KR20230089619A - System for contactless communication based on capacitive coupling - Google Patents

Abstract

The present invention relates to a non-contact communication system, and the non-contact communication system according to an embodiment includes a first transceiver, a capacitive coupling unit connected to the first transceiver, and a second transceiver connected to the capacitive coupling unit. , wherein the capacitive coupling unit includes a first coupler based on a first transmission plate connected to the transmission line of the first transceiver and a first reception plate connected to the reception line of the second transceiver and a second transmission line connected to the transmission line of the second transceiver. It further includes a second coupler based on the transmission plane and the second reception plane connected to the reception line of the first transceiver.

Description

Contactless communication system based on capacitive coupling {SYSTEM FOR CONTACTLESS COMMUNICATION BASED ON CAPACITIVE COUPLING}

The present invention relates to a contactless communication system, and more particularly, to a technical idea of a contactless connector based on capacitive coupling.

Existing technology for high-speed, non-contact transmission of data between communication subsystems without the intervention of a host processor is a method of wirelessly transmitting data using a contactless link using EHF, which enables broadband transmission and miniaturization of the transceiver. It has an advantage in that respect.

However, unlike the relatively low frequency band, the existing technology lacks the penetration performance of materials and has high path loss, so communication performance can easily deteriorate when an object exists on the non-contact link, and the process using ultra-high frequencies There is a problem that can cause electromagnetic interference and deterioration of human tissue.

In addition, when implementing technology for wired communication of several MHz used in vehicles, the non-contact link method using ultra-high frequencies, like the existing technology, has a data transmission rate and communication function that are higher than necessary, resulting in unnecessary inconvenience due to the installation of unnecessary functions. may incur costs.

Therefore, there is an increasing need for research on a non-contact connector structure that is compatible with the currently commercialized vehicle communication environment, can maintain constant communication performance from the external environment, has little electromagnetic interference, and can be implemented at low cost.

Korean Patent Registration No. 10-1881629, "Contactless Data Transmission System and Method"

An object of the present invention is to provide a non-contact communication system capable of transmitting a digital signal in a non-contact manner using a simple structure and low-cost configurable capacitor coupler.

In addition, the present invention is intended to provide a non-contact communication system capable of stably transmitting electrical signals using a capacitive coupler serving as a high-pass filter using a pair of conductor flat plates and a termination resistor.

In addition, the present invention is intended to provide a non-contact communication system capable of maximizing transmission efficiency of electrical signals by optimizing the size of the main capacitance component and the size of the leakage capacitance component through capacitance modeling.

In addition, the present invention is compatible with CAN communication currently used in vehicles, and is intended to provide a non-contact communication system capable of minimizing the number of wires and parts inside the vehicle by replacing the existing contact connector.

In addition, by applying a capacitive coupler, the present invention can prevent a short-circuit of a DC component that may occur from a power supply and compensate for a common mode offset voltage, thereby constructing a circuit that meets various communication standards. It is intended to provide a non-contact communication system having high scalability according to the present invention.

In addition, the present invention configures a high-speed serial transmission interface using a capacitive coupler, such as signal quality degradation caused by problems such as impedance mismatching or electrostatic phenomenon (ESD), and physical / chemical shock and heat generation in the vehicle environment. It is intended to provide a non-contact communication system capable of solving problems without using a complex and costly antenna structure.

A non-contact communication system according to an embodiment of the present invention includes a first transceiver, a capacitive coupling unit connected to the first transceiver, and a second transceiver connected to the capacitive coupling unit, wherein the capacitive coupling The second coupler based on the first transmission plate connected to the transmission line of the first transceiver and the first reception plane connected to the reception line of the second transceiver and the second transmission plate connected to the transmission line of the second transceiver and the first transceiver A second coupler based on a second receiving plate connected to the receiving line may be further included.

According to one side, the capacitive coupling unit generates voltage in the direction of a corresponding one of the first and second reception plates when a voltage is applied to one of the first and second transmission plates. An electric field is formed, and a signal may be transmitted in a non-contact manner based on the formed electric field.

According to one side, the capacitive coupling unit may operate as a high pass filter by further including a termination resistor.

According to one side, the capacitive coupling unit may include a first termination resistor connected to the first receiving plate and a second termination resistor connected to the second receiving plate.

