Communication device and communication system

Abstract

To allow the amplitude of a received signal to be increased.SOLUTION: A communication device is a communication device that performs wireless communication, and includes a first dielectric 152 and a second coupler provided on the first dielectric and coupled with a first coupler of another communication device by electric field coupling or magnetic field coupling. The second coupler has a first conductor 121a and a second conductor 121b. The first dielectric is provided with a hole 153, a recess, or a second dielectric having specific permittivity lower than that of the first dielectric, in at least part of an area projected onto an area between the first conductor and the second conductor.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present disclosure relates to a communication device and a communication system. [Background technology]

[0002] Connectors or harnesses are used to connect communication interfaces between electronic circuit boards or modules. However, if connections that currently use connectors or harnesses could be made wireless, there would be advantages such as simplifying the manufacturing process.

[0003] Patent Document 1 discloses a structure for shortening the distance between couplers (hereinafter referred to as couplers) in order to improve communication performance in a wireless communication system that transmits signals in a non-contact manner using electromagnetic field coupling. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 2017-118476 Summary of the Invention [Problem to be solved by the invention]

[0005] In recent years, the amount of data transmitted within and between devices has increased, creating a demand for high-speed communication in wireless communication systems. However, when communicating between devices, for example, couplers are generally placed inside the product housing, and housings have dimensional tolerances. As a result, depending on the device, the distance between couplers may be far apart, making it difficult to increase the received signal.

[0006] Furthermore, when it comes to communication within a device, there is a risk that couplers may come into contact with each other if they are placed too close due to tolerances in board thickness, etc., so it is necessary to leave some space between the couplers, which can result in the inability to ensure a sufficient received signal.

[0007] An object of the present disclosure is to enable the amplitude of a received signal to be increased. [Means for solving the problem]

[0008] The communication device is a communication device that performs wireless communication and has a first dielectric and a second coupler that is provided on the first dielectric and that couples to a first coupler of another communication device by electric field coupling or magnetic field coupling, the second coupler having a first conductor and a second conductor, and the first dielectric has a hole, a recess, or a second dielectric having a relative dielectric constant lower than that of the first dielectric in at least a portion of an area projected onto the area between the first conductor and the second conductor. [Effects of the Invention]

[0009] According to the present disclosure, the amplitude of a received signal can be increased. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 1 is a diagram illustrating an example of the configuration of a wireless communication system. [Figure 2] FIG. 2 is a waveform diagram showing an example of a signal. [Figure 3] FIG. 2 is an equivalent circuit diagram of a coupler. [Figure 4] FIG. 10 is a diagram showing a simulation result of an eye pattern of a received signal. [Figure 5] FIG. 2 is a diagram illustrating an example of the configuration of a coupler. [Figure 6] FIG. 10 is a diagram showing a simulation result of an eye pattern of a received signal. [Figure 7] FIG. 2 is a diagram illustrating an example of the configuration of a coupler. [Figure 8] FIG. 2 is a diagram illustrating an example of the configuration of a coupler. [Figure 9] FIG. 10 is a diagram showing a simulation result of an eye pattern of a received signal. [Figure 10] FIG. 10 is a diagram showing a simulation result of an eye pattern of a received signal. DETAILED DESCRIPTION OF THE INVENTION

[0011] (First embodiment) 1 is a diagram showing an example of the configuration of a wireless communication system 100 according to the first embodiment. The wireless communication system 100 has wireless communication modules 110 and 120, and performs wireless communication between the wireless communication modules 110 and 120.

[0012] The wireless communication module 110 includes a coupler 111 and a transmitter circuit 112. The coupler 111 includes two separated conductors 111a and 111b. The transmitter circuit 112 outputs differential signals of opposite phases from output terminals TX+ and TX- to conductors 111a and 111b, respectively. The output terminal TX+ of the transmitter circuit 112 outputs a positive signal of the differential signal to conductor 111a. The output terminal TX- of the transmitter circuit 112 outputs a negative signal of the differential signal, which is in opposite phase to the positive signal, to conductor 111b. The difference between the positive and negative signals output from the transmitter circuit 112 is defined as Vi.

