JP2003179526A - Non-contact communication system, and auxiliary device and method for non-contact communication - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To extend a communication range. <P>SOLUTION: A non-contact communication system comprises an R/W device 11 provided with an R/W antenna 22 resonating with a communication carrier frequency, a TAG device 12 provided with a TAG antenna 23 resonating with the communication carrier frequency, and an antenna sheet 61 operating as an antenna resonating with the communication carrier frequency. The R/W antenna 22 is electromagnetically coupled with a first coupling part 112 of the antenna sheet 61, and a second coupling part 113 is electromagnetically coupled with the TAG antenna 23 by a circulating magnetic field around a lead of the second coupling part 113 or the TAG antenna 23 produced by a line current flowing through the lead. The R/W device 11 and the TAG device 12 carry out non-contact communication with each other via the electromagnetically coupled R/W antenna 22, the antenna sheet 61, and the TAG antenna 23. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a non-contact communication system and a non-contact communication auxiliary device and method, and more particularly to a non-contact communication system and a non-contact communication auxiliary device capable of extending a communication distance. And about the method.

[0002]

2. Description of the Related Art ICs (Integr
A card system is a portable IC card and a so-called reader capable of reading out information stored in the IC card in a contactless manner and storing predetermined information in the IC card in a contactless manner. It is composed of a writer device (hereinafter referred to as R / W device).

That is, the IC card system is a highly convenient system capable of reading and writing information in a contactless manner, and in recent years, it is an alternative system to a conventional magnetic card system represented by a commuter pass or an authentication card, or physical distribution. It is used as a system.

Further, in a tape type storage device (for example, a video cassette tape) which cannot be randomly accessed,
Storing predetermined information in the IC memory in an index,
A contactless communication system is used in which predetermined information can be easily grasped in a contactless manner without access to a storage medium.

In such a non-contact communication system, it is practically essential that the transponder device (hereinafter referred to as a TAG device) such as an IC card is instantly operated in the magnetic field generated by the R / W device. Is.

Therefore, in practical application of the non-contact communication system, it is necessary to secure a distance (distance between the R / W device and the TAG device) at which the instantaneous operation is possible, that is, a practical communication distance. .

On the other hand, the usefulness of the non-contact communication technology has greatly expanded its application range, and various TAG devices have been devised. For example, a very small TAG device has been devised as compared with a normal card size TAG device.

[0008]

However, in the contactless communication system in which this ultra-small TAG device is used, the communication distance is limited to a very short distance, and it is difficult to secure a practical communication distance. There was a problem.

The present invention has been made in view of such a situation, and it is possible to extend the communication distance.

[0010]

A first contactless communication system of the present invention comprises a first contactless communication device having a first antenna that resonates at a communication carrier frequency, and a second contactless communication device that resonates at a communication carrier frequency. Of the second non-contact communication device, and a non-contact communication auxiliary device having a third antenna that resonates at the communication carrier frequency. The first and third antennas are electromagnetically coupled, and the second or The circulating magnetic field generated around the conductor by the line current flowing in the conductor of the third antenna electromagnetically couples the second and third antennas, and the first and second contactless communication devices are electromagnetically coupled first. And non-contact communication with each other via the third antenna and the third and second antennas.

The first to third antennas are loop antennas, and the loop area of the second antenna can be smaller than the loop areas of the first and third antennas.

The second antenna may be arranged close to the conducting wire of the third antenna.

The second antenna may be arranged on the loop surface of the third antenna.

The second antenna can be arranged so that the normal direction of the second antenna and the normal direction of the third antenna are perpendicular to each other.

The first value of the geometric coupling coefficient when the first and third antennas are electromagnetically coupled is adjusted by the first distance between the first and third antennas, and
The second value of the geometric coupling coefficient in the case where the second and third antennas are electromagnetically coupled is defined as the loop area ratio of the second and third antennas, and the second and third antennas shorter than the first distance. A second distance between the antennas can be adjusted to match the first and second values of the geometric coupling coefficient to a predetermined value.

The first non-contact communication device includes a generating means for generating a carrier signal having a communication carrier frequency, and a carrier signal transmitting means for superimposing and transmitting the first information on the carrier signal generated by the generating means. Further provision can be made.

The second non-contact communication device receives the carrier signal transmitted by the carrier signal transmitting means of the first non-contact communication device via the first to third antennas, and the receiving means. An electric power acquisition unit for acquiring electric power from the carrier signal received by, a first information acquisition unit for acquiring the first information superimposed on the carrier signal received by the reception unit, and a second information output unit The second information based on the second information output by the information output means and the second information output by the information output means.
And a modulation means for changing the receiving end impedance of the antenna.

The first non-contact communication device detects, via the first to third antennas, the amount of change in the receiving end impedance of the second antenna which is changed by the modulation means of the second non-contact communication device. And a second information acquisition unit that acquires the second information output by the output unit of the second non-contact communication device based on the change amount of the receiving end impedance of the second antenna detected by the detection unit. Information acquisition means may be further provided.

In the first contactless communication system of the present invention, the first antenna of the first contactless communication device that resonates at the communication carrier frequency and the third antenna of the contactless communication auxiliary device that resonates at the communication carrier frequency. Is electromagnetically coupled to the second antenna of the second non-contact communication device that resonates at the communication carrier frequency, or a line current flowing in the conductor of the third antenna is generated by a circulating magnetic field generated around the conductor. , Second
The third and third antennas are electromagnetically coupled, and the first and second non-contact communication devices are non-contacted with each other via the first and third antennas and the third and second antennas that are electromagnetically coupled. Be communicated.

A second non-contact communication system of the present invention includes a first non-contact communication device having a first antenna that resonates at a communication carrier frequency and a second non-contact communication device that has a second antenna resonating at a communication carrier frequency. The non-contact communication device of
Alternatively, the first magnetic field and the second magnetic field are electromagnetically coupled to each other by the circulating magnetic field generated by the line current flowing in the conductive line of the second antenna around the conductive line, and the first and second non-contact communication devices are It is characterized in that they perform non-contact communication with each other via the coupled first and second antennas.

The first and second antennas may be loop antennas having different loop areas.

The first and second antennas may be arranged so that the normal direction of the first antenna and the normal direction of the second antenna are perpendicular to each other.

