Wireless communication device and wireless system

Abstract

To provide a wireless communication device capable of suppressing self-resonance caused by parasitic components of electrodes and enabling high-speed data transmission.SOLUTION: The wireless communication device has a transmitter configured to transmit differential signals, and a receiver configured to receive differential signals via electromagnetic field coupling between the receiver and the transmitter. The receiver has a coupling conductor composed of two electrodes that receive differential signals via electromagnetic field coupling, a circuit element section disposed between the two electrodes, consisting of at least one high-pass filter and a resistor, and a receiving circuit connected to the coupling conductor. The cut-off frequency of the high-pass filter is lower than the self-resonant frequency of the coupling conductor.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a wireless communication device and a wireless communication system that transmit signals wirelessly. [Background technology]

[0002] In recent years, research and development has been conducted on close proximity wireless communication systems that communicate between multiple electrodes placed in close proximity through electromagnetic coupling. By replacing wired connections using connectors and harnesses for communication between electronic circuit boards and modules with wireless connections, the number of components at the connection point can be reduced, and the manufacturing process of the device can be simplified. Patent Document 1 discloses a wireless communication device that is applied to a rotating movable part and includes a transmitter and a receiver, and that performs wireless communication between each electrode through electromagnetic coupling. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 2021-168491 Summary of the Invention [Problem to be solved by the invention]

[0004] In the wireless communication device disclosed in Patent Document 1, a receiver resistor with a sufficiently high value is placed between the electrodes of the receiver to obtain a passband that does not attenuate the lowest frequency component of the data. However, with the configuration of Patent Document 1, self-resonance occurs at high frequencies due to the parasitic capacitance and inductance components of the electrodes. For example, when performing high-speed wireless communication using frequency components near the self-resonant frequency, the data deteriorates due to the effects of self-resonance. The present invention aims to provide a wireless communication device that suppresses self-resonance due to the parasitic components of the electrodes and enables high-speed data transmission. [Means for solving the problem]

[0005] A wireless communication device according to one aspect of the present invention comprises a transmitting device that transmits a differential signal and a receiving device that receives the differential signal by electromagnetic field coupling between the transmitting device, the receiving device comprising a coupling conductor consisting of two electrodes that receives the differential signal by electromagnetic field coupling, a circuit element unit that is arranged between the two electrodes and is composed of at least one high-pass filter and a resistor, and a receiving circuit that is connected to the coupling conductor, and the cutoff frequency of the high-pass filter is lower than the self-resonant frequency of the coupling conductor. [Effects of the Invention]

[0006] According to one aspect of the present invention, it is possible to provide a wireless communication device capable of wireless communication at higher speeds than conventional devices. [Brief explanation of the drawings]

[0007] [Figure 1] 1 is a diagram illustrating an example of a configuration of a wireless communication system according to a first embodiment. [Figure 2] FIG. 4 is a diagram illustrating a simulation result of the wireless communication system according to the first embodiment. [Figure 3] FIG. 10 is a diagram showing a simulation result regarding the impedance of a coupling system connected to the receiving device according to the first embodiment. [Figure 4] 3A and 3B are diagrams illustrating an example of the configuration of a receiving device according to the first embodiment and simulation results of the receiving device. [Figure 5] 5A and 5B are diagrams illustrating another configuration example of the receiving device according to the first embodiment and simulation results of the receiving device. [Figure 6] 10A and 10B are diagrams showing an example of a receiving device and a filter configuration of a circuit element unit according to a second embodiment, and diagrams showing simulation results thereof. [Figure 7] 10A and 10B are diagrams illustrating an example of the configuration of a receiving device according to a third embodiment, and simulation results of a correction circuit and a wireless communication device. [Figure 8] 10A and 10B are diagrams illustrating an example of the configuration of a coupling conductor. DETAILED DESCRIPTION OF THE INVENTION

[0008] First Embodiment Hereinafter, embodiments of the present invention will be described with reference to the drawings. Fig. 1(a) is a diagram showing an example of the configuration of a wireless communication system 100 in a first embodiment. The wireless communication system 100 is composed of a transmitting device 10 and a receiving device 20, and performs wireless communication. The transmitting device 10 is composed of a coupling conductor 101, a termination resistor 104, and a transmitting circuit 105, and the receiving device 20 is composed of a coupling conductor 201, circuit element sections 204 and 205, a resistor 206, and a receiving circuit 207. The coupling conductor 101 is composed of an electrode 102 and an electrode 103, and the coupling conductor 201 is composed of an electrode 202 and an electrode 203.

