure 1 The attenuation simulation diagram of the leakage cable based on symmetrical slot hole suppression of higher-order modes in the 0-6GHz range after optimization;

[0022] Figure 6 It shows Figure 1 Simulated coupling loss of a leakage cable based on symmetrical slots to suppress higher-order modes at 5 GHz.

[0023] The above figures include the following reference numerals:

[0024] 10. Inner conductor;

[0025] 20. Insulation layer;

[0026] 30, conductor layer; 31, slot hole group; 311, slot hole array; 3111, first slot hole unit; 31111, first slot hole; 3112, second slot hole unit; 31121, second slot hole;

[0027] 40, outer ring sleeve. DETAILED DESCRIPTION

[0028] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. The following description of at least one exemplary embodiment is merely illustrative in nature and is in no way limiting on the application or its applications or uses. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative work fall within the scope of protection of the present application.

[0029] As shown in the drawings, Figures 1 to 6 The present application provides a leakage cable based on symmetric slot holes for suppressing high-order modes, which comprises an inner conductor 10, an insulating layer 20, a conductor layer 30 and an outer ring sleeve 40 coaxially nested from inside to outside, a plurality of slot hole groups 31 are arranged on the conductor layer 30, and the plurality of slot hole groups 31 are distributed along the circumference of the conductor layer 30; each slot hole group 31 comprises a plurality of slot hole arrays 311 arranged axially along the conductor layer 30, each slot hole array 311 comprises a plurality of “>” shaped first slot holes 31111 and a plurality of “<” shaped second slot holes 31121, and each first slot hole 31111 and second slot hole 31121 is composed of two rectangular slots.

[0030] By arranging the “>” shaped first slot holes 31111 and “<” shaped second slot holes 31121 on the conductor layer 30, the propagation path of the high-order mode is destroyed, so that it cannot stably propagate in the leakage cable based on symmetric slot holes for suppressing high-order modes, thereby reducing the signal attenuation and the fluctuation of coupling loss, especially when the working frequency is close to or exceeds the cutoff frequency of the leakage cable, such arrangement can optimize the electromagnetic field distribution and radiation characteristics of the leakage cable based on symmetric slot holes for suppressing high-order modes in the target frequency band, effectively suppress the high-order mode, ensure the stable propagation of the signal, maintain the communication quality of the leakage cable based on symmetric slot holes for suppressing high-order modes in the high frequency band, improve the reliability and applicability of the leakage cable based on symmetric slot holes for suppressing high-order modes in the high frequency band application scenario, and solve the problem of high frequency attenuation and unstable signal transmission of the leakage cable in the high frequency band in the prior art.

[0031] As shown in the drawings, Figure 2As shown, each slot array 311 includes a first slot unit 3111 and a second slot unit 3112. The first slot unit 3111 includes a plurality of first slots 31111, and the second slot unit 3112 includes a plurality of second slots 31121. The number of first slots 31111 in the first slot unit 3111 is the same as the number of second slots 31121 in the second slot unit 3112.

[0032] The first slot unit 3111 is composed of multiple first slots 31111, and the second slot unit 3112 is composed of the same number of second slots 31121. The first slots 31111 and the second slots 31121 are in the form of ">" and "<", respectively, which helps to stabilize the transmission of electromagnetic waves. Setting the number of first slots 31111 and the number of second slots 31121 in the second slot unit 3112 is the same, which enhances the symmetry of the structure and the consistency of electromagnetic characteristics, avoids interference from higher-order modes, and ensures the signal transmission stability of the entire leakage cable based on symmetrical slot suppression of higher-order modes within the target frequency range.

[0033] like Figure 2 As shown, the number of first slots 31111 and second slots 31121 in each slot array 311 is the same, and the total number of first slots 31111 and second slots 31121 is 4-12.

