Frequency-expanding leaky coaxial cable

Abstract

The invention belongs to the technical field of wireless communication, and relates to a frequency-expanding leaky coaxial cable. The frequency-broadening leaky coaxial cable sequentially comprises an inner conductor, an insulating layer, an outer conductor and a sheath layer from inside to outside, the inner conductor is designed to be a square-wave tooth-shaped spiral corrugated pipe, and the roller pitch or the compression ratio of the inner conductor is designed to be periodically fluctuated and changed in the axial direction, so that the inductance can be improved, the high-frequency signal phase can be delayed, and the frequency-broadening leaky coaxial cable can be applied to the field of communication. The high-order mode excitation is effectively weakened; and the inner side surface of the outer conductor is provided with a tooth peak with an inverted V-shaped peak tip and a tooth groove with an arc-shaped groove bottom, so that a gap can be reduced, reflection and transmission loss of an electromagnetic signal can be reduced, and the requirements of low loss, large coverage range and wide frequency during mobile communication networking can be met. A standing wave diagram of the product shows that the 3.3-3.7 GHz interference peak value is greatly reduced and even basically disappears, so that the frequency-broadening leaky coaxial cable can continue to work after exceeding the cut-off frequency, and the working frequency is widened.

Description

Technical Field

[0001] The present application belongs to the field of wireless communication technology and relates to a spread spectrum leaky coaxial cable. Background Art

[0002] Leaky coaxial cable is a special coaxial cable with the function of electromagnetic wave radiation and reception. It is widely used in closed or complex spaces (such as tunnels, underground mines, subways, etc.) where wireless communication signals are difficult to directly cover.

[0003] With the rapid development of mobile communications, the demand for mobile communication channel capacity is increasing, and the operating frequency of mobile communication systems is getting higher and higher. However, due to the cutoff operating frequency of leaky coaxial cables, after exceeding a certain size, leaky coaxial cables are affected by higher-order harmonics. After exceeding the cutoff frequency, the standing wave and transmission loss performance of leaky coaxial cables deteriorate significantly, resulting in the fact that leaky coaxial cables can no longer be used after exceeding the cutoff frequency. This makes it difficult for large-sized leaky coaxial cables to meet the operating frequency requirements of current mobile communications 5G. As a result, when building mobile communication networks, only small-sized coaxial cables with greater transmission loss and smaller coverage can be used. Therefore, improvement is urgently needed. Summary of the Invention

[0004] In response to the defects of the existing technology, the present application provides a spread spectrum leaky coaxial cable, which can continue to work normally after exceeding the cutoff frequency, and can provide a higher operating frequency under large-size conditions, meeting the requirements of low loss, large coverage and high frequency in mobile communication networking.

[0005] The present application provides a spectrum-extending leaky coaxial cable, which comprises, from the inside to the outside, an inner conductor, an insulation layer, an outer conductor, and a sheath layer, wherein: The inner conductor is a spiral corrugated tube, the thread profile of the inner conductor is a square wave with rounded chamfers, the pitch of the corrugation of the inner conductor fluctuates periodically along the axial direction, or the compression ratio of the inner conductor fluctuates periodically along the axial direction; The outer conductor is an annular corrugated tube with slots. The outer conductor has a surface facing the insulating layer on which tooth peaks and tooth grooves are alternately arranged along the axial direction. The tooth peaks have inverted V-shaped peaks for sinking into the insulating layer, and the tooth grooves have arc-shaped groove bottoms for accommodating the insulating layer.

[0006] In this design, the inner conductor utilizes a square-wave-shaped spiral pattern, ensuring that the current direction is essentially perpendicular or parallel to the cable axis. This ensures a precise transmission direction and reduces the directional deviation of high-order mode interference signals. Furthermore, the periodic fluctuations in the pitch or compression ratio of the roller pattern disperse reflected signals beyond the cutoff frequency, preventing periodic superposition. This effectively suppresses high-order harmonic excitation, optimizes the cable's anti-interference capabilities, and enhances signal stability.