According to one side, the capacitive coupling unit includes a width of at least one of the first transmission flat plate, the first receiving flat plate, the second transmitting flat plate, and the second receiving flat plate, the length of the at least one flat plate, and the first transmitting flat plate. The size of at least one of the distance between the first receiving plate and the second transmitting plate and the second receiving plate is controlled so that the size of the main capacitance component is greater than or equal to a predetermined capacitance threshold and the size of the crosstalk capacitance component is It may be less than or equal to a preset crosstalk capacitance threshold.

According to one side, the main capacitance component may include at least one of a capacitance component between a first transmission plate and a first reception plate and a capacitance component between a second transmission plate and a second reception plate.

According to one side, the crosstalk capacitance component is a capacitance component between the first transmission plate and the second reception plate, a capacitance component between the first reception plate and the second transmission plate, a capacitance component between the first transmission plate and the second transmission plate, and It may include at least one capacitance component among capacitance components of the first receiving plate and the second receiving plate.

According to one side, the size of the main capacitance component may be 1pF to 200pF.

According to one side, the size of the crosstalk capacitance component may be 0.1% to 30% of the size of the main capacitance component.

According to one side, the width (w) of the at least one flat plate and the length (l) of the at least one flat plate may be 1 mm ≤ w, l ≤ 300 mm.

According to one side, the distance (d) of at least one of the distance between the first reception plate and the distance between the second transmission plate and the second reception plate may be 0.1 mm ≤ d ≤ 10 mm.

According to one side, the size of the capacitance component (C ₃ ) between the first transmission plate and the first reception plate and the size of the capacitance component (C ₄ ) between the second transmission plate and the second reception plate are determined through Equation 3 below. can

[Equation 3]

은 유전율, t는 적어도 하나의 평판의 두께, l은 적어도 하나의 평판의 길이, w는 적어도 하나의 평판의 폭, d는 제1 송신 평판과 제1 수신 평판 사이의 간격 또는 제2 송신 평판과 제2 수신 평판 사이의 간격을 의미한다.here,

is the permittivity, t is the thickness of the at least one plate, l is the length of the at least one plate, w is the width of the at least one plate, and d is the distance between the first transmitting plate and the first receiving plate or the second transmitting plate and It means the interval between the second receiving plates.

According to one side, the size of the capacitance component (C ₁ ) between the first transmission plate and the second reception plate and the size of the capacitance component (C ₂ ) between the first reception plate and the second transmission plate are obtained through Equation 4 below. can be determined

[Equation 4]

를 의미한다.Here, p is the distance between the center point of the first reception plane and the center point of the second transmission plane or the distance between the center point of the first transmission plane and the center point of the second reception plane,

means

According to one side, the size of the capacitance component (C ₅ ) of the first reception plate and the second reception plate and the size of the capacitance component (C ₆ ) between the first transmission plate and the second transmission plate may be determined through Equation 5 below. there is.

[Formula 5]

를 의미한다.here,

means

According to one embodiment, the present invention can transmit a digital signal in a non-contact method using a simple structure and low-cost configurable capacitor coupler.

According to one embodiment, the present invention can stably transmit electrical signals using a capacitive coupler serving as a high-pass filter using a pair of conductor plates and a termination resistor.

According to an embodiment, the size of the main capacitance component and the size of the leakage capacitance component are optimized through capacitance modeling, thereby maximizing transmission efficiency of an electrical signal.

According to one embodiment, by applying a capacitive coupler, the present invention can prevent a short circuit of a DC component that can occur from a power supply and compensate for a common mode offset voltage, thereby constructing a circuit that meets various communication standards. It is possible and can have high scalability accordingly.

According to an embodiment, the present invention configures a high-speed serial transmission interface using a capacitive coupler, thereby reducing signal quality caused by problems such as impedance mismatching or electrostatic phenomenon (ESD) and physical/chemical impact in the vehicle environment. and heat generation can be solved without using a complicated and costly antenna structure.

1 is a diagram illustrating a non-contact communication system according to an embodiment.
2 is a diagram illustrating an example of transmitting a signal in a non-contact method using a non-contact communication system according to an embodiment.
3 is a diagram illustrating an example in which a capacitive coupling unit serves as a high pass filter according to an exemplary embodiment.
4A to 4B are diagrams illustrating implementation examples of a capacitive coupling unit according to an exemplary embodiment.
5 is a diagram illustrating an example of performing capacitance modeling on a capacitive coupling unit according to an exemplary embodiment.
6A and 6B are diagrams illustrating an example of applying a non-contact communication system according to an embodiment to a vehicle environment.
7 is a diagram illustrating an example of implementing a non-contact communication system with a half-duplex CAN communication circuit according to an embodiment.
8A to 8D are diagrams illustrating simulation results of a non-contact communication system according to an embodiment.

