JP4770655B2 - Wireless IC device - Google Patents

Description

  The present invention relates to a wireless IC device, and more particularly to a wireless IC device used in an RFID (Radio Frequency Identification) system.

  In recent years, as an article management system, a reader / writer that generates an induction electromagnetic field and a wireless tag (hereinafter referred to as a wireless IC device) that stores predetermined information attached to the article are communicated in a contactless manner, and the information is transmitted. A communicating RFID system has been developed. As wireless IC devices used in the RFID system, for example, those described in Patent Documents 1 and 2 are known.

  In order to cope with a plurality of frequencies, Patent Document 1 discloses that a folded dipole antenna that resonates in a 900 MHz band formed with a conductive pattern on a dielectric sheet is disposed on the opposite side of the folded dipole antenna with the dielectric sheet interposed therebetween. A wireless IC device that operates in two frequency bands is described by arranging a half-wavelength parasitic element that resonates in the 2.4 GHz band formed by a conductive pattern and performing impedance matching for the two frequency bands. ing.

  Further, in Patent Document 2, in a wireless IC device composed of an antenna formed on a substrate and an IC chip, the antenna has a line shape with a length of approximately ½ wavelength and is fed at the center thereof. By forming the first conductor portion and the second conductor and the third conductor that are substantially perpendicular to each other between the first conductor portion, the 2.4 GHz band and the 5.8 GHz band can be obtained. A wireless IC device that can be used is described.

However, in any of the above-described wireless IC devices, the antenna has a complicated structure because it operates in two frequency bands, the production cost increases, and the shape of the antenna increases, so that the wireless IC device itself increases in size. Had the problem of doing. Furthermore, forming an antenna that can share three or more frequency bands is more complicated in shape and larger in size, and it has been difficult to realize a film-shaped wireless IC device.
JP 2005-236468 A JP 2004-295297 A

  SUMMARY OF THE INVENTION An object of the present invention is to provide a wireless IC device capable of supporting a plurality of frequency bands while being small and having a film shape.

In order to achieve the above object, the present invention provides:
A plurality of electromagnetic coupling modules; and a radiation plate on which the plurality of electromagnetic coupling modules are mounted.
The electromagnetic coupling module is connected to the wireless IC chip and the wireless IC chip, which is composed of a feed circuit board having a feed circuit including a resonant circuit having a predetermined resonant frequency,
Resonance circuits provided on the power supply circuit boards have different resonance frequencies,
It is characterized by.

  In the wireless IC device according to the present invention, the plurality of electromagnetic coupling modules configured by the wireless IC chip and the power feeding circuit board are electromagnetically coupled to the radiation plate, respectively. The frequency of the transmission signal radiated from the radiation plate and the frequency of the reception signal supplied to the wireless IC chip are substantially determined by the resonance frequency of the power supply circuit board constituting each electromagnetic coupling module. The fact that it is substantially determined is that the frequency may be slightly shifted due to the positional relationship between the feeder circuit board and the radiation plate. In other words, since the frequency of the transmission / reception signal in each electromagnetic coupling module is determined by the resonance frequency of each power supply circuit board, regardless of the shape, size, arrangement relationship, etc. of the radiation plate, the radiation plate is set to an arbitrary shape and size. The film shape can be maintained in a small size while supporting a plurality of frequency bands.

  In the wireless IC device according to the present invention, the radiation plate may be a metal material (including a nonmagnetic conductor and a dielectric), or may be composed of a nonmagnetic layer and a magnetic layer. . The radiation plate made of a non-magnetic metal material is electromagnetically coupled to the power supply circuit board and exchanges transmission / reception signals with the wireless IC chip. If the radiation plate is composed of a non-magnetic material layer and a magnetic material layer, radiation of high-frequency signals is blocked by the magnetic material layer, the radiation range of signals is limited, and efficient radiation becomes possible. If the nonmagnetic layer is disposed on the side where the electromagnetic coupling module is mounted, the electromagnetic coupling between the electromagnetic coupling module and the radiation plate is improved.