[0034] The structural symmetry of the slot array 311 is crucial for suppressing higher-order modes. To maintain this symmetry, the total number of first slots 31111 and second slots 31121 within each slot array 311 must be even, and between 4 and 12. By using an equal number of first slots 31111 and second slots 31121, the symmetry of the slot array 311 on the conductor layer 30 is maintained. This allows for an effective electromagnetic field distribution within the target frequency band, thereby suppressing the generation of higher-order modes and their interference with the transmission of the dominant mode. This ensures low attenuation and stable coupling of the signal at the over-cutoff frequency, optimizing the radiation efficiency of electromagnetic waves and the stability of signal transmission.

[0035] Optionally, before designing the parameters of the first slot 31111 or the second slot 31121, the period P of the slot array 311 can be determined first. It satisfies the following relationship with the lowest frequency of the leakage cable design based on symmetrical slot suppression of higher-order modes: P=2c(i-1). 1 / 3 / fe 2 +δ, where c is the propagation speed of electromagnetic waves in free space, e is the relative permittivity of the insulation layer, f represents the lowest frequency of the leaky cable's operation, i is the number of slot columns in each slot array, and the correction factor δ = ±10mm.

[0036] like Figure 3As shown, the included angle between the two rectangular slots that make up the first slot 31111 or the second slot 31121 is α, and the range of α is 15°~70°. The included angle openings of the first slot 31111 and the second slot 31121 in the same slot array 311 are opposite to each other in the axial direction of the conductor layer 30.

[0037] The included angle α between the two rectangular slots forming the first slot 31111 or the second slot 31121 is a key geometric parameter determining the radiation characteristics and coupling efficiency of the first slot 31111 or the second slot 31121. The size of this included angle α directly affects the leakage intensity and mode purity of the electromagnetic wave. Setting the included angle α in the range of 15° to 70° optimizes the radiation characteristics and coupling efficiency of the first slot 31111 or the second slot 31121, and stabilizes the higher-order modes by disrupting their propagation paths.

[0038] When the included angle α is too small, i.e., α < 15°, the structure of the first slot 31111 or the second slot 31121 tends to be narrow and long. Although this is beneficial for reducing conductor loss and signal attenuation, it will significantly weaken the external coupling capability of electromagnetic energy, resulting in insufficient radiation efficiency and increased coupling loss, making it difficult to meet communication coverage requirements. When the included angle α is too large, i.e., α > 70°, the opening of the first slot 31111 or the second slot 31121 is wide. Although this can enhance radiation intensity and improve coupling performance, it will excessively disturb the current distribution on the surface of the conductor layer 30, easily exciting unnecessary resonance and higher-order modes, resulting in unstable transmission signals and increased fluctuations in the attenuation curve, which in turn degrades the overall performance. Therefore, optimizing the included angle α to be between 15° and 70° can achieve the best balance between low attenuation and low coupling loss.

[0039] like Figure 3 As shown, the length of the rectangular slot forming the first slot 31111 or the second slot 31121 is L, and L ranges from 0.18λ to 0.25λ, where λ is the higher-order mode suppression frequency f. m The corresponding wavelength, f m The center suppression frequency value of the target higher-order mode.

[0040] The length L of the rectangular slot directly affects the effective frequency of high-order mode suppression. By limiting the size of L, the generation of high-order modes can be effectively suppressed, thereby maintaining good signal radiation quality and transmission stability under the condition of over-cutoff frequency, and improving the high-frequency performance of the leakage cable based on symmetrical slot suppression of high-order modes.

[0041] Specifically, taking 4.9GHz as the example target stable frequency, the wavelength corresponding to this frequency is λ≈61.2mm. Therefore, the length L of the rectangular slot that makes up the first slot 31111 or the second slot 31121 should be between 0.18λ and 0.25λ, that is, between 11mm and 15.3mm. After optimization, L is selected as 12.2mm, which corresponds to about 0.2 times the wavelength of 4.9GHz.

[0042] When L is in the range of 0.18λ to 0.25λ, it can not only effectively suppress the 4.9GHz high-order mode, but also ensure that the overall performance of the leakage cable based on symmetrical slot suppression of high-order modes does not deteriorate significantly in the target frequency band. If L < 0.18λ, although the high-frequency attenuation performance is still relatively good, the low-frequency attenuation performance begins to decline rapidly. If L > 0.25λ, the high-frequency attenuation performance deteriorates significantly, and the high-order mode stability capability decreases.