Specific structural or functional descriptions of the embodiments according to the concept of the present invention disclosed in this specification are only illustrated for the purpose of explaining the embodiments according to the concept of the present invention, and the embodiments according to the concept of the present invention These may be embodied in various forms and are not limited to the embodiments described herein.

Embodiments according to the concept of the present invention can apply various changes and can have various forms, so the embodiments are illustrated in the drawings and described in detail herein. However, this is not intended to limit the embodiments according to the concept of the present invention to specific disclosures, and includes modifications, equivalents, or substitutes included in the spirit and scope of the present invention.

Terms such as first or second may be used to describe various elements, but elements should not be limited by the terms. The terms are used only for the purpose of distinguishing one element from another element, for example, a first element may be termed a second element, and similar In short, the second component may also be referred to as the first component.

It is understood that when an element is referred to as being "connected" or "connected" to another element, it may be directly connected or connected to the other element, but other elements may exist in the middle. It should be. On the other hand, when an element is referred to as “directly connected” or “directly connected” to another element, it should be understood that no other element exists in the middle. Expressions describing the relationship between components, such as "between" and "directly between" or "directly adjacent to" should be interpreted similarly.

Terms used in this specification are only used to describe specific embodiments, and are not intended to limit the present invention. Singular expressions include plural expressions unless the context clearly dictates otherwise. In this specification, terms such as "comprise" or "have" are intended to designate that the described feature, number, step, operation, component, part, or combination thereof exists, but one or more other features or numbers, It should be understood that the presence or addition of steps, operations, components, parts, or combinations thereof is not precluded.

Unless defined otherwise, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art to which the present invention belongs. Terms such as those defined in commonly used dictionaries should be interpreted as having a meaning consistent with the meaning in the context of the related art, and unless explicitly defined in this specification, it should not be interpreted in an ideal or excessively formal meaning. don't

Hereinafter, embodiments will be described in detail with reference to the accompanying drawings. However, the scope of the patent application is not limited or limited by these examples. Like reference numerals in each figure indicate like elements.

1 is a diagram illustrating a non-contact communication system according to an embodiment.

Referring to FIG. 1 , the non-contact communication system 100 according to an embodiment can transmit a digital signal in a non-contact manner using a capacitor coupler that can be configured with a simple structure and low cost.

In addition, the non-contact communication system 100 can stably transmit electrical signals using a capacitive coupler serving as a high-pass filter using a pair of conductor plates and a termination resistor.

In addition, the non-contact communication system 100 can maximize transmission efficiency of electrical signals by optimizing the size of the main capacitance component and the size of the leakage capacitance component through capacitance modeling.

In addition, by applying a capacitive coupler, the non-contact communication system 100 prevents a DC component short circuit that may occur from a power supply and compensates for a common mode offset voltage, thereby constructing a circuit that meets various communication standards. It is possible and can have high scalability accordingly.

In addition, the non-contact communication system 100 configures a high-speed serial transmission interface using a capacitive coupler, thereby reducing signal quality caused by problems such as impedance mismatching or electrostatic phenomenon (ESD) and physical/chemical impacts in the vehicle environment. and heat generation can be solved without using a complicated and costly antenna structure.

To this end, the non-contact communication system 100 is connected to a first transceiver (Transceiver 1) 110, a capacitive coupling unit 130 connected to the first transceiver 110, and a capacitive coupling unit 130 A second transceiver (Transceiver 2) 120 may be included.

The capacitive coupling unit 130 is based on the first transmission plate 131 connected to the transmission line of the first transceiver 110 and the first reception plate 132 connected to the reception line of the second transceiver 120. 1 coupler, a second coupler based on the second transmission plate 133 connected to the transmission line of the second transceiver 120 and the second reception plate 134 connected to the reception line of the first transceiver 110 can

In other words, the capacitive coupling unit 130 may configure a plurality of capacitor couplers using a pair of conductor plates spaced apart at a predetermined interval, and the first transceiver 110 and the first transceiver 110 may use the configured plurality of capacitor couplers. Non-contact communication between the two transceivers 120 may be supported.