  The radiation plate may have an annular gap around the electromagnetic coupling module so as not to contact at least one of the plurality of electromagnetic coupling modules.

  Further, the power supply circuit board may include a power supply circuit including an inductance element, and the power supply circuit may include a plurality of resonance circuits including the inductance element. If the power feeding circuit is constituted by a plurality of resonance circuits, impedance matching between the wireless IC chip and the power feeding circuit and impedance matching between the power feeding circuit and the radiation plate can be satisfactorily performed in a wide frequency band. The plurality of resonance circuits can be composed of an inductance element and a capacitance element.

  The feeder circuit board may be a multilayer board formed by laminating a plurality of nonmagnetic layers or magnetic layers, and the capacitance element and the inductance element may be formed on the surface and / or inside the multilayer board. Furthermore, the resonance circuit may include an inductance element formed of a coiled electrode. By forming the inductance element with a coiled electrode, electromagnetic coupling with the radiation plate is improved.

  According to the present invention, since a plurality of electromagnetic coupling modules having different resonance frequencies are electromagnetically coupled to the radiation plate, signals in a plurality of frequency bands can be transmitted and received using a single radiation plate, and are small and have a film shape. Wireless IC devices can be obtained.

  Embodiments of a wireless IC device according to the present invention will be described below with reference to the accompanying drawings.

(Refer to FIGS. 1 to 5 of the first and second embodiments of the wireless IC device)
1 and 2 show a wireless IC device according to a first embodiment of the present invention, FIG. 3 shows a modification of the first embodiment, and FIGS. 4 and 5 show a second embodiment. 1 and 4 show the planar state of the wireless IC device, FIG. 2 shows the AA cross section of FIG. 1, and FIG. 5 shows the BB cross section of FIG.

  In these wireless IC devices, a plurality of electromagnetic coupling modules 1A and 1B having different resonance frequencies are mounted on the radiation plate 51 by bonding. The electromagnetic coupling module 1A operates at a frequency of 13.5 MHz band, for example, and the electromagnetic coupling module 1B operates at a frequency of 900 MHz band, for example.

  In the first embodiment shown in FIGS. 1 and 2, the radiation plate 51 is a long body made of a non-magnetic metal material such as an aluminum foil or a copper foil, that is, a film-like metal plate with open ends. It is provided on an insulating flexible resin film 50 such as PET. Further, in the modification of the first embodiment shown in FIG. 3 and the second embodiment shown in FIGS. 4 and 5, the radiation plate 51 is made of a nonmagnetic material layer 51a made of aluminum foil or copper foil and a magnetic material such as Ni. It is configured as an open both ends type in which a magnetic layer 51b made of a metal material is laminated.

  The electromagnetic coupling modules 1A and 1B generally include a power supply circuit board 10 provided with a known wireless IC chip 5 used in an RFID system and a power supply circuit including a resonance circuit having a predetermined resonance frequency (details will be described below). It consists of and. The wireless IC chip 5 is mounted by being adhered to the front surface of the power supply circuit board 10, and the rear surface (the surface on which the wireless IC chip 5 is not mounted) of the power supply circuit board 10 faces the radiation plate 51.

  The wireless IC chip 5 includes a clock circuit, a logic circuit, and a memory circuit, stores necessary information, and is directly connected to a power supply circuit built in the power supply circuit board 10.

  The power feeding circuit is a circuit for supplying a transmission signal having a predetermined frequency to the radiation plate 51, selects a reception signal having a predetermined frequency from the signal received by the radiation plate 51, and supplies it to the wireless IC chip 5. And a resonance circuit that resonates at the frequency of the transmission / reception signal.

