Signal transmission system

Abstract

A signal transmission system (10) comprises a wiring conductor (3) formed in an elliptical shape and having two foci (3a, 3b), a GND conductor plate (4) positioned opposite the wiring conductor (3), a driver (1) connected between one foci (3a) of the wiring conductor (3) and the GND conductor plate (4), a plurality of receivers (2a, 2b, 2c) connected between the wiring conductor (3) and the GND conductor plate (4), and a terminal circuit (5) connected between the other foci (3b) of the wiring conductor (3) and the GND conductor plate (4).

Description

Technology Field

[0001] The present disclosure relates to a signal transmission system. Background Technology

[0002] In signal transmission systems applied to printed circuit boards, driver ICs and receiver ICs are connected via wiring, and a termination resistor (or termination circuit) is provided near the receiver IC. When such a signal transmission system employs a bus wiring method consisting of a main line and branch lines, the signal input from the main line to the branch line may repeatedly reflect at the branching point or within the branch line. Consequently, the signal waveform becomes distorted due to the effects of multiple reflections, and signal quality deteriorates. As a result, normal signal transmission becomes difficult.

[0003] As a countermeasure, a technique for inserting a resistor into the branch line is provided. Such a conventional signal transmission system is disclosed, for example, in Patent Document 1. Prior art literature

[0004] [Patent Document 1] Japanese Patent Publication No. Hei 11-4263 The problem to be solved

[0005] However, since the signal transmission system disclosed in Patent Document 1 suppresses multiple reflections of the signal by means of resistance, as the number of branch lines increases (as the number of receiver ICs increases), the amplitude of the signal becomes smaller.

[0006] The present disclosure is made to solve the above-mentioned problem and aims to provide a signal transmission system capable of eliminating multiple reflections and suppressing amplitude degradation of a received signal, even when a plurality of receivers are provided for a single driver. means of solving the problem

[0007] A signal transmission system according to the present disclosure comprises a plate-shaped wiring conductor formed in an elliptical shape having two foci, a ground conductor disposed opposite to the wiring conductor, a driver connected between one foci of the wiring conductor and the ground conductor, a plurality of receivers connected between the wiring conductor and the ground conductor, and a terminal circuit connected between the other foci of the wiring conductor and the ground conductor. Effects of the invention

[0008] According to the present disclosure, even when a plurality of receivers are provided for a single driver, multiple reflections can be eliminated and the amplitude reduction of the received signal can be suppressed. Brief explanation of the drawing

[0009] FIG. 1 is a schematic diagram of a signal transmission system according to embodiment 1. FIG. 2 is a schematic diagram showing the connection structure of a driver. FIG. 2(a) is a plan view of the connection structure of a driver. FIG. 2(b) is a cross-sectional view taken along arrow II-II of FIG. 2(a). Figure 3 is a plan view showing the appearance of signal transmission. FIG. 4 is a schematic diagram of a signal transmission system according to embodiment 2. FIG. 5 is a schematic diagram of a signal transmission system according to embodiment 3. Figure 6 is a schematic diagram of a conventional signal transmission system. Specific details for implementing the invention

[0010] Hereinafter, in order to explain the present disclosure in more detail, an embodiment for carrying out the present disclosure will be described with reference to the accompanying drawings.

[0011] Embodiment 1.

[0012] A signal transmission system (10) according to embodiment 1 will be explained using FIGS. 1 to 3.

[0013] First, before describing the signal transmission system (10) according to embodiment 1, a general signal transmission system (50) applied to a printed circuit board will be described using FIG. 6. FIG. 6 is a schematic diagram of a conventional signal transmission system (50).

[0014] As shown in FIG. 6, the signal transmission system (50) comprises a driver (51), a receiver (52), a wiring conductor (53), a GND conductor plate (54), and a termination circuit (55). This signal transmission system (50) is provided, for example, on a printed circuit board (not shown).

[0015] Specifically, a driver (51) and a receiver (52) are mounted on the surface of a printed circuit board (not shown). The driver (51) and the receiver (52) are integrated circuits, such as an IC (Integrated Circuit). The driver (51) and the receiver (52) are connected by a wire conductor (53) that forms a line shape. A GND conductor plate (54) is disposed below the wire conductor (53). A dielectric (not shown) is interposed between the wire conductor (53) and the GND conductor plate (54). Additionally, a terminal circuit (55) is mounted right near the receiver (52) on the wire conductor (53). This terminal circuit (55) connects the wire conductor (53) and the GND conductor plate (54).

[0016] Additionally, the termination circuit (55) may be built into the receiver (52). Also, the termination circuit (55) is, for example, a termination resistor.

[0017] Accordingly, the signal output from the driver (51) is transmitted to the wiring conductor (53) and then reaches the receiver (52) and the termination circuit (55). The termination circuit (55) absorbs the signal, thereby suppressing signal degradation caused by multiple reflections. Additionally, the termination circuit (55) detects the voltage amplitude of the signal received by the receiver (52). Because of this, the signal transmission system (50) enables good signal transmission between the driver (51) and the receiver (52) without any reflected waves.

