Cable, active cable and communication system

Abstract

The invention provides a cable, an active cable and a communication system. Belongs to the technical field of communication. The cable comprises a dielectric layer, a first metal layer and at least two electrical cores, the dielectric layer is coated with the first metal layer, and the at least two electrical cores are located in the dielectric layer; the center distance S between any two battery cells satisfies 1.97 d < = S < = 3.60 d, the distance w between the center of any one battery cell and the inner wall of the first metal layer satisfies 1.15 d < = w < = 2.10 d, and d is the diameter of the battery cell and is determined according to the cable number of the cable. According to the invention, the cable can achieve the transmission of multiple paths of signals under the condition of a small wire diameter, thereby facilitating the weight reduction and thinning of the cable.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to the field of communication technology, in particular to a cable, an active cable and a communication system. BACKGROUND

[0002] In the field of communication, when networking is performed using routers, switches and computer devices, etc., since electrical modules have lower cost and power consumption compared with optical modules, it is desirable to use electrical modules as much as possible to perform interconnection between devices or within a device, and to implement large-scale networking.

[0003] For example, a passive cable or an active cable includes a cable and electrical modules connected at both ends of the cable. The electrical module at one end of the cable is plugged into one device, and the electrical module at the other end is plugged into another device, so that the two devices are interconnected through the active cable or the passive cable. The electrical module of the passive cable does not have an active chip, and is applied in a short-distance interconnection scenario. The electrical module of the active cable has an active chip, and can increase the interconnection distance, and is applied in a long-distance interconnection scenario.

[0004] With the expansion of the scale of networking, the number of communication devices included in the network architecture formed by networking is also increased. Therefore, the number of cables used is also increased. When a large number of cables are bundled together, the weight is relatively heavy, which can damage the device. A large number of cables bundled together occupy a large space, and are easy to block the ventilation duct of the device.

[0005] It can be seen that in the current large-scale networking using cables, there is a demand for weight reduction and thinning of the cables. SUMMARY

[0006] The present disclosure provides a cable, an active cable and a communication system, which can realize transmission of multiple signals at a smaller diameter.

[0007] In a first aspect, a cable is provided, the cable comprising a dielectric layer, a first metal layer and at least two electrical cores, the first metal layer being wrapped outside the dielectric layer, and the at least two electrical cores being located in the dielectric layer.

[0008] The diameter of the cable is determined according to the center distance S between any two electrical cores, the distance w between the center of any one electrical core and the inner wall of the first metal layer, and the diameter d of the electrical core. The cable is used to transmit multiple single-ended signals.

[0009] In the scheme shown in the present disclosure, a plurality of electrical cores are included in a single cable, and the plurality of electrical cores share the dielectric layer and the first metal layer, so that the diameter of the cable is relatively small, which is beneficial to weight reduction (referred to as weight reduction) and diameter thinning (referred to as thinning) of the cable.

[0010] In a possible implementation, the S and the w satisfy 1≤S / w≤2.5.

[0011] In the scheme shown in the present disclosure, in the case of 1≤S / w≤2.5, the wire diameter (such as the wire width) of the multi-core cable can be smaller than the total wire diameter of the bundled coaxial cable (in the case of the same electric core), so that the multi-core cable can realize the transmission of multiple signals at a smaller wire diameter.

[0012] In a possible implementation, the cross section of the dielectric layer is in the shape of a racetrack or an ellipse.

[0013] In the scheme shown in the present disclosure, in the case of the value of the center distance S between two electric cores meeting the design requirement and the value of the spacing w between the center of the electric core and the first metal layer also meeting the design requirement, the cross section of the dielectric layer is in the shape of a racetrack, which is beneficial to making the wire diameter of the cable narrower, and further making the cable transmit multiple single-ended signals at a smaller wire diameter.

[0014] In a second aspect, a cable is provided, which includes a dielectric layer, a first metal layer and at least two electric cores, the first metal layer is wrapped outside the dielectric layer, and the at least two electric cores are located in the dielectric layer.

[0015] The center distance S between any two electric cores satisfies 1.97d≤S≤3.60d, and the spacing w between the center of any one electric core and the inner wall of the first metal layer satisfies 1.15d≤w≤2.10d, where d is the diameter of the electric core and is determined according to the wire gauge of the cable.

[0016] In the scheme shown in the present disclosure, a plurality of electric cores are included in a single cable, and the plurality of electric cores share the dielectric layer and the first metal layer, so that the wire diameter of the cable is relatively small, which is beneficial to the weight reduction (referred to as reduction) and diameter thinning (referred to as thinning) of the cable. Further, the multi-core cable can be used to transmit multiple single-ended signals, and the crosstalk between signals is relatively low. One single-ended signal only needs one electric core, and compared with the transmission of differential signals (one differential signal needs two electric cores), the number of electric cores can be reduced by half on the basis of transmitting the same number of signals, which is further beneficial to the reduction and thinning of the cable. It can be seen that the cable provided in the present embodiment can realize the transmission of multiple signals at a smaller wire diameter, and further be beneficial to the reduction and thinning of the cable.

[0017] In a possible implementation, the center distance S between any two electric cores satisfies 2.55d≤S≤2.85d, and the spacing w between the center of any one electric core and the inner wall of the first metal layer satisfies 1.48d≤w≤1.66d.

[0018] In the scheme shown in the present disclosure, in the case where the relative dielectric constant εr of the dielectric layer is in the range of 2≤εr≤2.5, in order to realize the differential impedance Z D corresponding to the differential signal transmitted by the cable in the range of 80Ω≤Z D ≤110Ω, and the single-end impedance Z C corresponding to the single-end signal transmitted by the cable in the range of 40Ω≤Z C ≤55Ω, the value range of S can be 2.55d≤S≤2.85d, and the value range of w can be 1.48d≤w≤1.66d.

[0019] In a possible implementation, the center distance S between any two battery cells is 2.61d, and the distance w between the center of any battery cell and the inner wall of the first metal layer is 1.52d.

[0020] In the scheme shown in the present disclosure, generally, the relative dielectric constant εr of the dielectric layer is 2.1, in which case, in order to realize the differential impedance Z D corresponding to the differential signal transmitted by the cable in the range of 90Ω≤Z D ≤100Ω, and the single-end impedance Z C corresponding to the single-end signal transmitted by the cable is 50Ω, S is 2.61d, and w is 1.52d.

