Communication system

Abstract

The aim is to enable high-quality communication even when the relative positions of the first and second electrodes are misaligned. [Solution] The communication system has a first electrode and a second electrode that is electrically coupled, magnetically coupled, or electrically and magnetically coupled to the first electrode, wherein the second electrode has two or more bends in a predetermined direction, and the distance between the furthest points of the second electrode in a direction perpendicular to the predetermined direction is longer than the distance between the furthest points of the first electrode in a direction perpendicular to the predetermined direction.

Description

Technical Field

[0005]

[0001] The present disclosure relates to a communication system.

Background Art

[0002] With the development of wireless communication technology using electromagnetic field coupling, a system has been proposed that wirelessly connects the wiring of parts corresponding to translational and rotational movements in equipment such as production systems and robot devices, and performs high-speed data transmission. As a technique for proximity wireless communication corresponding to translational movement, as disclosed in Patent Document 1, a method of performing proximity wireless communication between coupled transmission lines is disclosed.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] As a means for performing wireless communication while translating, as in Patent Document 1, a transmission line can be used as a communication coupler. When replacing the wiring in equipment such as a production system with this communication coupler, it is necessary to install the communication coupler in a narrow space, and miniaturization of the coupler is required.

[0005] In addition, in order to perform stable communication while translating, it is necessary to maintain the facing state of the couplers and maintain a certain coupling state. However, due to mechanical constraints, lateral displacement between the couplers may not be avoided. In order to cope with lateral displacement in the form of Patent Document 1, it is necessary to thicken the signal lines of the couplers, which causes a problem that the thickness of the couplers increases.

[0006] An object of the present disclosure is to enable high-quality communication even when the relative positional relationship between the first electrode and the second electrode is displaced. [Means for solving the problem]

[0007] The communication system includes a first electrode and a second electrode that is electrically coupled, magnetically coupled, or electrically and magnetically coupled to the first electrode, wherein the second electrode has two or more bends in a predetermined direction, and the distance between the furthest points of the second electrode in a direction perpendicular to the predetermined direction is longer than the distance between the furthest points of the first electrode in a direction perpendicular to the predetermined direction. [Effects of the Invention]

[0008] According to this disclosure, high-quality communication can be performed even when the relative positional relationship between the first electrode and the second electrode is shifted. [Brief explanation of the drawing]

[0009] [Figure 1] This is a diagram showing the configuration of a wireless communication system according to the first embodiment. [Figure 2] This figure shows a specific configuration example of a wireless communication system according to the first embodiment. [Figure 3] This is a diagram illustrating the operating principle of the wireless communication system according to the first embodiment. [Figure 4] This is a diagram illustrating the operating principle of the wireless communication system according to the first embodiment. [Figure 5] This is a diagram illustrating the operating principle of the wireless communication system according to the first embodiment. [Figure 6] This figure shows the results of simulating the operation of the wireless communication system according to the first embodiment. [Figure 7] This figure shows the results of simulating the operation of the wireless communication system according to the first embodiment. [Figure 8] This is a diagram illustrating the operation of the wireless communication system according to the first embodiment. [Figure 9] This figure shows the results of simulating the operation of the wireless communication system according to the first embodiment. [Figure 10]It is a diagram showing a specific configuration example of a wireless communication system according to the first embodiment. [Figure 11] It shows the configuration of a wireless communication system according to the second embodiment. [Figure 12] It is a diagram showing a specific configuration example of a wireless communication system according to the second embodiment. [Figure 13] It is a diagram of the result of simulating the operation of a wireless communication system according to the second embodiment. [Figure 14] It is a diagram for explaining the operation of a wireless communication system according to the second embodiment.

Modes for Carrying Out the Invention

[0010] Hereinafter, preferred embodiments to which the present invention can be applied will be described in detail with reference to the drawings. In the following description, common reference numerals are assigned to common components across a plurality of drawings. Therefore, common components are described by referring to the plurality of drawings mutually, and the description of the components assigned with common reference numerals will be omitted as appropriate.

[0011] (First Embodiment) First, the first embodiment of the present disclosure will be described.