  The outline of the operation of the wireless IC device will be described. The power supply circuit in the power supply circuit board 10 of the electromagnetic coupling module 1A operates with a high frequency signal of 13.5 MHz band, and signals are exchanged with the wireless IC chip 5. In addition, the power supply circuit in the power supply circuit board 10 of the electromagnetic coupling module 1 </ b> B operates by a high-frequency signal in the 900 MHz band, and exchanges signals with the wireless IC chip 5. In the first embodiment, since the radiation plate 51 is a non-magnetic material, high-frequency signals are radiated in all directions. On the other hand, in the modification of the first embodiment and the second embodiment, since the radiation plate 51 includes the magnetic layer 51b, the high-frequency signal is blocked by the magnetic layer 51b, and the high-frequency signal is electromagnetically coupled to the electromagnetic coupling module 1A, Radiation is performed only on the surface side where 1B is mounted, and radiation efficiency is improved.

  In the modification of the first embodiment, the electromagnetic coupling module 1A operating in the 13.5 MHz band generates a magnetic field also in the nonmagnetic layer 51a and the magnetic layer 51b due to the magnetic field generated in the feeder circuit board 10, A high frequency signal accompanying the magnetic field is emitted. By providing the magnetic layer 51b as in this modification, it is possible to generate a stronger magnetic field than in the first embodiment, and to increase the amount of high-frequency signal radiation accompanying the magnetic field. Thereby, the communication distance of a wireless IC device can be lengthened. In the electromagnetic coupling module 1B operating in the 900 MHz band, a main magnetic field is generated from the feeder circuit board 10 to the nonmagnetic layer 51a by the skin effect, and a high frequency signal is generated and radiated by the magnetic field to the nonmagnetic layer 51a.

  In the second embodiment, as shown in FIGS. 4 and 5, the electromagnetic coupling module 1 </ b> A operating in the 13.5 MHz band is disposed in the gap 52 provided in the radiation plate 51 and bonded onto the resin film 50. ing. Even when the electromagnetic coupling module 1A is arranged so as to have the annular gap 52 so as not to contact the radiation plate 51, the magnetic layer 51b around the electromagnetic coupling module 1A is caused by the magnetic field generated in the power supply circuit board 10. A magnetic field is generated, and a current flowing around the module 1A flows through the magnetic layer 51b, generating a stronger magnetic field than in the first embodiment. In the electromagnetic coupling module 1B operating in the 900 MHz band, a main magnetic field is generated from the power supply circuit board 10 to the nonmagnetic layer 51a as in the modification of the first embodiment, and a high frequency signal is generated in the nonmagnetic layer 51a by the magnetic field. Generated and emitted.

  4 and 5, only the electromagnetic coupling module 1A operating in the 13.5 MHz band is directly bonded and mounted on the resin film 50 from which the radiation plate 51 is partially removed, but in the 900 MHz band. Only the electromagnetic coupling module 1 </ b> B that operates may be mounted by directly adhering onto the resin film 50 from which the radiation plate 51 is partially removed. Furthermore, both electromagnetic coupling modules 1 </ b> A and 1 </ b> B may be mounted directly on the resin film 50.

(Refer to Fig. 6 for connection form of electromagnetic coupling module)
The perspective view of FIG. 6 shows a connection form between the wireless IC chip 5 and the power supply circuit board 10 in the electromagnetic coupling modules 1A and 1B. In FIG. 6A, input / output terminals 7a and 17a are provided on the back surface of the wireless IC chip 5 and the front surface of the power supply circuit board 10, respectively. FIG. 6B shows another connection mode, in which ground terminals 7b and 17b are provided in addition to the input / output terminals 7a and 17a on the back surface of the wireless IC chip 5 and the front surface of the feeder circuit board 10, respectively. is there. However, the ground terminal 17b of the power feeding circuit board 10 is terminated and is not connected to other elements of the power feeding circuit board 10.