[0021] In a possible implementation, the center distance S between any two battery cells is the distance w between the center of any battery cell and the inner wall of the first metal layer is wherein εr is the relative dielectric constant of the dielectric layer.

[0022] In the scheme shown in the present disclosure, the relative dielectric constant εr of the dielectric layer is in the range of 1.2≤εr≤4, in order to realize the differential impedance Z D corresponding to the differential signal transmitted by the cable in the range of 80Ω≤Z D ≤110Ω, and the single-end impedance Z C corresponding to the single-end signal transmitted by the cable in the range of 40Ω≤Z C ≤55Ω, S is w is

[0023] In a possible implementation, the diameter d of the battery cell is in the range of 0.127mm≤d≤0.644mm.

[0024] In the scheme shown in the present disclosure, the diameter d of the electric core 3 can be in the range of 0.127mm to 0.644mm (including 0.127mm and 0.644mm), and the specific value of the diameter d of the electric core 3 is related to the type of the cable, for example, if the type of the cable is a 32AWG cable, d is 0.2mm, for example, if the type of the cable is a 30AWG cable, d is 0.26mm, for example, if the type of the cable is a 26AWG cable, d is 0.4mm.

[0025] In a possible implementation, the shape of the cross section of the dielectric layer is a racetrack or an ellipse.

[0026] In a possible implementation, the shape of the cross section of the dielectric layer is a racetrack, and the number of the electric cores is two, and the centers of the two electric cores are respectively located at the two centers of the dielectric layer.

[0027] In the scheme shown in the present disclosure, when the value of the center distance S of the two electric cores meets the design requirement, and the value of the spacing w between the center of the electric core and the first metal layer also meets the design requirement, the shape of the cross section of the dielectric layer is a racetrack, which is beneficial to make the wire diameter of the cable narrow, and further make the cable transmit multiple single-ended signals under a smaller wire diameter.

[0028] In a possible implementation, the center distance S of the two electric cores and the spacing w between the center of the electric core and the inner wall of the first metal layer satisfy 1≤S / w≤2.5.

[0029] In the scheme shown in the present disclosure, when 1≤S / w≤2.5, the wire diameter (such as the wire width) of the multi-core cable can be smaller than the total wire diameter of the bundled coaxial cable (in the case of the same electric core), so that the multi-core cable can realize the transmission of multiple signals under a smaller wire diameter.

[0030] In a possible implementation, the first metal layer includes a plurality of metal layers, the plurality of metal layers are arranged from inside to outside along the radial direction of the cable, and the spacing between two adjacent metal layers is greater than or equal to 0 and less than or equal to the current coupling distance.

[0031] In the scheme disclosed herein, the multi-core cable undergoes bending operations such as turns and folds during its installation. If the first metal layer breaks at any point, it will affect the impedance at that location, especially when the cable is transmitting single-ended signals, thus affecting the single-ended impedance and signal transmission. To avoid this situation, the first metal layer includes an inner metal layer and an outer metal layer, which are relatively close together. Because the first metal layer includes an inner and outer metal layer, the probability of both the inner and outer metal layers breaking simultaneously at the same location is relatively low, even if bending occurs during cable installation, thereby minimizing the possibility of signal interruption during signal transmission.

[0032] Thirdly, this disclosure provides an active cable, the active cable including a first electrical module, a second electrical module and the cable described in the first or second aspect, a first end of the cable being connected to the first electrical module and a second end of the cable being connected to the second electrical module.

[0033] Fourthly, this disclosure provides a passive cable, which includes a first electrical module, a second electrical module, and a cable as described in the first or second aspect, wherein a first end of the cable is connected to the first electrical module, and a second end of the cable is connected to the second electrical module.

[0034] Fifthly, this disclosure provides a communication system comprising a first communication device, a second communication device, and the active cable described in the third aspect, wherein the first communication device and the second communication device are connected via the active cable.

[0035] In a sixth aspect, this disclosure provides a communication system comprising a first communication device, a second communication device, and the passive cable described in the fourth aspect, wherein the first communication device and the second communication device are connected via the passive cable. Attached Figure Description

[0036] Figure 1 This is a schematic cross-sectional view of a two-core cable provided in an exemplary embodiment of this disclosure;

[0037] Figure 2 This is a schematic diagram illustrating the relationship between S and w in a two-core cable provided in an exemplary embodiment of this disclosure;

[0038] Figure 3 This is a schematic cross-sectional view of a two-core cable provided in an exemplary embodiment of this disclosure;

[0039] Figure 4The impedance curve diagram is obtained by simulating a two-core cable with εr = 2.1, d = 0.26 mm, S = 0.726 mm, and w = 1.19 mm.

[0040] Figure 5 The schematic diagram of the energy curve obtained by simulating a two-core cable with εr = 2.1, d = 0.26 mm, S = 0.726 mm, and w = 1.19 mm is shown below.

[0041] Figure 6 The impedance curve diagram is obtained by simulating a two-core cable with εr = 2.1, d = 0.26 mm, S = 0.67 mm, and w = 0.39 mm.

[0042] Figure 7 The schematic diagram of the energy curve obtained by simulating a two-core cable with εr = 2.1, d = 0.26 mm, S = 0.67 mm, and w = 0.39 mm is shown below.

[0043] Figure 8 The impedance curve diagram is obtained by simulating a cable with εr = 2.1, d = 0.4 mm, S = 1.03 mm, and w = 0.6 mm.

[0044] Figure 9 The schematic diagram of the energy curve obtained by simulating a cable with εr of 2.1, d of 0.4 mm, S of 1.03 mm, and w of 0.6 mm is shown below.

[0045] Figure 10 The impedance curve diagram is obtained by simulating a two-core cable with εr = 2.5, d = 0.26 mm, S = 1.05 mm, and w = 0.49 mm.

[0046] Figure 11 The schematic diagram of the energy curve obtained by simulating a two-core cable with εr of 2.5, d of 0.26 mm, S of 1.05 mm, and w of 0.49 mm is shown below.

[0047] Figure 12 The impedance curve diagram is obtained by simulating a two-core cable with εr = 2.5, d = 0.26 mm, S = 0.95 mm, and w = 0.44 mm.

[0048] Figure 13 The schematic diagram of the energy curve obtained by simulating a two-core cable with εr of 2.5, d of 0.26 mm, S of 0.95 mm, and w of 0.44 mm is shown below.

[0049] Figure 14 The impedance curve diagram is obtained by simulating a two-core cable with εr = 2.5, d = 0.26 mm, S = 0.78 mm, and w = 0.44 mm.