[0013] The wireless communication module 120 includes a coupler 121, a shaping circuit 122, a receiving circuit 123, and termination resistors Ra and Rb. The coupler 121 includes two separated conductors 121a and 121b.

[0014] Coupler 111 of wireless communication module 110 and coupler 121 of wireless communication module 120 are arranged close to and facing each other, and are coupled by electromagnetic coupling. Conductor 111a and conductor 121a are arranged close to and facing each other. Conductor 111b and conductor 121b are arranged close to and facing each other.

[0015] The wireless communication system 100 realizes wireless communication of differential signals between the wireless communication module 110 and the wireless communication module 120 by using electromagnetic coupling between the couplers 111 and 121. Specifically, the transmitting circuit 112 wirelessly transmits the differential signals to the shaping circuit 122 via the electromagnetic coupling between the couplers 111 and 121.

[0016] The termination resistor Ra is connected to the input terminal IN+ of the shaping circuit 122. The termination resistor Rb is connected to the input terminal IN- of the shaping circuit 122. The input terminals IN+ and IN- of the shaping circuit 122 wirelessly receive differential signals from the output terminals TX+ and TX- of the transmitting circuit 112 via electromagnetic coupling between the couplers 111 and 121. The input terminal IN+ of the shaping circuit 122 wirelessly receives a positive signal from the output terminal TX+ of the transmitting circuit 112 via electromagnetic coupling between the conductors 111a and 121a. The input terminal IN- of the shaping circuit 122 wirelessly receives a negative signal, which is out of phase with the positive signal, from the output terminal TX- of the transmitting circuit 112 via electromagnetic coupling between the conductors 111b and 121b. The difference between the positive and negative signals input to the shaping circuit 122 is denoted as Vr.

[0017] The shaping circuit 122 shapes the differential signal received by the input terminals IN+ and IN- and outputs the differential signal from the output terminals OUT+ and OUT-. The shaping circuit 122 shapes the signal received by the input terminal IN+ and outputs a positive signal from the output terminal OUT+. The shaping circuit 122 shapes the signal received by the input terminal IN- and outputs a negative signal that is out of phase with the positive signal from the output terminal OUT-. The difference between the positive and negative signals output by the shaping circuit 122 is defined as Vo. The signal Vo is a restored signal of the signal Vi.

[0018] The input terminals RX+ and RX- of the receiving circuit 123 input the differential signals output from the output terminals OUT+ and OUT- of the shaping circuit 122. The input terminals RX+ and RX- of the receiving circuit 123 input the differential signals output from the output terminals OUT+ and OUT- of the shaping circuit 122. The receiving circuit 123 performs reception processing on the differential signals input to the input terminals RX+ and RX-.

[0019] FIG. 2(a) is a diagram showing an example of an input signal Vi, a received signal Vr, and an output signal Vo under an ideal environment.

[0020] The termination resistors Ra and Rb in FIG. 1 have a high impedance, such as 22 kΩ. This makes the impedance of the termination resistors Ra and Rb greater than the impedance of the capacitive component resulting from the coupling between the couplers 111 and 121, even in the low-frequency range. As a result, the low-frequency components of the input signal Vi are transmitted to the shaping circuit 122 as the received signal Vr. As shown in FIG. 2(a), the received signal Vr is transmitted while maintaining the rectangular shape of "1" and "0." The input signal Vi is a rectangular wave of negative and positive voltages. The received signal Vr is also a rectangular wave of negative and positive voltages. For example, the shaping circuit 122 outputs a negative voltage output signal Vo when the received signal Vr is less than 0 V, and outputs a positive voltage (high level) output signal Vo when the received signal Vr is equal to or greater than 0 V. The output signal Vo is equivalent to the input signal Vi.

[0021] FIG. 2(b) is a diagram showing an example of the input signal Vi, the received signal Vr, and the output signal Vo when external noise is mixed into the coupler 111 or 121. The input signal Vi in FIG. 2(b) is the same as the input signal Vi in FIG. 2(a). However, when external noise is mixed into the coupler 111 or 121, the noise may be mixed into the received signal Vr in FIG. 2(b). For example, the shaping circuit 122 outputs a negative voltage output signal Vo when the received signal Vr is less than 0 V, and outputs a positive voltage (high level) output signal Vo when the received signal Vr is 0 V or higher. When noise is mixed into the received signal Vr, the output signal Vo becomes different from the input signal Vi, resulting in a communication error.