According to one side, the capacitive coupling unit 130 transmits voltage to either one of the first transmission plane 131 and the second transmission plane 133 when a voltage is applied to the first reception plane 132 and the second reception plane. An electric field is formed in the direction of one of the corresponding receiving plates among the flat plates 134, and a signal may be transmitted in a non-contact manner based on the generated electric field.

Specifically, when a signal is transmitted from the first transceiver 110 to the second transceiver 120, the capacitive coupling unit 130 transmits a signal through the transmission line of the first transceiver 110 to the first transmission plate 131. A voltage corresponding to the signal is applied, and when the voltage is applied to the first transmission plate 131, an electric field is formed in the direction from the first transmission plate 131 to the first receiving plate 132 and transmitted in the form of an electric field. Since the signal is induced in the form of a voltage on the first receiving plate 132 , the signal can be transferred to the second transceiver 120 in a non-contact manner.

Similarly, when a signal is transmitted from the second transceiver 120 to the first transceiver 110, the capacitive coupling unit 130 transmits a signal to the second transmission plate 133 through the transmission line of the second transceiver 120. When a voltage corresponding to the signal is applied and the voltage is applied to the second transmission plate 133, an electric field is generated in the direction from the second transmission plate 133 to the second reception plate 134, and the signal transmitted in the form of an electric field Since is induced in the form of a voltage to the second receiving plate 134, the signal can be transmitted to the first transceiver 110 in a non-contact manner.

According to one side, the capacitive coupling unit 130 may operate as a high pass filter by further including a termination resistor. Preferably, the capacitive coupling unit 130 may include a first termination resistor connected to the first receiving plate 132 and a second termination resistor connected to the second receiving plate 134 .

Meanwhile, the size of the main capacitance component and the size of the leakage capacitance component of the capacitive coupling unit 130 may be optimized through capacitance modeling, thereby improving signal transmission efficiency.

Specifically, the capacitive coupling unit 130 has a width of at least one of the first transmission plate 131, the first reception plate 132, the second transmission plate 133, and the second reception plate 134. a size of at least one of a length of at least one flat plate and a distance between the first transmitting flat plate 131 and the first receiving flat plate 132 or between the second transmitting flat plate 133 and the second receiving flat plate 134 may be controlled so that the size of the main capacitance component is greater than or equal to a preset capacitance threshold and the size of the crosstalk capacitance component is less than or equal to the preset crosstalk capacitance threshold.

For example, the length, width and spacing of the plates may be the same for all plates.

Also, the preset capacitance threshold may be 10pF, and the preset crosstalk capacitance threshold may be 30% of the size of the main capacitance component.

According to one side, the main capacitance component is a factor determining signal transmission performance, and a capacitance component between the first transmission plate 131 and the first reception plate 132 and the second transmission plate 133 and the second reception plate ( 134) may include at least one capacitance component among capacitance components.

According to one side, the crosstalk capacitance component is an element that increases the crosstalk component of a signal, and is a capacitance component between the first transmission plate 131 and the second reception plate 134, and the first reception plate 132 and the second 2 Among the capacitance component between the transmission plates 133, the capacitance component between the first transmission plate 131 and the second transmission plate 133, and the capacitance component between the first reception plate 132 and the second reception plate 134 It may include at least one capacitance component.

A capacitance modeling process for the capacitive coupling unit 130 will be described in more detail with reference to FIG. 5 in the following embodiment.

2 is a diagram illustrating an example of transmitting a signal in a non-contact method using a non-contact communication system according to an embodiment.

Referring to FIG. 2 , a non-contact communication system according to an embodiment may include a capacitive coupling unit 200 having a plurality of couplers based on a pair of conductive plates, and the capacitive coupling unit 200 may include Through this, digital signals can be transmitted in a non-contact manner.

Specifically, the non-contact communication system transfers the conditioned signal in the form of an electric field through the capacitive coupling unit 200 after conditioning the digital signal transmitted from the first transceiver, and the loss occurred in the transmission process The digital signal may be finally transferred to the second transceiver through a signal processing process for compensating for and converting the communication signal into a standard of a predetermined communication signal.