[0007] At the same time, through structural optimization of the outer conductor, the inverted V-shaped peaks of the outer conductor can sink (or embed) into the insulation layer to form a bite, preventing relative sliding or separation. The arc-shaped grooves in the outer conductor can accommodate the insulation layer, reducing the radial gap between the outer conductor and the insulation layer, and reducing electromagnetic signal reflection. This design can improve the cable's voltage standing wave ratio and reduce transmission loss, especially for TE electromagnetic waves exceeding the cutoff frequency.

[0008] Therefore, under the joint optimization design of the inner conductor and the outer conductor, by suppressing high-order harmonic excitation and reducing the reflection of electromagnetic signals, the cable operating frequency can be broadened and improved, so that the leaky coaxial cable has significant low loss and low standing wave capabilities, and can provide a wider operating frequency under large-size conditions, meeting the low loss, low standing wave and high frequency requirements in mobile communication networking.

[0009] In addition, the square wave thread design with rounded chamfers in the inner conductor and the arc-shaped groove bottom design of the tooth groove in the outer conductor can provide deformation space for the cable, making the insulation layer less susceptible to extrusion damage, while buffering bending stress and extending the service life of the cable. This is conducive to the curved arrangement and routing of cables under complex spatial conditions, so as to achieve large-area coverage of mobile communication equipment signals in complex spaces.

[0010] As a further preferred embodiment, an identification structure is provided on the outer surface of the sheath layer, the identification structure and the slot are respectively provided at two radial ends of the cable, and the identification structure extends along the axial direction of the sheath layer.

[0011] As a further preferred embodiment, the inner conductor includes a tooth peak section and a tooth bottom section, wherein: The axial length of the tooth peak section is greater than the axial length of the tooth bottom section; The sum of the axial length of the tooth peak section and the axial length of the tooth bottom section is equal to the roller pitch of the inner conductor.

[0012] As a further preferred embodiment, the side wall surfaces of the tooth bottom section and the tooth peak section include a tooth bottom chamfered section, a linear flat section and a tooth peak chamfered section, and the tooth peak chamfered section, the linear flat section and the tooth bottom chamfered section are smoothly connected in sequence from outside to inside along the radial direction of the inner conductor.

[0013] As a further preference, the radial length of the linear flattening section is not less than four times the radial length of the tooth bottom chamfering section, and the radial length of the tooth peak chamfering section is the same as the radial length of the tooth bottom chamfering section.

[0014] As a further preference, in the same periodic fluctuation change, the roller pitch / compression ratio of the inner conductor first changes from large to small and then changes from small to large, or the roller pitch / compression ratio of the inner conductor first changes from small to large and then changes from large to small.

[0015] As a further preference, the inner conductor is a single-helix or multi-helix spiral corrugated tube.

[0016] As a further preference, the radial gap between the insulating layer and the outer conductor is less than 1 mm.

[0017] As a further preferred embodiment, the cable is prepared by the following method: Providing a smooth outer conductor strip, and performing roller processing on the smooth outer conductor strip in a preset roller pattern to obtain a roller-grained conductor; A cable core is provided, and the outer surface of the cable core is subjected to longitudinal wrapping and rounding of the corrugated conductor to obtain an outer conductor circular tube, wherein the cable core comprises an inner conductor and an insulating layer wrapped around the outer circumference of the inner conductor; The outer circumference of the outer conductor tube is subjected to a sheath layer hot extrusion molding, and the outer conductor tube is preheated based on the heat energy of the hot extruded sheath layer, the preheating temperature is within the temperature range of 120°C to 180°C, and then cooled and shaped to obtain a cable.