[0050] Figure 15 The schematic diagram of the energy curve obtained by simulating a two-core cable with εr of 2.5, d of 0.26 mm, S of 0.78 mm, and w of 0.44 mm is shown below.

[0051] Figure 16 This is a schematic diagram of a communication system provided in an exemplary embodiment of this disclosure.

[0052] Explanation of reference numerals in the attached figures

[0053] 1. Dielectric layer; 2. First metal layer; 3. Cell; 4. Return conductor; 5. Second metal layer.

[0054] 100. First communication equipment; 200. Second communication equipment; 300. Active cable; 301. Cable; 302. Electrical module. Detailed Implementation

[0055] To make the objectives, technical solutions, and advantages of this disclosure clearer, the embodiments of this disclosure will be described in further detail below with reference to the accompanying drawings.

[0056] This embodiment relates to a cable, specifically a multi-core cable, comprising multiple electrical cores. This cable can be used in active cables, which can be either AEC (active electrical cable) or ACC (active copper cable). Regardless of the type, the active cable structurally includes the cable itself and electrical modules connected to both ends of the cable. In the AEC active cable, the chip within the electrical module is a retimer chip, while in the ACC active cable, the chip within the electrical module is a redriver chip.

[0057] This cable can also be used in passive direct attach cables (DACs). A passive DAC also structurally includes a cable and electrical modules connected to both ends of the cable, except that these electrical modules do not contain active chips. Because passive DACs do not have active chips in their electrical modules, they are generally used in short-distance interconnect scenarios.

[0058] This cable can also be used to interconnect chips. For example, a direct connection between a chip and a cable can be achieved by having one end of the cable encapsulated within the chip and the other end extending out for external connection. Another direct connection method involves soldering one end of the cable to a circuit board, soldering the chip's pads to the circuit board, and then implementing the direct connection between the chip and the cable through traces on the circuit board.

[0059] This cable can also be used to interconnect devices within a chassis. The cable can be directly connected to the device via a cable connector. For example, a single cable can be connected to a single cable connector, which in turn connects to the device (e.g., through a plug-in or fusion splice). Alternatively, multiple cables can be bundled together and connected to a single cable connector, which in turn connects to the device (e.g., through a plug-in or fusion splice).

[0060] In scenarios involving chip-to-chip interconnection, chip-to-device interconnection, or device-to-device interconnection within a chassis or cabinet, cables offer lower insertion loss compared to traces on a printed circuit board (PCB), provided the same length and transmission frequency. Therefore, in chip-to-chip, chip-to-device, and device-to-device interconnection scenarios within a chassis or cabinet, cables can replace PCB traces to reduce insertion loss.

[0061] This embodiment does not limit the specific application scenario of the cable, and can be illustrated by using the application of the cable in active cables. Active cables are used to interconnect two devices, and also to interconnect two components or two chips within a device.

[0062] The cable provided in this embodiment comprises multiple cores within a single cable. These cores share a dielectric layer and a return layer, resulting in a smaller cable diameter, which facilitates weight reduction and diameter reduction. Furthermore, this multi-core cable can transmit multiple single-ended signals with low crosstalk between signals. Each single-ended signal requires only one core, compared to transmitting differential signals (which require two cores). This reduces the number of cores by half while transmitting the same number of signals, further contributing to weight reduction and diameter reduction. Therefore, the cable provided in this embodiment can achieve multi-signal transmission with a smaller wire diameter.

[0063] For example, if the number of transmitted signals remains constant, such as transmitting two signals, the cable provided in this embodiment can transmit two signals (specifically, two single-ended signals) using only two wires. Traditional cables, on the other hand, either require four wires to transmit two signals (specifically, two differential signals) or two coaxial cables to transmit two signals (specifically, two single-ended signals). In either case, the cables used in traditional methods to transmit two signals are thicker and heavier.

[0064] Therefore, the multi-core cable provided in this embodiment can transmit multiple signals with a smaller wire diameter, which is beneficial for reducing the weight and making the cable thinner.

[0065] The multi-core cable shown in this embodiment will be described below.

[0066] First, it should be noted that the multi-core cable described in this embodiment refers to a cable in which all the battery cores are arranged in a single dielectric layer. This differs from a multi-core cable formed by bundling multiple coaxial cables, and also from a multi-core cable formed by bundling multiple differential cables. While a multi-core cable formed by bundling multiple coaxial cables can transmit multiple single-ended signals, the total diameter of the bundled cable is determined by the diameter of each individual coaxial cable, resulting in a larger total diameter, thicker cable, and heavier weight, failing to achieve the goals of weight reduction and thinner cable design. The multi-core cable described in this embodiment, however, is not a bundled cable, but a single cable comprising multiple battery cores. Therefore, unless otherwise specified, the term "multiple battery cores" in the following text refers to the battery cores within the same cable.

[0067] like Figure 1 The diagram shown is a cross-sectional view of the cable. (For reference) Figure 1 As shown, the cable includes a dielectric layer 1, a first metal layer 2, and at least two electrical cores 3. Figure 1 Example 3: Two battery cells from China and Israel. (Continue to refer to...) Figure 1 As shown, the first metal layer 2 covers the dielectric layer 1, and at least two battery cores 3 are arranged in the dielectric layer 1. The cable diameter is determined based on the center distance S between the two battery cores 3, the distance w between the center of the battery core 3 and the inner wall of the first metal layer 2, and the diameter d of the battery core 3. The multi-core cable determined by the above parameters can be used to transmit multiple single-ended signals.

[0068] While bundling multiple coaxial cables creates a multi-core cable, the diameter of this type of cable is determined by the diameter of each individual coaxial cable before bundling. This allows for the transmission of multiple single-ended signals with a relatively large diameter. In contrast, in this embodiment, the multiple cores 3 of the multi-core cable are arranged within the same dielectric layer and the same metal layer. The diameter of this type of multi-core cable is determined by the aforementioned S, w, and d, enabling the transmission of multiple single-ended signals with a smaller diameter. This, in turn, facilitates weight reduction and cable thinning.

[0069] The structural features of the cable will be described first, followed by its dimensional features.

[0070] Regarding the cross-sectional shape of cables: The cross-sectional shape of a cable can be any shape, such as circular, elliptical, racetrack-shaped, or even rectangular. In applications, the design principle for the cross-sectional shape of the cable can be to choose a shape that minimizes the wire diameter and lightens the weight while meeting dimensional requirements. For example, if the spacing S between two battery cores and the spacing w between the battery core and the return layer meet the requirements, the chosen shape will minimize the wire diameter and weight of the cable. For example, the cross-sectional shape of the cable can be as follows: Figure 1 The following description uses a runway-shaped cable as an example, as shown in the illustration.