3 is a diagram illustrating an example in which a capacitive coupling unit serves as a high pass filter according to an exemplary embodiment.

Referring to FIG. 3 , a non-contact communication system according to an embodiment may include a capacitive coupling unit 300 having a plurality of couplers (AC Caps) based on a pair of conductive flat plates, the capacitive coupling unit 300 may operate as a high pass filter by further including a termination resistor (R _t ) disposed on each receiving line of a plurality of couplers (AC Cap).

Specifically, the capacitive coupling unit 300 is a digital signal in the form of a square wave when the value of the time constant composed of the resistance value of the capacitance and the termination resistor (R _t ) constituted by the flat plate pair of the coupler (AC Cap) is small. Loss of the DC component may occur, and thus a signal in a differential form may be transmitted through the receiving line.

Here, the criterion for determining whether the square wave is distorted is as shown in Equation 1 below.

[Equation 1]

That is, the time constant consisting of the product of the termination resistance and the capacitance can differentiate the signal and maintain the square wave when it is very small and large, respectively, than a certain multiple of the unit interval time, and the capacitance according to one embodiment The active coupling unit 300 is designed to maintain a high capacitance value and termination resistance value, so that square wave signal transmission performance can be improved.

More specifically, the capacitive coupling unit 300 configures a coupler (AC Cap) with a structure of a thin and wide conductor plate to maximize signal transmission performance, and a high termination resistance (R _t ) of 50 kΩ ≤ R _t ≤ 1 MΩ It can be configured with an impedance resistor to minimize loss in the process of transmitting a square wave signal and to maintain the existing signal level.

4A to 4B are diagrams illustrating implementation examples of a capacitive coupling unit according to an exemplary embodiment.

Referring to FIGS. 4A and 4B , reference numeral 410 shows a schematic diagram of a capacitive coupling unit according to an embodiment, and reference numeral 420 shows a sample image of an actually implemented capacitive coupling unit.

The capacitive coupling unit is disposed on a first coupler 411 disposed on a transmission/reception line corresponding to the first signal (Signal 1) and a transmission/reception line corresponding to the second signal (Signal 2), as shown by reference numerals 410 and 420. It may include a second coupler 412 and an input/output port 413 formed on adjacent surfaces of the first coupler 411 and the second coupler 412 .

For example, the first signal Signal 1 may be a signal transferred from the first transceiver to the second transceiver, and the second signal Signal 2 may be a signal transferred from the second transceiver to the first transceiver.

Specifically, when two types of signals ('High' signal and 'Low' signal) are applied to each plate pair of the capacitive coupling unit, an electric field is formed from the transmitting plate to the receiving plate as the potential difference increases, and the receiving plate As the electric field signal transmitted from is received, a voltage signal is induced, and through this, non-contact signal transmission can be implemented.

For example, when a 'High' signal is applied to the transmission plane of the first coupler 410 through the input/output port 413 of the capacitive coupling unit, an electric field is formed from the transmission plane of the first coupler 410 to the reception plane. The signal transmitted in the form of an electric field is induced in the form of a voltage to the first receiving plate 132, and the signal in the form of the induced voltage can be transmitted to the transceiver through the input/output port 413.

5 is a diagram illustrating an example of performing capacitance modeling on a capacitive coupling unit according to an exemplary embodiment.

Referring to FIG. 5 , a capacitive coupling unit 500 according to an embodiment includes a first coupler based on a first transmission plate 510 and a first reception plate 520, and a second transmission plate 530. and a second coupler based on the second receiving plate 540 .

According to one side, the capacitive coupling unit 500 is a first transmission plate 510, a first reception plate 520, a second transmission plate 530, and a second reception plate 540 of at least one plate. A width (w) and a length (l) of at least one flat plate between the first transmitting plate 131 and the first receiving plate 132 or between the second transmitting plate 133 and the second receiving plate 134 The size of at least one of the intervals d of is controlled so that the size of the main capacitance component is greater than or equal to a preset capacitance threshold and the size of the crosstalk capacitance component is less than or equal to the preset crosstalk capacitance threshold.

Specifically, the main capacitance component is a capacitance component (C ₃ ) between the first transmission plate 510 and the first reception plate 520 and a capacitance component between the second transmission plate 530 and the second reception plate 540. (C ₄ ) It may include at least one capacitance component.