[0043] like Figure 3 As shown, the width of the rectangular groove that makes up the first slot 31111 or the second slot 31121 is W, and W ranges from 0.15L to 0.25L.

[0044] The width W primarily controls the slot resonance and energy coupling strength, which affects the electrical performance of the leaky cable across various frequency bands. When W is too small (W < 0.15L), it leads to insufficient energy coupling, decreased electromagnetic leakage efficiency, and deterioration of higher-order mode suppression. Simultaneously, performance at multiple points within the target frequency band deteriorates significantly. When W is too large (W > 0.25L), it results in excessive energy coupling, excessively affecting the main mode transmission and also causing performance degradation.

[0045] By limiting the range of W to 0.15L to 0.25L, the structure of the first slot 31111 or the second slot 31121 can maintain appropriate resonance characteristics and energy coupling strength, without excessively weakening the current continuity of the conductor layer 30, nor causing a significant decrease in electromagnetic leakage performance, thereby achieving a balance between high-order mode suppression and signal transmission.

[0046] like Figure 3 As shown, the distance between the two sharp corners of two adjacent first slots 31111 is D, or the distance between the two sharp corners of two adjacent second slots 31121 is D, where D ranges from 0.18λ to 0.25λ, and λ is the higher-order mode suppression frequency f. m The corresponding wavelength, f m The center suppression frequency value of the target higher-order mode.

[0047] D is a core variable of the structural periodic layout, and has a significant influence on electromagnetic field distribution and radiation characteristics. If D is too small, the coupling between adjacent first slot holes 31111 or second slot holes 31121 will be intensified, causing electromagnetic field distribution disorder and increasing attenuation fluctuation. If D is too large, the radiation structure will be too sparse, reducing the radiation efficiency and increasing the coupling loss.

[0048] By setting the range of D to 0.18λ to 0.25λ, the signal transmission quality of the leakage cable based on symmetric slot holes for suppressing high-order modes can be ensured in the target frequency band while overcoming high-order mode interference, reducing transmission attenuation, and improving coupling stability, thereby optimizing high-frequency communication performance.

[0049] In some embodiments, the spacing S between two adjacent slot hole groups 31 in the circumferential direction of the conductor layer 30 is in the range of 0.12λ to 0.2λ, where λ is the wavelength corresponding to the center suppression frequency f m of the target high-order mode. m

[0050] By precisely controlling the size of S, a balance point between high-order mode suppression and electrical performance can be found, enabling efficient signal radiation and transmission. If S is too small, the interference between the two adjacent slot hole groups 31 will be intensified, which is not conducive to signal transmission. If S is too large, the coupling effect between the two adjacent slot hole groups 31 will be weakened, reducing signal radiation efficiency.

[0051] By setting the range of S to 0.12λ to 0.2λ, the generation of high-order modes can be effectively suppressed, while ensuring low coupling loss and low attenuation of the signal, thereby improving the comprehensive communication performance of the leakage cable based on symmetric slot holes for suppressing high-order modes at the super cutoff frequency.

[0052] In some embodiments, L = 0.3[1 + kln(1 + f / f m )][λ / (e) 1 / 2 ], where 0.2 < k < 0.5, e is the relative permittivity of the conductor layer 30, and f is the lowest frequency of the working frequency of the leakage cable based on symmetric slot holes for suppressing high-order modes.

[0053] This formula is used to calculate the optimal size of the rectangular slot length L to ensure the signal transmission performance of the leakage cable based on symmetric slot holes for suppressing high-order modes at high frequencies. By adjusting the value of the parameter k, the length L of the rectangular slot can be precisely controlled for specific working frequencies and medium properties, effectively suppressing high-order modes.

[0054] L is not an optimal solution for a single frequency point, but needs to be adjusted according to the working frequency range f m ​The size of L is calculated by the above formula, and the electromagnetic leakage performance and signal coupling strength of the leakage cable based on the symmetric slot hole for suppressing high-order modes can reach the best balance at the target frequency, so that the high-order mode is stabilized, the overall performance of the leakage cable based on the symmetric slot hole for suppressing high-order modes is stable in the target frequency band, the signal attenuation and coupling loss are avoided to be deteriorated, and the reliability of the communication transmission of the leakage cable based on the symmetric slot hole for suppressing high-order modes after the cutoff frequency is improved.