[0018] In general, the above technical solutions conceived by this application have the following technical advantages compared with the existing technologies: 1. By designing the inner conductor as a spiral corrugated tube with a square-wave profile and arranging the pitch or compression ratio of the inner conductor's corrugation to fluctuate periodically along the axial direction, this cable can enhance inductance, delay the phase of high-frequency signals, and effectively weaken the excitation of high-order modes. Furthermore, by designing the inner surface of the outer conductor with tooth peaks with inverted V-shaped peaks and tooth grooves with arc-shaped groove bottoms, the gap is reduced, thereby reducing the reflection and transmission loss of electromagnetic signals, thereby meeting the low-loss, wide coverage, and wide-frequency requirements of mobile communication networks.

[0019] 2. The square-wave thread design with rounded chamfers in the inner conductor and the curved groove bottom design in the outer conductor provide space for cable deformation, making the insulation layer less susceptible to compression damage. It also buffers bending stress and extends the cable's service life. This facilitates the curved arrangement and routing of cables in complex spaces, facilitating large-area coverage of mobile communication device signals in complex spaces. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 This is a structural diagram of a spread spectrum leaky coaxial cable provided in an embodiment of the present application; Figure 2 is a cross-sectional view of an outer conductor provided in an embodiment of the present application; Figure 3 This is a partial cross-sectional view of a spread spectrum leaky coaxial cable provided in an embodiment of the present application; Figure 4 This is a diagram showing the square wave tooth profile of the inner conductor provided in an embodiment of the present application; Figure 5 Schematic diagram of the distribution of the tooth bottom chamfered section, linear flattened section and tooth peak chamfered section provided in the embodiment of the present application; Figure 6 1 is a schematic cross-sectional view of a spread spectrum leaky coaxial cable provided in an embodiment of the present application; Figure 7 This is a manufacturing process flow chart of a spectrum-extended leaky coaxial cable provided in an embodiment of the present application; Figure 8 This is a voltage standing wave ratio test diagram of an existing leaky coaxial cable provided in an embodiment of the present application; Figure 9 This is a voltage standing wave ratio test diagram of a spread spectrum leaky coaxial cable provided in an embodiment of the present application.

[0021] Throughout the drawings, the same reference numerals are used to denote the same elements or structures, wherein: 1. Inner conductor; 2. Insulation layer; 3. Outer conductor; 4. Sheath layer; 4-1. Identification structure; 5. Inverted V-shaped peak; 6. Arc-shaped groove bottom; 7. Tooth bottom section; 8. Tooth peak section; 9. Tooth bottom chamfered section; 10. Linear flat section; 11. Tooth peak chamfered section; 100. Slot hole; 200. Radial clearance. DETAILED DESCRIPTION

[0022] In order to make the purpose, technical solutions and advantages of this application more clear, the following further describes this application in detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain this application and are not intended to limit this application.

[0023] The following is combined with Figures 1-9 This application is described in further detail.

[0024] The embodiment of the present application discloses a spectrum spreading leaky coaxial cable. Figures 1-6The top-spectrum leaky coaxial cable comprises, from the inside to the outside, an inner conductor 1, an insulating layer 2, an outer conductor 3, and a sheath layer 4. The inner conductor 1 is a spiral corrugated tube, the thread profile of the inner conductor 1 presenting a square wave with a rounded chamfer (i.e., the surface thread of the inner conductor 1 presenting a square wave profile with a rounded chamfer), and the pitch of the roller corrugation of the inner conductor 1 fluctuates periodically along the axial direction, or the compression ratio of the inner conductor 1 fluctuates periodically along the axial direction. The outer conductor 3 is an annular corrugated tube with a slot 100, and the surface of the outer conductor 3 facing the insulating layer 2 is alternately provided with tooth peaks and tooth grooves along the axial direction. The tooth peaks have inverted V-shaped peaks 5 for sinking into the insulating layer 2, and the tooth grooves have arc-shaped groove bottoms 6 for accommodating the insulating layer 2.

[0025] In this design, the inner conductor 1 utilizes a square-wave-shaped thread profile, ensuring that the current direction is essentially perpendicular or parallel to the cable axis. This ensures a precise transmission direction and reduces the directional deviation of high-order mode interference signals. Furthermore, the periodic fluctuations in the roller pitch or compression ratio disperse reflected signals beyond the cutoff frequency, preventing periodic superposition. This effectively suppresses high-order harmonic excitation, optimizes the cable's anti-interference capabilities, and enhances signal stability.

