CABLE SIGNAL TRANSMISSION SYSTEM

Abstract

Cable signal transmission system, including: a differential driver to generate a differential signal between a positive-phase signal and a negative-phase signal from a signal that is input into the differential driver; a splitter to divide the positive-phase signal into two or more split positive-phase signals, and to divide the negative-phase signal into two or more split negative-phase signals; and a multi-core cable, having four or more cores, which is connected to the splitter in order to transmit each of the signals separately after division by the splitter, wherein in the multi-core cable each of the following inner cables: two or more inner cables, via which the split positive-phase signals are transmitted, and two or more inner cables, via which the split negative-phase signals are transmitted, are arranged adjacent to one another.

Description

AREA OF TECHNOLOGY

[0001] The present disclosure relates to a cable signal transmission system. BACKGROUND ON THE STATE OF THE TECHNOLOGY

[0002] Conventionally, a technology related to a differential signal cable is disclosed, which is used to transmit high-speed digital signals of several Gbit / s or more. In the technical field of differential signal cables, various proposals have been submitted that aim to improve signal transmission performance and interference resistance (for example, patent literature 1). REFERENCE LIST PATENT LITERATURE

[0003] Patent Literature 1: JP 2011-86458 A

[0004] Patent Literature 2: US 2016 / 0372236A1 discloses a wiring element comprising a first module with a first communication unit, second modules with respective second communication units, a cable module with cables connecting the first communication unit to the second communication units, and a branch module arranged at a prescribed position in the cable module. The branch module has a first cable entry section into which the cables are inserted in bundled form and a second cable entry section into which the cables are inserted separately. In a first state, the branch module is fixed to at least one of the cables, and in a second state, it is made movable relative to the cables. One end section of the cables is connected to the first module in bundled form, and the other end sections of the cables are connected separately to the respective second modules.

[0005] Patent literature 3: EP 3 430 633 B1 discloses a cable for transmitting electrical signals, with an outer sheath made of an electrically insulating material and at least N conductors n with N ≥ 2 and N ∈ |N, which are arranged inside the outer sheath, wherein each conductor m has a total of M conductors made of an electrically conductive material with M ≥ 1 and M ∈ |N, wherein the wire m with ∈ [1, M], m ∈ |N of the conductor n with n ∈ [1, N], n ∈ IN is surrounded by a dielectric with a predetermined value for the relative permittivity εr (m,n) > 1.

[0006] Patent Literature 4: US 2016 / 0036112A1 discloses a differential signal cable comprising a pair of signal conductors arranged parallel and longitudinally within the differential signal cable, an insulator covering one circumference of the pair of signal conductors as a whole, with only the insulator located between the pair of signal conductors, and a shield conductor provided on an outer circumference of the insulator. A spacing between the pair of signal conductors is set such that an even-numbered impedance of the pair of signal conductors, the spacing of which is fixed by embedding in the insulator and covered by the shield conductor, is in the range of 1.5 to 1.9 times an odd-numbered impedance to achieve improved skew and differential-mode insertion loss, which occurs during the transmission of high-speed signals of at least 10 Gbps. SUMMARY OF THE INVENTIONAL PROBLEM

[0007] In cable signal transmission using a conventional cable for differential signals, a cable with a design that includes a physical grounding conductor, such as a shielding conductor or a drain conductor, was used to improve signal transmission performance and interference resistance.

[0008] One objective of the present disclosure is to provide a cable signal transmission system with a cable design that eliminates the need for a physical grounding conductor, such as a shielding conductor or a drain conductor. SOLUTION TO THE PROBLEM

[0009] A cable signal transmission system according to the present disclosure comprises: a differential driver for generating a differential signal between a positive-phase signal and a negative-phase signal from a signal input to the differential driver; a splitter for dividing the positive-phase signal into two or more positive-phase signals and the negative-phase signal into two or more negative-phase signals; and a multi-core cable having four or more cores connected to the splitter for transmitting each of the signals separately after division by the splitter. In the multi-core cable, each of two or more inner conductors through which the divided positive-phase signals are transmitted is arranged adjacent to a corresponding pair of two or more inner conductors through which the divided negative-phase signals are transmitted. ADVANTAGEOUS EFFECTS OF THE INVENTION