(Refer to the first example of the power supply circuit board, FIGS. 7 to 10)
Here, a detailed configuration of the power supply circuit board 10 of the electromagnetic coupling module 1B that operates with a high-frequency signal in the 900 MHz band will be described. In the feeder circuit board 10, as shown as an equivalent circuit in FIG. 7, the feeder circuit 16 includes inductance elements L1 and L2 that are magnetically coupled to each other. The inductance element L1 is connected to the wireless IC chip 5 via the capacitance elements C1a and C1b. The power supply terminals 19a and 19b to be connected (corresponding to the input / output terminals 17a and 17a in FIG. 6A) are connected, and the inductance element L1 is connected in parallel via the inductance element L2 and the capacitance elements C2a and C2b. ing. In other words, the power feeding circuit 16 includes an LC series resonance circuit including an inductance element L1 and capacitance elements C1a and C1b, and an LC series resonance circuit including an inductance element L2 and capacitance elements C2a and C2b. Each resonance circuit is coupled by a mutual inductance indicated by M in FIG. Both the inductance elements L1 and L2 are magnetically coupled to the radiation plate 51.

  Specifically, as shown in FIG. 8 as an example, the feeder circuit board 10 is obtained by laminating, pressing, and firing ceramic sheets 41a to 41i made of a dielectric. In other words, the power supply terminals 19a and 19b and the via-hole conductors 49a and 49b are formed on the sheet 41a, the capacitor electrodes 42a and 42b are formed on the sheet 41b, and the capacitor electrodes 43a and 43b and the via-hole conductors 49c and 49d are formed on the sheet 41c. The capacitor electrode 44a, 44b and the via-hole conductors 49c, 49d, 49e, 49f are formed on the sheet 41d.

  Further, the conductor pattern 45a, 45b, 45c for connection and via hole conductors 49d, 49g, 49h, 49i are formed on the sheet 41e. Conductive patterns 46a and 47a and via-hole conductors 49g, 49i, 49j and 49k are formed on the sheet 41f. Conductive patterns 46b and 47b and via-hole conductors 49g, 49i, 49j and 49k are formed on the sheet 41g. Conductive patterns 46c and 47c and via-hole conductors 49g, 49i, 49j and 49k are formed on the sheet 41h. Furthermore, conductor patterns 46d and 47d are formed on the sheet 41i.

  By laminating the above sheets 41a to 41i, the conductor patterns 46a to 46d are connected via the via-hole conductor 49j to form the inductance element L1, and the conductor patterns 47a to 47d are connected via the via-hole conductor 49k to generate an inductance. Element L2 is formed. The capacitance element C1a is composed of electrodes 42a and 43a, and the capacitance element C1b is composed of electrodes 42b and 43b. The capacitance element C2a is composed of electrodes 43a and 44a, and the capacitance element C2b is composed of electrodes 43b and 44b.

  One end of the inductance element L1 is connected to the capacitor electrode 43a via the via-hole conductor 49g, the connecting conductor pattern 45c, and the via-hole conductor 49c, and the other end is connected to the capacitor electrode 43b via the via-hole conductor 49d. One end of the inductance element L2 is connected to the capacitor electrode 44a via the via-hole conductor 49i, the connecting conductor pattern 45a, and the via-hole conductor 49e, and the other end is connected to the capacitor via the via-hole conductor 49h, the connecting conductor pattern 45b, and the via-hole conductor 49f. Connected to the electrode 44b.

  The power supply terminal 19a is connected to the capacitor electrode 42a via the via-hole conductor 49a, and the power supply terminal 19b is connected to the capacitor electrode 42b via the via-hole conductor 49b.

  In the power supply circuit board 10 having the above configuration, the LC series resonance circuit including the inductance elements L1 and L2 magnetically coupled to each other resonates, and the inductance elements L1 and L2 function as radiation elements. In addition, the inductance element L2 is electromagnetically coupled to the inductance element L1 via the capacitance elements C2a and C2b, so that the impedance (usually 50Ω) of the wireless IC chip 5 connected to the power supply terminals 19a and 19b and the spatial impedance ( 377Ω) as a matching circuit.