In addition, the crosstalk capacitance component is a capacitance component between the first transmitting plate 510 and the second receiving plate 540 (C ₁ ), and a capacitance component between the first receiving plate 520 and the second transmitting plate 530 ( C ₂ ), a capacitance component between the first receiving plate 520 and the second receiving plate 540 (C ₅ ) and a capacitance component between the first transmitting plate 510 and the second transmitting plate 530 (C ₆ ) It may include at least one capacitance component.

For example, the size of the main capacitance component may be 1pF to 200pF, and the size of the crosstalk capacitance component may be 0.1% to 30% of the size of the main capacitance component.

In addition, the width (w) and length (l) of the plate may be 1 mm ≤ w, l ≤ 300 mm, and the interval (d) may be 0.1 mm ≤ d ≤ 10 mm.

Meanwhile, the thickness t of the flat plate may be 0 mm < t ≤ 5 mm, and the distance p between the center point of the transmission plate and the center point of the receiving plate may be 0 < t ≤ 50 mm.

Capacitance modeling of the capacitive coupling unit 500 may be performed based on Equation 2 below, and preferably, the size of the main capacitance component and the crosstalk capacitance component may be optimized through Equations 3 to 5 below.

[Equation 2]

Specifically, the size of the capacitance component (C ₃ ) between the first transmission plate 510 and the first reception plate 520 and the capacitance component (C 3 ) between the second transmission plate 530 and the second reception plate 540 The size of ₄ ) can be determined through Equation 3 below.

[Equation 3]

은 유전율, t는 평판의 두께, l은 평판의 길이, w는 평판의 폭, d는 제1 송신 평판(510)과 제1 수신 평판(520) 사이 또는 제2 송신 평판(530)과 제2 수신 평판(540) 사이의 간격을 의미한다.here,

is the dielectric constant, t is the thickness of the plate, l is the length of the plate, w is the width of the plate, and d is between the first transmission plate 510 and the first reception plate 520 or between the second transmission plate 530 and the second It refers to the spacing between the receiving plates 540.

In addition, the magnitude of the capacitance component (C ₁ ) between the first transmission plate 510 and the second reception plate 540 and the capacitance component (C 1 ) between the first reception plate 520 and the second transmission plate 530 ₂ ) can be determined through Equation 4 below.

[Equation 4]

Here, p denotes the distance between the center point of the transmission plane and the center point of the reception plane.

In addition, the size of the capacitance component (C ₅ ) of the first receiving plate 520 and the second receiving plate 540 and the capacitance component (C ₆ ) between the first transmission plate 510 and the second transmission plate 530 ) The size of can be determined through Equation 5 below.

[Formula 5]

6A and 6B are diagrams illustrating an example of applying a non-contact communication system according to an embodiment to a vehicle environment.

Referring to FIGS. 6A and 6B , the non-contact communication system according to an embodiment can be applied to a vehicle environment and used for high-speed serial communication.

Specifically, the non-contact communication system may be applied to CAN (Controller Area Network) communication, which is one of the most commonly used communications in vehicles, to configure non-contact connector circuits such as reference numerals 610 to 620.

For example, as shown in reference numerals 610 to 620, the non-contact communication system transmits the CAN-High signal of the CAN communicator to the coupler, separates it into a normal phase and an antiphase, transmits the signal to the receiving end, and transmits the signal in the opposite direction. Similarly, only the CAN-High signal of the communicator is transmitted to the coupler, and then separated into two phase signals and transmitted to the receiving side.

7 is a diagram illustrating an example of implementing a non-contact communication system with a half-duplex CAN communication circuit according to an embodiment.

Referring to FIG. 7 , a non-contact communication system 700 according to an embodiment may include a plurality of communication circuits provided between a first transceiver (Transceiver 1) and a second transceiver (Transceiver 2).

The plurality of communication circuits include transmit buffers 710-1 and 710-2 connected to the transmit and receive lines of the first transceiver (Transceiver 1) and the second transceiver (Transceiver 2), a capacitive coupler (720-1, 720-2), non-inverting amplifiers (730-1, 730-2), D-flip-flops (740-1, 740-2), DC control circuits (750-1, 750-2) and receive buffers (760- 1, 760-2), and may further include a resistor 120 between the transmission line and the reception line and having a predetermined size.