[0022] Therefore, the level of the received signal Vr must be made higher than the noise to prevent communication errors from occurring even when external noise is mixed into the coupler 111 or 121. Therefore, in this embodiment, weakening the coupling between the conductors 121a and 121b that receive the differential signal is effective in increasing the level of the received signal Vr, as will be shown below.

[0023] 3 is a diagram showing equivalent circuits of couplers 111 and 121. Capacitor 301 represents the coupling capacitance between conductors 111a and 121a. Capacitor 302 represents the coupling capacitance between conductors 121a and 121b. Capacitor 303 represents the coupling capacitance between conductors 111b and 121b. Capacitor 304 represents the coupling capacitance between conductors 111a and 111b. Note that FIG. 3 shows an equivalent circuit of only the electric field coupling, which is the main component of the electromagnetic field coupling of couplers 111 and 121.

[0024] FIG. 4(a) shows the simulation results of the eye pattern of the received signal Vr when the coupling capacitance 302 is large, where the capacitance value of the coupling capacitance 302 is 0.5 pF. FIG. 4(b) shows the simulation results of the eye pattern of the received signal Vr when the coupling capacitance 302 is small, where the capacitance value of the coupling capacitance 302 is 0.25 pF. The capacitance values ​​of the coupling capacitances 301, 303, and 304 in FIG. 4(a) are the same as the capacitance values ​​of the coupling capacitances 301, 303, and 304 in FIG. 4(b), respectively. The amplitude of the received signal Vr when the coupling capacitance 302 in FIG. 4(b) is small is larger than the amplitude of the received signal Vr when the coupling capacitance 302 in FIG. 4(a) is large. The input signal Vi is 5 Gbps and is a signal of approximately 1 Vpp.

[0025] Fig. 5(a) is a perspective view showing an example of the structure of dielectrics 151 and 152 and conductors 111a, 111b, 121a, and 121b according to a comparative example. Fig. 5(b) is a plan view of dielectric 152 and conductors 121a and 121b in Fig. 5(a). Conductors 111a and 111b are provided on dielectric 151, such as an FR4 substrate. Conductors 121a and 121b are provided on dielectric 152, such as an FR4 substrate.

[0026] FIG. 5(c) is a perspective view showing a structural example of the dielectrics 151 and 152, the conductors 111a, 111b, 121a, and 121b, and the perforated portion 153 according to the first embodiment. FIG. 5(d) is a plan view showing the dielectric 152, the conductors 121a and 121b, and the perforated portion 153 of FIG. 5(c). The conductors 111a and 111b are provided on a dielectric 151 such as an FR4 substrate. The conductors 121a and 121b are provided on a dielectric 152 such as an FR4 substrate. In the dielectric 152, a perforated portion 153 is provided in a region projected onto a region between the conductors 121a and 121b. The perforated portion 153 is a through-hole in the dielectric 152.

[0027] The coupling capacitance between conductors 121a and 121b in Figures 5(c) and (d) is smaller than the coupling capacitance between conductors 121a and 121b in Figures 5(a) and (b). As described above, the amplitude of the received signal Vr when the coupling capacitance is small in Figure 4(b) is larger than the amplitude of the received signal Vr when the coupling capacitance is large in Figure 4(a). Therefore, the amplitude of the received signal Vr from conductors 121a and 121b in Figures 5(c) and (d) is larger than the amplitude of the received signal Vr from conductors 121a and 121b in Figures 5(a) and (b).

[0028] Fig. 6(a) is a diagram showing the simulation results of the eye patterns of the received signal Vr of the conductors 121a and 121b in Fig. 5(a) and (b). The amplitude value 601 of the received signal Vr is 251 mVpp.

[0029] Fig. 6(b) is a diagram showing the simulation results of the eye patterns of the received signal Vr of the conductors 121a and 121b in Fig. 5(c) and (d). The amplitude value 602 of the received signal Vr is 307 mVpp.