In the second contactless communication system of the present invention, the first antenna of the first contactless communication device that resonates at the communication carrier frequency or the second contactless communication device that resonates at the communication carrier frequency. The first and second antennas are electromagnetically coupled by the circulating magnetic field generated around the conductor by the line current flowing in the conductor of the second antenna, and the electromagnetically coupled first
Also, the first and second non-contact communication devices are mutually contactlessly communicated via the second antenna.

The non-contact communication auxiliary device of the present invention includes a relay antenna that resonates at the communication carrier frequency, and the relay antenna is electromagnetically coupled to another first antenna that resonates at the communication carrier frequency, and at the same time, Due to the circulating magnetic field generated around the conductor, the line current flowing in the conductor or the conductor of the other second antenna that resonates at the communication carrier frequency
The information and power communicated between the first and second antennas are electromagnetically coupled to the first antenna to relay in a contactless manner.

The relay antenna has a capacitor that constitutes a resonance circuit that resonates at the communication carrier frequency, and an antenna coil that acts as an inductance. The antenna coil has a first coupling portion that electromagnetically couples with the first antenna.
A second antenna and a second coupling portion which is electromagnetically joined can be provided.

A sheet-shaped base material may be further provided, and the antenna coil and the capacitor may be formed in a pattern on the surface of the base material.

The first and second coupling portions may be configured as the same antenna coil pattern.

The surface of the substrate comprises a first surface and a second surface which is not parallel to the first surface, and the antenna coil pattern is circulated over the first and second surfaces. You can

The normal direction of the first surface and the normal direction of the second surface may be perpendicular to each other.

The second antenna is arranged on the first or second surface and is arranged close to the pattern of the antenna coil formed on the arranged first or second surface. You can

In the non-contact communication assisting method of the present invention, the relay antenna resonating at the communication carrier frequency is electromagnetically coupled to the other first antenna resonating at the communication carrier frequency, and the conductor of the relay antenna or the communication carrier frequency is used. The circulating magnetic field generated around the conductor by the line current flowing in the conductor of the other second antenna that resonates with each other causes the relay antenna and the second antenna to be electromagnetically coupled to each other, and the first and second antennas are electromagnetically coupled to each other. It is characterized in that information and electric power communicated between the first and second antennas are relayed in a non-contact manner by the relay antenna which is formed.

In the non-contact communication auxiliary device and method of the present invention, a relay antenna resonating at the communication carrier frequency,
While being electromagnetically coupled to the other first antenna that resonates at the communication carrier frequency, a line current that flows through the conductor of the relay antenna or the conductor of the other second antenna that resonates at the communication carrier frequency is generated around the conductor. The circulating magnetic field electromagnetically couples the relay antenna and the second antenna, and the relay antennas electromagnetically coupled to the first and second antennas respectively transmit and receive information and power to be communicated between the first and second antennas. It is relayed without contact.

[0033]

1 shows an example of the configuration of a non-contact communication basic system 1 to which the present invention is applied.

As shown in FIG. 1, the non-contact communication basic system 1 includes an R / W device 11 including an R / W main device 21 and an R / W antenna 22, a TAG antenna 23, and an LS (Load Swi).
tching) modulation circuit 24 and TAG main unit 25
The AG device 25 is a system that performs non-contact communication with each other.

Although not shown, the R / W main unit 21 includes a microcomputer for controlling communication, an encoding circuit for encoding Manchester code, a decoding circuit for decoding Manchester code, and a predetermined communication. Carrier wave generation circuit that generates a carrier wave (carrier signal) at the carrier frequency, ASK (Amplitude Shi
ft Keying) modulation circuit, ASK demodulation circuit, and power amplification circuit. As the R / W main unit 21,
Conventional R / W masters can be used. Therefore, R
Since the structure and operation of the components of the / W main unit 21 can be easily understood by those skilled in the art, detailed description thereof is omitted.

The R / W antenna 22 includes a resistor Ra, a coil La,
And a resonance circuit composed of a capacitor Ca. That is, the R / W antenna 22 operates as a loop antenna with its coil La portion and also as an LCR resonance circuit that resonates at a predetermined communication carrier frequency.

Similar to the R / W antenna 22, the TAG antenna 23 has a resonance circuit composed of a resistor Rb, a coil Lb, and a capacitor Cb. That is, the TAG antenna 23
Of the coil Lb operates as a loop antenna for electromagnetically coupling with the R / W antenna 22 through the mutual inductance M and resonates at a predetermined communication carrier frequency.
It also operates as an LCRC resonance circuit.

The TAG main unit 25 has an IC (not shown).
Power supply generation circuit, clock extraction circuit, logic circuit, A
An SK demodulation circuit, a memory for storing data, and the like are provided. As the TAG main unit 25, the conventional T
AG master devices can be used. Therefore, the configuration and operation of the components of the TAG main unit 25 can be easily understood by those skilled in the art, and detailed description thereof will be omitted.

The LS modulation circuit 25 includes a load resistor Rc and a MOS (M
(etal oxide semiconductor) switch 38 is a circuit connected in series.

Next, the operation of the non-contact communication basic system 1 will be described.

When the TAG antenna 23 of the TAG device 12 is arranged to face the R / W antenna 22 of the R / W device 11 at a predetermined distance (communication distance), the TAG antenna 23 and the R / W antenna 22 Are electromagnetically coupled by the mutual inductance M by the magnetic field generated in the normal direction of the R / W antenna 22, and resonate with the communication carrier frequency of the communication carrier signal output from the R / W main unit 21. As a result, the R / W device 11 and the TAG device 12 can perform non-contact communication with each other via the R / W antenna 22 and the TAG antenna 23.

The data transmitted from the R / W main unit 21 (hereinafter referred to as the first information) is encoded and ASK-modulated in the R / W main unit 21, and the ASK modulated signal ( A communication carrier signal on which the first information is superimposed) is supplied to the TAG main unit 25 via the electromagnetically coupled R / W antenna 22 and TAG antenna 23, and the LS modulation circuit 24.

In the TAG main unit 25, the supplied ASK modulated signal is demodulated and decoded to become the original first information, and if this first information is the data stored in the memory, 1 information is stored in memory, while
When the first information is the information read instruction data, predetermined information is read from the memory based on the first information.

The DC component signal removed when the ASK modulated signal is demodulated serves as a power source for an IC (not shown) or the like.

These responses or the data read from the memory (hereinafter referred to as the second information) are supplied from the TAG device 12 to the R / W device 11 as follows.

