JP2007053810A - Radio ic tag device compatible with metal - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a radio IC tag device compatible with metal etc., that has simple configuration and can extend a communication distance by plane circuit resonance to an incident radio signal. <P>SOLUTION: The radio IC tag device includes a radio IC tag having an electric field radiation component of a linear polarized wave, a ground conductor on a surface of a dielectric, and a radio wave converting resonant reflector made of a patch conductor which has open boundaries on another surface of the dielectric and at both ends of first and second orthogonal resonance axes and also performing plane circuit resonance at first and second resonance frequency respectively by the first and the second resonance axes. The radio IC tag is provided on the second surface of the dielectric of the radio wave converting resonant reflector or the patch conductor so that the electric field radiation component of the linear polarized wave of the radio IC tag and the resonance axes of the radio wave converting resonant reflector may be substantially in the same direction. Then a first radio signal is converted into a second radio signal through the plane circuit resonance of the patch conductor to be reflected to the radio IC tag and a third radio signal from the radio IC tag is converted into a fourth radio signal through plane circuit resonance to the patch conductor to be reflected. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a metal-compatible wireless IC tag device used, for example, in a wireless mobile object identification system (hereinafter referred to as an RFID system).

  In recent years, the Ministry of Internal Affairs and Communications has listed “ubiquitous” as a keyword for next-generation technology that replaces IT. “Ubiquitous” means “being everywhere” in Latin and means expanding the world of information and communications to all substances. The wireless IC tag is regarded as a basic technology of the ubiquitous society, and is used by being affixed to various objects or embedded on the surface thereof. In addition, wireless IC tags are used in various processes from the manufacture of goods to physical distribution and disposal, such as the use of goods traceability, and are used in different communication modes such as short-distance and long-distance communications. Wide form and communication performance are required.

  In general, an RFID system includes an interrogator that is also called a scanner and has a reader / writer function, and a responder that is a wireless IC tag. The radio signal emitted from the interrogator is received by the transponder, and the transponder is activated by the power of the radio signal, and the transponder digitally modulates the radio carrier according to the tag information stored in the built-in memory, and is modulated. A wireless signal is generated and returned to the interrogator. In response to this, the interrogator obtains tag information by digitally demodulating the received radio signal. Wireless IC tags are mounted on various products, and are being considered for efficiency in the production, distribution, sales, and recycling processes of products, and in many fields such as management of people and goods, ensuring safety, and electronic advertising. Yes. There are various characteristics and forms of wireless IC tags that are more appropriate in these usage forms, and various wireless IC tags are being developed and used. The most common small wireless IC tag is a dipole antenna in which a tag IC is mounted. This is shown in FIG. A configuration example of a general tag IC is shown in FIG. These will be described in detail later.

  By the way, when this kind of general small wireless IC tag is mounted on various metal casings, containers, metal-coated casings, etc., it is affected by the metal and affects the wireless communication of the RFID system. give. In order to solve this problem, for example, Patent Document 1 and Non-Patent Document 1 disclose an example of a metal-compatible wireless IC tag that can be mounted on a metal body (hereinafter referred to as a first conventional example). Yes. The first conventional example is a wireless IC tag in which a tag IC is connected between an antenna and a ground conductor using a ½ wavelength microstrip line resonator, and is opposed to the antenna via a dielectric. Since there is a ground conductor on the side, even if the ground conductor side is attached to a metal body or the like, basically, the radio wave radiation is not affected and communication is not hindered. Effective communication is possible for a linearly polarized radio signal having an electric field component parallel to the direction.

  Patent Document 2 discloses an example of a wireless IC tag using a circularly polarized flat antenna (hereinafter referred to as a second conventional example). The second conventional example is characterized in that a conductor portion is formed toward the ground conductor at an appropriate position in the radiation conductor of the planar antenna, and a tag IC is connected between the conductor portion and the ground plane. Since the radio wave radiated from the planar antenna is radiated only in the radiation surface direction opposite to the ground conductor, the ground conductor side can be attached to the metal body.