[0071] In one example, the cross-sectional shape of the dielectric layer 1 and the cross-sectional shape of the first metal layer 2 are both related to the cross-sectional shape of the cable. For example, if the cross-sectional shape of the cable is racetrack-shaped, then the cross-sectional shape of the dielectric layer 1 is racetrack-shaped, and the cross-sectional shape of the first metal layer 2 is a racetrack-shaped ring.

[0072] In one example, the cross-sectional shape of each battery cell 3 is generally circular. Due to its small diameter, the battery cell 3 is also called a wire core. The diameters of different batteries cell 3 can be the same or different. In this embodiment, we take the example that all batteries cell 3 have the same diameter, d. The value of the diameter d of the battery cell 3 can range from 0.127mm to 0.644mm (inclusive). The specific value of the diameter d of the battery cell 3 is related to the type of cable. For example, if the cable type is 32AWG cable, then d is 0.2mm; if the cable type is 30AWG cable, then d is 0.26mm; and if the cable type is 26AWG cable, then d is 0.4mm.

[0073] Regarding the cable material: The dielectric layer 1 is made of an insulating medium, which buffers and protects the battery core 3, and also provides electrical isolation between the battery core 3 and the first metal layer 2. The dielectric layer 1 can be a single insulating material. Therefore, the relative permittivity εr at all locations within the dielectric layer 1 is equal, with a value ranging from 1.2 ≤ εr ≤ 4, specifically 2 ≤ εr ≤ 2.5, and typically taken as 2.1.

[0074] In one example, the first metal layer 2 is mainly used to realize signal return, forming a closed signal loop with the battery cell 3; therefore, the first metal layer 2 is also called the return layer. The material of the first metal layer 2 is a conductive metal layer, specifically copper, such as a copper braided layer. The battery cell 3 is used as a signal circuit, so its material is also a conductive metal, such as copper; therefore, the battery cell is also called a copper core.

[0075] The number of battery cells 3 can be two or more. This embodiment does not limit this, and the example is that the cable includes two battery cells 3.

[0076] Regarding the distribution of multiple battery cells 3 in dielectric layer 1.

[0077] As described above, the cross-sectional shape of dielectric layer 1 is racetrack-shaped, which is formed by two semicircles on the left and right and a rectangle in the middle. In a scheme where the number of cells 3 is two, refer to... Figure 1 As shown, the centers of the two cells 3 can be located at the two centers of the dielectric layer 1, respectively.

[0078] The center distance S between the two battery cells 3 follows a certain relationship. If S is too small, it will mainly affect the differential impedance of the cable, while if S is too large, it will increase the cable diameter. The value of S can be determined based on the differential impedance of the cable, the single-ended impedance, the relative permittivity εr of the dielectric layer 1, and the diameter d of the battery cell 3. The range of values ​​for S will be introduced below.

[0079] The spacing w between the battery cell 3 and the first metal layer 2 also satisfies a certain relationship. If w is too small, it will mainly affect the single-ended impedance of the cable, while if w is too large, it will increase the cable diameter. The value of w can also be determined based on the differential impedance of the cable, the single-ended impedance, the relative permittivity εr of the dielectric layer 1, and the diameter d of the battery cell 3. The range of values ​​for w will be introduced below.

[0080] In one example, the ratio of S to w also satisfies a certain relationship, such as... Figure 2 The diagram shows the relationship between S and w, where (a) represents the diagram where S / w > 2, (b) represents the diagram where S / w = 2, (c) represents the diagram where 1 < S / w < 2, (d) represents the diagram where S / w = 1, and (e) represents the diagram where d < S / w < 1.

[0081] refer to Figure 2 As shown, the larger the S / w ratio, the larger the cable diameter; the smaller the S / w ratio, the smaller the cable diameter. However, the smaller the S / w ratio, the smaller the differential impedance of the cable. The differential impedance is generally 93Ω or 100Ω. Therefore, in order to ensure that the cable diameter is smaller than the total diameter of the bundled coaxial cable, the values ​​of S and w must be 1≤S / w≤2.5, provided that the values ​​of S and w can transmit both differential signals and multiple single-ended signals.

[0082] It should be noted that when the number of cells 3 is greater than 2, S can be the center distance between any two cells 3, or the minimum center distance among multiple center distances. Similarly, w can be the distance between the center of any cell 3 and the first metal layer 2, or the minimum distance among all distances w.

[0083] In schemes where the number of battery cells 3 is greater than 2, the distance S between any two battery cells 3 can be equal or unequal, but regardless of whether they are equal or unequal, the range of values ​​for S is the same. Similarly, in schemes where the number of battery cells 3 is greater than 2, the distance between the center of battery cell 3 and the first metal layer 2 can be equal everywhere or unequal everywhere, but regardless of whether they are equal everywhere, the range of values ​​for w is the same. If the distance between the center of battery cell 3 and the first metal layer 2 is equal everywhere, then the distances between the centers of different battery cells 3 and the first metal layer 2 can be equal or unequal, but regardless of whether they are equal or unequal, the range of values ​​for w is the same. In the example below, the number of battery cells is two, the diameters of the two battery cells are equal, the distance between the center of the battery cell and the first metal layer 2 is equal everywhere, and the distance between the center of each battery cell and the first metal layer 2 is equal.

[0084] In application, the multi-core cable will undergo bending operations such as turns and bends. If the first metal layer 2 breaks at a certain point, it will affect the single-ended impedance at that point, thereby affecting the transmission of single-ended signals. To avoid this situation, the first metal layer 2 can include multiple metal layers arranged together from the inside to the outside, and the spacing between two adjacent metal layers is relatively close to enable current coupling.

[0085] For example, the first metal layer 2 includes two metal layers, denoted as an inner metal layer and an outer metal layer. The inner metal layer covers the dielectric layer 1, and the outer metal layer covers the inner metal layer. The outer and inner metal layers can be adjacent or spaced apart, but the spacing cannot be too large. It must be sufficient to allow current to couple from the inner metal layer to the outer metal layer, and vice versa. Therefore, the spacing between the outer and inner metal layers is greater than or equal to 0 and less than or equal to the current coupling distance.