[0012] FIG. 1 is a schematic diagram showing a schematic configuration of a wireless communication system 10 according to the first embodiment. As shown in FIG. 1, the wireless communication system 10 includes a transmission electrode 101, a buffer 102, a terminator 103, a transmission signal source 104, a reception electrode 111, a reception circuit 112, and a terminator 113.

[0013] As shown in FIG. 2, the transmission coupler 131 has a transmission electrode 101 of a differential line and a ground conductor 121. The transmission coupler 131 is formed, for example, on a printed circuit board.

[0014] The transmission signal source 104 forms a transmission signal Vi and is connected to the buffer 102.

[0015] The buffer 102 receives the single-ended transmission signal Vi generated by the transmission signal source 104 and outputs a differential transmission signal to the transmission electrode 101.

[0016] One end of the transmission electrode 101 is connected to the buffer 102. The transmission electrode 101 receives the differential transmission signal generated by the buffer 102 and transmits a wireless differential transmission signal.

[0017] The terminator 103 is connected to the other end of the transmission electrode 101 to which the buffer 102 is not connected, and impedance-matches the transmission line.

[0018] As shown in FIG. 2, the receiving coupler 132 has a receiving electrode 111 and a ground conductor 122 of a differential line. The receiving coupler 132 is formed, for example, on a printed circuit board. The receiving electrode 111 is electromagnetically coupled to the transmission electrode 101 and receives a wireless differential reception signal from the transmission electrode 101.

[0019] Here, the receiving electrode 111 may be capacitively coupled, inductively coupled, or capacitively and inductively coupled to the transmission electrode 101.

[0020] The receiving circuit 112 is connected to one end of the receiving electrode 111, processes the differential reception signal Vr received by the receiving electrode 111, and outputs a single-ended signal Vo.

[0021] The terminator 113 is connected to the other end of the receiving electrode 111 to which the receiving circuit 112 is not connected, and impedance-matches the transmission line.

[0022] As shown in FIG. 1, the transmission electrode 101 is longer than the receiving electrode 111 in a predetermined direction. While maintaining the distance from the transmission electrode 101, the receiving electrode 111 has means for relatively moving while the positional relationship between the center of the receiving electrode 111 and the center of the transmission electrode 101 changes with respect to the direction perpendicular to the predetermined direction (hereinafter referred to as lateral displacement), and performs wireless communication while moving. The transmission electrode 101 and the receiving electrode 111 are relatively movable in a predetermined direction.

[0023] As shown in Figure 1, the receiving electrode 111 has a meander shape with multiple bends along a predetermined direction. The distance between the furthest points of the receiving electrode 111 in the direction perpendicular to the predetermined direction is longer than the distance between the furthest points of the transmitting electrode 101 in the direction perpendicular to the predetermined direction. The transmitting electrode 101 has a straight shape.

[0024] Figure 2 shows an example of the configuration of a transmission line according to the first embodiment. The transmitting coupler 131 and the receiving coupler 132 are each formed on a printed circuit board.

[0025] The transmitting coupler 131 has a ground conductor 121 provided on the lower surface of the printed circuit board and a transmitting electrode 101 of the differential line provided on the upper surface of the printed circuit board. The receiving coupler 132 has a ground conductor 122 provided on the upper surface of the printed circuit board and a receiving electrode 111 of the differential line provided on the lower surface of the printed circuit board.

[0026] Figure 3 shows the transmission line shown in Figure 2 viewed vertically from the receiving electrode 111 side. Figure 3(a) shows the transmitting electrode 101 and the receiving electrode 111 facing each other without lateral displacement. Figure 3(b) shows the transmitting electrode 101 and the receiving electrode 111 facing each other with a small amount of lateral displacement. Figure 3(c) shows the transmitting electrode 101 and the receiving electrode 111 facing each other with a large amount of lateral displacement.

[0027] Figure 4 shows a view from the receiving electrode 111 side, when the receiving electrode 111 is not bent in the transmission line shown in Figure 2. The transmitting electrode 101 and receiving electrode 111 shown in Figure 4 are assumed to be formed as differential lines with equal impedance, having the same line width and line spacing, on a substrate of the same thickness as the transmitting electrode 101 and receiving electrode 111 shown in Figure 3.