[0030] It can be seen that amplitude value 602 in Fig. 6(b) is approximately 1.22 times the amplitude value 601 in Fig. 6(a). Here, the input signal Vi is 5 Gbps and is a signal of approximately 1 Vpp. Note that the eye pattern shapes in Figs. 6(a) and (b) differ from those in Figs. 4(a) and (b) because Figs. 4(a) and (b) are simulation results using ideal capacitance that does not include the parasitic inductance and parasitic resistance of the coupler structure.

[0031] As described above, according to this embodiment, by providing perforated portion 153 in the region of dielectric 152 projected onto the region between conductor 121a and conductor 121b, it is possible to reduce the coupling capacitance between conductor 121a and conductor 121b. This allows wireless communication system 100 to increase the amplitude of received signal Vr and reduce communication errors due to noise.

[0032] 5(c) and 5(d) show the case where the length of the perforated portion 153 is the same as the length of the long sides of the conductors 121a and 121b, but is not limited to this. The length of the perforated portion 153 may be shorter or longer than the length of the long sides of the conductors 121a and 121b.

[0033] 5(c) and 5(d), the perforated portions 153 are provided along the long side direction of the conductors 121a and 121b, but are not limited thereto. As shown in FIG. 7, the perforated portions 153 may be provided along the long side direction and the short side direction of the conductors 121a and 121b.

[0034] 5(c) and 5(d), perforations 153 are provided in the region of dielectric 152 projected onto the region between conductors 121a and 121b, but recesses may be provided instead of perforations 153. The thickness of the recesses is thinner than the thickness of dielectric 152. That is, the region of dielectric 152 projected onto the region between conductors 121a and 121b is thinner than the other regions.

[0035] In addition, in Figures 5(c) and (d), perforation portion 153 is provided in the area projected onto the area between conductor 121a and conductor 121b, but instead of perforation portion 153, a material having a relative dielectric constant lower than the relative dielectric constant of dielectric 152 may be provided.

[0036] Furthermore, in this embodiment, a structure for reducing the coupling capacitance between conductors 121a and 121b of wireless communication module 120 has been shown, but reducing the coupling capacitance between conductors 111a and 111b of wireless communication module 110 also has the effect of increasing the amplitude of received signal Vr. Therefore, perforated portion 153 may be provided in the region of dielectric 151 that is projected onto the region between conductors 111a and 111b.

[0037] As described above, the wireless communication system 100 includes the wireless communication modules 110 and 120. The wireless communication modules 110 and 120 are each a wireless communication device that performs wireless communication. The wireless communication module 110 includes a coupler 111 and a dielectric 151. The coupler 111 includes a conductor 111a and a conductor 111b, and is provided on the dielectric 151. The dielectric 151 is, for example, a substrate.

[0038] Wireless communication module 120 includes coupler 121 and dielectric 152. Coupler 121 includes conductor 121a and conductor 121b, is provided on dielectric 152, and is coupled to coupler 111 by electric field coupling or magnetic field coupling. Dielectric 152 is, for example, a substrate.

[0039] Dielectric 152 has holes (perforated portions 153), recesses, or a dielectric having a lower relative dielectric constant than that of dielectric 152 in at least a part of the area projected onto the area between conductors 121a and 121b.

[0040] In the above-mentioned recess, the thickness of at least a portion of the area of ​​the dielectric 152 projected onto the area between the conductors 121a and 121b is thinner than the thickness of the area of ​​the dielectric 152 projected onto the area between the conductors 121a and 121b.

[0041] The conductors 111a and 111b transmit differential signals wirelessly, and the conductors 121a and 121b transmit differential signals wirelessly. Note that the couplers 111 and 121 may each transmit a single signal wirelessly.

[0042] The coupler 111 is a transmitting coupler. The transmitting circuit 112 outputs an input signal (transmitting signal) Vi to the coupler 111. The coupler 121 is a receiving coupler. The shaping circuit 122 is connected to the conductor 121a and the conductor 121b. The termination resistors Ra and Rb are connected to the input terminals IN+ and IN- of the shaping circuit 122, respectively, and have a resistance value (e.g., 22 kΩ) such that the receiving signal Vr of the coupler 121 becomes approximately rectangular. Note that the termination resistors Ra and Rb may each have a resistance value (e.g., 50 Ω) such that the receiving signal Vr becomes an approximately differentiated signal with respect to the input signal Vi.