[0086] The current coupling distance is the distance at which current can be coupled. For example, the maximum value of the current coupling distance is between 0.1 mm and 0.2 mm.

[0087] Since the first metal layer 2 includes an inner metal layer and an outer metal layer, the probability of the inner metal layer and the outer metal layer breaking at the same location simultaneously is relatively low, even if the cable is bent during field installation. This can minimize the possibility of signal interruption during cable signal transmission.

[0088] In one example, the multi-core cable includes not only the dielectric layer 1, the first metal layer 2, and the battery core 3 described above, but also other structures, such as... Figure 3As shown, the cable also includes multiple return conductors 4, which are easy to weld to the ground plane. These multiple return conductors 4 can be fixed outside the first metal layer 2 to play a return function. The number of return conductors 4 can be equal to the number of battery cells 3. The return conductors 4 correspond one-to-one with the battery cells 3. The return conductor 4 corresponding to a certain battery cell 3 is arranged near that battery cell 3.

[0089] In other examples, a return conductor 4 may also be placed at the center of dielectric layer 1.

[0090] In other examples, the multi-core cable may also include a second metal layer 5, which covers the first metal layer 2 as a shielding layer to shield signals transmitted by adjacent cables, for example, such as... Figure 3 As shown, the second metal layer 5 covers the first metal layer 2, and a plurality of return conductors 4 are located between the first metal layer 2 and the second metal layer 5.

[0091] In other examples, multicore cables may also include a sheath, which serves as a protective layer and is located on the outermost layer of the cable.

[0092] Of course, the cable may also include other structures, which will not be listed in this embodiment.

[0093] The above describes the structural characteristics of the cable. The following section will introduce the dimensional characteristics of the cable. The dimensional characteristics of the cable mainly refer to the range of values ​​for the center distance S between the two battery cores 3 and the range of values ​​for the distance w between the center of the battery core 3 and the first metal layer 2.

[0094] The values ​​of S and w represent the constraints that allow the cable to transmit both differential and single-ended signals with a relatively small wire diameter.

[0095] The general criteria for judging whether a cable can transmit differential signals are that the differential impedance value is close to 93Ω or 100Ω during transmission. It's also important to check if the insertion loss curve of the differential signal is smooth and if there are any sudden, significant drops in the curve. Insertion loss is the ratio of the reflected power of the differential cell to the input power, caused by discontinuities in the differential impedance. If the differential impedance is close to 93Ω or 100Ω and the insertion loss curve is relatively smooth without significant drops, then the cable can transmit differential signals.

[0096] When transmitting multiple differential signals, it is also necessary to consider the degree of crosstalk between the two signals. For a certain differential signal, if the insertion loss is small and the crosstalk is low, or if the insertion loss is large but the crosstalk is very low, or if the crosstalk is severe but the insertion loss is small, then the signal energy received at the receiving end is relatively large. This indicates that the cable is practical for transmitting multiple differential signals and can indeed transmit multiple differential signals.

[0097] Therefore, if a cable has a differential impedance close to 93Ω or 100Ω when transmitting differential signals, a relatively smooth insertion loss curve, and an insertion loss to crosstalk ratio (ICR) greater than 20dB when transmitting multiple differential signals, then it can be concluded that the cable is capable of transmitting multiple differential signals. An ICR greater than 20dB indicates either low insertion loss and low crosstalk, or relatively high insertion loss but very low crosstalk, or relatively severe crosstalk but very low insertion loss.

[0098] Similarly, the criteria for judging whether a cable transmits a single-ended signal are as follows: whether the single-ended impedance is continuous during transmission, whether the single-ended impedance is close to 50Ω, whether the insertion loss curve of the single-ended signal is smooth, whether there are no obvious abrupt changes on the curve, and whether the insertion loss crosstalk ratio (ICR) is greater than 20dB.

[0099] Therefore, the range of values ​​for S and w can be set based on whether the single-ended impedance meets the design requirements, the differential impedance meets the design requirements, and the insertion loss crosstalk ratio (ICR) is greater than 20dB.

[0100] From the following formulas for single-ended impedance and differential impedance, it can be seen that the values ​​of S and εr are positively correlated with d, specifically with... The value of w is positively correlated with εr and d, and the value of w is also positively correlated with εr and d, specifically with It is positively correlated with d. Based on theoretical calculations and simulation verification, S can be calculated using the following formula, and w can be calculated using the following formula.

[0101] Single-ended impedance formula:

[0102] Differential impedance formula:

[0103] S-formula:

[0104] w formula:

[0105] The S formula can be further simplified to obtain... Further simplification of the formula for w yields:

[0106] In one example, the relative permittivity εr of dielectric layer 1 is related to the material of dielectric layer 1, and the value of εr is generally in the range of 1.2 ≤ εr ≤ 4. Therefore, given that the value of εr is generally in the range of 1.2 ≤ εr ≤ 4, substituting εr as 1.2 into the equation... This gives us the lower limit of the range of values ​​for S. Substituting εr = 4 into the equation... This allows us to obtain the upper limit of the range of values ​​for S, and thus, the specific range of values ​​for S is: After further adjustment, the result is 1.97d≤S≤3.60d.

[0107] Similarly, substituting εr = 1.2 into... This gives us the lower limit of the range of values ​​for w. Substituting εr = 4 into the equation... This allows us to obtain the upper limit of the range of values ​​for w, and thus, the specific range of values ​​for w. After further refinement, the result is 1.15d≤w≤2.10d.

[0108] Therefore, when the relative permittivity εr of dielectric layer 1 satisfies 1.2≤εr≤4, the range of S is 1.97d≤S≤3.60d, and the range of w is 1.15d≤w≤2.10d. Multi-core cables satisfying this dimensional relationship can transmit both differential and single-ended signals. Specifically, the differential impedance for transmitting differential signals must satisfy 80Ω≤Z. D ≤110Ω, the single-ended impedance for transmitting a single-ended signal must satisfy 40Ω≤Z. C ≤55Ω.

[0109] It should be noted that, for the condition S satisfies 1.97d≤S≤3.60d and w satisfies 1.15d≤w≤2.10d, the closer the value of S is to the lower limit, the closer the differential impedance is to 80Ω; the closer the value of S is to the upper limit, the closer the differential impedance is to 110Ω. Similarly, the closer the value of w is to the lower limit, the closer the single-ended impedance is to 40Ω; the closer the value of w is to the upper limit, the closer the single-ended impedance is to 55Ω.