[0028] Figure 4(a) shows the transmitting electrode 101 and the receiving electrode 111 facing each other without any lateral displacement. Figure 4(b) shows the transmitting electrode 101 and the receiving electrode 111 facing each other with a small amount of lateral displacement. Figure 4(c) shows the transmitting electrode 101 and the receiving electrode 111 facing each other with a large amount of lateral displacement.

[0029] Figure 5 schematically shows the waveforms of the input signal Vi, received signal Vr, and output signal Vo in the wireless communication system 10 shown in Figure 1. The dotted thresholds Th1 and Th2 shown in Figure 5 are lines that represent an example of comparator thresholds of the receiving circuit 112. The input signal Vi is the signal generated by the transmission signal source 104. The received signal Vr is the signal received by the receiving electrode 111. The output signal Vo is the signal output from the receiving circuit 112, and is the waveform obtained by reconstructing the input signal Vi based on the received signal Vr. The receiving circuit 112 reconstructs the single-ended transmission signal Vi based on the differential received signal received by the receiving electrode 111 and outputs the output signal Vo.

[0030] The receiving circuit 112 maintains the output signal Vo at a high level when the received signal Vr becomes greater than the threshold Th1. Then, when the received signal Vr becomes less than the threshold Th2, the receiving circuit 112 maintains the output signal Vo at a low level.

[0031] Figure 5(a) shows the waveform when the linear receiving electrode 111 and transmitting electrode 101 are facing each other without lateral displacement, as shown in Figure 4(a). Figure 5(b) shows an example of the waveform when the linear receiving electrode 111 and transmitting electrode 101 are facing each other with lateral displacement, as shown in Figure 4(c).

[0032] Figure 5(c) shows the waveform when the receiving electrode 111 and transmitting electrode 101, which have a bent portion, are facing each other without any lateral displacement, as shown in Figure 3(a). Figure 5(d) shows the waveform when the receiving electrode 111 and transmitting electrode 101, which have a bent portion, are facing each other with the same amount of lateral displacement as in Figure 5(b), as shown in Figure 3(c).

[0033] As shown in Figures 5(a) and (b), with a linear receiving electrode 111, as the transmitting electrode 101 and the receiving electrode 111 shift laterally relative to each other, the received signal Vr decreases, and the comparator of the receiving circuit 112 can no longer detect the waveform of the received signal Vr. This is because, as shown in Figure 4, as the lateral shift increases, the area between the transmitting electrode 101 and the receiving electrode 111 decreases, and the coupling between the transmitting electrode 101 and the receiving electrode 111 weakens.

[0034] On the other hand, as shown in Figures 5(c) and (d), in the case of the receiving electrode 111 having a bent portion in this embodiment, even if it shifts laterally, the received signal Vr does not decrease, and the waveform of the received signal Vr can be easily detected. This is because, as shown in Figure 3, since the receiving electrode 111 is bent, the amount of decrease in the opposing area between the transmitting electrode 101 and the receiving electrode 111 when it shifts laterally is suppressed, making it easier to maintain the coupling state between the transmitting electrode 101 and the receiving electrode 111.

[0035] Figure 6 shows the results of an electromagnetic field simulation performed on the transmission line shown in Figure 3, and the waveform of the received signal Vr was analyzed. Figures 6(a), (b), and (c) are the analysis results corresponding to the conditions shown in Figures 3(a), (b), and (c), respectively. In Figure 6(a), where there is no lateral shift, the peak value of the received signal Vr is approximately 34mV. In Figure 6(b), where the lateral shift is small, the peak value of the received signal Vr is approximately 34mV. In Figure 6(c), where the lateral shift is large, the peak value of the received signal Vr is approximately 24mV. In this case, if the absolute values ​​of the comparator thresholds Th1 and Th2 are set to around 20mV, the received signal Vr can be detected.