The coupling coefficient k of the adjacent inductance elements L1 and L2 is represented by k ² = M ² / (L1 × L2), and is preferably 0.1 or more. In the power feeding circuit 16, it is about 0.8975. Further, since the LC resonance circuit composed of the capacitance elements C1a, C1b, C2a, C2b and the inductance elements L1, L2 is configured as a lumped constant type resonance circuit, it can be miniaturized as a stacked type. Furthermore, since the capacitance elements C1a and C1b are interposed in the power supply terminals 19a and 19b, a low-frequency surge can be cut and the wireless IC chip 5 can be protected from the surge.

  As a result of simulation by the present inventor based on the equivalent circuit shown in FIG. 7, the reflection characteristics shown in FIG. 9 can be obtained between the power supply terminals 19 a to 19 b of the power supply circuit board 10. As is clear from FIG. 9, the center frequency is 915 MHz, and a reflection characteristic of −10 dB or more is obtained in a wide band of 850 to 970 MHz.

  FIG. 10 shows the directivity (magnetic field strength) in the XY plane of the feeder circuit board 10. The X axis, Y axis, and Z axis correspond to the arrows X, Y, and Z shown in FIG.

  The electromagnetic coupling module 1B including the power supply circuit board 10 having the above configuration receives a high-frequency signal (for example, 900 MHz band) radiated from a reader / writer (not shown) by the radiation plate 51 and mainly magnetically with the radiation plate 51. Receiving a predetermined frequency band by resonating the coupled feeding circuit 16 (an LC series resonance circuit including an inductance element L1 and capacitance elements C1a and C1b and an LC series resonance circuit including an inductance element L2 and capacitance elements C2a and C2b). Only the signal is supplied to the wireless IC chip 5. On the other hand, after taking out predetermined energy from this received signal, applying information reflected in the radio IC chip 5 with this energy as a driving source, and applying reflection modulation to the input signal, and matching it to a predetermined frequency by the power feeding circuit 16, A transmission signal is transmitted from the inductance elements L1 and L2 of the power feeding circuit 16 to the radiation plate 51 through magnetic field coupling, and is transmitted from the radiation plate 51 to the reader / writer.

  In particular, in the first example, the reflection characteristic has a wide frequency band as shown in FIG. This is because the power feeding circuit 16 is configured by a plurality of LC resonance circuits including inductance elements L1 and L2 that are magnetically coupled with each other with a high degree of coupling.

  In the electromagnetic coupling module 1B, the wireless IC chip 5 is directly connected to the power supply circuit board 10 including the power supply circuit 16, and the power supply circuit board 10 is rigid. It can be well positioned and mounted on the feeder circuit board 10. In addition, since the power supply circuit board 10 is made of a ceramic material and has heat resistance, the wireless IC chip 5 can be soldered to the power supply circuit board 10. That is, since the ultrasonic bonding method is not used, the wireless IC chip 5 can be mounted at low cost, and there is no possibility that the wireless IC chip 5 is damaged by the pressure applied during the ultrasonic bonding, and the self-alignment action by solder reflow can be used.

  In the power feeding circuit 16, the resonance frequency characteristic is determined by a resonance circuit including inductance elements L1 and L2 and capacitance elements C1a, C1b, C2a, and C2b. The resonance frequency of the signal radiated from the radiation plate 51 substantially corresponds to the self-resonance frequency of the power feeding circuit 16, and the maximum gain of the signal depends on the size and shape of the power feeding circuit 16, and between the power feeding circuit 16 and the radiation plate 51. It is substantially determined by at least one of the distance and the medium. That is, in the power supply circuit board 10, the frequency of the signal radiated from the radiation plate 51 is substantially determined by the resonance frequency of the resonance circuit (feed circuit 16). Virtually independent.