[0010] Since the cable signal transmission system according to the present disclosure has the aforementioned design, a virtual perfect conductor wall (hereinafter referred to as an "electrical wall") is generated at a boundary where an inner cable for a positive-phase signal and an inner cable for a negative-phase signal are adjacent to each other, and functions as a grounding conductor. Therefore, the cable signal transmission system according to the present disclosure can eliminate the need for a conductor for shielding and a drain wire, which are physical grounding conductors. BRIEF DESCRIPTION OF THE DRAWINGS Fig. Figure 1 is a schematic representation of a cable signal transmission system using a typical two-wire cable. Fig. Figure 2 is a schematic representation of a cable signal transmission system in embodiment 1; Fig. Figure 3 is a schematic representation of a cable signal transmission system in embodiment 2; Fig. Figure 4 is a schematic representation of a cable signal transmission system in embodiment 3; and Fig. Figure 5 is a schematic representation of a cable signal transmission system in embodiment 4. DESCRIPTION OF THE EXECUTION FORMSExecution form 1.

[0011] Fig. Figure 2 is a schematic representation of a cable signal transmission system in embodiment 1. The cable transmission system comprises: a cable section 1b, which includes a multi-core cable with four conductors, wherein the multi-core cable includes two inner cables for positive-phase signals and two inner cables for negative-phase signals; and a differential driver 3a, which serves as a differential signal source. The two inner cables for the positive-phase signals include the positive-phase signal conductors 2p1 and 2p2 at their respective centers, and the outer peripheries of the positive-phase signal conductors are covered by corresponding dielectrics 1a. Similarly, the two inner cables for the negative-phase signals include the negative-phase signal conductors 2n1 and 2n2 at their respective centers, and the outer peripheries of the negative-phase signal conductors are covered by dielectrics 1a.The differential driver 3a generates a positive-phase signal and a negative-phase signal from a high-speed digital signal. The splitter 4 divides the positive-phase signal into two or more positive-phase signals and the negative-phase signal into two or more negative-phase signals. After division, the two positive-phase signals are connected to their respective positive-phase signal conductors 2p1 and 2p2. Similarly, after division, the two negative-phase signals are connected to their respective negative-phase signal conductors 2n1 and 2n2.

[0012] In cable section 1b, which contains the multi-core cable, of the cable signal transmission system according to embodiment 1, each of the two inner cables over which the split positive-phase signals are transmitted is arranged adjacent to the two inner cables over which the negative-phase signals are transmitted. Specifically, the positive-phase signal conductors 2p1 and 2p2 are arranged diagonally, and the negative-phase signal conductors 2n1 and 2n2 are also arranged diagonally.

[0013] In cable section 1b, which contains the multi-core cable according to embodiment 1, the positive-phase signal conductors 2p1 and 2p2 are connected at one end of the cable section to respective positive-phase signal output pins of the differential driver 3a, which serves as the differential signal source, and the negative-phase signal conductors 2n1 and 2n2 are connected to respective negative-phase signal output pins of the differential driver 3a, which serves as the differential signal source. More specifically, the cable signal transmission system according to the present disclosure divides each of the positive-phase and negative-phase signals into split signals and transmits these split signals using different signal conductors. The transmission endpoint has a design that combines the split signals into a single signal after division and utilizes the combined signal.

[0014] In the cable signal transmission system according to embodiment 1, a differential line is formed over which the positive-phase signals and the negative-phase signals are transmitted. Furthermore, since in the cable signal transmission system of the present disclosure the positive-phase signals are arranged in such a way as to be adjacent to the negative-phase signals, electrical walls 10a and 10b are formed between the positive-phase signals and the negative-phase signals. These electrical walls 10a and 10b function as virtual grounding lines.

[0015] An advantageous effect of the cable signal transmission system according to embodiment 1 becomes clear when comparing this embodiment with the case in which a positive-phase signal and a negative-phase signal are transmitted without splitting each of these signals. Fig. Figure 1 is a schematic representation of the case of transmitting a positive-phase signal and a negative-phase signal without splitting either signal. Although an electrical barrier 10 is also formed between the positive-phase signal and the negative-phase signal in this case, the amount of electrical barrier formed is lower compared to that of the cable signal transmission system according to embodiment 1, which is shown in Fig. Figure 2 shows that the number of electrical walls is small. It turns out that splitting each of the positive-phase and negative-phase signals into split signals results in a larger number of electrical walls.

[0016] As mentioned above, in the cable signal transmission system according to the present disclosure, while cable section 1b itself uses a multi-core cable with a typical design, cable section 1b is split and connected to the differential driver 3a, which serves as a differential signal source. As a result, a transmission mode for differential signals is achieved in which many virtual ground lines are generated, thus improving the resistance of the entire cable transmission system to disturbance. Therefore, the cable signal transmission system according to the present disclosure can eliminate the need for a conductor for shielding and a drain line, which are physical ground lines. Furthermore, since a typical, low-cost cable that is normally used can be employed instead of a cable with a special design, a cost reduction is to be expected. Design 2.