[0036] Figure 7 shows the results of an electromagnetic field simulation performed on the transmission line shown in Figure 4, and the waveform of the received signal Vr was analyzed. Figures 7(a), (b), and (c) are the analysis results corresponding to the conditions shown in Figures 4(a), (b), and (c), respectively. In Figure 7(a), where there is no lateral shift, the peak value of the received signal Vr is approximately 36mV. In Figure 7(b), where the lateral shift is small, the peak value of the received signal Vr is approximately 26mV. In Figure 7(c), where the lateral shift is large, the peak value of the received signal Vr is approximately 6mV. In this case, it is difficult to set the comparator thresholds Th1 and Th2, and there is a high possibility that the received signal Vr cannot be detected correctly.

[0037] The above results indicate that by giving the receiving electrode 111 a bent shape, it is possible to reduce the amount of decrease in the received signal Vr when it shifts laterally.

[0038] Furthermore, the receiving electrode 111 needs to have two or more bent sections in a predetermined direction, as shown in Figure 3.

[0039] Figure 8 shows a view from the receiving electrode 111 side, vertically, in the transmission line shown in Figure 2, where the receiving electrode 111 has only one bend. Figure 8(a) shows the transmitting electrode 101 and the receiving electrode 111 facing each other without lateral displacement. Figure 8(b) shows the receiving electrode 111 facing each other with lateral displacement to the left, which is the direction in which it is not bent. Figure 8(c) shows the receiving electrode 111 facing each other with lateral displacement to the right, which is the direction in which it is bent.

[0040] Figure 9 shows the results of an electromagnetic field simulation performed on the transmission line shown in Figure 8, and the waveform of the received signal Vr was analyzed. Figures 9(a), (b), and (c) are the analysis results corresponding to the states shown in Figures 8(a), (b), and (c), respectively. In Figure 9(a), where there is no lateral shift, the peak value of the received signal Vr is approximately 32mV. In Figure 9(b), where there is a lateral shift to the left, the peak value of the received signal Vr is approximately 30mV. In Figure 9(c), where there is a lateral shift to the right, an inverted received signal Vr is obtained.

[0041] The above results indicate that when the receiving electrode 111 has only one bend, the coupling weakens depending on the direction of lateral displacement, causing the received signal Vr to decrease or even be inverted. Therefore, it is necessary for the receiving electrode 111 to have two or more bends.

[0042] Based on these results, forming the receiving electrode 111 using a transmission line with a bent section has the effect of making it more resistant to lateral displacement without changing the substrate. This makes it possible to make the antenna thinner.

[0043] The receiving electrode 111 is shorter than the transmitting electrode 101 in a predetermined direction. In this embodiment, the electrode with a shorter length in a predetermined direction is described as the receiving electrode 111, and the electrode with a longer length in a predetermined direction is described as the transmitting electrode 101. However, the shorter coupler may be the transmitting coupler and the longer coupler may be the receiving coupler.

[0044] In this embodiment, the transmitting coupler 131 and the receiving coupler 132 were described assuming that the transmission line is a differential line, but a microstrip line or a grounded coplanar line may also be used. In the case of a grounded coplanar line, the shape of the ground conductor, which is in the same plane as the transmission line, is bent in the same way as the transmission line.

[0045] In this embodiment, the shape of the transmission line is shown as a meander shape that draws a sine curve (sine wave), but the shape of the meander is not limited to this. Figure 10 shows an example of the meander shape of the transmission line of the receiving electrode 111 that can obtain the effects of this embodiment.

[0046] According to the first embodiment, even if the transmitting electrode 101 and the receiving electrode 111 are laterally misaligned with each other, the coupling between the transmitting electrode 101 and the receiving electrode 111 can be maintained, thus realizing a thin wireless communication system 10 that enables stable communication.

[0047] (Second embodiment) Next, a second embodiment will be described. In the first embodiment, the case in which a coupler with a short length in a predetermined direction is formed in a transmission line having a bent portion was described. Therefore, in the second embodiment, a similar effect is shown in the case in which a coupler with a long length in a predetermined direction has a bent portion.

[0048] Figure 11 is a schematic diagram showing the general configuration of the wireless communication system 20 according to the second embodiment. In Figure 11, components with the same functions as those shown in Figure 1 are denoted by the same reference numerals, and their detailed explanations are omitted.