[0018] Here, when a signal transmission method is adopted in a signal transmission system (50) that enables the transmission of a signal from a single driver (51) toward a plurality of receivers (52), there is a risk that signal reflection may occur at the branching portion of the wiring conductor (53). When such signal reflection occurs, in addition to the quality of the corresponding signal deteriorating, the amplitude of the signal decreases as the number of terminal circuits (55) increases. To solve this problem, it is considered to reduce the number of terminal circuits (55). However, if the number of terminal circuits (55) is reduced, the signal is reflected at the wiring end where the receiver (52) is connected, causing a significant deterioration in signal quality.

[0019] In this regard, as shown in FIG. 1, a signal transmission system (10) according to embodiment 1 comprises one driver (1), a plurality of receivers (2a, 2b, 2c), a wiring conductor (3), a GND conductor plate (grounding conductor) (4), and a termination circuit (5). Such a signal transmission system (10) is provided, for example, on a printed circuit board.

[0020] Specifically, the driver (1), receiver (2a, 2b, 2c), and terminal circuit (5) are connected between the wiring conductor (3) and the GND conductor plate (4). The wiring conductor (3) and the GND conductor plate (4) are arranged to face each other.

[0021] That is, one end of the driver (1) is connected to the wiring conductor (3), while the other end of the driver (1) is connected to the GND conductor plate (4). One end of the receiver (2a, 2b, 2c) is connected to the wiring conductor (3), while the other end of the receiver (2a, 2b, 2c) is connected to the GND conductor plate (4). One end of the terminal circuit (5) is connected to the wiring conductor (3), while the other end of the terminal circuit (5) is connected to the GND conductor plate (4).

[0022] Additionally, the driver (1) and receivers (2a, 2b, 2c) are integrated circuits, for example, ICs (Integrated Circuits). Also, FIG. 1 shows an example of a signal transmission system (10) equipped with three receivers (2a, 2b, 2c). The number of receivers may be two or more.

[0023] The wiring conductor (3) is a flat conductor forming an elliptical shape. This wiring conductor (3) has two foci (3a, 3b). One end of the driver (1) is connected to one foci (3a) of the wiring conductor (3). One end of the terminal circuit (5) is connected to the other foci (3b) of the wiring conductor (3). Additionally, one end of the receiver (2a, 2b, 2c) is connected to the outer circumferential edge (3c) of the wiring conductor (3). The connection position of one end of the receiver (2a, 2b, 2c) to the wiring conductor (3) can be any position as long as it is the outer circumferential edge (3c).

[0024] The GND conductor plate (4) is positioned below the wiring conductor (3). The wiring conductor (3) and the GND conductor plate (4) are positioned parallel to each other. A dielectric (not shown) is interposed between the wiring conductor (3) and the GND conductor plate (4). The GND conductor plate (4) has the same elliptical shape as the wiring conductor (3) and also has the same size. Additionally, the GND conductor plate (4) may be larger than the size of the wiring conductor (3).

[0025] In addition, in FIG. 1, the driver (1), receivers (2a, 2b, 2c), and terminal circuit (5) are shown as being placed between the wiring conductor (3) and the GND conductor plate (4), but in reality, they have the connection structure shown in FIG. 2. Since the connection structure of the driver (1), receivers (2a, 2b, 2c), and terminal circuit (5) is the same, FIG. 2 illustrates the connection structure of the driver (1) among them.

[0026] As shown in FIG. 2, the driver (1) is provided on the wiring conductor (3). One terminal of the driver (1) is connected to one focal point (3a). The other terminal of the driver (1) is connected to the GND conductor plate (4) through a via (6). The via (6) reaches the GND conductor plate (4) through a through hole (3d) formed in the wiring conductor (3). At this time, the via (6) does not come into contact with the through hole (3d).

[0027] Accordingly, as shown in FIG. 3, the signal output from the driver (1) spreads in all directions within a parallel plate formed by a wiring conductor (3) and a GND conductor plate (4). At this time, since the parallel plate has an elliptical shape, the signal spread within the elliptical plate is reflected once at its outer edge and then converges at a focal point (3b) on the other side. Since a terminal circuit (5) is provided at this focal point (3b), all signals are absorbed by the terminal circuit (5). In this way, the reflection of the signal occurs only once at the outer edge (3c) of the wiring conductor (3) (parallel plate). Therefore, the receivers (2a, 2c, 2b) connected to the outer edge (3c) do not receive multiple reflections of the signal.

[0028] Accordingly, the signal transmission system (10) can achieve good signal transmission without being affected by multiple reflections, even if the signal transmission method has multiple receivers (2a, 2b, 2c) for one driver (1). In addition, the signal transmission system (10) can suppress the reduction in amplitude of the received signal because the terminal circuit (5) remains one even if the number of receivers (2a, 2b, 2c) increases. Furthermore, the signal transmission system (10) can suppress manufacturing costs because complex control circuits are not required.