[0009] The configuration of the transmitter 10 will now be described. A transmitter circuit 105 of the transmitter 10 inputs a transmission signal to a coupling conductor 101. The transmission signal input to the coupling conductor 101 may be a signal modulated by a carrier wave or a baseband signal that is not modulated. However, in the present invention, transmission of a baseband signal that is not modulated will be described. The transmission signal transmitted from the transmitter circuit 105 is a differential signal. The transmission signal may be a digital binary signal encoded using a code such as 8B10B, or a multi-level signal with three or more values. Two electrodes, electrode 102 and electrode 103, each have one end connected to the output of the transmitter circuit 105 and the other end terminated at a resistor with an impedance approximately equal to the differential impedance of the coupling conductor 101. Therefore, a signal is transmitted from the transmitter circuit 105 to the termination resistor 104.

[0010] The coupling conductor 101 may be formed on a substrate or may be formed from a metal plate, etc. The coupling conductor 101 may also have a GND conductor that serves as a reference potential for signals applied to the electrodes 102 and 103.

[0011] Next, the configuration of the receiving device 20 will be described. Fig. 1(b) is a detailed diagram of the receiving device 20 of the wireless communication system 100, showing a view from the surface coupled to the coupling conductor 101. The coupling conductor 201 is formed on a dielectric substrate 212. Furthermore, the circuit element section 204 is formed from a circuit in which a filter 208 and a resistor 209 are connected in series, and the circuit element section 205 is formed from a circuit in which a filter 210 and a resistor 211 are connected in series. Furthermore, the coupling conductor 201 is connected to the receiving circuit 207 via a signal line from an end of the coupling conductor 101 that is close to the end to which the termination resistor 104 is connected.

[0012] The coupling conductor 201 has an electrode 202 and an electrode 203. The coupling conductor 101 of the transmitting device 10 and the coupling conductor 201 of the receiving device 20 are arranged close to each other so as to face each other, and are a coupler that couples by an electromagnetic field. FIG. 1(c) is a cross-sectional view of the coupling electrode 101 of the transmitting device 10 and the coupling electrode 202 of the receiving device 20 of the wireless communication system 100 when they are arranged to face each other. As can be seen from FIG. 1(c), the electrodes 102 and 202 are arranged to face each other, and the electrodes 103 and 203 are arranged to face each other. The coupling electrode 101 is formed on a dielectric substrate 106. The distance in the Z-axis direction between the coupling electrodes 101 and 102 is denoted as d.

[0013] A differential signal is output from the transmitting circuit, and differential signals of opposite phases are input to electrodes 102 and 103, and differential signals of opposite phases are also output to electrodes 202 and 203. The output differential signals are input to receiving circuit 207.

[0014] 1 have the characteristics of a high-pass filter. A high-pass filter has the characteristic that the impedance becomes very high at frequencies lower than the cutoff frequency of the filter, and becomes very low at frequencies higher than the cutoff frequency. In other words, it is a filter that only passes signals with frequencies higher than the cutoff frequency.

[0015] Therefore, the impedance of the circuit element sections 204 and 205 becomes very high at frequencies lower than the cutoff frequency, and becomes the impedance of the resistors 209 and 211 at frequencies higher than the cutoff frequency. The impedance of the resistors 209 and 211 is set to the coupling system impedance described below. As a result, at frequencies higher than the cutoff frequency, the coupling conductor 201 is matched by the resistors 209 and 211, and the influence of self-resonance due to the parasitic components of the coupling conductor 201 can be suppressed.

[0016] Furthermore, since matching is performed by resistors 209 and 211, the occurrence of standing waves can be suppressed, and the lengths of electrodes 202 and 203 in the Y-axis direction can be set to any value.

[0017] The resistor 206 of the receiving device 20 is connected to the transmission path between the coupling conductor 201 and the receiving circuit 207. The resistor 206 is set to a high impedance, for example, 1 kΩ or more. By increasing the impedance value of the resistor 206, the impedance of the resistor 206 becomes larger not only at high frequencies but also at low frequencies than the impedance of the capacitive component caused by the coupling between the coupling conductors 101 and 201. This allows low-frequency transmission signals to be transmitted to the receiving circuit 207. Therefore, if the signal transmitted from the coupling conductor 101 is a square wave, the signal input from the coupling conductor 201 to the receiving circuit 207 will have an approximately square waveform. Note that if the input impedance of the receiving circuit 207 is sufficiently larger than the impedance of the capacitive component caused by the coupling and the impedance of the resistors 209 and 211 at the lowest frequency of the transmission signal, the resistor 206 can be omitted.