JP 2000-332523 A. JP 2002-353735 A. Hiroaki Kogure, “The World of Wireless Learning with an Electromagnetic Simulator”, CQ Publisher, pp. 118, issued on June 20, 2001.

  In these first and second conventional examples, the device configuration is complicated, and a design corresponding to each of linearly polarized waves and circularly polarized waves can be made. However, once manufactured, it is difficult to change the polarized waves. There was a problem. In addition, a general small wireless IC tag has a problem that a communication distance between an interrogator and a responder of the RFID system is relatively short. Furthermore, in the production process, one independent small wireless IC tag is attached to a board or component, and in the logistics process, it is mounted on a finished product, a packing box or a container and used as a metal-compatible wireless IC tag capable of long-distance communication. For example, it is difficult to continuously use one small wireless IC tag in various processes.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a metal-compatible wireless IC tag device that solves the above-described problems, has a simpler device configuration than conventional examples, and can handle metals. In addition, an object of the present invention is to extend the communication distance of an independent small wireless IC tag, and with one small wireless IC tag used by itself, an operation or characteristic suitable for various utilization processes can be obtained. An object of the present invention is to provide a metal-compatible wireless IC tag device that can be realized and is highly usable.

Metal-compatible wireless IC tag device according to the present invention,
A wireless IC tag having a linearly polarized field emission component;
A dielectric having first and second surfaces substantially parallel to each other;
A ground conductor provided on the first surface of the dielectric;
Provided on the second surface of the dielectric, open at both ends of the first and second resonance axes orthogonal to each other, and predetermined first and second at the first and second resonance axes, respectively. A radio wave conversion resonant reflector comprising a patch conductor that resonates in a planar circuit at a resonance frequency of
The wireless IC tag is attached to the radio wave conversion resonant reflector so that the direction of the linearly polarized field emission component of the radio IC tag and one resonance axis of the radio wave conversion resonant reflector substantially coincide with each other. On the second surface of the dielectric or on the patch conductor;
As a received wave having a communication frequency that is one of the first resonance frequency, the second resonance frequency, and the frequency between the first resonance frequency and the second resonance frequency. The incident first radio signal is caused to resonate in a planar circuit by the patch conductor, converted to a second radio signal, reflected by the radio IC tag, and a third radio signal having the communication frequency from the radio IC tag. The patch conductor is made to resonate in a planar circuit, converted into a fourth radio signal, and reflected as a transmission wave.

  The terms “provided on the surface” or “provided on the conductor” may be provided directly on the surface or the conductor, respectively, or may be provided from the surface or the conductor via a gap. . Furthermore, the term “provided” shall include being formed, affixed or attached, simply placed or mounted, and the like.

Therefore, according to the present invention, the following specific effects can be obtained.
(1) The configuration of the radio wave polarization conversion resonant reflector is very simple and can be easily manufactured. By using the small wireless IC tag, a metal-compatible wireless IC tag device can be easily manufactured. be able to.
(2) By using the planar circuit resonance, the propagation gain can be substantially increased and the communication distance can be extended as compared with the single use of a small wireless IC tag.
(3) Since the metal-compatible wireless IC tag device can easily convert the polarization, it can cope with different polarizations so as to be compatible with the radio signal of the RFID system, thereby realizing a suitable system. it can.
(4) For example, a wireless communication device that is a wireless IC tag can be used alone, and the propagation gain is substantially increased by using a radio wave polarization conversion resonant reflector, and as a metal-compatible wireless IC tag device, etc. A wide range of usage can be made according to the application.

  Hereinafter, embodiments according to the present invention will be described with reference to the drawings. In addition, the same code | symbol is attached | subjected about the same component.