That is, in the LS modulation circuit 24, the switch 38 is switched according to the second information (data of 0 or 1), and the TAG device 12 viewed from the R / W antenna 22.
The equivalent load of the antenna (1) (the load of the circuit including the TAG antenna 23 and the LS modulation circuit 24 (resistor Rc)) is changed.

In the R / W device 11, this load fluctuation appears as a load fluctuation of the R / W antenna 22 due to non-contact electromagnetic coupling between the R / W antenna 22 and the TAG antenna 23. Therefore, the R / W main device 21
Amplitude fluctuation component of communication carrier signal, that is, ASK modulation signal (second
(2) is acquired as the communication carrier signal on which the information of (1) is superimposed, and is demodulated and decoded to obtain the second information.

Thus, the non-contact communication basic system 1
Is a system for performing non-contact communication using electromagnetic coupling, and the strength of this electromagnetic coupling is based on the non-contact communication basic system 1
It is closely related to the communication distance.

Therefore, the applicant of the present invention has the R / W as described above.
The aspect of electromagnetic coupling between the antenna 22 and the TAG antenna 23 was analyzed as so-called double tuning. The analysis result will be described below.

That is, for the electromagnetic coupling between these antennas, the loss Q (Quality Factor) of each antenna circuit is used.
There is a critical coupling coefficient (hereinafter referred to as critical coupling coefficient k0) that is physically determined by r), which is exactly determined by geometric factors such as antenna shape and distance (hereinafter geometrical coefficient). The present applicant analyzed the aspect of the electromagnetic coupling between the R / W antenna 22 and the TAG antenna 23 by utilizing the fact that the maximum transfer gain is obtained at the time when it coincides with the geometrical coupling coefficient k). .

Specifically, the critical coupling coefficient k0 is a coefficient representing the electric characteristic of the antenna, which is obtained by the Q value of each antenna circuit as shown in the following equation (1).

[0052]

[Equation 1]

However, Q1 represents the Q value of the R / W antenna 22, and Q2 represents the Q value of the TAG antenna 23.

On the other hand, the geometric coupling coefficient k is a coefficient corresponding to the geometrical arrangement of both antennas, as described above.

When all the magnetic fluxes generated from one antenna cross the other antenna, that is, when two antennas of the same size are abutted against each other, the geometric coupling coefficient k of The value takes a maximum value of 1, and when two antennas are aligned in the middle on one axis as shown in FIG. 2A (when the respective geometric centers of the two antennas are aligned). ), The value of the geometric coupling coefficient k is estimated as shown in the following equation (2).

[0056]

[Equation 2]

However, as shown in FIG. 2A, r1 is
Set the diameter of the R / W antenna 22 (loop diameter of the coil La) to r2
Is the diameter of the TAG antenna 23 (loop diameter of the coil Lb),
x represents the distance between the R / W antenna 22 and the TAG antenna 23, respectively. That is, k (x) represents the geometric coupling coefficient k at the distance x between the R / W antenna 22 and the TAG antenna 23.

The correspondence between the distance x between the R / W antenna 22 and the TAG antenna 23 and the geometric coupling coefficient k (x) calculated by this equation (2) is shown in FIG. 2B. There is.

However, the curve (antenna diameter 3.6 mm) 41
The diameters of the R / W antenna 22 and the TAG antenna 23 are
The geometrical coupling coefficient k (x) is represented when 3.6 mm (when the diameters of both antennas are small).

The curve (antenna diameter 10 mm) 42 represents the geometric coupling coefficient k (x) when the diameters of the R / W antenna 22 and the TAG antenna 23 are 10 mm (when the diameters of both antennas are large). It represents.

Curve (combination of antenna diameter 3.6mm and 10mm)
43 is a geometrical shape when one of the R / W antenna 22 and the TAG antenna 23 has a diameter of 3.6 mm and the other has a diameter of 10 mm (when a large diameter and a small diameter are combined). It represents the coupling coefficient k (x).

Now, since the Q value of the resonant antennas such as the R / W antenna 22 and the TAG antenna 23 is generally high, as a result, as shown in equation (1), the critical coupling coefficient k0 The value of is small. Therefore, in the non-contact communication basic system 1, a small value can be applied as the value of the geometric coupling coefficient k that provides the optimum communication state. For example, when the Q values of the R / W antenna 22 and the TAG antenna 23 are 10 respectively, the critical coupling coefficient k0
Is 0.1, and the non-contact communication basic system 1 is in the optimum communication state when the value of the geometric coupling coefficient k is 0.1.

As described above, when the non-contact communication basic system 1 is used (when the system in which the resonance system is configured is used), as compared with the case where the system in which the resonance system is not configured is used. As a result, the value of the critical coupling coefficient k0 becomes small, and as a result, the value of the geometric coupling coefficient k that provides the optimum communication state can also be small.

The relationship between the geometric coupling coefficient k (x) and the distance x between two antennas is a curve (antenna diameter).
Combination of 3.6mm and 10mm) 43 and curve (antenna diameter 3.6mm)
There is not much difference with 41. That is, even if only one (one) of the antennas is made large, the communication distance (distance between two antennas) x at which the value of the geometric coupling coefficient k that provides the optimum communication state is obtained is not extended so much.

On the other hand, when the value of the geometric coupling coefficient k that provides the optimum communication state is large (for example, the curve 43 and the curve 41).
In comparison with the case where the geometric coupling coefficient k is 0.15 or more), if only one antenna is enlarged, the geometric coupling coefficient k that provides the optimum communication state can be obtained.
Becomes rather shorter.

Thus (as shown in FIG. 2B),
In the contactless communication system 1 in which the ultra-small TAG device 12 is used, that is, when the TAG antenna 23 is smaller than usual, a value of the geometric coupling coefficient k sufficient for communication can be obtained. / W device 11 and microminiature TAG device 12 are placed closer than usual (R / W antenna 22 and TAG
The distance x to the antenna 23 needs to be shortened).

Therefore, the applicant has adopted, for example, an antenna sheet 61 as shown in FIG. 3 as a relay antenna (antenna whose purpose is to extend the communication range).

That is, the antenna sheet 61 is, for example,
Sheet-shaped substrate 7 with antenna coil Lc and capacitor Cc
1 is formed as a pattern.

The type of the capacitor Cc is not limited as long as it is thin. For example, a chip component or the like may be used.

In the antenna sheet 61, the portion of the antenna coil Lc operates as a loop antenna, and
As shown in FIG. 3B, it also operates as a closed circuit composed of an antenna coil Lc and a capacitor Cc, that is, an LC resonance circuit that resonates at a predetermined communication carrier frequency.