[0017] Fig. Figure 3 is a schematic representation of a cable signal transmission system in embodiment 2. In embodiment 1, the mode in which a multi-core cable, in which four cores are arranged in a ring, is used as cable section 1b of the cable signal transmission system was explained. In embodiment 2, a mode is explained in which a multi-core cable, also having four cores, is used as cable section 1b, but in which the four cores are arranged in a row.

[0018] There is no difference between embodiment 1 and embodiment 2, except for the design of cable section 1b. To avoid repetition, an explanation of the common section is therefore omitted. Fig. Figure 3 shows that the electrical walls 10a, 10b, and 10c are also formed in a case where cable section 1b comprises a multi-core cable in which four cores are arranged in a row. It can also be seen that in this case a larger number of electrical walls are formed than in the case shown in Figure 3. Fig. 1. Case shown, in which a positive-phase signal and a negative-phase signal are transmitted without splitting each of these signals.

[0019] In the case of the mode shown in embodiment 2, in the cable signal transmission system according to the present disclosure, while the cable section 1b itself uses a multi-core cable with a typical design, the cable section is split and connected to a differential driver 3a, which serves as a differential signal source. As a result, a transmission mode for differential signals is achieved in which many virtual ground lines are generated, thus improving the resistance of the entire cable transmission system to disturbance. Therefore, the cable signal transmission system according to the present disclosure can eliminate the need for a conductor for shielding and a drain line, which are physical ground lines.Furthermore, since a typical, low-cost cable that is normally used can be used instead of a cable with a special design, a cost reduction can be expected. Design 3.

[0020] Fig. Figure 4 is a schematic representation of a cable signal transmission system in embodiment 3. In embodiments 1 and 2, the mode in which cable section 1b, comprising a multi-core cable having four cores, is used as cable section 1b of the cable signal transmission system was explained. In embodiment 3, a mode in which a cable section 1b, comprising a multi-core cable with five or more cores, is used as cable section 1b of a cable signal transmission system is explained. Fig. Figure 4 shows cable section 1b, which comprises a multi-core cable with eighteen cores. In the cable signal transmission system of embodiment 3, five or more of the five inner cables that are adjacent to each other are used, and the configuration of the four inner cables is determined such that each positive-phase signal and each negative-phase signal are adjacent to each other. More specifically, in the cable signal transmission system of embodiment 3, cable section 1b is a multi-core cable with five or more cores, and four inner cables are selected from the five or more inner cables and used such that, among the selected inner cables, each of two inner cables over which split positive-phase signals are transmitted is adjacent to two inner cables over which split negative-phase signals are transmitted.

[0021] In the case of the mode described in embodiment 3, in the cable transmission system according to the present disclosure, while cable section 1b itself uses a multi-core cable with a typical design, the cable section is split and connected to the differential driver 3a, which serves as a differential signal source. As a result, a transmission mode for differential signals is achieved in which many virtual ground lines are generated, thus improving the resistance of the entire cable transmission system to disturbance. Therefore, the cable signal transmission system according to the present disclosure can eliminate the need for a conductor for shielding and a drain line, which are physical ground lines.Furthermore, since a typical, low-cost cable that is normally used can be used instead of a cable with a special design, a cost reduction can be expected. Design 4.

[0022] Fig. Figure 5 is a schematic representation of a cable signal transmission system in embodiment 4. A common feature between embodiment 3 and embodiment 4 is that a cable section 1b, comprising a multi-core cable with five or more cores, is used. However, in the cable signal transmission system according to embodiment 4, a positive-phase signal from a differential driver 3a is connected to three or more signal conductors, and a negative-phase signal from the differential driver 3a is connected to three or more other signal conductors. Fig.Figure 5 shows cable section 1b, which comprises a multi-core cable with eighteen cores. In the cable signal transmission system of embodiment 4, the configuration of the internal cables used is determined such that a positive-phase signal and a negative-phase signal are adjacent to each other. In a typical example, within cable section 1b, which comprises a multi-core cable, several groups of four-phase signals are arranged: two positive-phase signals arranged diagonally to each other, and two negative-phase signals arranged diagonally to each other, as shown in embodiment 1.