[0018] The receiving circuit 207 shapes or amplifies the signal transmitted from the coupling conductor 201 and outputs the signal to a subsequent circuit. Examples of a configuration for shaping a signal include an emitter follower circuit and a differential amplifier circuit. If the signal transmitted from the coupling conductor 201 can be processed as a received signal as is, the shaping function may be omitted.

[0019] Fig. 2 shows the simulation results of the transfer characteristics of the coupling conductors 101 and 102 and the eye pattern of the signal input to the receiving circuit 207 in the configuration of the wireless communication system in Fig. 1. The simulation results are shown for the cases where the circuit element units 204 and 205 are provided and where they are not provided. The simulation results are for the case where the distance d between the coupling conductors 101 and 201 is 2 mm.

[0020] In the simulation, resistor 206 in Figure 1 is set to a resistance value of 22 kΩ. However, it may be smaller than 22 kΩ as long as it is higher than the impedance of the capacitive component due to the coupling between coupling conductor 101 and coupling conductor 201 at the lowest frequency fl of the transmission signal. Capacitors are arranged as high-pass filters 208 and 210 in circuit element sections 204 and 205. In the simulation, the value of the capacitor is set to 0.4 pF. The cutoff frequency fc of the high-pass filter is set to a value that satisfies the following formula when the self-resonant frequency due to the parasitic component of coupling conductor 201 is set to fp.

[0021]

number

[0022] In other words, the cutoff frequency of the high-pass filter should be equal to or higher than the minimum frequency of the transmission signal and equal to or lower than the self-resonant frequency. In the present invention, the minimum frequency of the transmission signal refers to, for example, when a 10 Gbps baseband signal is 8B10B encoded and transmitted via coupling conductors 101 and 102, the maximum number of consecutive bits is 5. Since the fundamental frequency is 5 GHz, the minimum frequency of the transmission signal is set to 1 GHz, which is one-fifth of the fundamental frequency. However, the minimum frequency varies depending on the transmission signal speed, encoding method, error rate required for the system, and other factors.

[0023] FIG. 2(a) shows the simulation results of the transfer characteristics when a differential signal is transmitted from the coupling conductor 101 to the coupling conductor 201. The horizontal axis represents frequency, and the vertical axis represents the amount of transfer. The dashed line 220 represents the transfer characteristics when the circuit element units 204 and 205 are not provided, while the solid line 221 represents the transfer characteristics when the circuit element units 204 and 205 are provided. The dashed line 220 shows peaking around 7 GHz. This is due to self-resonance caused by the parasitic components of the coupling conductor 201. In other words, it can be seen that the self-resonance frequency of the coupling conductor 201 is approximately 7 GHz. On the other hand, the solid line 221 shows that peaking is suppressed. This is because the circuit element units 204 and 205 function as resistors 209 and 211 to provide matching in the high frequency range. FIG. 2(b) shows the eye pattern of the signal input to the receiving circuit 207 when a 10-Gbps serial signal is transmitted when the circuit element units 204 and 205 are not provided. Figure 2(c) shows the eye pattern when a 10 Gbps serial signal is transmitted when the circuit element sections 204 and 205 are arranged. It can be seen that there is an eye opening in Figure 2(c), and it can be confirmed that the waveform distortion has been improved.

[0024] Here, the coupled system impedance, which is the value of the resistors 209 and 211, will be described in detail using FIG. 3. The coupled system impedance is the matching impedance of the receiving-side coupled conductor 201 when the transmitting-side coupled conductor 101 and the receiving-side coupled conductor 201 are facing each other. FIG. 3(a) shows the reflection characteristics when the impedance of the resistors 209 and 211 is changed at each distance d between the coupled conductor 101 and the coupling conductor 201. The impedance at the lowest point of each graph is the coupled system impedance. That is, when d = 1 mm, the coupled system impedance (Zoc1) is approximately 160 Ω; when d = 2 mm, the coupled system impedance (Zoc2) is approximately 200 Ω; when d = 3 mm, the coupled system impedance (Zoc3) is approximately 220 Ω; and when d = 4 mm, the coupled system impedance (Zoc4) is approximately 220 Ω. The reflection characteristics of the coupled conductor 201 alone, when the coupled conductor 201 is not facing the coupled conductor 101, are also shown. As can be seen from this figure, the characteristic impedance (Zo) of the coupled conductor 201 alone is approximately 220 Ω, which is approximately equal to Zoc3 and Zoc4. Furthermore, Figure 3(b) shows a graph of the relationship between the distance d and the coupled system impedance. It can be seen that the smaller the distance d, the greater the difference between the characteristic impedance and the coupled system impedance. This is because the coupling between the coupled conductor 201 and the coupled conductor 101 becomes stronger.