In this example, the size of the antenna sheet 61 (loop diameter of the coil Lc (loop area))
Is approximately equal to the size of the R / W antenna 22 (loop diameter (loop area) of the coil La).

Further, in this example, the antenna sheet 61 is formed as a sheet, but if it is a structure that can perform the above-described two operations (operation as a loop antenna and operation as an LC resonance circuit). The configuration is not limited.

By the way, if the sizes of the TAG antenna 23 and the R / W antenna 22 (loop diameters (loop areas) of the respective coils Lb and La) are substantially equal, that is, the sizes of the antenna sheet 61 and the TAG antenna 23 are large. If (the loop diameters (loop areas) of the respective coils Lc and Lb) are substantially equal to each other, the antenna sheet 61 can theoretically be arranged as shown in FIG.

That is, the antenna sheet 61, the TAG antenna 23, and the R / W antenna 22 (each coil Lc, L
b and the loop plane of La are parallel, and the geometric center of each antenna (each coil)
The antenna sheet 61 is disposed between the TAG antenna 23 and the R / W antenna 22 so that the respective normals from the loops of Lc, Lb, and La) are aligned with each other. Can theoretically function as a relay antenna.

However, in the non-contact communication basic system 1 in which the microminiature TAG device 12 is used, as described above, the sizes of the TAG antenna 23 and the R / W antenna 22 (the loop diameters of the coils Lb and La, respectively) are set. (Loop area) is very different.

Therefore, when the antenna sheet 61 is applied to the non-contact communication basic system 1 in which the microminiature TAG device 12 is used, the antenna sheet 61 and the TAG antenna 23 are used.
And the size (loop diameter (loop area) of each coil Lc and Lb) are very different, and as shown in the curve (combination of antenna diameter 3.6 mm and 10 mm) 43 of FIG. Is arranged as shown in FIG. 4, a sufficient value of the geometric coupling coefficient k cannot be obtained.

That is, when the antenna sheet 61 is arranged as shown in FIG. 4 for the contactless communication system 1 in which the microminiature TAG device 12 is used, the antenna sheet 61 functions as a relay antenna. Can not be fully exerted.

The arrangement as shown in FIG. 4 actually means that the antenna sheet 61 is arranged in the space between the R / W antenna 22 and the TAG antenna 23. That is, even if the arrangement shown in FIG. 4 is considered to be a practical arrangement, the manufacturer or the like attaches the antenna sheet 61 to the arrangement shown in FIG.
It is difficult to actually arrange as shown in.

Therefore, the present applicant has proposed that the geometric coupling coefficient k
From the viewpoint of matching with the critical coupling coefficient k0,
The arrangement position of the antenna sheet 61 when the sizes of the TAG antenna 23 and the antenna sheet 61 are very different was analyzed, and the appropriate arrangement position of the antenna sheet 61 was clarified. Hereinafter, the analysis result, that is, an appropriate arrangement position of the antenna sheet 61 will be described.

As a precondition, as described above,
The R / W antenna 22 is considered to be much larger than the TAG antenna 23, and the antenna sheet 61 includes the R / W antenna 2
For the purpose of obtaining a sufficient value of the geometrical coupling coefficient k for 2, the antenna has a size comparable to that of the R / W antenna 22.

The R / W antenna 22 and the TAG antenna 23
Since there is a dual relationship with R / W antenna 22 and TAG
The following discussion holds even if the antenna 23 is replaced.

When the TAG antenna 23 and the antenna sheet 61 whose sizes are very different from each other are used, the critical coupling coefficient k0 becomes a large value if the system is a non-resonant system. The value of coupling coefficient k cannot be obtained.

Therefore, so that the system becomes a resonance system,
Here, it is assumed that the TAG antenna 23 and the antenna sheet 61 are arranged as shown in FIG. 5A.

That is, the positions where the central axes (geometrical centers) of the antenna sheet 61 and the TAG antenna 23 are aligned with each other (the center of the TAG antenna 23 is
When the position (positioned at (0, 0, 0)) is used as a reference, the TAG antenna 23 is arranged shifted by x1 in the x-axis direction or z1 in the z-axis direction (TAG antenna 2
The center of 3 is the coordinates (x1,0,0) or (0,0,
z1) will be placed).

FIG. 5B shows the antenna sheet 61 in this way.
And the TAG antenna 23 are arranged, the geometrical coupling coefficient k between the antenna sheet 61 and the TAG antenna 23
Represents the appearance of.

In FIG. 5B, the curve (x shift) 81
Is the geometric coupling coefficient k (x1) between the antenna sheet 61 and the TAG antenna 23 when the TAG antenna 23 is shifted by x1 in the x-axis direction (x1 is 0 to 30 m).
m), while the curve (z shift) 82 is TAG
The antenna sheet 61 and the TAG antenna 2 when the antenna 23 is arranged shifted by z1 in the z-axis direction
Geometrical coupling coefficient k (z1) with 3 (z1 is 0 to 30 mm)
Is represented.

As shown by the curve (z shift) 82,
When the TAG antenna 23 is arranged shifted in the z-axis direction, or as shown by the curve (x shift) 81,
When the TAG antenna 23 is arranged without being significantly shifted in the x-axis direction (when the TAG antenna 23 is arranged near the geometric center of the antenna sheet), a sufficient value of the geometric coupling coefficient k is obtained. Absent.

On the other hand, as shown in point 81-1, TAG
When the antenna 23 is arranged with a shift of about 17 mm in the x-axis direction, that is, when it is arranged on the same plane of the antenna sheet 61 and in the vicinity of the conducting wire of the antenna sheet 61,
Value of relatively large geometric coupling coefficient k (k (17) = 0.08)
Is obtained.

When arranged in this way, the TAG antenna 2
3 can be more strongly affected by the loop magnetic field generated around the conducting wire of the antenna sheet 61. In other words, if the TAG antenna 23 is arranged so that the plane of the TAG antenna 23 (the loop surface of the coil Lb of the TAG antenna 23) crosses more the magnetic flux loop generated by the line current flowing in the conducting wire of the antenna sheet 61. , The electromagnetic coupling becomes stronger.

Specifically, as shown in FIG. 6A, the antenna sheet 61 (antenna coil Lc) receives the magnetic field Hr from the R / W antenna 22, a voltage is induced, and an induced current ir is generated. This induced current ir is the antenna sheet 6
A loop magnetic field Ha is created around the conductor 1.