  The resonant circuit may also serve as a matching circuit for matching the impedance of the wireless IC chip 5 and the impedance of the radiation plate 51. Alternatively, the power feeding circuit board 10 may further include a matching circuit that is configured by an inductance element and a capacitance element and is provided separately from the resonance circuit. If an attempt is made to add a function of a matching circuit to the resonance circuit, the design of the resonance circuit tends to be complicated. If a matching circuit is provided separately from the resonance circuit, the resonance circuit and the matching circuit can be designed independently.

(Refer to the second example of the power supply circuit board, FIG. 11 and FIG. 12)
Next, a detailed configuration of the power supply circuit board 10 of the electromagnetic coupling module 1A that operates with a high frequency signal in the 13.5 MHz band will be described. In the power supply circuit board 10, as shown as an equivalent circuit in FIG. 11, the power supply circuit 16 includes inductance elements L1 and L2 that are magnetically coupled to each other (indicated by a symbol M), and one end of the inductance element L1 is connected to the capacitance element C1. It is connected to the wireless IC chip 5 via the electrode 131a, and is connected to one end of the inductance element L2 via the capacitance element C2. The other ends of the inductance elements L1 and L2 are connected to the wireless IC chip 5 via connection electrodes 131b, respectively. In other words, the power feeding circuit 16 includes an LC series resonance circuit composed of an inductance element L1 and a capacitance element C1, and an LC series resonance circuit composed of an inductance element L2 and a capacitance element C2, and the inductance element L1. , L2 are magnetically coupled to the radiation plate 51.

  Specifically, as shown in FIG. 12 as an example, the power supply circuit board 10 is obtained by laminating, pressing, and firing ceramic sheets 141a to 141e made of a dielectric. That is, the connection electrode 131a is connected to the capacitor electrode 133 through the via-hole conductor 132a, and the capacitor electrode 133 is opposed to the capacitor electrode 134 to form a capacitance element C1. Further, the capacitor electrode 134 is opposed to the capacitor electrode 135 to form a capacitance element C2. The connection electrode 131b is connected to the conductor patterns 136a and 137a branched in a bifurcated manner via the via-hole conductor 132b, the conductor pattern 136a is connected to the conductor pattern 136b via the via-hole conductor 132c, and further via the via-hole conductor 132d. The conductor pattern 136c is connected to the conductor pattern 136d through a via-hole conductor 132e. The conductor pattern 136d is connected to the capacitor electrode 134 through a via-hole conductor 132f.

  On the other hand, the conductor pattern 137a is connected to the conductor pattern 137b via the via-hole conductor 132g, further connected to the conductor pattern 137c via the via-hole conductor 132h, and further connected to the capacitor electrode 135 via the via-hole conductor 132i. . The conductor patterns 136a, 136b, and 136c constitute an inductance element L1, and the conductor patterns 137a, 137b, and 137c constitute an inductance element L2.

  In FIG. 12, the conductor patterns 136a to 136c and 137a to 137c constituting the inductance elements L1 and L2 are illustrated as a three-layer structure for simplification, but actually, the conductor patterns 136a to 136c and 137a to 137c are configured with more layers. ing.

  The operational effects of the feeder circuit board 10 having the above configuration are basically the same as those in the first example. The wireless IC device 1A receives a high-frequency signal (for example, 13.5 MHz band) radiated from a reader / writer (not shown) by the radiation plate 51 and is mainly magnetically coupled to the radiation plate 51. (LC series resonance circuit consisting of inductance element L1 and capacitance element C1 and LC series resonance circuit consisting of inductance element L2 and capacitance element C2) are resonated, and only a received signal in a predetermined frequency band is supplied to the wireless IC chip 5. On the other hand, a predetermined energy is extracted from the received signal, information stored in the wireless IC chip 5 is subjected to reflection modulation on the input signal using this energy as a driving source, and matched to a predetermined frequency by the power feeding circuit 16. The transmission signal is transmitted from the inductance elements L1 and L2 of the power feeding circuit 16 to the radiation plate 51 through magnetic field coupling, and transmitted from the radiation plate 51 to the reader / writer.