[0025] Figure 3(c) shows the simulation results of the transfer characteristics when a differential signal is transmitted from the coupled conductor 101 to the coupled conductor 201 when the impedance of the resistors 209 and 211 is changed. Note that, similar to the simulation conditions in Figure 2, the distance d between the coupled conductors 209 and 211 is 2 mm. The dashed line 220 and the solid line 221 are the same as those in Figure 2. The line 222 represents the transfer characteristics when the impedance of the resistors 209 and 211 is half the coupled system impedance, and the line 223 represents the transfer characteristics when the impedance of the resistors 209 and 211 is twice the coupled system impedance. As can be seen from Figure 3(c), even when the resistors 209 and 211 deviate slightly from the coupled system impedance, peaking is suppressed compared to when the circuit element units 204 and 205 are not provided. In other words, the peaking suppression effect is achieved even when the impedance is between half and twice the coupled system impedance.

[0026] 1 desirably have a cutoff frequency characteristic that includes the fundamental frequency component of the signal that passes through them. Specifically, when a 10 Gbps baseband signal is transmitted from coupling conductor 101 through 102, 5 GHz is the fundamental frequency component. Therefore, a high-pass filter with a passband characteristic that includes at least 5 GHz is provided.

[0027] In this embodiment, the coupling conductor 201 is connected to the receiving circuit 207 via a signal line from the end of the coupling conductor 201 closest to the end connected to the termination resistor 104. However, the same peaking suppression effect can be achieved by connecting the opposite end of the coupling conductor 201, i.e., the end closer to the end connected to the transmitting circuit 105, to the receiving circuit 207 via a signal line. FIG. 4(a) shows a configuration in which the end closer to the end connected to the transmitting circuit 105 is connected to the receiving circuit 207 via a signal line. Furthermore, FIG. 4(b) shows the results of a transfer characteristic simulation for the configuration shown in FIG. 4(a). Graphs 220 and 221 are similar to those in FIG. 2(a), and 224 is the transfer characteristic for the configuration shown in FIG. 4(a). Graph 224 confirms that peaking is suppressed more effectively than graph 220.

[0028] Furthermore, in this embodiment, the circuit element sections 204 and 205 are arranged on both ends of the coupling conductor 201, but the circuit element section may be arranged on only one end.

[0029] 5(a) and 5(b) show configuration diagrams in which the circuit element section is arranged only at one end.

[0030] Furthermore, the results of a transfer characteristic simulation for the configurations of Figures 5(a) and (b) are shown in Figure 5(c). 220 and 221 are graphs similar to Figure 2(a), 225 is the transfer characteristic for the configuration of Figure 5(a), and 226 is the transfer characteristic for the configuration of Figure 5(b). As can be seen from 225 and 226, it can be confirmed that peaking has been suppressed compared to 220.

[0031] <Second embodiment> In the first embodiment, the circuit element units 204 and 205 are configured from a series circuit of a filter and a resistor. In the second embodiment, another high-pass filter configuration is shown.

[0032] 6(a) and 6(b) show the circuit configurations of the receiving device 20 and the high-pass filters of the circuit element units 204 and 205 in this embodiment. The transmitting device 10 and the signal transmission method are the same as those in the first embodiment, and the same components in the receiving device 20 are denoted by the same reference numerals and will not be described again.

[0033] In Figure 6(a), circuit element sections 204 and 205 each have two high-pass filters. Figure 6(b) shows an example circuit configuration for high-pass filters 208, 210, 213, and 214. They are composed of capacitors 215 and 216, inductor 217, and resistor 218. This is a second-order Chebyshev filter configuration, but the order and type of filter are not important as long as it functions as a high-pass filter. For example, Bessel, Gaussian, Butterworth, and other types are also acceptable. Furthermore, the filter does not have to be composed solely of passive elements. In Figures 6(a) and 6(b), resistor 218 of filter 210 is connected to resistor 218 of filter 214. This is because inductor 217 requires a point at an intermediate potential to function. When transmitting low-frequency signals, inductor 218 has low impedance and is short-circuited, resulting in an impedance imbalance in the circuit element section. Resistor 218 is placed to eliminate this imbalance.