Relationship between conventional example and embodiment.
As described above, the wireless IC tag is mounted on various articles, and is efficient in the production, distribution, sales, and recycling processes of the article, or in many fields such as management of people, goods, ensuring safety, and electronic advertisement. Utilization has been studied, and the characteristics and forms of tags that are more appropriate in these utilization forms are various, and various tags are being developed and utilized. Compared to other wireless communication devices, a desirable requirement that is very important for wireless IC tags is to be more compact, lighter, and to substantially increase the propagation gain of wireless communication devices in order to expand the range of use. It is. In many cases, the wireless IC tag is directly attached to various articles and objects, and therefore can operate on any object such as a metal object or a ferroelectric substance. In other words, it must be a metal-compatible wireless IC tag (on-metal wireless IC tag) that is not affected by the mounted object, and when the wireless IC tag is attached to an article, restrict the direction (polarization axis) of the wireless IC tag. In addition, since the wireless IC tag mounted article moves through various processes, the facing state of the communicating interrogator with the antenna is not constant, and can cope with circular polarization characteristics. Therefore, if there is a means that can be mounted on any object by converting the polarization characteristics of a normal small tag equivalently and substantially increasing the propagation gain in a simple manner for various applications. Can provide a very effective method.

  The most typical wireless IC tag shown in FIG. 38 can be formed simply and inexpensively by simply forming the dipole antenna 8b on the dielectric substrate 8c and connecting the tag IC 8a. The tag IC 8a shown in FIG. 39 includes an asynchronous MPU 30, a nonvolatile memory 31, a power regeneration circuit 32, a high-frequency communication line 33, and the like. Some have an external communication port 34. Here, the asynchronous MPU 30 is a controller for controlling the operation of the entire tag IC 8a, and has an external communication port 34, for example. The nonvolatile memory 31 is a memory for storing tag information of the tag IC. The power regeneration circuit 32 receives the activation radio signal received by the antenna 8b, regenerates the power, and supplies it to the components 30, 31, and 33. The high-frequency communication circuit 33 includes a wireless transmitter, digitally modulates a wireless carrier wave according to tag information read from the nonvolatile memory 31 by the asynchronous MPU 30, and radiates the wireless carrier wave toward the interrogator 20 using the antenna 8b. Since the wireless IC tag emits radio waves 360 degrees around the longitudinal axis of the dipole antenna, wireless communication with the interrogator is possible from a circumferential direction other than the longitudinal axis. It may be convenient. The wireless IC tag is effective for linearly polarized waves having an electric field component E parallel to the longitudinal axis, but receives a wireless signal from an interrogator orthogonal to the longitudinal axis of the wireless IC tag. I can't. However, radio signals are radiated in the surrounding direction, and the antenna gain is low, so it is difficult for long-distance communication. Furthermore, there are no problems in mounting on articles made of fibers or thin paper materials that are not easily affected by radio signals, but various metal containers and containers, equipment cases coated with metal conductors, These wireless IC tags cannot be used due to the influence of a metal conductor to be mounted on an object such as a vehicle. In particular, wireless IC tags are often used in production, logistics, distribution, and repair processes, and the RFID IC tag mounting object may change during the process, so tags that can handle metals are extremely effective and indispensable. It is. Furthermore, in the application, the radio signal from the interrogator may be linearly polarized, but circular polarization is desirable in consideration of the mounting of the wireless IC tag and the degree of freedom of wireless communication.

  According to an embodiment of the present invention, as will be described in detail later, a planar resonant circuit is provided for a small general independent wireless IC tag in which radio wave radiation such as the above-described wireless IC tag radiates in the peripheral direction. By using the resonant polarization converting / reflecting means that can convert the polarization using a metal conductor, it is possible to implement a metal-compatible wireless IC tag device that can substantially increase the propagation gain. In addition, by simply placing an independent wireless IC tag at a specific position on the upper side of the radio wave polarization conversion resonant reflector, it is possible to operate corresponding to wireless signals having various polarizations from the interrogator. It is a feature.