Therefore, in FIG. 5, the TAG antenna 2
Although only the analysis in the case where 3 and the antenna sheet 61 are on the same plane was performed, as described above, if the loop magnetic field Ha around the conducting wire of the antenna coil Lc of the antenna sheet 61 is available, The arrangement position of the TAG antenna 23 is not limited. That is, the TAG antenna 23 and the antenna sheet 61 do not have to be arranged on the same plane.

For example, as shown in FIG. 6B, the TAG antenna 23 is in contact with any one side of the rectangular antenna pattern (antenna coil Lc) of the antenna sheet 61 and is generated around that side. The loop magnetic field Ha is preferably installed so as to be greatly affected. In this case, the value of the geometric coupling coefficient k between the antenna sheet 61 and the TAG antenna 23 is maximized.

In addition, as shown in FIG. 6C, the magnetic field Ht from the TAG antenna 23 is efficiently transmitted to the antenna sheet 61 as shown in FIG. 6C. To be done.

As described above, ((curve (x
Shift) 81), the TAG antenna 23 and the antenna sheet 61 are arranged as shown in FIG. 6B (for example, the center of the TAG antenna 23 is the coordinate (1
(7, 0, 0)) and the value of the geometrical coupling coefficient k reaches its maximum value (k as shown at point 81-1).
(17) = 0.08), the value of the geometric coupling coefficient k is far less than 1, but it is relatively small because the TAG antenna 23 and the antenna sheet 61 have a resonance system. A sufficient induced voltage can be obtained even in the coupling coefficient.

On the other hand, when the TAG antenna 23 is arranged at the geometric center of the antenna sheet 61 (when the center of the TAG antenna 23 is arranged at (0,0,0)), the conductor wire of the antenna sheet 61 is formed. The influence of the loop magnetic field Ha generated in the surroundings on the TAG antenna 23 and the influence of the magnetic field Ht from the TAG antenna 23 on the antenna sheet 61 become very small, and as a result, the geometric coupling coefficient is increased.
The value of k is rather small (k (0) = about 0.015).

This is characteristic when the TAG antenna 23 and the antenna sheet 61 are very different in size.

By the way, the contactless communication technology has a very wide range of applications, and various application technologies have been proposed. As described above, in the contactless communication system once designed, the R / W antenna 22, Alternatively, the communication distance of the system is defined when the specifications of the TAG antenna 23 are determined.

That is, in the contactless communication system in which the TAG antenna 23 is designed small, no matter how large the R / W antenna 22 is designed thereafter, the curve (combination of antenna diameters 3.6 mm and 10 mm) 43 in FIG. As shown in (1), the communication distance becomes extremely short commensurate with the TAG antenna 23 as long as the TAG antenna 23 is small. The reverse is also the same, and as shown by a curve (antenna diameter 3.6 mm) 41 and a curve (antenna diameter 10 mm) 42 in FIG. 2B, both antennas are upsized in order to increase the communication distance. There is a need.

However, although the R / W device 11 has a degree of freedom in designing the device and can have a large antenna, the TAG device 12 such as a standardized cassette is used.
Has a small degree of freedom in designing equipment, and it is difficult to have a large antenna.

Therefore, as described above, the antenna sheet 61 utilizing the resonance phenomenon is used in the non-contact communication basic system 1, and it is properly used.
By being arranged in the vicinity of 3, the R / W antenna 21
And the TAG antenna 23 can communicate with each other at a sufficient communication distance via the antenna sheet 61.

Further, by disposing the antenna sheet 61 near the TAG antenna 23, the TAG antenna 2
3 and the antenna sheet 61 can be handled together.

However, in order for the antenna sheet 61 to be effectively used as a relay antenna, the antenna sheet 6 must be used.
The value of the geometric coupling coefficient k between 1 and the R / W antenna 22 and the value of the geometric coupling coefficient k between the antenna sheet 61 and the TAG antenna 23 need to be appropriately adjusted.

In this example, the values of these two geometric coupling coefficients k shall be matched to the values of the critical coupling coefficient k0, respectively. FIG. 7 shows how the critical coupling coefficient k and the geometric coupling coefficient k0 are matched by the antenna sheet 61.

Note that FIG. 7B corresponds to FIG. 5B described above, while FIG. 7C corresponds to FIG. 2B described above.

As shown by the curve k (z) 102 in FIG. 7C, at the long distance z1 between the R / W antenna 22 and the antenna sheet 61, with respect to the value of the critical coupling coefficient k0 lowered by the effect of resonance. The geometric coupling coefficient k (z) is matched, while the antenna sheet 61 and the TAG antenna 23 take advantage of very different antenna diameter sizes, as shown by the curve k (x) 101 in FIG. 7B. Then, in the vicinity of the conducting wire of the antenna sheet 61, the geometric coupling coefficient k
(x) is matched.

By the way, when the antenna sheet 61 and the TAG antenna 23 are about the same size, when the antenna sheet 61 and the TAG antenna 23 are arranged in the vicinity of each other, they are in a tightly coupled state and the resonance frequency is The phenomenon occurs that the frequency deviates from the communication carrier frequency and sufficient resonance cannot be obtained at the communication carrier frequency. That is, regarding matching in the vicinity of the antenna sheet 61 and the TAG antenna 23, the difference in size between the two is very effective.

The respective antennas thus matched are actually arranged, for example, as shown in FIG. 7A.

That is, when the antenna sheet 61 is used as a reference, the distance between the center of the R / W antenna 22 and the center of the antenna sheet 61 is z1 and the surface (loop surface of the coil La) and the antenna are Surface of seat 61 (coil Lc
Are arranged in parallel with each other (the R / W antenna 22 and the antenna sheet 61 are arranged to face each other with a distance z1).

Further, in the TAG antenna 23, the distance from the center of the antenna sheet 61 is x1, that is, the antenna sheet 6
The antenna pattern (coil Lc) is arranged near one side of the antenna pattern (coil Lc), and is arranged so as to be greatly affected by the loop magnetic field around one side (conductor) of the antenna pattern.

Specifically, as shown in FIG. 8A, for example, the TAG device 12 includes a side 61 a of the antenna sheet 61.
Can be arranged on the same plane so as to contact with.