[0034] FIG. 6(c) shows the simulation results of the transfer characteristics when a differential signal is transmitted from the coupling conductor 101 to the coupling conductor 201 in the configurations of FIGS. 6(a) and 6(b). In the simulation, the capacitors 215 and 216 are set to 0.43 pF, the inductor 217 is set to 4.6 nH, and the resistor 218 is set to 50 Ω. The horizontal axis represents frequency, and the vertical axis represents the transfer amount. 227 represents the transfer characteristics when the high-pass filter of FIG. 6(b) is implemented. The dashed line 220 and the solid line 221 are the same graphs as those in FIG. 2. It can be seen that the peaking occurring around 7 GHz in 220 can be suppressed in this embodiment as well. Furthermore, comparing 227 and 221, it can be seen that the transfer amount of 227 is larger. As such, the use of a second-order Chebyshev filter configuration can increase the transfer amount.

[0035] <Third embodiment> This embodiment shows a configuration in which a correction circuit is further connected after the receiving circuit 207. Fig. 7(a) is a configuration diagram in which a correction circuit 217 is connected after the receiving circuit 207. The transmitting device 10 and the signal transmission method are the same as those in the first embodiment, and the same components of the receiving device 20 are denoted by the same reference numerals and will not be described again.

[0036] In FIG. 7(a), a correction circuit 217 is connected to the output section of the receiving circuit 207 used in the second embodiment. FIG. 7(b) shows the frequency characteristics of the correction circuit 217. The horizontal axis represents frequency, and the vertical axis represents the amount of transmission from the input section to the output section. The correction circuit 217 has a characteristic in which the transmission amount increases as the frequency characteristic becomes lower. FIG. 7(c) shows the simulation results showing the transfer characteristics when a differential signal is transmitted from the coupling conductor 101 to the coupling conductor 201. The horizontal axis represents frequency, and the vertical axis represents the amount of transmission. 228 shows the transfer characteristics when the correction circuit is connected. It can be seen that the difference between the low-frequency characteristic and the peak value of the frequency characteristic is suppressed compared to 221. This is because the low-frequency component is emphasized by the correction circuit 217, which has the frequency characteristic of FIG. 7(b), compared to the frequency characteristic of 221.

[0037] The order of the correction circuit 217 and the receiving circuit 207 may be interchanged, or the correction circuit 217 may be incorporated into the receiving circuit 207. Furthermore, the frequency characteristics of the correction circuit 217 are not limited to those of the present embodiment, and may be selected according to the application. For example, the correction circuit 217 may have a characteristic that attenuates high-frequency characteristics, or a characteristic that emphasizes frequency characteristics near a certain frequency.

[0038] The coupling conductors 101 and 201 in the first to third embodiments may be coupled by electric field coupling alone, by magnetic field coupling alone, or by both electric field coupling and magnetic field coupling. As long as the electrodes 102 and 202 and the electrodes 103 and 103 face each other, the transmitting device 10 and the receiving device 20 may be moved.

[0039] In the first to third embodiments, the configuration has been described in which the shape of the coupling conductor is a rectangular parallelepiped. However, the shape of the coupling conductors 101 and 201 is not limited to a rectangular parallelepiped, and may be other than a rectangular parallelepiped as long as the electrodes 102 and 202, and the electrodes 103 and 203, are arranged to face each other. For example, the coupling conductors may have rounded corners as shown in FIG. 8(a), an ellipse as shown in FIG. 8(b), or a polygon as shown in FIG. 8(c). If the width of the coupling conductor in the X-axis direction is not uniform, the positions for placing the circuit element units 204 and 205 are determined, and then the impedance with the best match is treated as the coupling system impedance.

[0040] (Other embodiments) The disclosure of this embodiment also includes the following configuration.

[0041] (Configuration 1) a transmitter for transmitting a differential signal; a receiving device that receives a differential signal by electromagnetic field coupling with the transmitting device, the receiving device includes a coupling conductor composed of two electrodes that receive a differential signal by electromagnetic field coupling, a circuit element unit disposed between the two electrodes and composed of at least one high-pass filter and a resistor, and a receiving circuit connected to the coupling conductor; A wireless communication device, wherein the cutoff frequency of the high-pass filter is lower than the self-resonant frequency of the coupling conductor.

[0042] (Configuration 2) 2. The wireless communication device according to claim 1, wherein the high-pass filter is composed of at least one capacitor.