  In particular, in the second example, the capacitor electrodes 133, 134, 135 and the inductor conductor patterns 136 a to 136 c and 137 a to 137 c are arranged adjacent to each other in parallel to the radiation plate 51. Therefore, the magnetic field formed by the inductor conductor patterns 136a to 136c and 137a to 137c is not blocked by the capacitor electrodes 133, 134, and 135, and the radiation characteristics from the inductor conductor patterns 136a to 136c and 137a to 137c are improved. .

(Other examples)
The wireless IC device according to the present invention is not limited to the above-described embodiments, and various modifications can be made within the scope of the gist thereof.

  For example, various circuit configurations such as an LC series resonance circuit and an LC parallel resonance circuit can be adopted as the resonance circuit constituting the power supply circuit, and may be a lumped constant type or a distributed constant type. Further, the number of electromagnetic coupling modules coupled to one radiation plate may be three or more. Furthermore, the information stored in the wireless IC chip and the form using the information using a reader / writer are arbitrary.

1 is a plan view showing a first embodiment of a wireless IC device according to the present invention. It is AA sectional drawing of FIG. It is sectional drawing which shows the modification of 1st Example. It is a top view which shows 2nd Example of the radio | wireless IC device which concerns on this invention. It is BB sectional drawing of FIG. It is a perspective view which shows the connection state of a radio | wireless IC chip and a electric power feeding circuit board. FIG. 3 is an equivalent circuit diagram illustrating a first example of a feeder circuit board. It is a top view which decomposes | disassembles and shows the electric power feeding circuit board which is the said 1st example. It is a graph which shows the reflective characteristic of the electromagnetic coupling module provided with the said 1st example. It is a chart figure of the XY plane which shows the directivity of the electromagnetic coupling module provided with the said 1st example. FIG. 6 is an equivalent circuit diagram illustrating a second example of a power feeding circuit board. It is a perspective view which decomposes | disassembles and shows the electric power feeding circuit board which is the said 2nd example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1A, 1B ... Electromagnetic coupling module 5 ... Wireless IC chip 10 ... Feeding circuit board 16 ... Feeding circuit L1, L2 ... Inductance element C1a, C1b, C2a, C2b, C1, C2 ... Capacitance element 51 ... Radiation plate 51a ... Nonmagnetic material Layer 51b ... Magnetic layer 52 ... Air gap

Claims (10)

A plurality of electromagnetic coupling modules; and a radiation plate on which the plurality of electromagnetic coupling modules are mounted.
The electromagnetic coupling module is connected to the wireless IC chip and the wireless IC chip, which is composed of a feed circuit board having a feed circuit including a resonant circuit having a predetermined resonant frequency,
Resonance circuits provided on the power supply circuit boards have different resonance frequencies,
A wireless IC device characterized by the above.   The wireless IC device according to claim 1, wherein the radiation plate is made of a metal material.   The wireless IC device according to claim 1, wherein the radiation plate includes a nonmagnetic material layer and a magnetic material layer.   4. The wireless IC device according to claim 3, wherein the non-magnetic layer is disposed on a side on which the electromagnetic coupling module is mounted.   The wireless IC device according to claim 4, wherein the radiation plate has an annular gap around the electromagnetic coupling module so as not to contact at least one of the plurality of electromagnetic coupling modules.   6. The wireless IC device according to claim 1, wherein the power supply circuit board includes a power supply circuit including an inductance element.   The wireless IC device according to claim 6, wherein the power feeding circuit includes a plurality of resonance circuits including the inductance element.   The wireless IC device according to claim 7, wherein the plurality of resonance circuits include an inductance element and a capacitance element. The feeder circuit board is a multilayer board formed by laminating a plurality of nonmagnetic layers or magnetic layers,
The capacitance element and the inductance element are formed on a surface and / or inside of the multilayer substrate;
The wireless IC device according to claim 6, wherein:   The wireless IC device according to claim 7, wherein the resonance circuit includes an inductance element formed of a coiled electrode.

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