[0110] It should be noted that, considering the error, any error within ±10% falls within the above range. For example, considering the error of ±10%, the range of S is 1.97d×(1±10%)≤S≤3.60d×(1±10%), and the range of w is 1.15d×(1±10%)≤w≤2.10d×(1±10%).

[0111] In one example, the relative permittivity εr of dielectric layer 1 further ranges from 2 ≤ εr ≤ 2.5. Therefore, given that the range of εr is generally 2 ≤ εr ≤ 2.5, substituting εr = 2 into the equation... This allows us to obtain the lower limit of the range of values ​​for S, and substitute εr = 2.5 into the equation. This allows us to obtain the upper limit of the range of values ​​for S, and thus, the specific range of values ​​for S is: After further adjustment, the result is 2.55d≤S≤2.85d.

[0112] Similarly, substituting εr as 2 into This allows us to obtain the lower limit of the range of values ​​for w, and substitute εr = 2.5 into the equation. This allows us to obtain the upper limit of the range of values ​​for w, and thus, the specific range of values ​​for w. After further adjustment, the result is 1.48d≤w≤1.66d.

[0113] In one example, when the relative permittivity εr of dielectric layer 1 satisfies 2 ≤ εr ≤ 2.5, the value range of S is 2.55d ≤ S ≤ 2.85d, and the value range of w is 1.48d ≤ w ≤ 1.66d. A multi-core cable satisfying this dimensional relationship can transmit both differential and single-ended signals. Furthermore, the differential impedance corresponding to the transmission of differential signals can satisfy 80Ω ≤ Z. D ≤110Ω, the single-ended impedance for transmitting a single-ended signal must satisfy 40Ω≤Z. C ≤55Ω.

[0114] It should be noted that, for the condition S satisfies 2.55d≤S≤2.85d and w satisfies 1.48d≤w≤1.66d, the closer the value of S is to the lower limit, the closer the differential impedance is to 80Ω; the closer the value of S is to the upper limit, the closer the differential impedance is to 110Ω. Similarly, the closer the value of w is to the lower limit, the closer the single-ended impedance is to 40Ω; the closer the value of w is to the upper limit, the closer the single-ended impedance is to 55Ω.

[0115] It should be noted that, considering the error, any error within ±10% falls within the above range. For example, considering the error of ±10%, the range of S is 2.55d×(1±10%)≤S≤2.85d×(1±10%), and the range of D is 1.48d×(1±10%)≤w≤1.66d×(1±10%).

[0116] In one example, the relative permittivity εr of dielectric layer 1 is typically 2.1. Therefore, substituting εr = 2.1 into the above formula... S is 2.61d. Substituting this into the above formula... With w = 1.52d, a multi-core cable satisfying this dimensional relationship can transmit both differential and single-ended signals. Furthermore, the differential impedance for transmitting differential signals meets the requirement of 90Ω ≤ Z. D ≤100Ω, for example, if the differential impedance is 93Ω, the single-ended impedance corresponding to the transmission of a single-ended signal is 50Ω.

[0117] It should be noted that, taking into account the error, any error within ±10% falls within the above range. For example, after taking into account the error of ±10%, S is 2.61d×(1±10%) and w is 1.52d×(1±10%).

[0118] The above is an introduction to the dimensional characteristics of the cable. The simulation results of the cable will be presented below.

[0119] First, let's introduce the above S formula. The origin of w formula The origin of.

[0120] For example Figure 1 The example of a two-core cable shown uses a dielectric layer 1 with a relative permittivity εr of 2.1, a single-ended impedance ZC of 50Ω, a differential impedance ZD of 100Ω, and a core diameter d of 0.26mm. Based on the aforementioned differential impedance formula... and the formula for single-ended impedance The calculated values ​​are S = 0.723 mm and w = 0.429 mm.

[0121] Simulations were performed on a two-core cable with S = 0.723 mm and w = 0.429 mm, and the results were as follows: Figure 4 The impedance curve shown, and as Figure 5 The diagram shows the insertion loss and crosstalk curves for transmitting two single-ended signals. Figure 4 The horizontal axis represents the time, such as... Figure 4 A point on the curve shown represents the impedance at a certain moment (or location).

[0122] refer to Figure 4 As shown, when this cable transmits differential signals, the corresponding differential impedance is around 100Ω, indicating that the differential impedance meets the expected value. (Continue to refer to...) Figure 4 As shown, when this cable transmits a single-ended signal, the corresponding single-ended impedance is around 54Ω, indicating that the single-ended impedance deviates from the expected value (50Ω). (Reference) Figure 5 As shown, when transmitting two single-ended signals at a transmission frequency of 28GHz, the insertion loss crosstalk ratio (ICR) is 50dB, which is much greater than 20dB. This indicates that the signal-to-noise ratio for transmitting single-ended signals is good within a bandwidth of 0 to 28GHz, thus demonstrating the practicality of the cable for transmitting single-ended signals.

[0123] Because the theoretically calculated single-ended impedance (54Ω) deviates from the expected value (50Ω), S and w need to be adjusted to ensure that the differential impedance matches the expected value, the single-ended impedance matches the expected value, and the ICR is greater than 20dB.

[0124] Simulations using high frequency structure simulator (HFSS) software showed that when w is 0.39mm and S is 0.67mm, the single-ended impedance is close to 50Ω and the differential impedance is close to 93Ω. When transmitting two single-ended signals, the insertion loss and crosstalk difference (ICR) is greater than 20dB, indicating that the cable with w of 0.39mm and S of 0.67mm can transmit both single-ended and differential signals well.

[0125] like Figure 6 The figure shows the impedance curve obtained from a simulation of a two-core cable with εr = 2.1, d = 0.26 mm, S = 0.67 mm, and w = 0.39 mm. Figure 7 The figure shows the simulation results for a two-core cable with εr = 2.1, d = 0.26 mm, S = 0.67 mm, and w = 0.39 mm, yielding the insertion loss curve and crosstalk curve.

[0126] refer to Figure 6 As shown, when transmitting differential signals, the cable's differential impedance is around 93Ω, which is close to the expected value. (Continue to refer to...) Figure 6 As shown, when transmitting a single-ended signal, the corresponding single-ended impedance is around 50Ω, which is close to the expected value. (Reference) Figure 7 As shown, when transmitting two single-ended signals at a transmission frequency of 28GHz, the insertion loss crosstalk ratio (ICR) is 59dB, which is much greater than 20dB. This indicates that the signal-to-noise ratio for transmitting single-ended signals is good within a bandwidth of 0 to 28GHz, thus demonstrating the practicality of the cable for transmitting single-ended signals.