[0043] As described above, according to this embodiment, it is possible to increase the amplitude of the received signal Vr, suppress communication errors due to noise, and improve communication quality without shortening the distance between the coupler 111 and the coupler 121.

[0044] (Second embodiment) In the first embodiment, a configuration in which perforated portion 153 or the like is provided in dielectric 151 or 152 has been described. In communication within a device, couplers 111 and 121 are each fixed to a different member within a housing, and there is often air between coupler 111 and coupler 121. However, in communication between devices, couplers 111 and 121 are each mounted in different product housings, and therefore coupler 111 and coupler 121 are sandwiched between two product housings. In the second embodiment, the structure of the housing between coupler 111 and coupler 121 will be described.

[0045] FIG. 8(a) is a perspective view showing an example of the structure of dielectrics 151 and 152, conductors 111a, 111b, 121a, and 121b, and product housings 181 and 182 according to a comparative example. FIG. 8(b) is a plan view showing dielectric 152, conductors 121a and 121b, and product housing 182 of FIG. 8(a) as viewed from above. Product housings 181 and 182 are made of, for example, resin. Conductors 111a and 111b are provided on dielectric 151, such as an FR4 substrate. Dielectric 151 is mounted on product housing 181. Conductors 111a and 111b are sandwiched between product housing 181 and dielectric 151. Conductors 121a and 121b are provided on dielectric 152, such as an FR4 substrate. Dielectric 152 is mounted on product housing 182. The conductors 121 a and 121 b are sandwiched between the product housing 182 and the dielectric 152 .

[0046] FIG. 8(c) is a perspective view showing a structural example of the dielectrics 151 and 152, the conductors 111a, 111b, 121a, and 121b, the product housing 181 and 182, and the perforated portion 183 according to the second embodiment. FIG. 8(d) is a plan view showing the dielectric 152, the conductors 121a and 121b, the product housing 182, and the perforated portion 183 of FIG. 8(c). The product housings 181 and 182 are made of, for example, resin. The conductors 111a and 111b are provided on the dielectric 151, such as an FR4 substrate. The dielectric 151 is mounted on the product housing 181. The conductors 111a and 111b are sandwiched between the product housing 181 and the dielectric 151. The conductors 121a and 121b are provided on the dielectric 152, such as an FR4 substrate. The dielectric 152 is mounted on the product housing 182. Conductors 121a and 121b are sandwiched between product housing 182 and dielectric 152. Perforated portion 183 is provided in product housing 182 in an area projected onto the area between conductors 121a and 121b. Perforated portion 183 is a through-hole in product housing 182.

[0047] The coupling capacitance between conductors 121a and 121b in Figures 8(c) and (d) is smaller than the coupling capacitance between conductors 121a and 121b in Figures 8(a) and (b). As described above, the amplitude of the received signal Vr when the coupling capacitance is small in Figure 4(b) is larger than the amplitude of the received signal Vr when the coupling capacitance is large in Figure 4(a). Therefore, the amplitude of the received signal Vr from conductors 121a and 121b in Figures 8(c) and (d) is larger than the amplitude of the received signal Vr from conductors 121a and 121b in Figures 8(a) and (b).

[0048] Fig. 9(a) is a diagram showing the simulation results of the eye patterns of the received signal Vr of the conductors 121a and 121b in Fig. 8(a) and (b). The amplitude value 901 of the received signal Vr is 406 mVpp.

[0049] Fig. 9(b) is a diagram showing the simulation results of the eye patterns of the received signal Vr of the conductors 121a and 121b in Fig. 8(c) and (d). The amplitude value 902 of the received signal Vr is 493 mVpp.

[0050] It can be seen that the amplitude value 902 in Fig. 9(b) is approximately 1.21 times the amplitude value 901 in Fig. 9(a). Here, the input signal Vi is 5 Gbps and is a signal of approximately 1 Vpp.

[0051] As described above, according to this embodiment, by providing perforated portion 183 in the area of ​​product housing 182 that is projected onto the area between conductors 121a and 121b, it is possible to reduce the coupling capacitance between conductors 121a and 121b. This allows wireless communication system 100 to increase the amplitude of received signal Vr and reduce communication errors due to noise.