As described above, the non-contact communication system 111 in which the antenna sheet 61 is added to the non-contact communication basic system 1 of FIG. 1 is configured as shown in FIG. 8B. In addition, in FIG. 8B, the non-contact communication basic system 1 of FIG.
Corresponding reference numerals are given to the portions corresponding to.

In this configuration example, as described above,
The antenna sheet 61, which is a relay antenna, is used in the R / W device 1.
1 R / W antenna 22 and TAG antenna 23 of TAG device 12
It is located between and.

The antenna sheet 61 is, as described above,
It is formed as a closed circuit including a coil Lc and a capacitor Cc. That is, the antenna sheet 61 is the coil
The first coupling part 112 of Lc operates as a loop antenna for electromagnetically coupling with the R / W antenna 22 by the mutual inductance M, and the second coupling part 11 of the coil Lc thereof.
3 operates as an antenna for electromagnetically coupling with the TAG antenna 23 with a mutual inductance M, and also operates as an LC resonance circuit that resonates at a predetermined communication carrier frequency.

The first coupling portion 112 corresponds to the entire loop of the antenna pattern (coil Lc) of the antenna sheet 61 in FIG. 8A, while the second coupling portion 113 mainly corresponds to the antenna pattern of the antenna sheet 61. One side 61a
Equivalent to. That is, as described above, the second coupling portion 11
By the loop magnetic field generated by the line current flowing in the conductor of 3,
The second coupling unit 113 and the TAG antenna 23 (coil Lb) are electromagnetically coupled.

The other structure is similar to that of FIG.

The operation of the antenna sheet 61 is as described above, and the operation of the contactless communication system 111 is as follows.
Since the operation is basically the same as that of the non-contact communication basic system 1 of FIG. 1, the description thereof will be omitted.

The antenna sheet 61 and the TAG antenna 12 have the above-described condition, that is, the current flowing through the conductor wire of any side of the antenna pattern (coil Lc) of the antenna sheet 61 or the conductor wire of the coil Lb of the TAG antenna 12. Due to the circulating magnetic field generated around these conducting wires, the antenna sheet 61 and the TAG antenna 12 have a mutual inductance M.
If the condition of electromagnetically coupling is satisfied, it can be freely arranged.

For example, the antenna sheet 61 and the TAG antenna 12 can be arranged as shown in FIG.

FIG. 9A shows an example in which the TAG device 12 and the antenna sheet 61-1 are arranged on independent planes. However, the second connecting portion 113 in FIG. 8B mainly corresponds to the side 61-1a of the antenna pattern (coil Lc).

In FIG. 9B, the substrate (sheet) 71 of the antenna sheet 61-2 has an L-shaped plane, that is, a plane 61-2a parallel to the xy plane and a plane 61-2 parallel to the xz plane. 2b
In this example, the sheet is formed of a flat sheet. The TAG device 12 is arranged, for example, on the surface 61-2b and in contact with the side 61-2c of the antenna pattern (coil Lc). That is, the second connecting portion 113 of FIG. 8B.
Is mainly the side 61-2c of the antenna pattern (coil Lc)
Equivalent to.

Similar to FIG. 9B, FIG. 9C shows that the substrate (sheet) 71 of the antenna sheet 61-3 has an L-shaped plane, that is, a plane 61-3a and an xz plane parallel to the xy plane. It is an example formed by a flat sheet composed of a surface 61-3b parallel to. However, the surface 61-3b is shown in FIG.
Smaller than the surface 61-2b of B, for example, the TAG device 12
The size is so small that it can fit in. That is, the TAG device 12 is arranged, for example, on the surface 61-3b so as to be in contact with the three sides of the side 61-3c, the side 61-3d, and the side 61-3e of the antenna pattern (coil Lc). That is, the second connection portion 113 of FIG. 8B mainly corresponds to the sides 61-3c, 61-3d, and 61-3e of the antenna pattern (coil Lc).

As described above, the antenna sheet 61 and the TAG antenna 12 can be arranged in various shapes in consideration of the mounting place and size, the manufacturing process, and the like, and are very close to each other. Since they can be arranged, the antenna sheet 61 and the TAG device 12 can be operated as the same device as needed.

In other words, the antenna sheet 61 and the TAG antenna 23 can be regarded as an integrated antenna. That is, if the antenna sheet 61 is used, the expansion of the communication range can be easily achieved without changing the TAG antenna 23.

However, as described above, the size difference between the antenna sheet 61 and the TAG antenna 23 needs to be very different. Because the antenna sheet 61 and the TAG
When the size of the antenna 23 is almost equal to that of the antenna 23, the antenna sheet 61 and the TAG antenna 23 need to be spaced apart from each other in order to match the geometrical coupling coefficient k with the low critical coupling coefficient k0. This is because it is difficult to say that the expansion of the communication range was easily achieved in practical use.

In particular, the arrangement method as shown in FIG. 9A, that is, the normal direction of the antenna sheet 61-1 and the TAG
The arrangement method of arranging the TAG antenna 23 of the device 12 so as to be perpendicular to the normal direction is not applicable to the conventional communication system in which two antennas face each other and communicate, and It became possible only when the method using the loop magnetic field was adopted. This arranging method is sufficiently effective even in the following application examples.

That is, FIG. 10 shows a configuration example of a video cassette system to which the contactless communication system 111 of FIG. 8 is applied.

Currently, a small TA as shown in FIG. 10A
Video cassette 121 with G device 12 embedded and R / W
A video cassette system including a video cassette player 122 to which an antenna 22 is attached has been commercialized.

In this system, when the video cassette 121 is mounted in the video cassette player 122, the TAG device 1 embedded in the video cassette 121 is used.
2 (TAG antenna 23) and the R / W antenna 22 attached to the video deck face each other at a short distance, and non-contact communication is performed in the video cassette player 122.

The TAG antenna 23 is manufactured in a very small size in conformity with the shape of the video deck cassette 121, and is mainly used for a short distance (video de-cassette player 122).
It is an antenna intended for communication.

Regarding such a video cassette 121 as well, the communication distance can be easily changed only by adding the antenna sheet 61 as shown in FIG. 10B without changing the TAG device 12 of the main body of the video cassette 121. Can be changed.

That is, as shown in FIG. 10B, when the sheet-shaped antenna sheet 61 is housed in the video cassette case 122 together with the video cassette 121, the antenna sheet 61 and the TAG antenna 23 are optimal. Since they are arranged in a positional relationship, the communication distance of the TAG antenna 23 is apparently extended as a result.