[0127] The above applies when the relative permittivity εr of dielectric layer 1 is 2.1 and the diameter d of cell 3 is 0.26 mm. For any d and any εr, we have the formula S: w formula:

[0128] For example, if εr remains constant, changing the value of d can be achieved by scaling S and w proportionally based on the single-ended impedance formula and the differential impedance formula, according to the scaling factor of d.

[0129] If εr is still 2.1, and d is 0.4 mm, then S is... That is, S is 1.03mm, and w is That is, w is 0.6mm.

[0130] Of course, with d = 0.4 mm and εr = 2.1, S and w can also be determined by combining the single-ended impedance formula and the differential impedance formula with simulation. The S determined by the impedance formula is basically consistent with the S calculated by the S formula, and the w determined by the impedance formula is basically consistent with the w calculated by the w formula.

[0131] like Figure 8 The figure shows the impedance curve obtained from a simulation of a cable with εr = 2.1, d = 0.4 mm, S = 1.03 mm, and w = 0.6 mm. Figure 9 The figure shows the single-ended signal insertion loss curve and single-ended signal crosstalk curve obtained by simulating a cable with εr = 2.1, d = 0.4 mm, S = 1.03 mm, and w = 0.6 mm.

[0132] refer to Figure 8 As shown, when the cable transmits a differential signal, the corresponding differential impedance Z is... C When transmitting a single-ended signal, the corresponding single-ended impedance Z is 93Ω. D The value of 50Ω indicates that, for this cable size, both the differential impedance and the single-ended impedance match the expected value. (Reference) Figure 9 As shown, when transmitting two single-ended signals at a transmission frequency of 28GHz, the insertion loss crosstalk ratio (ICR) is 63dB, which is much greater than 20dB. This indicates that the signal-to-noise ratio for transmitting single-ended signals is good within a bandwidth of 0 to 28GHz, thus demonstrating the practicality of the cable for transmitting single-ended signals.

[0133] For example, if d is still 0.26 mm, but εr is 2.5, then S is... That is, S is 0.74 mm, and w is That is, w is 0.43mm.

[0134] In one example, d is 0.26 mm and εr is 2.5. S and w can also be determined by combining the single-ended impedance formula and the differential impedance formula with simulation. S determined by the impedance formula is basically consistent with S calculated by the S formula, and w determined by the impedance formula is basically consistent with w calculated by the w formula.

[0135] For example, based on the single-ended impedance formula and the differential impedance formula, S1 is calculated to be 1.05 mm and w1 to be 0.49 mm. Simulation of a cable of this size yields the following results: Figure 10 The impedance curve shown, and as Figure 11 The insertion loss curve and crosstalk curve are shown below. (Reference)Figure 10 As shown, the single-ended impedance is approximately 54Ω, and the differential impedance is approximately 103Ω. (Reference) Figure 11 As shown, when transmitting two single-ended signals, the insertion loss-to-crosstalk ratio (ICR) is 45 dB. It is evident that although the difference between insertion loss and crosstalk meets the requirements, both the single-ended impedance and the differential impedance deviate from their commonly used values.

[0136] Adjusting S1 and w1, such as multiplying them both by a coefficient of 0.9, yields S2 of 0.95mm and w2 of 0.44mm. Simulating a cable of this size yields the following results: Figure 12 The impedance curve shown, and as Figure 13 The insertion loss curve and crosstalk curve are shown below. (Reference) Figure 12 As shown, the single-ended impedance is approximately 50Ω, and the differential impedance is approximately 97Ω. (Reference) Figure 13 As shown, when transmitting two single-ended signals, the insertion loss-to-crosstalk ratio (ICR) is 43 dB. It is evident that although the difference between insertion loss and crosstalk meets the requirements, the differential impedance still deviates from the expected value.

[0137] Adjust S2 while keeping w2 unchanged, and change S2 to S3, where S3 is 0.78mm. Simulate the cable of this size and obtain the following results. Figure 14 The impedance curve shown, and as Figure 15 The insertion loss curve and crosstalk curve are shown below. (Reference) Figure 14 As shown, the single-ended impedance is approximately 50Ω, and the differential impedance is approximately 94Ω. (Reference) Figure 15 As shown, when transmitting two single-ended signals, the insertion loss crosstalk ratio (ICR) is 66 dB. It is evident that the single-ended impedance matches the expected value, the differential impedance also matches the expected value, and the ICR meets the requirements.

[0138] Therefore, based on the impedance formula and simulation results, S is finally determined to be 0.78 mm and w to be 0.44 mm. Substituting d = 0.26 mm and εr = 2.5 into the above S formula yields S = 0.74 mm, and substituting them into the w formula yields w = 0.43 mm. It can be seen that S and w determined by the impedance formula and simulation are basically consistent with S and w determined by the S and w formulas, demonstrating the universality of the aforementioned S and w formulas.

[0139] It should be noted that in applications, after determining the values ​​of S and w for the cable using the above S and w formulas, the values ​​of S and w will be fine-tuned during the manufacturing of cables of this size to enable the cable to better transmit single-ended and differential signals.

[0140] In this embodiment, a single cable includes multiple battery cores that share a dielectric layer and a first metal layer, resulting in a smaller cable diameter. This facilitates weight reduction and diameter reduction. Furthermore, this multi-core cable can transmit multiple single-ended signals with low crosstalk. Each single-ended signal requires only one battery core, compared to transmitting differential signals (which requires two cores). This reduces the number of cores by half while transmitting the same number of signals, further contributing to weight reduction and diameter reduction. Therefore, the cable provided in this embodiment can achieve multi-signal transmission with a smaller wire diameter.

[0141] This embodiment also provides an active cable or a passive cable, illustrated with an active cable, such as... Figure 16 The diagram shows a scenario where two communication devices are interconnected using an active cable. (Reference) Figure 16 As shown, the active cable 300 includes two electrical modules 302 and the aforementioned cable 301. One electrical module 302 is located at the first end of the cable 301, and the other electrical module 302 is located at the second end of the cable 301. Similarly, the passive cable also includes the aforementioned cable and two electrical modules, with one electrical module connected to the first end of the cable and the other connected to the second end. The main difference between active and passive cables is that the PCB of the electrical modules in an active cable has an active chip, while the PCB of the electrical modules in a passive cable does not have an active chip.