[0055] In some embodiments, D = c [1.2-0.15ln (a f m / f)] 1 / α [2 / (e+1)] 1 / 2 / π(f+f m ), wherein a is the number of slot hole groups 31, e is the relative dielectric constant of the conductor layer 30, and f is the lowest frequency of the working frequency of the leakage cable based on the symmetric slot hole for suppressing high-order modes.

[0056] Figure 4 The attenuation simulation result of the conventional leakage cable after optimization in the range of 0-6GHz is shown in the figure, from 3.4GHz, the high-order mode begins to affect, the attenuation performance gradually begins to deteriorate, and the attenuation stability in the range of 4.6GHz-5.2GHz is poor, which is difficult to support the communication signal of the high frequency band.

[0057] Comparison Figure 4 , Figure 5 It can be seen that the technical scheme of the present application effectively stabilizes the high-order mode, so that the leakage cable based on the symmetric slot hole for suppressing high-order modes realizes good attenuation performance in the frequency range of 0-5.4GHz.

[0058] In addition, Figure 6 The simulation coupling loss of the leakage cable based on the symmetric slot hole for suppressing high-order modes at 5GHz is shown in the figure, the influence of the high-order mode below 5GHz is effectively suppressed, and the coupling loss at 5GHz is low and stable.

[0059] The D value can be accurately calculated by the above formula, the interaction between the adjacent first slot hole 31111 or second slot hole 31121 is strengthened, the performance fluctuation caused by excessive signal coupling is eliminated, the synergy between high-order mode suppression and overall performance improvement is ensured, and the stability and low attenuation characteristics of the signal transmission of the leakage cable based on the symmetric slot hole for suppressing high-order modes are maintained.

[0060] It is to be understood that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of example embodiments in accordance with the present application. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms "comprises" and / or "comprising," when used in this specification, specify the presence of stated features, steps, operations, devices, components and / or combinations thereof, but do not preclude the presence or addition of one or more other features, steps, operations, devices, components and / or combinations thereof.

[0061] The relative arrangement of components and steps, numerical expressions, and numerical values set forth in the examples are not intended to limit the scope of the application unless otherwise specifically stated. It is to be understood that the drawings are not necessarily to scale of the various parts shown in the drawings. Techniques, methods, and apparatus known to those of ordinary skill are not discussed in detail because they would be understood that such techniques, methods, and apparatus are considered part of the art. In all examples shown and discussed herein, any specific values are to be interpreted as merely exemplary and not limiting. Thus, other examples of the example embodiments can have different values. It is noted that like numbers and letters on the figures identify like parts throughout the several views, and thus, once an item is defined in one figure, it is not necessary to discuss it further in connection with other figures where it is understood that the item will be present.

[0062] In the description of the present application, it is to be understood that the orientation or positional relationships indicated by orientation words such as "front, back, upper, lower, left, right", "horizontal, vertical, perpendicular, horizontal" and "top, bottom" are generally based on the orientation or positional relationships shown in the drawings, and are only for the convenience of describing the present application and simplifying the description. Without the opposite indication, these orientation words do not indicate and imply that the indicated device or element must have a particular orientation or be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the scope of protection of the present application. The orientation words "inner, outer" refer to the inner and outer relative to the contour of each component.

[0063] For purposes of the description hereinafter, the terms "upper", "lower", "right", "left", "rear", "front", "vertical" and "horizontal" as can be perceived herein relative to the accompanying drawings refer to the orientation of the components being described. However, it is to be understood that the spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if a device described herein relative to the other device or structure is inverted, then a spatially relative term such as "above" can be interpreted as meaning "below" or "below" can be interpreted as meaning "above". The device can also be oriented in other ways (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly. The devices can be otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly.

[0064] In addition, it should be pointed out that the use of the terms "first", "second" and the like in connection with various elements is merely intended for identification, and does not constitute a special meaning, and therefore cannot be interpreted as a limitation on the scope of protection of the present application.