[0052] In this embodiment, the configuration in which the couplers 111 and 121 are formed on the dielectrics 151 and 152 such as substrates has been described, but the couplers 111 and 121 do not have to be formed on the dielectrics 151 and 152. For example, the couplers 111 and 121 may be conductors made of conductive plates.

[0053] In addition, although the present embodiment illustrates a case in which the length of the perforated portion 183 is the same as the length of the long sides of the conductors 121a and 121b, the length of the perforated portion 183 is not limited to this. The length of the perforated portion 183 may be shorter or longer than the length of the long sides of the conductors 121a and 121b.

[0054] Furthermore, in this embodiment, perforated portion 183 is provided in the region of product casing 182 that is projected onto the region between conductors 121a and 121b, but a recess may be provided instead of perforated portion 183. The thickness of the recess is thinner than the thickness of product casing 182. That is, the region of product casing 182 that is projected onto the region between conductors 121a and 121b is thinner than other regions.

[0055] In addition, in this embodiment, perforated portion 183 is provided in the region of product casing 182 projected onto the region between conductors 121a and 121b, but is not limited to perforated portion 183. A material with a lower dielectric constant than that of product casing 182 may be provided in the region of product casing 182 projected onto the region between conductors 121a and 121b.

[0056] Furthermore, in this embodiment, a structure for reducing the coupling capacitance between conductors 121a and 121b of wireless communication module 120 has been shown, but reducing the coupling capacitance between conductors 111a and 111b of wireless communication module 110 also has the effect of increasing the amplitude of received signal Vr. Therefore, perforated portion 183 may be provided in the area of ​​product housing 181 that is projected onto the area between conductors 111a and 111b.

[0057] As described above, wireless communication module 110 has coupler 111, dielectric 151, and product housing (exterior) 181. Coupler 111 has conductor 111a and conductor 111b, and is provided on dielectric 151. Dielectric 151 is, for example, a substrate. Product housing 181 is a dielectric (resin).

[0058] Wireless communication module 120 has coupler 121, dielectric 152, and product housing 182. Coupler 121 has conductor 121a and conductor 121b, is provided on dielectric 152, and is coupled to coupler 111 by electric field coupling or magnetic field coupling. Dielectric 152 is, for example, a substrate. Product housing 182 is a dielectric (resin). Product housings 181 and 182 are provided between coupler 111 and coupler 121.

[0059] Product housing 182 has a hole (e.g., perforation 183), a recess, or a dielectric with a relative dielectric constant lower than that of product housing 182 in at least a portion of the area projected onto the area between conductors 121a and 121b.

[0060] The recess is such that the thickness of at least a portion of the area of ​​product housing 182 projected onto the area between conductors 121a and 121b is thinner than the thickness of the area of ​​product housing 182 projected onto the area between conductors 121a and 121b.

[0061] As described above, according to this embodiment, it is possible to increase the amplitude of the received signal Vr, suppress communication errors due to noise, and improve communication quality without shortening the distance between the coupler 111 and the coupler 121.

[0062] (Third embodiment) In the first and second embodiments, the dielectrics 151 and 152 and the product housings 181 and 182 are provided with the perforated portions 153 and 183 in order to reduce the coupling capacitance between the conductors 121a and 121b or between the conductors 111a and 111b, respectively.

[0063] In the third embodiment, the distance between the conductors 121a and 121b is further increased to reduce the coupling capacitance between the conductors 121a and 121b and increase the amplitude of the received signal Vr. In the case of small consumer devices, the mounting area of ​​the coupler 121 is very small, so the distance between the conductors 121a and 121b is also short. However, in the case of large production equipment or factory machinery, there is ample mounting area for the coupler 121, so it is possible to increase the distance between the conductors 121a and 121b.

[0064] In Figures 5(c) and (d), the distance between conductors 111a and 111b is 1 mm, and the distance between conductors 121a and 121b is 1 mm. Figure 6(b) shows the simulation results of the eye pattern of the received signal Vr of conductors 121a and 121b in Figures 5(c) and (d). As described above, the amplitude value 602 of the received signal Vr is 307 mVpp.