[0142] Continue to refer to Figure 16 As shown, both the first communication device 100 and the second communication device 200 have electrical interfaces on their panels. Thus, the electrical module 302 at the first end of the cable 301 is inserted into the electrical interface of the first communication device 100, thereby interconnecting the first end of the active cable 300 with the first communication device 100. The electrical module 302 at the second end of the cable 301 is inserted into the electrical interface of the second communication device 200, thereby interconnecting the second end of the active cable 300 with the second communication device 200.

[0143] In this way, the first communication device 100 and the second communication device 200 can send and receive data via an active cable.

[0144] This embodiment also provides a communication system, see reference. Figure 16As shown, the communication system includes a first communication device 100, a second communication device 200, and the aforementioned active cable 300. The first communication device 100 and the second communication device 200 are connected via the active cable 300. For example, one end of the active cable 300 has an electrical module 302 connected to the first communication device 100, and the other end has an electrical module 302 connected to the second communication device 200. In short-distance interconnection scenarios, the active cable 300 can also be replaced with a passive cable.

[0145] The terminology used in the embodiments of this disclosure is for illustrative purposes only and is not intended to limit the disclosure. Unless otherwise defined, the technical or scientific terms used in the embodiments of this disclosure should be understood in their ordinary sense by one of ordinary skill in the art to which this disclosure pertains. The terms "first," "second," and similar terms used in this specification and claims do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Similarly, "a" or "an," and similar terms do not indicate a quantity limitation, but rather indicate the presence of at least one. The terms "comprising," "including," and similar terms mean that the elements or objects preceding "comprising" or "including" encompass the elements or objects listed following "comprising" or "including" and their equivalents, but do not exclude other elements or objects. "Upper," "lower," "left," "right," etc., are used only to indicate relative positional relationships; when the absolute position of the described object changes, the relative positional relationship may also change accordingly. "A plurality" refers to two or more, unless otherwise expressly defined.

[0146] The above description is merely an optional embodiment of this disclosure and is not intended to limit this disclosure. Any modifications, equivalent substitutions, improvements, etc., made within the principles of this disclosure should be included within the protection scope of this disclosure.

Claims

1. A cable, characterized by The cable comprises a medium layer (1), a first metal layer (2) and at least two electric cores (3), the first metal layer (2) is coated outside the medium layer (1), and the at least two electric cores (3) are located in the medium layer (1). The diameter of the cable is determined according to the center distance S between any two electric cores (3), the distance w between the center of any one electric core (3) and the inner wall of the first metal layer (2), and the diameter d of the electric core (3), and the cable is used for transmitting multi-channel single-ended signals.

2. The cable of claim 1, wherein, The values of S and w satisfy 1≤S / w≤2.

5.

3. The cable of claim 1, wherein, The shape of the cross section of the medium layer (1) is a racetrack type or an elliptical shape.

4. A cable, characterized by The cable comprises a medium layer (1), a first metal layer (2) and at least two electric cores (3), the first metal layer (2) is coated outside the medium layer (1), and the at least two electric cores (3) are located in the medium layer (1). The center distance S between any two electric cores (3) satisfies 1.97d≤S≤3.60d, and the distance w between the center of any one electric core (3) and the inner wall of the first metal layer (2) satisfies 1.15d≤w≤2.10d, wherein d is the diameter of the electric core (3) and is determined according to the wire gauge of the cable.

5. The cable of claim 4, wherein, The center distance S between any two electric cores (3) satisfies 2.55d≤S≤2.85d, and the distance w between the center of any one electric core (3) and the inner wall of the first metal layer (2) satisfies 1.48d≤w≤1.66d.

6. The cable of claim 5, wherein, The relative dielectric constant of the medium layer (1) is in the range of 2≤εr≤2.5, the differential impedance Z D of the differential signal transmitted by the cable is in the range of 80Ω≤Z D ≤110Ω, and the single-end impedance Z C of the single-end signal transmitted by the cable is in the range of 40Ω≤Z C ≤55Ω.

7. The cable of claim 4, wherein, The center distance S between any two electric cores (3) is 2.61d, and the distance w between the center of any one electric core (3) and the inner wall of the first metal layer (2) is 1.52d.

8. The cable of claim 7, wherein, The relative permittivity εr of the dielectric layer (1) is 2.1, and the differential impedance Z corresponding to the differential signal transmitted by the cable is... D The value range is 90Ω≤Z D ≤100Ω, the single-ended impedance Z corresponding to the transmission of a single-ended signal C It is 50Ω.

9. A cable according to any one of claims 4 to 8, characterised in that, The center distance S between any two battery cells (3) is The distance w between the center of any one battery cell (3) and the inner wall of the first metal layer (2) is Wherein, εr is the relative dielectric constant of the dielectric layer (1).

10. A cable according to any one of claims 4 to 9, characterised in that, The relative dielectric constant of the medium layer (1) is in the range of 1.2≤εr≤4, the differential impedance Z D of the differential signal transmitted by the cable is in the range of 80Ω≤Z D ≤110Ω, and the single-end impedance Z C of the single-end signal transmitted by the cable is in the range of 40Ω≤Z C ≤55Ω.

11. A cable according to any one of claims 4 to 10, characterised in that, The diameter d of the electric core (3) ranges from 0.127mm to 0.644mm.

12. A cable according to any one of claims 4 to 11, characterised in that, The shape of the cross section of the medium layer (1) is a racetrack type or an elliptical shape.

13. A cable according to any one of claims 4 to 12, characterised in that, The shape of the cross section of the medium layer (1) is a racetrack type, and the number of the electric cores (3) is two, and the centers of the two electric cores (3) are located at the two centers of the medium layer (1), respectively.

14. The cable of claim 13, wherein, The center distance S between the two electric cores (3) and the distance w between the center of the electric core (3) and the inner wall of the first metal layer (2) satisfy 1≤S / w≤2.

5.

15. A cable according to any one of claims 4 to 14, characterised in that, The first metal layer (2) comprises a plurality of metal layers, the plurality of metal layers are arranged from inside to outside along the radial direction of the cable, and the distance between any two adjacent metal layers is greater than or equal to 0 and less than or equal to the current coupling distance.

16. An active cable, characterized by The active cable comprises a first electric module, a second electric module and the cable of any one of claims 4 to 15, the first end of the cable is connected with the first electric module, and the second end of the cable is connected with the second electric module.

17. A communication system, characterized by The communication system comprises a first communication device, a second communication device and the active cable of claim 16, and the first communication device and the second communication device are connected through the active cable.

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