[0049] As shown in Figure 11, the wireless communication system 20 includes a transmitting electrode 201, a buffer 102, a terminator 103, a transmitting signal source 104, a receiving electrode 211, a receiving circuit 112, and a terminator 113.

[0050] The transmitting coupler has a transmitting electrode 201 of the differential line and a ground conductor, and is formed, for example, on a printed circuit board.

[0051] The transmission signal source 104 is connected to the buffer 102.

[0052] The transmitting electrode 201 has a buffer 102 connected to one end and a terminator 103 connected to the other end.

[0053] The receiving coupler has a receiving electrode 211 and a ground conductor of the differential line and is formed, for example, on a printed circuit board. The receiving electrode 211 is electromagnetically coupled to the transmitting electrode 201 and receives the radio signal generated by the transmitting electrode 201.

[0054] The receiving circuit 112 is connected to one end of the receiving electrode 211.

[0055] The terminator 113 is connected to the other end of the receiving electrode 211 that is not connected to the receiving circuit 112.

[0056] Buffer 102 receives a single-ended transmission signal Vi and outputs a differential transmission signal to the transmitting electrode 201. The transmitting electrode 201 is an electrode of the differential line that transmits the differential transmission signal. The receiving electrode 211 is an electrode of the differential line that receives the differential reception signal Vr. The receiving circuit 112 reconstructs the single-ended transmission signal Vi based on the differential reception signal Vr received by the receiving electrode 211.

[0057] As shown in Figure 11, the transmitting electrode 201 is longer in a predetermined direction than the receiving electrode 211, and the receiving electrode 211 has means to move relative to the transmitting electrode 201 while shifting laterally, and performs wireless communication while moving. The transmitting electrode 201 and the receiving electrode 211 are movable relative to each other in a predetermined direction.

[0058] As shown in Figure 11, the transmitting electrode 201 has a meander shape with multiple bends along a predetermined direction. The distance between the furthest points of the transmitting electrode 201 in the direction perpendicular to the predetermined direction is longer than the distance between the furthest points of the receiving electrode 211 in the direction perpendicular to the predetermined direction. The receiving electrode 211 has a straight shape. The receiving electrode 211 is shorter than the transmitting electrode 201 in the predetermined direction.

[0059] The transmitting electrode 201 has a first bend, a second bend, and a third bend. The distance between the first bend and the second bend in a predetermined direction is approximately the same as the distance between the second bend and the third bend in a predetermined direction.

[0060] Figure 12 shows an example of the configuration of a transmission line according to the second embodiment. The transmitting coupler and the receiving coupler are each formed on a printed circuit board. The transmitting coupler has a transmitting electrode 201 of the differential line and a ground conductor. The receiving coupler has a receiving electrode 211 of the differential line and a ground conductor.

[0061] Figure 12(a) shows the transmitting electrode 201 and the receiving electrode 211 facing each other without any lateral displacement. Figure 12(b) shows the transmitting electrode 201 and the receiving electrode 211 facing each other with a small amount of lateral displacement. Figure 12(c) shows the transmitting electrode 201 and the receiving electrode 211 facing each other with a large amount of lateral displacement.

[0062] Figure 13 shows the results of an electromagnetic field simulation performed on the transmission line shown in Figure 12, and the waveform of the received signal Vr was analyzed. Figures 13(a), (b), and (c) are the analysis results corresponding to the conditions shown in Figures 12(a), (b), and (c), respectively. In Figure 13(a), where there is no lateral shift, the peak value of the received signal Vr is approximately 34mV. In Figure 13(b), where there is a small lateral shift, the peak value of the received signal Vr is approximately 36mV. In Figure 13(c), where there is a large lateral shift, the peak value of the received signal Vr is approximately 24mV. In this case, if the absolute values ​​of the comparator thresholds Th1 and Th2 are set to around 20mV, the received signal Vr can be detected.

[0063] The above results indicate that by giving the transmitting electrode 201 a bent shape, it is possible to reduce the amount of decrease in the received signal Vr when it shifts laterally.