[0026] At the same time, by optimizing the structure of the outer conductor 3, the inverted V-shaped peak 5 in the outer conductor 3 can sink into (or be called embedded in) the insulating layer 2 to form a bite, preventing the outer conductor 3 and the insulating layer 2 from sliding or separating relative to each other; and the arc-shaped groove bottom-shaped tooth groove in the outer conductor 3 can accommodate the insulating layer 2, reducing the radial gap 200 between the outer conductor 3 and the insulating layer 2, thereby reducing the reflection of the electromagnetic signal; this design can improve the voltage standing wave ratio of the cable and reduce the transmission loss, especially for TE electromagnetic waves exceeding the cutoff frequency.

[0027] Under this design, by optimizing the structure of the inner conductor 1 and the outer conductor 3, suppressing high-order harmonic excitation and reducing the reflection of electromagnetic signals, the cable operating frequency can be improved and broadened, so that the leaky coaxial cable has significant low loss and low standing wave capabilities, and can provide a wider operating frequency under large-size conditions, meeting the low loss, low standing wave and high frequency requirements of mobile communication networking.

[0028] At the same time, the square wave thread design with rounded chamfers in the inner conductor 1 and the arc-shaped groove bottom 6 design of the tooth groove in the outer conductor 3 can jointly provide deformation space for the cable, making the insulating layer 2 less susceptible to extrusion damage, buffering bending stress, and extending the service life of the cable. This is beneficial for users to arrange and route cables in complex spatial conditions and to provide large-area coverage of mobile communication equipment signals in complex spaces.

[0029] Furthermore, in some embodiments, the surface thread of the inner conductor 1 (ie, the thread structure of the spiral corrugated tube) is obtained by roller corrugation, such as Figure 4 As shown, the inner conductor 1 includes a tooth bottom section 7 and a tooth peak section 8, and the tooth bottom section 7 and the tooth peak section 8 are alternately arranged along the axial direction of the inner conductor 1 and smoothly connected to each other.

[0030] Preferably, the axial length of the tooth peak segment 8 is greater than the axial length of the tooth bottom segment 7 , and the sum of the axial lengths of the tooth peak segment 8 and the axial lengths of the tooth bottom segment 7 is equal to the roller pitch of the inner conductor 1 .

[0031] Generally speaking, the axial length of the tooth bottom segment 7 is 1 / 4 of the axial length of the tooth peak segment 8. to For easier understanding, Figure 4 The dimension mark Y in the figure indicates the axial length of the tooth peak section 8, the dimension mark X indicates the axial length of the tooth bottom section 7, and the dimension mark P indicates the roller pitch of the inner conductor 1.

[0032] With this design, the longer crest section 8 provides greater structural rigidity for the inner conductor 1, enhancing its resistance to external compression. Furthermore, combined with the small chamfered corners of the surface threads, the inner conductor 1 exerts less pressure on the insulation layer 2, making it less likely to cause indentations. The relatively shorter base section 7 acts as a buffer zone to disperse bending stress, preventing stress concentration in a single location that can lead to metal fatigue fracture. This improves the cable's flexibility and extends its bending fatigue life.

[0033] Further, such as Figure 5 As shown, in some embodiments, the side wall surfaces of the tooth bottom segment 7 and the tooth peak segment 8 include a tooth bottom chamfered segment 9, a linear flat segment 10 and a tooth peak chamfered segment 11, and the tooth peak chamfered segment 11, the linear flat segment 10 and the tooth bottom chamfered segment 9 are smoothly connected in sequence from outside to inside along the radial direction of the inner conductor 1.