In other words, the size of the TAG antenna 23 is apparently expanded to the size of the antenna sheet 61, and the R / W device (R / W mounted on the video cassette player 122) corresponding thereto is used. R different from W device 11
/ W device) is used to enable communication over a long distance.

Thus, in the non-contact communication basic system 1 originally intended for short-distance communication, only the antenna sheet 61 is added, and the communication distance is extended without changing the main body of the TAG device 12. Can be done.
For example, the user can perform non-contact communication simply by inserting the video cassette case 122 into the video cassette 121 together with the antenna sheet 61 and holding it over another R / W device.

Further, the antenna sheet 61 is, for example, as shown in FIG.
In the case of the shape like A, the antenna sheet 61 is formed into a single sheet shape as described above (as shown in FIG. 10B), or in the case of the shape like FIG. It can be formed in an index sheet shape (L-shape).

As described above, the size of the antenna sheet 61 is changed according to the corresponding R / W antenna 22, so that the determining factor of the communication distance is the R / W antenna 22 and the TAG.
R / W antenna 22 instead of antenna 23 combination
And the antenna sheet 61. This means that the antenna of the TAG device 12 is regarded as the antenna sheet 61 from the R / W antenna 22.

That is, the antenna sheet 61 is a small TAG.
When properly installed near the antenna 23, the TA
The same effect as when the G antenna 23 is changed can be obtained. Therefore, the manufacturer or the like can design a new R / W antenna regardless of the size of the TAG antenna 23 and extend the communication distance of the TAG device 12.

Further, since the antenna sheet 61 is used in contact with the TAG antenna 23, both can be handled as one body, which is very convenient in actual use.

Furthermore, the antenna sheet 61 can be realized with a very simple structure including only two elements, that is, the antenna pattern (coil Lc) and the capacitor Cc having a small capacity for adjusting resonance, The antenna device can be manufactured at a low cost and has a relatively high degree of freedom in arrangement.

Therefore, in the non-contact communication system 111 to which the antenna sheet 61 is applied, the TAG antenna 23 is unavoidably designed to be small for space reasons, but it is required to extend the communication distance of the TAG device 12 depending on the application. This is a particularly effective system in cases such as when

Further, the non-contact communication system 111 can make one TAG antenna 23 correspond to a plurality of R / W antennas other than the R / W antenna 22. That is, the manufacturer can design a plurality of R / W antennas according to the communication distance suitable for the arrangement space and the application, and as a result, in addition to the video cassette system as described above, various contactless communication can be performed. It is possible to manufacture a system or device in which the technology is used.

As described above, the non-contact communication system 111
Is characterized by using a loop magnetic field around the antenna conductor, which is clearly different from the conventional non-contact communication system using a magnetic field generated in the normal direction of the antenna pattern plane (coil loop plane). Is.

By the way, the method of utilizing the loop magnetic field around the conducting wire of the antenna is similarly applied when the antenna sheet 61 is not used and the sizes of the two antennas are very different. You can

That is, in the non-contact communication basic system 1 of FIG. 1, if the R / W antenna 22 is much larger than the TAG antenna 23, as shown in FIG.
When the G antenna 23 is arranged near the center position 131 of the antenna sheet 61 so that the normal direction of the G antenna 23 and the normal direction of the R / W antenna 22 are aligned, the R / W device 11 is
It becomes difficult to read information from the AG device 12.

On the other hand, when the TAG antenna 23 is arranged near the edge position 132 where the loop magnetic field generated around the conducting wire of the R / W antenna 22 is received, that is, when the TAG antenna 23 is arranged,
The / W device 11 can read information from the TAG device 12.

As described above, the above-mentioned method (method using the loop magnetic field around the conducting wire of the antenna) is applied to the non-contact communication system in which the TAG antenna is arranged at the edge of the R / W antenna for communication. be able to.

In FIG. 11, the R / W antenna 2
2 is much larger than the TAG antenna 23, the R / W antenna 22 is the TAG antenna 2.
The method described above (method utilizing the loop magnetic field around the antenna conducting wire) can be applied even in the case of being much smaller than the case of 3.

Further, in the present specification, the system means
It represents a processing unit and an entire apparatus including a plurality of apparatuses.

[0148]

As described above, according to the non-contact communication system and the non-contact communication auxiliary device and method of the present invention,
The communication distance can be extended.

[Brief description of drawings]

FIG. 1 is a diagram showing a configuration example of a non-contact communication basic system to which the present invention is applied.

FIG. 2 is a diagram showing an example of a relationship between a distance, a diameter, and a geometric coupling coefficient between an R / W antenna and a TAG antenna of the contactless communication basic system of FIG.

FIG. 3 is a diagram showing a configuration example of an antenna sheet to which the present invention is applied.

FIG. 4 is a diagram showing a configuration example of an arrangement of the antenna sheet of FIG.

FIG. 5 is a diagram showing an example of the relationship between the arrangement position of the antenna sheet of FIG. 3 and the TAG antenna of the non-contact communication basic system of FIG. 1 and the geometric coupling coefficient.

6 is a diagram illustrating the principle of the antenna sheet of FIG. 3 and an example of the relationship between the antenna sheet of FIG. 3 and the arrangement position of the TAG antenna of the non-contact communication basic system of FIG.

7 is a view showing the matching of the geometric coupling coefficient between the antenna sheet of FIG. 3 and the TAG antenna of the non-contact communication basic system of FIG. 1, and the R / of the antenna sheet of FIG. 3 and the non-contact communication basic system of FIG. It is a figure which shows typically the example of matching of a geometric coupling coefficient with a W antenna.

8 is a diagram showing a configuration example of a contactless communication system to which the present invention is applied, in which the antenna sheet of FIG. 3 is mounted on the contactless communication basic system of FIG.

9 is an antenna sheet of the contactless communication system of FIG.
It is a figure which shows the structure of the mounting example of a TAG antenna.

10 is a diagram showing a configuration example of a video cassette system to which the contactless communication system of FIG. 8 is applied.

11 is a diagram showing a configuration of an application example of the arrangement of the TAG antenna and the R / W antenna of the non-contact communication basic system of FIG.