  The above-described conventional example is a configuration method of an independent metal-compatible wireless IC tag itself in which a tag IC component is directly connected between a radiating conductor and a grounded conductor of a patch antenna (planar antenna). The basic point of view is different from the target method for forming metal-compatible wireless IC tags. That is, in the embodiment according to the present invention, a general independent wireless IC tag composed of a small antenna and a tag IC, which is used by itself, and a radio wave polarization conversion resonant reflector are combined, and the propagation gain is substantially reduced. A metal-compatible wireless IC tag device suitable for excellent circularly polarized communication increased in size is easily created. At present, it is the smallest communication device, and is particularly effective for wireless IC tags that are attached to various objects for various purposes. Since the independent wireless IC tag is very small, even if it is placed above the radio wave polarization conversion resonant reflector, the effect of shielding the radio signal of the incoming wave is small, and the incoming signal acts on the radio wave polarization conversion resonance reflector. The signal is reflected and an effective signal is given to the wireless IC tag. In addition, the ground conductor surface of the radio wave polarization conversion resonant reflector disposed below is used as a mounting surface for various objects, thereby exhibiting the effect as a metal-compatible wireless IC tag device. The independent wireless IC tag only needs to be arranged in a specific positional relationship between the radiation electric field direction and the resonance electric field direction of the radio wave polarization conversion resonant reflector. The radio wave polarization conversion resonant reflector itself has no effect, but exhibits a special effect when combined with an independent wireless IC tag having linearly polarized radiation characteristics. At this time, the radio wave polarization conversion resonant reflector propagates with the radio IC tag placed on the front surface by matching the radio IC tag and the electric field polarization axis by radio wave polarization conversion, and strengthening the radio wave intensity due to resonance reflection. Substantially increase the gain. Various polarization signals can be handled by changing the arrangement position of the independent wireless IC tag. In addition, the radio wave polarization conversion resonant reflector reflects the radio wave to the back surface, thereby providing a metal-compatible radio IC tag device suitable for various applications.

First embodiment.
FIG. 1 is a plan view showing the configuration of a radio wave polarization conversion resonant reflector 10 according to the first embodiment of the present invention. FIG. 2 is a longitudinal sectional view taken along line AA ′ of FIG.

  1 and 2, a ground conductor 2 is formed on the entire back surface of a dielectric substrate 1 having two surfaces substantially parallel to each other, and the front surface of the dielectric substrate 1 (hereinafter also referred to as a radiation surface). ) Is formed into a square patch conductor 3. Here, the center O of the patch conductor 3 is set as the coordinate center, the X axis and the Y axis are defined so as to be parallel to each side of the patch conductor 3, the X axis is set to a reference 0 degree direction, and the X axis is The azimuth angle θ is determined toward the Y-axis direction, and so on.

  As shown below, the patch conductor 3 becomes an open boundary at both ends of two resonance axes RA1 and RA2 orthogonal to each other, and is planar circuit-resonated at resonance frequencies fl and fh different from each other at these resonance axes RA1 and RA2. Includes two planar circuit resonators. The length of the diagonal line connecting the vertex 101 at the azimuth angle θ = 135 degrees of the patch conductor 3 and the vertex 102 at the azimuth angle θ = −45 degrees of the patch conductor 3 is L1, and the diagonal line is The resonance axis RA1 of one planar circuit resonator is assumed. Further, an isosceles triangular notch 3a is formed at the virtual vertex 103 at the position of the azimuth angle θ = 45 degrees of the patch conductor 3, and the virtual vertex 104 at the position of the azimuth angle θ = −135 degrees of the patch conductor 3 is formed. An isosceles triangular notch 3b is formed. The length of the patch conductor 3 on the diagonal line connecting these virtual vertices 103 and 104 is Lh, and the axis of the length Lh is the resonance axis RA2 of the second planar circuit resonator.