[0034] Preferably, the linear flattened section 10 is a generally radially extending plane, while the tooth base chamfered section 9 and the tooth peak chamfered section 11 are both arc segments formed by 90-degree chamfers. Preferably, the radial length of the linear flattened section 10 is no less than four times the radial length of the tooth base chamfered section 9, and the radial length of the tooth peak chamfered section 11 is preferably the same as that of the tooth base chamfered section 9. With this design, the surface profile of the inner conductor 1 is relatively rounded and smooth, optimizing the electric field and protecting the insulating layer 2.

[0035] For ease of understanding, Figure 5 The dimension R1 in the figure indicates the radial length of the tooth bottom chamfered section 9, the dimension L indicates the radial length of the linear flat section 10, the dimension R2 indicates the radial length of the tooth peak chamfered section 11, and the dimension D indicates the roller groove depth of the inner conductor 1.

[0036] Furthermore, in some embodiments, during the same periodic fluctuation, the pitch or compression ratio of the inner conductor 1 first changes from large to small, and then changes from small to large. In some other embodiments, during the same periodic fluctuation, the pitch or compression ratio of the inner conductor 1 first changes from small to large, and then changes from large to small.

[0037] Under this design, by regularly controlling the roller pitch or compression ratio of the inner conductor 1, the interference of high-order harmonics on the extended spectrum leaky coaxial cable can be reduced, so that the extended spectrum leaky coaxial cable can continue to work effectively after exceeding the cutoff frequency.

[0038] It should be clear that when the roller corrugation pitch of the inner conductor 1 is designed to fluctuate periodically along the axial direction, since the sum of the axial length of the tooth bottom segment 7 and the axial length of the tooth peak segment 8 is equal to the roller corrugation pitch, the axial length of the tooth bottom segment 7 and the axial length of the tooth peak segment 8 in the inner conductor 1 will also change along with the change of the roller corrugation pitch.

[0039] To this end, when the roller pitch of the inner conductor 1 fluctuates periodically along the axial direction, it is preferred to select the ratio of the axial length of the tooth bottom segment 7 to the axial length of the tooth peak segment 8 as a fixed ratio value, and then calculate the axial length of the tooth bottom segment 7 and the axial length of the tooth peak segment 8 based on this fixed ratio value and the actual value of the roller pitch. Generally speaking, the fixed ratio value is controlled and set by technical personnel based on standard specifications and experience.

[0040] It is clear that when designing the compression ratio of the inner conductor 1 to fluctuate periodically along the axial direction, it is preferred to set the depth of the inner conductor 1 to fluctuate periodically along the axial direction to achieve the purpose of periodic fluctuation of the compression ratio of the inner conductor 1, wherein the depth is the radial distance from the peak of the current tooth peak segment 8 on the outer surface of the inner conductor 1 to the bottom valley of the adjacent tooth bottom segment 7. The depth change adjustment is achieved by setting the radial distance between the tooth peak segment 8 and the tooth bottom segment 7 in sequence along the axial direction.

[0041] Furthermore, in some embodiments, the inner conductor 1 is a single-helix spiral corrugated tube, and in some other embodiments, the inner conductor 1 is a multi-helix (such as a double-helix) spiral corrugated tube.

[0042] Furthermore, in some embodiments, the insulating layer 2 is a foamed insulating layer, preferably made of polyethylene material.

[0043] Furthermore, in some embodiments, the radial gap 200 between the insulating layer 2 and the outer conductor 3 is less than 1 mm. More preferably, the radial gap 200 between the insulating layer 2 and the outer conductor 3 is 0.2 mm to 0.8 mm.

[0044] By controlling the size of the radial gap 200, the purpose of reducing the reflection of electromagnetic signals can be achieved; generally speaking, the control of the radial gap 200 can be achieved by adjusting the surface structure design of the outer conductor 3 mentioned above, or by controlling it based on the production process and method of the cable, or by combining the surface structure design and the manufacturing process and method.

[0045] Further, such as Figure 7 As shown, in some embodiments, the extended spectrum leaky coaxial cable is manufactured by the following method: S1: providing a smooth outer conductor strip, and performing roller corrugation on the smooth outer conductor strip in a preset roller corrugation shape to obtain a roller corrugated conductor.