[0064] Furthermore, the transmitting electrode 201 has two or more bent portions, and the length of the receiving electrode 211 in a predetermined direction must be greater than or equal to the length of the transmitting electrode 201 including the two bent portions in that predetermined direction.

[0065] Figure 14 shows a view from the receiving electrode 211 side when the receiving electrode 211 is of a length that includes only one bend in the transmitting electrode 201, in the second embodiment. Figure 14(a) shows the transmitting electrode 201 and the receiving electrode 211 facing each other without lateral displacement. Figure 14(b) shows the receiving electrode 211 facing each other with lateral displacement to the left. Figure 14(c) shows the receiving electrode 211 facing each other with lateral displacement to the right.

[0066] As shown in Figure 14, if the receiving electrode 211 is long enough to include only one bend in the transmitting electrode 201, the coupling can be maintained when the receiving electrode 211 and the transmitting electrode 201 are laterally shifted in one direction, but the coupling cannot be maintained when they are laterally shifted in the other direction, depending on the relative position of the receiving electrode 211 and the transmitting electrode 201 in a predetermined direction. Therefore, the transmitting electrode 201 must have two or more bends, and the length of the receiving electrode 211 in a predetermined direction must be greater than or equal to the length of the transmitting electrode 201 including the two bends in that predetermined direction.

[0067] According to the second embodiment, even if the transmitting electrode 201 and the receiving electrode 211 are laterally misaligned with each other, the coupling between the transmitting electrode 201 and the receiving electrode 211 can be maintained, thus realizing a thin wireless communication system 20 that enables stable communication.

[0068] As described above, according to the first and second embodiments, a thin transmit coupler and a receive coupler are provided that can maintain the coupling between the transmit coupler and the receive coupler even when they are laterally misaligned, thereby improving communication quality.

[0069] Furthermore, the embodiments described above are merely examples illustrating how to implement this disclosure, and they should not be interpreted as limiting the technical scope of this disclosure. In other words, this disclosure can be implemented in various ways without departing from its technical concept or its main features.

[0070] This embodiment includes the following configuration. (Item 1) The first electrode and The first electrode is coupled to a second electrode which is electrically coupled, magnetically coupled, or electrically and magnetically coupled. The second electrode has two or more bends in a predetermined direction, A communication system characterized in that the distance between the furthest points of the second electrode in the predetermined direction and the direction perpendicular to it is longer than the distance between the furthest points of the first electrode in the predetermined direction and the direction perpendicular to it. (Item 2) The communication system according to item 1, characterized in that the first electrode has a linear shape. (Item 3) The communication system according to item 1 or 2, characterized in that the second electrode has a meander shape. (Item 4) The second electrode has a first bent portion, a second bent portion, and a third bent portion. The communication system according to any one of items 1 to 3, characterized in that the distance in the predetermined direction between the first bend and the second bend is substantially the same as the distance in the predetermined direction between the second bend and the third bend. (Item 5) The first electrode described above is an electrode of a differential line, The communication system according to any one of items 1 to 4, characterized in that the second electrode is an electrode of a differential line. (Item 6) A first coupler having the first electrode and a first ground conductor, The communication system according to any one of items 1 to 5, further comprising a second coupler having the second electrode and a second ground conductor. (Item 7) The first coupler is a microstrip track, The communication system according to item 6, characterized in that the second coupler is a microstrip line. (Item 8) The first coupler is a coplanar track, The communication system according to item 6, characterized in that the second coupler is a coplanar line. (Item 9) The communication system according to any one of items 1 to 8, characterized in that the first electrode and the second electrode are relatively movable in the predetermined direction. (Item 10) The aforementioned first electrode is a transmitting electrode, The communication system according to any one of items 1 to 9, characterized in that the second electrode is a receiving electrode. (Item 11) The communication system according to any one of items 1 to 10, characterized in that the second electrode is shorter than the first electrode in the predetermined direction. (Item 12) The transmitting electrode is an electrode of a differential transmission line that transmits a differential transmission signal. The receiving electrode is an electrode of a differential transmission line that receives a differential reception signal. A buffer that receives a single-ended transmission signal and outputs a differential transmission signal to the transmission electrode, The communication system according to item 10, further comprising a receiving circuit that restores the single-ended transmission signal based on the differential reception signal received by the receiving electrode. (Item 13) The first electrode is a receiving electrode, The communication system according to any one of items 1 to 9, characterized in that the second electrode is a transmitting electrode. (Item 14) The communication system according to any one of items 1 to 10, 13, characterized in that the first electrode is shorter than the second electrode in the predetermined direction. (Item 15) The communication system according to item 14, characterized in that the length of the first electrode in the predetermined direction is greater than or equal to the length of the second electrode including the two bends in the predetermined direction. (Item 16) The transmitting electrode is an electrode of a differential transmission line that transmits a differential transmission signal. The receiving electrode is an electrode of a differential transmission line that receives a differential reception signal. A buffer that receives a single-ended transmission signal and outputs a differential transmission signal to the transmission electrode, The communication system according to item 13, further comprising a receiving circuit that restores the single-ended transmission signal based on the differential reception signal received by the receiving electrode. [Explanation of Symbols]