[0065] The preferred embodiments of the present application have been described above with the purpose of enabling not only the best modes contemplated by the inventors of carrying out the application, but also as examples of embodiments of the present application. It is to be understood that many variations and modifications can be made to the present application without departing from the spirit and scope of the present application. Any modifications, equivalent replacements, improvements, and the like made within the spirit and principles of the present application shall be included in the scope of the present application.

Claims

1. A leakage cable based on symmetrical slot for suppressing high order mode, characterized in that, The cable comprises an inner conductor (10), an insulation layer (20), a conductor layer (30) and an outer ring (40) coaxially nested from inside to outside, a plurality of slot groups (31) are arranged on the conductor layer (30), and the plurality of slot groups (31) are distributed along the circumference of the conductor layer (30); each slot group (31) comprises a plurality of slot arrays (311) arranged axially along the conductor layer (30), each slot array (311) comprises a plurality of ">" shaped first slot holes (31111) and a plurality of "<" shaped second slot holes (31121), and each first slot hole (31111) and second slot hole (31121) is composed of two rectangular slots.

2. The leakage cable based on symmetric slot for suppressing high order mode according to claim 1, characterized in that, Each slot array (311) comprises a first slot hole unit (3111) and a second slot hole unit (3112), the first slot hole unit (3111) comprises a plurality of first slot holes (31111), the second slot hole unit (3112) comprises a plurality of second slot holes (31121), and the number of first slot holes (31111) in the first slot hole unit (3111) is the same as that of second slot holes (31121) in the second slot hole unit (3112).

3. The cable of claim 1, wherein, The number of first slot holes (31111) and second slot holes (31121) in each slot array (311) is the same, and the total number of first slot holes (31111) and second slot holes (31121) is 4-12.

4. The cable of claim 3, wherein, The included angle between the two rectangular slots constituting the first slot hole (31111) or the second slot hole (31121) is α, and the range of α is 15°-70°, the included angle between the first slot hole (31111) and the second slot hole (31121) in the same slot array (311) opens in the axial direction of the conductor layer (30) and is opposite to each other.

5. The cable of claim 3, wherein, The length of the rectangular slot constituting the first slot hole (31111) or the second slot hole (31121) is L, L ranges from 0.18λ to 0.25λ, λ is the center suppression frequency value of the target high-order mode m corresponding wavelength, f m is the center suppression frequency value of the target high-order mode.

6. The cable of claim 5, wherein, The width of the rectangular slot constituting the first slot hole (31111) or the second slot hole (31121) is W, and the range of W is 0.15L-0.25L.

7. The cable of claim 3, wherein, The distance between two sharp corners of two adjacent first slots (31111) is D, or the distance between two sharp corners of two adjacent second slots (31121) is D, D is in the range of 0.18λ to 0.25λ, λ is the high-order mode suppression frequency point f m Corresponding wavelength, f m The center suppression frequency value of the target high-order mode.

8. The cable of claim 1, wherein, In the conductor layer (30) circumferentially, the interval between two adjacent groove hole groups (31) is S, S ranges from 0.12λ to 0.2λ, λ is the high-order mode suppression frequency point f m Corresponding wavelength, f m The center suppression frequency value of the target high-order mode.

9. The leakage cable based on symmetric slot holes for suppressing high order modes according to claim 5, wherein L = 0.3 [1 + k ln(l + f / f m )][λ / (e) 1 / 2 ], where 0.2 < k < 0.5, e is the relative permittivity of the conductor layer (30), and f is the lowest frequency of the operating frequency of the leakage cable based on the symmetric slot hole for suppressing high-order modes.

10. The leakage cable based on symmetric slot holes for suppressing high order modes according to claim 7, wherein D = c [1.2 - 0.15 ln (af m / f)] 1 / α [2 / (e+1)] 1 / 2 / π(f+f m ), where a is the number of the slot groups (31), e is the relative dielectric constant of the conductor layer (30), and f is the lowest frequency of the working frequency of the leakage cable based on the symmetric slot for suppressing high-order modes.

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