According to one side, the capacitive couplers 720-1 and 720-2 include a coupler based on a pair of conductive plates (C _eq ) and a termination resistor (R _term ) connected to a receiving plate of the coupler (C _eq ). It can act as a high pass filter.

Specifically, the non-contact communication system 700, when a signal is generated from either one of the first transceiver (Transceiver 1) and the second transceiver (Transceiver 2), transmit buffers (710-1, 710-2) and capacitor A square wave signal may be partially distorted and transmitted in a non-contact manner through the active couplers 720-1 and 720-2.

Next, the non-contact communication system 700 compensates the attenuation due to the filter using the non-inverting amplifiers 730-1 and 730-2, and then uses the D-flip-flops 740-1 and 740-2 to It can recover square wave signals in normal phase and out of phase.

Next, the non-contact communication system 700 adjusts the DC level using the DC control circuits 750-1 and 750-2 to construct a signal that meets the standards of CAN-High and CAN-Low, and then receives the signal. Non-contact communication may be completed by transmitting the restored signal through the buffers 760-1 and 760-2.

On the other hand, when the ground of the transmission line divided by the capacitive couplers 720-1 and 720-2 and the reception line are not connected, the non-contact communication system 700 has a long feedback circuit, so that resonance occurs in a specific frequency band. may occur or the signal quality may be greatly deteriorated.

Accordingly, the non-contact communication system 700 may form a return circuit of the shortest distance by connecting the grounds of both ends using the chassis ground of the vehicle.

According to one side, the non-contact communication system 700 may transmit signals in various forms by using a part of a vehicle frame or body as a flat plate of a coupler (C _eq ) used as a non-contact connector.

In addition, the space (air gap) between the pair of flat plates of the coupler (C _eq ) may be implemented in a structure that passes through glass or packing rubber inside the vehicle as well as air, and even in this case, intact signal transmission is possible.

8A to 8D are diagrams illustrating simulation results of a non-contact communication system according to an embodiment.

Referring to FIGS. 8A to 8D , reference numerals 810 to 840 denote waveforms of signals measured at nodes a ₁ , a ₂ , a ₃ , a ₄ , and b ₁ shown in the non-contact communication system of FIG. 7 .

In the non-contact communication system, a digital signal such as reference numeral 810 may be output from a transceiver, and the digital signal may be changed into a square wave signal having some loss, such as reference numeral 820, while passing through a capacitive coupler.

Specifically, the non-contact communication system can maintain the square wave signal level more stably by applying a high impedance resistor as the termination resistor, but the time constant becomes excessively large, which may cause delay in signal transmission, and some loss in the square wave signal. It may be difficult to use it for communication immediately after it is generated.

To solve this problem, a non-contact communication system may amplify a signal passing through a capacitive coupler and restore a waveform using a signal processing circuit.

Specifically, the non-contact communication system uses a D-flip-flop that receives a signal that has passed through a capacitive coupler and a non-inverting amplifier as an input and generates a square wave by outputting a voltage higher than the threshold voltage as a constant voltage as shown by reference numeral 830. At this time, the D-flip-flop can also generate an inverting output.

That is, in the non-contact communication system, two types of signals whose phases are inverted from each other appear as output, and by adjusting the DC level, the CAN communication signal can be completely restored as shown by reference numeral 840.

As a result, using the present invention, a digital signal can be transmitted in a non-contact manner using a simple structure and low-cost configurable capacitor coupler.

In addition, according to the present invention, electrical signals can be stably transmitted using a capacitive coupler serving as a high-pass filter using a pair of conductor plates and a termination resistor.

In addition, if the present invention is used, the size of the main capacitance component and the size of the leakage capacitance component are optimized through capacitance modeling, thereby maximizing the transmission efficiency of the electric signal.

In addition, if the present invention is used, by applying a capacitive coupler, it is possible to prevent a short circuit of a DC component that may occur from a power supply and to compensate for a common mode offset voltage, thereby configuring a circuit that meets various communication standards. and can have high scalability.

In addition, if the present invention is used, by configuring a high-speed serial transmission interface using a capacitive coupler, signal quality degradation caused by problems such as impedance mismatching or electrostatic phenomenon (ESD) and physical / chemical impact of the vehicle environment and Problems such as heat generation can be solved without using a complex and costly antenna structure.