[0043] (Configuration 3) 3. The wireless communication device according to claim 1, wherein the cutoff frequency of the high-pass filter is equal to or higher than the lowest frequency of the differential signal.

[0044] (Configuration 4) 4. The wireless communication device according to any one of configurations 1 to 3, wherein the circuit element section is connected to an end of at least one of the two electrodes.

[0045] (Configuration 5) 4. The wireless communication device according to any one of configurations 1 to 3, wherein the circuit element section is connected to one end and the other end of the two electrodes.

[0046] (Configuration 6) The wireless communication device according to any one of configurations 1 to 4, wherein the high-pass filter of the circuit element unit is connected to at least one end of one of the two electrodes, and the resistor is connected to at least one end of the other of the two electrodes.

[0047] (Configuration 7) The wireless communication device according to any one of configurations 1 to 6, wherein the resistance is equal to or greater than half the value of the coupling system impedance of the coupling conductor and equal to or less than twice the characteristic impedance of the coupling conductor.

[0048] (Configuration 8) 8. The wireless communication device according to any one of configurations 1 to 7, wherein the high-pass filter is a Chebyshev filter.

[0049] (Configuration 9) 9. The wireless communication device according to any one of configurations 1 to 8, wherein a correction circuit is connected to an output section of the receiving circuit.

[0050] (Configuration 10) 10. The wireless communication device according to any one of configurations 1 to 9, wherein the electrode of the coupling conductor has a rectangular parallelepiped shape.

[0051] (Configuration 11) 2. The wireless communication device according to claim 1, wherein the transmitter has two electrodes for transmitting a differential signal.

[0052] (Configuration 12) A receiving device that receives a differential signal by electromagnetic field coupling with another communication device, a coupling conductor consisting of two electrodes that receive a differential signal through the electromagnetic coupling; A receiving device comprising: a circuit element section arranged between the two electrodes and consisting of at least one high-pass filter and a resistor; and a receiving circuit connected to the coupling conductor, wherein the cutoff frequency of the high-pass filter is lower than the self-resonant frequency of the coupling conductor. [Explanation of symbols]

[0053] 100 Wireless Communication System 10 Transmitting device 20 Receiving device

Claims

1. a transmitter for transmitting a differential signal; a receiving device that receives a differential signal by electromagnetic field coupling with the transmitting device, the receiving device includes a coupling conductor composed of two electrodes that receive a differential signal by electromagnetic field coupling, a circuit element unit disposed between the two electrodes and composed of at least one high-pass filter and a resistor, and a receiving circuit connected to the coupling conductor; A wireless communication device, wherein the cutoff frequency of the high-pass filter is lower than the self-resonant frequency of the coupling conductor.

2. 2. The wireless communication device according to claim 1, wherein the high-pass filter comprises at least one capacitor.

3. 2. The wireless communication device according to claim 1, wherein the cutoff frequency of the high-pass filter is equal to or higher than the lowest frequency of the differential signal.

4. 2. The wireless communication device according to claim 1, wherein the circuit element portion is connected to an end of at least one of the two electrodes.

5. 2. The wireless communication device according to claim 1, wherein the circuit element section is connected to one end and the other end of the two electrodes.

6. 2. The wireless communication device according to claim 1, wherein the high-pass filter of the circuit element section is connected to at least one end of one of the two electrodes, and the resistor is connected to at least one end of the other of the two electrodes.

7. 2. The wireless communication device according to claim 1, wherein the resistance is equal to or greater than half the value of the coupling system impedance of the coupling conductor and equal to or less than twice the characteristic impedance of the coupling conductor.

8. 2. The wireless communication device according to claim 1, wherein the high-pass filter is a Chebyshev filter.

9. 2. The wireless communication device according to claim 1, wherein a correction circuit is connected to an output of the receiving circuit.

10. The wireless communication device according to claim 1 , wherein the electrode of the coupling conductor has a rectangular parallelepiped shape.

11. 2. The wireless communication device according to claim 1, wherein the transmitter has two electrodes for transmitting a differential signal.

12. A receiving device that receives a differential signal by electromagnetic field coupling with another communication device, a coupling conductor consisting of two electrodes that receive a differential signal by electromagnetic field coupling; a circuit element unit arranged between the two electrodes and configured with at least one high-pass filter and a resistor; a receiving circuit connected to the coupling conductor; and A receiving device, characterized in that the cutoff frequency of the high-pass filter is lower than the self-resonant frequency of the coupling conductor.

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