[0046] Generally speaking, it is necessary to first lay the outer conductor smooth tape, and then perform roller corrugation on the outer conductor smooth tape according to the required roller corrugation pitch and roller corrugation shape.

[0047] S2: A cable core is provided. A roller-corrugated conductor is longitudinally rolled onto the outer surface of the cable core to produce an outer conductor tube. The cable core comprises an inner conductor 1 and an insulating layer 2 wrapped around the outer circumference of the inner conductor 1. The cable core is typically fabricated on-site prior to the longitudinal rolling process, or a prefabricated cable core may be used. In this step, the outer conductor tube is wrapped around the outer surface of the insulating layer 2.

[0048] S3: hot extrusion forming the sheath layer 4 on the outer periphery of the outer conductor round tube, and preheating the outer conductor round tube based on the heat energy of the hot extruded sheath layer 4, the preheating temperature is in the range of 120℃~180℃, and then cooling and shaping to obtain the cable, and then winding the cable into a coil.

[0049] In this step, by preheating the outer conductor tube, the insulating layer 2 inside the tube can be softened, so that the outer conductor tube can be properly sunken into the insulating layer 2, promoting the bonding of the insulating layer 2 with the outer conductor tube, and reducing the size of the radial gap 200. Generally speaking, the radial gap 200 can be reduced by 20%-50% compared with traditional cables.

[0050] In addition, in this method, the finished cable product is preferably pulled at a preset speed by a pulling device. Generally speaking, the speed should be selected between 5 m / min and 50 m / min.

[0051] In other embodiments, after the longitudinal wrapping and rolling process is completed, the outer conductor 3 may be preheated using preheating equipment such as an electric heating wire.

[0052] Further, such as Figure 6As shown, in some embodiments, an identification structure 4-1 is provided on the outer surface of the jacket layer 4 along the axial direction. The identification structure 4-1 and the slot 100 are provided at the radial ends of the cable, and the identification structure 4-1 extends along the axial direction of the jacket layer 4. The identification structure 4-1 can be a plurality of slot identification lines. When a single slot identification line is provided, the single slot identification line should be located 180° from the center of the slot.

[0053] For ease of understanding, Figure 8 Shows a traditional inches (i.e. ) Specifications of leaky coaxial cable (selected from the 1 specified in the industry standard YD / T2491 Inch standard cable) standing wave ratio test chart, by Figure 8 It can be seen that the conventional cable has a large interference peak at 3.3 GHz to 3.7 GHz after the cutoff frequency. In a test, it was measured that the radial gap 10 between the outer conductor 3 and the insulating layer 2 of the conventional cable is 1.8 mm on average.

[0054] Compared with the above-mentioned conventional leaky coaxial cable, a leaky coaxial cable differs from the above-mentioned conventional leaky coaxial cable in that: the inner conductor 1 of the leaky coaxial cable is a spiral corrugated tube, the surface thread of the inner conductor 1 presents a square wave tooth profile with rounded chamfers (that is, the tooth profile of the thread structure presents a square wave with rounded chamfers), and the depth D of the inner conductor 1 fluctuates periodically along the axial direction (that is, the periodic fluctuation of the compression ratio is achieved by the periodic fluctuation of the depth).

[0055] The depth D of the inner conductor 1 is 2.0 mm, 2.1 mm, 2.2 mm, 2.3 mm, and 2.4 mm. The depth changes periodically in the order of 2.0 mm, 2.1 mm, 2.2 mm, 2.3 mm, 2.4 mm, 2.3 mm, 2.2 mm, 2.1 mm, and 2.0 mm.

[0056] The pitch of the roller pattern of the inner conductor 1 is 10.2 mm, and the ratio of the axial length of the tooth bottom section 7 to the axial length of the tooth peak section 8 is: ; The axial length of the tooth bottom segment 7 is 3.06mm, and the axial length of the tooth peak segment 8 is 7.14mm.