As described above, although the embodiments have been described with limited drawings, those skilled in the art can make various modifications and variations from the above description. For example, the described techniques may be performed in a different order than the described method, and/or the described devices, structures, devices, circuits, etc., may be combined or combined in a different form than the described method, or other components Or even if it is replaced or substituted by equivalents, appropriate results can be achieved.

Therefore, other implementations, other embodiments, and equivalents of the claims are within the scope of the following claims.

100: non-contact communication system 110: first transceiver
120: second transceiver 130: capacitive coupling unit
131: first transmission plane 132: first reception plane
133: second transmission plane 134: second reception plane

Claims (14)

a first transceiver;
a capacitive coupling unit connected to the first transceiver; and
A second transceiver connected to the capacitive coupling unit
including,
The capacitive coupling part,
A first coupler based on a first transmission plate connected to a transmission line of the first transceiver and a first reception plate connected to a reception line of the second transceiver; and
A second coupler based on a second transmission plate connected to the transmission line of the second transceiver and a second reception plate connected to the reception line of the first transceiver
A non-contact communication system further comprising a. According to claim 1,
The capacitive coupling part,
When a voltage is applied to one of the first transmission plate and the second transmission plate, an electric field is formed in the direction of the corresponding one of the first reception plate and the second reception plate. Transmitting a signal in a non-contact manner based on the formed electric field
Contactless communication system. According to claim 1,
The capacitive coupling part,
Further including a termination resistor to act as a high pass filter
Contactless communication system. According to claim 3,
The capacitive coupling part,
A first termination resistor connected to the first receiving plate and a second termination resistor coupled to the second receiving plate
Contactless communication system. According to claim 1,
The capacitive coupling part,
a width of at least one of the first transmission plane, the first reception plane, the second transmission plane and the second reception plane, a length of the at least one plane, the first transmission plane and the first transmission plane The size of at least one of the distance between the receiving plates and the distance between the second transmitting plate and the second receiving plate is controlled so that the size of the main capacitance component is equal to or greater than a predetermined capacitance threshold and the size of the crosstalk capacitance component is below the set crosstalk capacitance threshold.
Contactless communication system. According to claim 5,
The main capacitance component includes at least one of a capacitance component between the first transmission plate and the first reception plate and a capacitance component between the second transmission plate and the second reception plate.
Contactless communication system. According to claim 5,
The crosstalk capacitance component is a capacitance component between the first transmission plane and the second reception plane, a capacitance component between the first transmission plane and the second transmission plane, and a capacitance component between the first transmission plane and the second transmission plane. A capacitance component and at least one capacitance component of the capacitance components of the first receiving plate and the second receiving plate
Contactless communication system. According to claim 5,
The size of the main capacitance component is 1pF to 200pF
Contactless communication system. According to claim 5,
The size of the crosstalk capacitance component is 0.1% to 30% of the size of the main capacitance component.
Contactless communication system. According to claim 5,
The width (w) of the at least one flat plate and the length (l) of the at least one flat plate are 1 mm ≤ w, l ≤ 300 mm
Contactless communication system. According to claim 5,
At least one distance (d) of the distance between the first receiving plates and the distance between the second transmitting plate and the second receiving plate is 0.1 mm ≤ d ≤ 10 mm.
Contactless communication system. According to claim 6,
The size of the capacitance component (C ₃ ) between the first transmission plate and the first reception plate and the size of the capacitance component (C ₄ ) between the second transmission plate and the second reception plate are determined through Equation 3 below. felled
[Equation 3]

here,

is the dielectric constant, t is the thickness of the at least one plate, l is the length of the at least one plate, w is the width of the at least one plate, and d is the distance between the first transmission plate and the first reception plate or the the interval between the second transmit plate and the second receive plate,
Contactless communication system. According to claim 7,
The size of the capacitance component (C ₁ ) between the first transmission plate and the second reception plate and the size of the capacitance component (C ₂ ) between the first reception plate and the second transmission plate are obtained through Equation 4 below. determined
[Equation 4]

Here, p is the distance between the center point of the first reception plane and the center point of the second transmission plane or the distance between the center point of the first transmission plane and the center point of the second reception plane,

person
Contactless communication system. According to claim 7,
The size of the capacitance component (C ₅ ) of the first reception plate and the second reception plate and the size of the capacitance component (C ₆ ) between the first transmission plate and the second transmission plate are determined by Equation 5 below:
[Formula 5]

here,

person,
Contactless communication system.

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