  Here, the lengths Ll and Lh of the patch conductor 3 are set as follows. In the first planar circuit resonator of the patch conductor 3, at a communication frequency f0 between two resonance frequencies fl and fh that are close to each other and preferably their approximate average frequency, the resonance axis RA1 of length L1 Planar circuit resonance occurs at a resonance frequency fl lower than the communication frequency f0. On the other hand, in the second planar circuit resonator of the patch conductor 3, the planar circuit resonates at a resonance frequency fh higher than the communication frequency f0 by the resonance axis RA2 having the length Lh at the communication frequency f0. Further, the phase of the communication frequency f0 is substantially delayed by 45 degrees from the resonance frequency fl in the resonance phase characteristic by the resonance axis RA1, and the phase of the communication frequency f0 is the resonance phase characteristic by the resonance axis RA2 and the resonance frequency fh. Is set to deviate substantially 45 degrees from the first position. Therefore, the two planar circuit resonators of the patch conductor 3 are formed via the dielectric substrate 1 when the radio signal of the communication frequency f0 is incident at the communication frequency f0 or a frequency in the vicinity thereof and the planar circuit resonates. An electromagnetic field of the radio signal is generated between the patch conductor 3 and the ground conductor 2, and is in a direction perpendicular to the surface of the dielectric substrate 1 by the patch conductor 3 and the ground conductor 2 through the dielectric substrate 1. Thus, the electromagnetic wave of the radio signal is radiated in a direction from the ground conductor 2 toward the patch conductor 3 (hereinafter referred to as a radiation direction). These operations can be realized without a power supply circuit.

  FIG. 3 is a plan view showing the configuration and operation of a metal-compatible wireless IC tag device 50 in which the wireless IC tag 8 is placed on the radio wave polarization conversion resonant reflector 10 of FIG. FIG. 4 is a longitudinal sectional view taken along line B-B ′ in FIG. 3 and a side view of the interrogator 20, showing the positional relationship and operation between the metal-compatible wireless IC tag device 50 in FIG. 3 and the interrogator 20.

  3 and 4, the circularly polarized radio signal from the interrogator 20 is converted into a linearly polarized radio signal by the radio wave polarization conversion resonant reflector 10, and the radio wave polarization conversion resonance reflector 10 is converted. The operation of transmitting to the wireless IC tag 8 mounted on the patch conductor 3 via the tag mounting base 9 will be described below. The wireless IC tag 8 radiates a linearly polarized wireless signal using, for example, the general dipole antenna 8b shown in FIG. 38. As shown in FIG. Is mounted so that the longitudinal direction thereof extends along the X axis, and for example, the wireless IC tag 8 is attached to the radiation surface of the patch conductor 3 or the dielectric substrate 1 using an adhesive tape. Alternatively, a bag-shaped storage body for storing the wireless IC tag 8 is provided on the radiation surface, and the wireless IC tag 8 is inserted into the storage body for storage. The tag mounting base 9 corresponds to the form of the wireless IC tag 8 and is used as necessary. If the wireless IC tag 8 is casing with a dielectric and has an appropriate thickness, the tag mounting base 9 is used. 9 may not be used.

  In FIG. 4, an interrogator 20 having an antenna 20A extends in a direction perpendicular to the surface of the dielectric substrate 1 of the radio wave polarization conversion resonant reflector 10 and from the ground conductor 2 toward the radiation surface. In this position, the antenna 20A is provided to face the radiation surface of the radio wave polarization conversion resonant reflector 10. Here, the circularly polarized radio signal 20S is transmitted from the antenna 20A of the interrogator 20 to the radio wave polarization conversion resonant reflector 10, and the electric field component of the rotating circularly polarized radio signal 20S is Eic. Since the circularly polarized radio signal 20S is represented by two linearly polarized radio signals that are orthogonal to each other and have a phase difference of 90 degrees, the two separated signals are respectively shown in the polarization cross-sectional view 20L of FIG. (The polarization cross-sectional view is a view in a cross section parallel to the radiation surface.) The electric field components are shown as Eia and Eib. Here, the electric field component Eib is a left-handed circularly polarized wave whose phase is advanced by 90 degrees from the electric field component Eia. When these two linearly polarized radio signals are incident on the radio wave polarization conversion resonant reflector 10, the electric field component Eia resonates in a plane circuit with the resonance axis RA2 of the patch conductor 3 having a higher resonance frequency fh, and the patch conductor 3 A current Ia is generated on the resonance axis RA2. On the other hand, the electric field component Eib resonates in a planar circuit with the resonance axis RA1 of the patch conductor 3 having a lower resonance frequency fl, and generates a current Ib on the resonance axis RA1 of the patch conductor 3. By these currents Ia and Ib, linearly polarized electric fields Ea and Eb parallel to the respective currents are re-radiated from the patch conductor 3 in the radiation direction.