[Explanation of symbols]

1 Non-contact communication basic system, 11 R / W device, 1
2 TAG device, 21 R / W main device, 22 R / W antenna, 23 TAG antenna, 24 LS modulation circuit, 2
5 TAG main device, 61 antenna sheet, 71 substrate, 111 non-contact communication device, 112 first coupling part, 113 second coupling part, Ra, Rb, Rc resistance,
La, Lb coil, Lc antenna coil, Ca, Cb, Cc capacitor, Ha, Hr, Ht magnetic field, ir, it induced current

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Hiroshi Hosomi             6-735 Kita-Shinagawa, Shinagawa-ku, Tokyo Soni             -Inside the corporation F-term (reference) 5B058 CA15 KA24                 5K012 AA03 AB03 AC06 AC08 AC10                       BA02

Claims (20)

[Claims] 1. A first non-contact communication device including a first antenna that resonates at a communication carrier frequency, a second non-contact communication device including a second antenna that resonates at the communication carrier frequency, and the communication. A non-contact communication auxiliary device including a third antenna that resonates at a carrier frequency, wherein the first and third antennas are electromagnetically coupled to each other, and a line current flowing in a conductor of the second or third antenna. By the circulating magnetic field generated around the conductor,
The second and third antennas are electromagnetically coupled, and the first and second contactless communication devices are electromagnetically coupled to the first and third antennas, and the third and second antennas. A non-contact communication system, which is characterized by performing non-contact communication with each other via an antenna. 2. The first to third antennas are loop antennas, and the loop area of the second antenna is smaller than the loop areas of the first and third antennas. The contactless communication system according to claim 1. 3. The contactless communication system according to claim 2, wherein the second antenna is arranged close to the conducting wire of the third antenna. 4. The contactless communication system according to claim 3, wherein the second antenna is arranged on the loop surface of the third antenna. 5. The third antenna according to claim 3, wherein the second antenna is arranged such that a normal line direction of the second antenna and a normal line direction of the third antenna are perpendicular to each other. Contactless communication system. 6. A first value of a geometric coupling coefficient when the first and third antennas are electromagnetically coupled is adjusted by a first distance between the first and third antennas. At the same time, the second value of the geometric coupling coefficient when the second and the third antennas are electromagnetically coupled is set to the loop area ratio of the second and the third antennas, and the first value.
Adjusting a second distance between the second and third antennas that is shorter than a distance of, and matching the first and second values of the geometric coupling coefficient to a predetermined value. The non-contact communication system according to claim 1. 7. The first non-contact communication device, a generating unit that generates a carrier signal of the communication carrier frequency, and superimposes first information on the carrier signal generated by the generating unit and transmits the carrier signal. The non-contact communication system according to claim 1, further comprising carrier signal transmitting means. 8. The second non-contact communication device transmits the carrier signal transmitted by the carrier signal transmitting means of the first non-contact communication device via the first to third antennas. Receiving means for receiving, power obtaining means for obtaining power from the carrier signal received by the receiving means, and first information for obtaining the first information superimposed on the carrier signal received by the receiving means No. 1 information acquisition means, information output means for outputting second information, and modulation means for changing the receiving end impedance of the second antenna based on the second information output by the information output means. The non-contact communication system according to claim 7, further comprising: 9. The first non-contact communication device, wherein the change amount of the receiving end impedance of the second antenna is changed by the modulation means of the second non-contact communication device, The information output of the second non-contact communication device based on the detecting means for detecting via the third antenna and the change amount of the receiving end impedance of the second antenna detected by the detecting means. The non-contact communication system according to claim 8, further comprising: a second information acquisition unit that acquires the second information output by the unit. 10. A first non-contact communication device including a first antenna that resonates at a communication carrier frequency, and a second non-contact communication device including a second antenna that resonates at the communication carrier frequency, The first antenna and the second antenna are electromagnetically coupled by a circulating magnetic field generated around the conductor by a line current flowing in the conductor of the first or second antenna, and the first and second antennas are electromagnetically coupled to each other. The second non-contact communication device performs non-contact communication with each other via the electromagnetically coupled first and second antennas. 11. The contactless communication system according to claim 10, wherein the first and second antennas are loop antennas having different loop areas. 12. The first and second antennas are respectively arranged such that a normal line direction of the first antenna and a normal line direction of the second antenna are perpendicular to each other. The contactless communication system according to claim 11. 13. A relay antenna that resonates at a communication carrier frequency, the relay antenna being electromagnetically coupled to another first antenna that resonates at the communication carrier frequency, the conductor wire of the relay antenna, or the communication carrier. A line current flowing in a conductor of another second antenna that resonates at a frequency is electromagnetically coupled to the second antenna by a circulating magnetic field generated around the conductor, and communication is performed between the first and second antennas. A non-contact communication auxiliary device, which relays stored information and power in a non-contact manner. 14. The relay antenna includes a capacitor that forms a resonance circuit that resonates at the communication carrier frequency, and an inductance, and the antenna coil includes a first coupling portion that electromagnetically couples with the first antenna. The non-contact communication auxiliary device according to claim 13, further comprising a second coupling portion that is electromagnetically joined to the second antenna. 15. A sheet-shaped base material is further provided, and the antenna coil and the capacitor are formed in a pattern on a surface of the base material.
6. The contactless communication auxiliary device according to item 6. 16. The first and second coupling portions are
The non-contact communication auxiliary device according to claim 15, wherein the antenna coils are configured as the same pattern of the antenna coil. 17. The surface of the base material comprises a first surface and a second surface that is not parallel to the first surface, and the pattern of the antenna coil has the first and the second surfaces. The non-contact communication auxiliary device according to claim 15, wherein the non-contact communication auxiliary device circulates over two surfaces. 18. A normal line direction of the first surface and a normal line direction of the second surface are perpendicular to each other.
7. The contactless communication auxiliary device according to item 7. 19. The antenna according to claim 1, wherein the second antenna is arranged on the first or second surface, and the antenna coil is formed on the arranged first or second surface. The non-contact communication auxiliary device according to claim 18, wherein the non-contact communication auxiliary device is arranged in proximity to the pattern. 20. A non-contact communication auxiliary method for a non-contact communication auxiliary device comprising a relay antenna resonating at a communication carrier frequency, wherein the relay antenna and another first antenna resonating at the communication carrier frequency are electromagnetically coupled. In addition, the circulating magnetic field generated around the conductor by the line current flowing in the conductor of the relay antenna or the conductor of the other second antenna that resonates at the communication carrier frequency causes the relay antenna and the second antenna to Electromagnetically coupling, and relaying information and power communicated between the first and second antennas in a contactless manner by the relay antennas electromagnetically coupled to the first and second antennas, respectively. A characteristic non-contact communication assistance method.