[0057] The chamfer of the thread structure is a ninety-degree chamfer, and the radius of the chamfer and the radial length of the linear flat section 10 are selected according to the real-time depth of the inner conductor 1, and the value is = = When the depth is 2.0 mm, the radial length of the linear flat section 10 is 1.5 mm, the chamfer radius of the tooth bottom chamfer section 9 is 0.25 mm, and the chamfer radius of the tooth peak chamfer section 11 is 0.25 mm.

[0058] In addition, the outer conductor 3 of the leaky coaxial cable is an annular corrugated tube. The outer conductor 3 has a surface facing the insulating layer 2, and the tooth peaks and tooth grooves are alternately arranged along the axial direction. The tooth peaks and tooth grooves are smoothly connected. The tooth peaks have an inverted V-shaped peak 5 for sinking into the insulating layer 2, and the tooth grooves have an arc-shaped groove bottom 6 for accommodating the insulating layer 2. Among them, the roller corrugation depth H is 0.51mm, the arc radius R of the arc groove bottom 6 is 0.5mm, and the angle between the tooth groove surface and the axis is 0.5mm. The angle is 20°, the pitch P is 3 mm, the compression ratio is 1.015, and the radial gap 200 between the outer conductor 3 and the insulating layer 2 of the final product is 0.3 mm on average.

[0059] Further, Figure 9 A 1 based on the above size design is shown inches (i.e. ) Leaky coaxial cable standing wave ratio test diagram, by Figure 9 It can be seen that after adopting the design scheme of this application, the standing wave of the frequency-spreading leaky coaxial cable Figure 3 The interference peak in the 3.3GHz-3.7GHz range is greatly reduced, meeting the industry standard requirement of an interference peak of ≤1.4, allowing the cable to continue operating in the 3.3GHz-3.7GHz range after exceeding the cutoff frequency, significantly broadening the operating frequency.

[0060] It should be noted that Figure 8 and Figure 9 In the VSWR test diagram shown, the horizontal axis represents the test frequency, the vertical axis represents the VSWR test value, "Trl" in the diagram represents "test window", "S11" represents "instrument test port", "SWR" represents "voltage standing wave ratio", "Ref" represents "bottom line value", "Start" represents "starting frequency", "Stop" represents "stop frequency", "Cor" represents "calibrated status", and "IFBW" represents "swept bandwidth".

[0061] It should be noted that the compression ratio of the inner conductor 1 indicates the degree of dimensional change of the conductor material after compression or extrusion during the production process. Specifically, it usually refers to the ratio of the outer diameter of the conductor after corrugation to the original smooth conductor diameter.

[0062] It should be noted that the selection of relevant values ​​such as the roller pitch and depth in this leaky coaxial cable should comply with the relevant design standards in the industry standards.

[0063] It should be noted that the slots 4 - 1 provided on the outer conductor 3 are preferably through holes, which are preferably distributed along the axial direction of the cable and are mainly used for transmitting and receiving signals.

[0064] It should be understood that expressions such as "include" and "may include" used in this application indicate the existence of the disclosed functions, operations, or constituent elements, and do not limit one or more additional functions, operations, and constituent elements. In this application, terms such as "include" and / or "have" may be interpreted as indicating a specific characteristic, number, operation, constituent element, component, or combination thereof, but may not be interpreted as excluding the existence or possibility of adding one or more other characteristics, numbers, operations, constituent elements, components, or combinations thereof.

[0065] It should be understood that the terms "center", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present application.

[0066] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of the technical features being referred to. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. Throughout the description of this application, "plurality" means two or more, unless otherwise specifically defined.

[0067] In this application, unless otherwise specified or limited, the terms "mounted," "connected," "connect," "fixed," etc. should be understood broadly. For example, they can refer to fixed connection, detachable connection, or integral connection; mechanical connection or electrical connection; direct connection or indirect connection through an intermediate medium; or internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in this application based on specific circumstances.

[0068] It is easy for those skilled in the art to understand that the above is only a preferred embodiment of the present application and is not intended to limit the present application. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present application should be included in the scope of protection of the present application.