  As described above, the currents Ia and Ib on the resonance axes RA2 and RA1 of the patch conductor 3 are generated with the phase of the current Ia being advanced by 90 degrees from the phase of the current Ib. On the other hand, since the electric field component Eia of the radio signal arriving at the radio wave polarization conversion resonant reflector 10 is incident with a phase delay of 90 degrees compared to the electric field component Eib, the phase difference of 90 degrees of the current generated thereby. And the phases of the electric field components Ea and Eb of the radio signal re-radiated from the patch conductor 3 are in phase. Therefore, as shown in FIG. 4, two linearly polarized electric field components Ea and Eb that are orthogonal and in-phase are combined with each other and reflected and radiated as a linearly polarized radio signal El converted from a circularly polarized wave. Re-radiated toward the wireless IC tag 8 in the direction. This may be regarded as a radio wave being radiated from the current Ir obtained by combining the current Ia and the current Ib. Here, since the wireless IC tag 8 is executed as described above, it can be received with respect to the electric field component along the X axis, so that the reflected wireless signal is effectively received by the dipole antenna of the wireless IC tag 8. Is done. In response to this, the wireless IC tag 8 reproduces the power of the received wireless signal and starts up, and then is load-modulated according to the tag information stored in the memory in the wireless IC tag 8, that is, the wireless carrier wave is digitally modulated. As a result, a radio signal is generated, transmitted to the radio wave polarization conversion resonant reflector 10, and returned to the interrogator 20 via the radio wave polarization conversion resonance reflector 10. In the operation of the radio wave polarization conversion resonant reflector 10 here, a process opposite to the operation from the interrogator 20 to the wireless IC tag 8 is executed.

  As described above, the radio wave polarization conversion resonant reflector 10 converts the incident circularly polarized radio signal into a linearly polarized radio signal and matches it with the radiation electric field axis of the radio IC tag 8 placed in front. In addition, an effective wireless signal is supplied, and the surface of the ground conductor 2 of the radio wave polarization conversion resonant reflector 10 becomes a mounting surface on an object, so that the metal-compatible wireless IC tag device 50 can be constructed. The radio wave polarization conversion resonant reflector 10 is a passive body, and has a reversible polarization conversion function.

  3 and 4, the radio signal transmitted from the interrogator 20 has a circular polarization, and the electric field component Eia of the linearly polarized radio signal decomposed into two orthogonal waves is compared with the electric field component Eib. In the case of left-handed circularly polarized wave delayed by 90 degrees, in the case of right-handed circularly polarized wave whose phase difference between the two waves is opposite, the circularly polarized wave of the incoming radio signal is 90 degrees from the above example. It is converted to a radio signal of different orthogonal linear polarization. Therefore, the wireless IC tag 8 is disposed in parallel on the Y axis. In this case, the arrangement position of the wireless IC tag 8 is indicated by a dotted line. Note that the wireless IC tag 8 has an electric field component in the same direction even if the linearly polarized radiation electric field axis is arranged parallel to the diagonal line of the square patch conductor 3, and thus the wireless IC tag 8 is wireless. A signal is supplied and operation is possible. Further, even if at least the radiation electric field axis of the wireless IC tag 8 is arranged substantially parallel to the straight line connecting the end portion of the patch conductor 3 and the central portion thereof, the same operation is performed.

  Further, the case where the radio signal from the interrogator 20 is right-handed circularly polarized wave can be explained in the same manner as described above, and thus the explanation is omitted. When the wireless signal from the interrogator 20 is circularly polarized, the operation is exactly the same even if the metal-compatible wireless IC tag device 50 is rotated opposite to the wireless signal from the interrogator 20.