[0071] 10, 20 Wireless communication systems 101, 201 Transmitting electrodes 102 buffers 103, 113 Terminator 104 Transmitting signal source 111, 211 Receiving electrodes 112 Receiving Circuit

Claims

1. The first electrode and The first electrode is coupled to a second electrode which is electrically coupled, magnetically coupled, or electrically and magnetically coupled. The second electrode has two or more bent portions in a predetermined direction. A communication system characterized in that the distance between the furthest points of the second electrode in the predetermined direction and the direction perpendicular to it is longer than the distance between the furthest points of the first electrode in the predetermined direction and the direction perpendicular to it.

2. The communication system according to claim 1, characterized in that the first electrode has a linear shape.

3. The communication system according to claim 1, characterized in that the second electrode has a meander shape.

4. The second electrode has a first bent portion, a second bent portion, and a third bent portion. The communication system according to claim 1, characterized in that the distance in the predetermined direction between the first bend and the second bend is substantially the same as the distance in the predetermined direction between the second bend and the third bend.

5. The first electrode is an electrode of a differential line, The communication system according to claim 1, characterized in that the second electrode is an electrode of a differential line.

6. A first coupler having the first electrode and a first ground conductor, The communication system according to claim 1, further comprising a second coupler having the second electrode and a second ground conductor.

7. The first coupler is a microstrip track, The communication system according to claim 6, characterized in that the second coupler is a microstrip line.

8. The first coupler is a coplanar track, The communication system according to claim 6, characterized in that the second coupler is a coplanar line.

9. The communication system according to claim 1, characterized in that the first electrode and the second electrode are relatively movable in the predetermined direction.

10. The first electrode is a transmitting electrode, The communication system according to claim 1, characterized in that the second electrode is a receiving electrode.

11. The communication system according to claim 1, characterized in that the second electrode is shorter than the first electrode in the predetermined direction.

12. The transmitting electrode is an electrode of a differential transmission line that transmits a differential transmission signal. The receiving electrode is an electrode of a differential transmission line that receives a differential reception signal. A buffer that receives a single-ended transmission signal and outputs a differential transmission signal to the transmission electrode, The communication system according to claim 10, further comprising a receiving circuit that restores the single-ended transmission signal based on the differential reception signal received by the receiving electrode.

13. The first electrode is a receiving electrode, The communication system according to claim 1, characterized in that the second electrode is a transmitting electrode.

14. The communication system according to claim 1, characterized in that the first electrode is shorter than the second electrode in the predetermined direction.

15. The communication system according to claim 14, characterized in that the length of the first electrode in the predetermined direction is greater than or equal to the length of the second electrode including the two bent portions in the predetermined direction.

16. The transmitting electrode is an electrode of a differential transmission line that transmits a differential transmission signal. The receiving electrode is an electrode of a differential transmission line that receives a differential reception signal. A buffer that receives a single-ended transmission signal and outputs a differential transmission signal to the transmission electrode, The communication system according to claim 13, further comprising a receiving circuit that restores the single-ended transmission signal based on the differential reception signal received by the receiving electrode.

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