[0065] FIG. 10(a) shows the simulation results of the eye pattern of the received signal Vr when the distance between the conductors 121a and 121b is 2 mm. The size of the perforation 153 and the distance between the conductors 111a and 111b are the same as those in FIGS. 5(c) and 5(d). The amplitude value 1001 of the opening of the eye pattern of the received signal Vr in FIG. 10(a) is 328 mVpp. It can be seen that the amplitude value 1001 in FIG. 10(a) is larger than the amplitude value 602 in FIG. 6(b). Increasing the distance between the conductors 121a and 121b reduces the coupling capacitance between the conductors 121a and 121b, thereby increasing the amplitude value 1001 of the received signal Vr.

[0066] FIG. 10(b) shows the simulation results of the eye pattern of the received signal Vr when the distance between the conductors 111a and 111b is 2 mm and the distance between the conductors 121a and 121b is 2 mm. The amplitude value 1002 of the opening of the eye pattern of the received signal Vr in FIG. 10(b) is 351 mVpp. It can be seen that the amplitude value 1002 in FIG. 10(b) is larger than the amplitude value 1001 in FIG. 10(a). Increasing the distance between the conductors 111a and 111b reduces the coupling capacitance between the conductors 111a and 111b, thereby increasing the amplitude value 1002 of the received signal Vr. Furthermore, because the distance between the conductors 111a and 111b and the distance between the conductors 121a and 121b are the same, the opposing area between the coupler 111 and the coupler 121 increases, and the coupling capacitance between the coupler 111 and the coupler 121 increases. This makes it possible to increase the amplitude value 1002 of the received signal Vr.

[0067] As described above, according to this embodiment, the distance between the conductors 121a and 121b and / or the distance between the conductors 111a and 111b is increased. This reduces the coupling capacitance between the conductors 121a and 121b and / or the coupling capacitance between the conductors 111a and 111b. The wireless communication system 100 increases the amplitude of the received signal Vr and reduces communication errors due to noise.

[0068] 10(a) and 10(b), the distance between conductor 121a and conductor 121b is 2 mm, and the length of perforated portion 153 is 1 mm. Instead of perforated portion 153, a recess or a dielectric having a lower dielectric constant than that of dielectric 152 may be provided. The distance between conductor 121a and conductor 121b is longer than the length of perforated portion 153, the recess, or the dielectric having a lower dielectric constant than that of dielectric 152. This allows wireless communication system 100 to increase the amplitude of received signal Vr and reduce communication errors due to noise.

[0069] In the first to third embodiments, simulation results are shown when the termination resistors Ra and Rb are set to a high impedance (22 kΩ), but even when the termination resistors Ra and Rb are set to approximately 50 Ω, the amplitude of the received signal Vr can be increased.

[0070] In the first to third embodiments, the couplers 111 and 121 are formed on the dielectrics (substrates) 151 and 152. The material of the dielectrics (substrates) 151 and 152 is not limited to FR4, and may be Teflon (registered trademark) or polyimide.

[0071] Furthermore, in the first to third embodiments, the couplers 111 and 121 are formed on the dielectrics 151 and 152 such as substrates, but the present invention is not limited to this. The couplers 111 and 121 may be manufactured by a mechatronic integrated device (MID) method in which a laser is irradiated onto a special resin (dielectric) and plating is applied only to the laser-irradiated portions. In other words, the couplers 111 and 121 may be manufactured by a method (MID) in which a metal is plated onto a dielectric.

[0072] Furthermore, in the first to third embodiments, since the wireless communication system 100 transmits differential signals, it is preferable that the structures of the couplers 111 and 121 are symmetrical. That is, it is preferable that the shapes of the conductors 111a and 111b are the same, and that the shapes of the conductors 121a and 121b are the same.

[0073] Furthermore, in the first to third embodiments, the conductors 111a, 111b, 121a, and 121b are rectangular, but they may be partially circular, elliptical, or diamond-shaped.

[0074] Furthermore, in the first to third embodiments, the wireless communication system 100 transmits differential signals, but the present invention is not limited to this, and the wireless communication system 100 may transmit a single signal.