[0029] In addition, in the signal transmission system (10), the outer periphery (3c) of the wiring conductor (3) and the outer periphery of the GND conductor plate (4) may be connected by a plurality of vias. In this case, the signal is a modulated signal that does not contain a DC component, and the receivers (2a, 2b, 2c) are capable of detecting the current value of the modulated signal. Because of this, the signal transmission system (10) can reduce unnecessary radiation from the side of the parallel plate.

[0030] In addition, the signal transmission system (10) can be applied not only to substrates but also to cloths and sheets, etc.

[0031] Above, the signal transmission system (10) according to embodiment 1 can eliminate multiple reflections and suppress the reduction in amplitude of the received signal even when a plurality of receivers (2a, 2b, 2c) are provided for one driver (1).

[0032] Embodiment 2.

[0033] A signal transmission system (20) according to embodiment 2 will be explained using FIG. 4.

[0034] The signal transmission system (10) according to embodiment 1 connects all receivers (2a, 2b, 2c) to the outer circumference (3c) of the wiring conductor (3) which has an elliptical shape. In contrast, as shown in FIG. 4, the signal transmission system (20) according to embodiment 2 connects all receivers (2a, 2b, 2c) to the inner side of the outer circumference (3c) of the wiring conductor (3) which has an elliptical shape.

[0035] Accordingly, the signal output from the driver (1) spreads in all directions within the parallel plate formed by the wiring conductor (3) and the GND conductor plate (4). At this time, since the parallel plate has an elliptical shape, the signal spread within the elliptical plate is reflected once at its outer edge and then converges at the other focal point (3b). Since a termination circuit (5) is provided at this focal point (3b), all signals are absorbed by the termination circuit (5). In this way, the reflection of the signal occurs only once at the outer edge (3c) of the wiring conductor (3) (parallel plate). For this reason, the receivers (2a, 2c, 2b) connected to the inside of the outer edge (3c) do not receive multiple reflections of the signal.

[0036] In summary, the signal transmission system (20) according to embodiment 2 can greatly increase the freedom of placement of the receivers (2a, 2b, 2c) by connecting the receivers (2a, 2b, 2c) to the inside of the outer circumference (3c) of the wiring conductor (3).

[0037] Embodiment 3.

[0038] A signal transmission system (30) according to embodiment 3 will be explained using FIG. 5.

[0039] The signal transmission system (30) according to embodiment 3 is provided with a driver (1) instead of the terminal circuit (5) of the signal transmission system (10) according to embodiment 1. In addition, among the drivers (1), the one connected to the focus (3a) is designated as the first driver (1a), and the one connected to the focus (3b) is designated as the second driver (1b).

[0040] Drivers (1a, 1b) have an input impedance equal to the input impedance of the termination circuit (5). Because of this, driver (1b) can operate as the termination circuit (5). Because of this, driver (1a) and driver (1b) can output a signal from either side.

[0041] Above, the signal transmission system (30) according to embodiment 3 can eliminate multiple reflections and suppress the reduction in amplitude of the received signal even when a plurality of receivers (2a, 2b, 2c) are provided for one driver (1a) or one driver (1b).

[0042] Furthermore, within the scope of the present disclosure, a free combination of each embodiment, a modification of any component in each embodiment, or the omission of any component in each embodiment is possible.

[0043] [Industrial Applicability]

[0044] A signal transmission system according to the present disclosure can eliminate multiple reflections and suppress amplitude degradation of a received signal even when a plurality of receivers are provided for a single driver, and is suitable for use in printed circuit boards, etc. Explanation of the symbols

[0045] 1, 1a, 1b driver, 2a, 2b, 2c receiver, 3 wiring conductor, 3a, 3b focus, 3c outer periphery, 3d through hole, 4 GND conductor plate, 5 termination circuit, 10, 20, 30 signal transmission system.

Claims

Claim 1 A signal transmission system characterized by comprising: a plate-shaped wiring conductor formed in an elliptical shape having two foci; a grounding conductor disposed opposite to the wiring conductor; a driver connected between one foci of the wiring conductor and the grounding conductor; a plurality of receivers connected between the wiring conductor and the grounding conductor; and a terminal circuit connected between the other foci of the wiring conductor and the grounding conductor. Claim 2 A signal transmission system according to claim 1, characterized in that the plurality of receivers are connected to the outer periphery of the wiring conductor. Claim 3 A signal transmission system according to claim 1, characterized in that the plurality of receivers are connected to the inner side of the outer circumference of the wiring conductor. Claim 4 A signal transmission system according to claim 1, wherein the termination circuit is a termination resistor. Claim 5 A signal transmission system according to claim 1, characterized in that a second driver is provided in place of the above-mentioned termination circuit. Claim 6 A signal transmission system according to claim 1, wherein the grounding conductor is a plate-shaped conductor with an outer circumference formed in an elliptical shape, and has vias connecting the outer circumference of the wiring conductor and the outer circumference of the grounding conductor, wherein the signal output from the driver is a modulated signal that does not include a DC component, and the plurality of receivers detect the current value of the modulated signal. Claim 7 A signal transmission system characterized in that, in any one of claims 1 to 6, the wiring conductor, the ground conductor, the driver, the receiver, and the termination circuit are mounted on the surface of any one of a printed circuit board, a cloth, and a sheet.

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