Claims

1. A spectrum spreading leaky coaxial cable, characterized in that: The cable comprises, from the inside to the outside, an inner conductor (1), an insulating layer (2), an outer conductor (3) and a sheath layer (4), wherein: The inner conductor (1) is a spiral corrugated tube, the thread profile of the inner conductor (1) is a square wave with a rounded chamfer, the pitch of the roller corrugation of the inner conductor (1) fluctuates periodically along the axial direction, or the compression ratio of the inner conductor (1) fluctuates periodically along the axial direction; The outer conductor (3) is an annular corrugated tube with a slot (100), and a surface of the outer conductor (3) facing the insulating layer (2) is provided with tooth peaks and tooth grooves alternately arranged along the axial direction, the tooth peaks having an inverted V-shaped peak tip (5) for sinking into the insulating layer (2), and the tooth grooves having an arc-shaped groove bottom (6) for accommodating the insulating layer (2).

2. The extended spectrum leaky coaxial cable according to claim 1, characterized in that: The outer surface of the sheath layer (4) is provided with an identification structure (4-1), the identification structure (4-1) and the slot (100) are arranged at two radial ends of the cable, and the identification structure (4-1) extends along the axial direction of the sheath layer (4).

3. The extended spectrum leaky coaxial cable according to claim 1, characterized in that: The inner conductor (1) comprises a tooth bottom section (7) and a tooth peak section (8), wherein: The axial length of the tooth peak section (8) is greater than the axial length of the tooth bottom section (7); The sum of the axial length of the tooth peak section (8) and the axial length of the tooth bottom section (7) is equal to the roller pitch of the inner conductor (1).

4. The extended spectrum leaky coaxial cable according to claim 3, characterized in that: The side wall surfaces of the tooth bottom section (7) and the tooth peak section (8) include a tooth bottom chamfered section (9), a linear flattened section (10) and a tooth peak chamfered section (11), and the tooth peak chamfered section (11), the linear flattened section (10) and the tooth bottom chamfered section (9) are smoothly connected in sequence from outside to inside along the radial direction of the inner conductor (1).

5. The extended spectrum leaky coaxial cable according to claim 4, characterized in that: The radial length of the linear flattening section (10) is not less than four times the radial length of the tooth bottom chamfering section (9), and the radial length of the tooth peak chamfering section (11) is the same as the radial length of the tooth bottom chamfering section (9).

6. The extended spectrum leaky coaxial cable according to claim 1, characterized in that: In the same periodic fluctuation change, the roller pitch / compression ratio of the inner conductor (1) first changes from large to small and then changes from small to large, or the roller pitch / compression ratio of the inner conductor (1) first changes from small to large and then changes from large to small.

7. The extended spectrum leaky coaxial cable according to claim 1, characterized in that: The inner conductor (1) is a single-helix or multi-helix spiral corrugated tube.

8. The extended spectrum leaky coaxial cable according to any one of claims 1 to 7, characterized in that: The radial gap (200) between the insulating layer (2) and the outer conductor (3) is less than 1 mm.

9. The extended spectrum leaky coaxial cable according to any one of claims 1 to 7, characterized in that: The cable is manufactured by the following method: Providing a smooth outer conductor belt, and performing roller processing on the smooth outer conductor belt in a preset roller shape to obtain a roller-corrugated conductor; A cable core is provided, and the outer surface of the cable core is subjected to longitudinal wrapping and rounding treatment of the corrugated conductor to obtain an outer conductor round tube, wherein the cable core comprises an inner conductor (1) and an insulating layer (2) wrapped around the outer circumference of the inner conductor (1); The outer circumference of the outer conductor round tube is subjected to hot extrusion molding of a sheath layer (4), and the outer conductor round tube is preheated based on the heat energy of the hot extruded sheath layer (4), the preheating temperature being within a temperature range of 120° C. to 180° C., and then cooled and molded to obtain a cable.

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