[0023] It can be assumed that the selection of the inner cables for positive-phase signals and the inner cables for negative-phase signals is carried out as follows. First, one of the inner cables is configured so that, as far as possible, it and any other inner cable adjacent to it are not used for in-phase signals. This is because an electrical barrier, which acts as a virtual ground, is not created even when in-phase signals are adjacent to each other. Furthermore, it is desirable to equalize the number of positive-phase signals and the number of negative-phase signals after splitting. This is because the amplitudes of the split positive-phase signals and the split negative-phase signals are made equal to each other.In another typical example, an arrangement is used in which each of the inner cables for positive-phase signals and a corresponding at least one of the inner cables for negative-phase signals are geometrically symmetrical to each other.

[0024] In the case of the mode shown in embodiment 4, in the cable signal transmission system according to the present disclosure, while cable section 1b itself uses a multi-core cable with a typical design, the cable section is split and connected to the differential driver 3a, which serves as a differential signal source. As a result, a transmission mode for differential signals is achieved in which many virtual ground lines are generated, thus improving the resistance of the entire cable transmission system to disturbance. Therefore, the cable signal transmission system according to the present disclosure can eliminate the need for a conductor for shielding and a drain line, which are physical ground lines.Furthermore, since a typical, low-cost cable that is normally used can be used instead of a cable with a special design, a cost reduction can be expected. Design 5.

[0025] A mode in which a cable signal transmission system according to the present disclosure utilizes a cable system that is wired within a building is also considered. Typically, a cable system or cabling installation is installed in many buildings, such as office buildings. Furthermore, such a cable system may have an unused signal conductor. Since a cable signal transmission system according to the present disclosure can utilize a multi-core cable with a typical configuration, it is possible to configure a cable signal transmission system using an unused signal conductor of a cable system wired within a building.

[0026] In the cable signal transmission system according to the present disclosure, as in the mode shown in embodiment 5, where a cable section 1b itself utilizes a multi-core cable with a typical design, the cable section is split and connected to a differential driver 3a, which serves as a differential signal source. As a result, a differential signal transmission mode is achieved in which many virtual ground lines are generated, thus providing an improvement in the resistance of the entire cable transmission system to disturbance. Therefore, the cable signal transmission system according to the present disclosure can be configured using an unused signal conductor of a cable system wired in a building. REFERENCE MARK LIST

[0027] 1a Dielectric, 1b Cable section, 2p, 2p1, 2p2 positive phase signal conductor, 2n, 2n1, 2n2 negative phase signal conductor, 3a Differential signal source or differential driver, 4 Splitter and 10, 10a, 10b, 10c electrical wall.

Claims

[1] Cable signal transmission system, comprising: a differential driver to generate a differential signal between a positive-phase signal and a negative-phase signal from a signal that is input into the differential driver; a splitter to divide the positive-phase signal into two or more split positive-phase signals, and to divide the negative-phase signal into two or more split negative-phase signals; and a multi-core cable, having four or more cores, which is connected to the splitter in order to transmit each of the signals separately after division by the splitter, wherein in the multi-core cable each of the following inner cables: two or more inner cables, via which the split positive-phase signals are transmitted, and two or more inner cables, via which the split negative-phase signals are transmitted, are arranged adjacent to one another. [2] Cable signal transmission system according to claim 1, wherein in the multi-core cable two of the two or more inner cables, via which the split positive-phase signals are transmitted, are arranged diagonally, and two of the two or more inner cables, via which the split negative-phase signals are transmitted, are arranged diagonally. [3] Cable signal transmission system according to claim 1, wherein in the multi-core cable the two or more inner cables, via which the split positive-phase signals are transmitted, and the two or more inner cables, via which the split negative-phase signals are transmitted, are arranged in a line. [4] Cable signal transmission system according to claim 1, wherein the multi-core cable has five or more cores, and at least four inner cables are selected from the five or more inner cables to be used in such a way that each of the following inner cables: two inner cables through which the split positive-phase signals are transmitted, and two or more inner cables through which the split negative-phase signals are transmitted, are arranged adjacent to one another. [5] Cable signal transmission system according to claim 4, wherein in the multi-core cable the inner cables are selected to be used in such a way that any two adjacent selected inner cables are not used for signals in phase. [6] Cable signal transmission system according to claim 4, wherein in the multi-core cable the number of inner cables through which the split positive-phase signals are transmitted and the number of inner cables through which the split negative-phase signals are transmitted are equal. [7] Cable signal transmission system according to claim 4, wherein in the multi-core cable each of the inner cables for the split positive-phase signals and a corresponding at least one of the inner cables for the split negative-phase signals are arranged in such a way as to be symmetrical to each other.

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