[0075] In the first to third embodiments, a conductor may be arranged on the opposing surface of the conductors 111a and 111b, and the conductor may function as a transmission line with the conductor as a reference plane. In this case, one end of the conductors 111a and 111b may be terminated with a resistor that matches the characteristic impedance of the transmission line.

[0076] Furthermore, in the first to third embodiments, the input signal Vi is a baseband signal, but it may also be a modulated signal.

[0077] It should be noted that the above-described embodiments merely illustrate specific examples of implementing the present disclosure, and the technical scope of the present disclosure should not be construed as being limited by these embodiments. In other words, the present disclosure can be implemented in various forms without departing from its technical concept or main features. [Explanation of symbols]

[0078] 100 wireless communication system, 110, 120 wireless communication module, 111, 121 coupler, 112 transmitting circuit, 122 shaping circuit, 123 receiving circuit, 151, 152 dielectric, 153, 183 perforation, 181, 182 product housing

Claims

1. A communication device for wireless communication, a first dielectric; a second coupler provided on the first dielectric and coupled to a first coupler of another communication device by electric field coupling or magnetic field coupling; the second coupler has a first conductor and a second conductor; A communication device characterized in that the first dielectric has a hole, a recess, or a second dielectric having a dielectric constant lower than that of the first dielectric in at least a part of an area projected onto a region between the first conductor and the second conductor.

2. The communication device according to claim 1 , wherein the first dielectric is a substrate.

3. A communication device for wireless communication, a second coupler that couples with the first coupler of the other communication device by electric field coupling or magnetic field coupling; a first dielectric disposed between the first coupler and the second coupler; the second coupler has a first conductor and a second conductor; A communication device characterized in that the first dielectric has a hole, a recess, or a second dielectric having a dielectric constant lower than that of the first dielectric in at least a part of an area projected onto a region between the first conductor and the second conductor.

4. 4. The communication device according to claim 3, wherein the first dielectric is a housing.

5. The communication device according to any one of claims 1 to 4, characterized in that the thickness of at least a portion of the region of the first dielectric projected onto the region between the first conductor and the second conductor is thinner than the thickness of the region of the first dielectric projected onto the region between the first conductor and the second conductor.

6. 6. The communication device according to claim 1, wherein the distance between the first conductor and the second conductor is longer than the length of the hole, the recess, or the second dielectric.

7. 7. The communication device according to claim 1, wherein the first conductor and the second conductor wirelessly communicate differential signals.

8. 8. The communication device according to claim 1, wherein the second coupler is a receiving coupler.

9. 9. The communication device according to claim 8, further comprising a shaping circuit connected to the first conductor and the second conductor.

10. 10. The communication device according to claim 9, further comprising a termination resistor connected to an input terminal of the shaping circuit.

11. 11. The communication device according to claim 10, wherein the termination resistor has a resistance value such that the signal received by the second coupler has a substantially rectangular shape.

12. 8. The communication device according to claim 1, wherein the second coupler is a transmitting coupler.

13. 13. The communication device according to claim 12, further comprising a transmission circuit that outputs a transmission signal to the second coupler.

14. 14. The communication device according to claim 1, wherein the second coupler is manufactured by a metal-on-dielectric (MID) method.

15. a first communication device for wireless communication; a second communication device for wireless communication; the first communication device has a first coupler; the second communication device a first dielectric; a second coupler provided on the first dielectric and coupled to the first coupler by electric field coupling or magnetic field coupling; the second coupler has a first conductor and a second conductor; A communication system characterized in that the first dielectric has a hole, a recess, or a second dielectric having a dielectric constant lower than that of the first dielectric in at least a part of an area projected onto a region between the first conductor and the second conductor.

16. a first communication device for wireless communication; a second communication device for wireless communication; the first communication device has a first coupler; the second communication device a second coupler coupled to the first coupler by electric field coupling or magnetic field coupling; a first dielectric disposed between the first coupler and the second coupler; the second coupler has a first conductor and a second conductor; A communication system characterized in that the first dielectric has a hole, a recess, or a second dielectric having a dielectric constant lower than that of the first dielectric in at least a part of an area projected onto a region between the first conductor and the second conductor.

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