Modification of the first embodiment.
FIG. 5 is a plan view showing the configuration and operation of a metal-compatible wireless IC tag device 50 according to a modification of the first embodiment of the present invention. FIG. 6 is a longitudinal sectional view taken along line CC ′ of FIG. 5 and a side view of the interrogator 20 showing the positional relationship and operation between the metal-compatible wireless IC tag device 50 of FIG. 5 and the interrogator 20. In this modification, as in the first embodiment, the wireless IC tag 8 includes a dipole antenna, and transmits and receives linearly polarized radio signals having a radiation field parallel to the longitudinal direction of the dipole antenna. As shown in FIG. 5, the wireless IC tag 8 is disposed on the patch conductor 3 in the lateral direction including the center O and along the X axis. In the modification, referring to FIGS. 5 and 6, the linearly polarized radio signal from the interrogator 20 is converted into a circularly polarized radio signal by the radio wave polarization conversion resonant reflector 10, and the radio wave An operation of transmitting to the wireless IC tag 8 mounted on the patch conductor 3 of the polarization conversion resonant reflector 10 via the tag mounting base 9 will be described below.

  In FIG. 6, a case is considered where the radio signal transmitted from the interrogator 20 is transmitted as a linearly polarized radio signal 20S having an electric field component Ei in the vertical direction in FIG. First, when the radio wave polarization conversion resonant reflector 10 is not present, the radiation linear polarization axis of the wireless IC tag 8 is arranged so as to be orthogonal to the electric field component Ei. Therefore, the radio signal 20S from the interrogator 20 cannot excite the dipole antenna of the wireless IC tag 8 even when the electric field strength is relatively large, and the wireless IC tag 8 cannot be activated.

  However, as shown in FIG. 6, when the radio wave polarization conversion resonant reflector 10 is arranged behind the radio IC tag 8, first, the radio signal 20 </ b> S from the interrogator 20 is sent to the radio wave polarization conversion resonance reflector 10. On the other hand, it enters along the Y axis and resonates with the planar circuit resonator in the radio wave polarization conversion resonant reflector 10. That is, the electric field component Ei of the incoming linearly polarized radio signal 20S can be decomposed into two waves of in-phase electric field components Eia and Eib orthogonal to each other, as shown in the polarization sectional view 20L parallel to the radiation surface. Two waves excite the radio wave polarization conversion resonant reflector 10. These radio signals resonate in a plane resonance circuit and generate induced currents Ia and Ib parallel to these electric field components Eia and Eib on the patch conductor 3, respectively. Here, since the current Ia generated on the resonance axis RA2 of the patch conductor 3 resonates in a planar circuit at a resonance frequency fh higher than the communication frequency f0, the phase thereof is 45 degrees from the resonance frequency fh at the communication frequency f0. move on. On the other hand, the current Ib generated on the resonance axis RA1 of the patch conductor 3 resonates in a planar circuit at a resonance frequency fl lower than the communication frequency f0, so that the phase is delayed by 45 degrees from the resonance frequency fl at the communication frequency f0. . Furthermore, these currents Ia and Ib generate and radiate electric field components Era and Erb parallel to them. These two radiated electric field components Era and Erb have a phase difference of 90 degrees, and the electric field component Era has a phase advance of 90 degrees relative to the electric field component Erb, and these electric field components are reflected and re-radiated. Ec becomes a circularly polarized radio signal 10S. As a result, as shown in FIG. 6, the radio signal 10S advances in the right direction in FIG. 6 while rotating the electric field component Ec of the re-radiated circularly polarized radio signal 10S. An electric field component parallel to the antenna is generated, and in response to this, the wireless IC tag 8 is activated.

Here, if the metal-compatible wireless IC tag device 50 is rotated from the position of FIG. 5 about the center O in a state where the linear polarization axis from the interrogator 20 is fixed to be parallel to the Y-axis, the radio wave Although the generation intensity of the circularly polarized radio signal by the polarization conversion resonant reflector 10 becomes small, the polarization changes from the circular polarization to the elliptical polarization by the rotation, and becomes the linear polarization by the further rotation. Due to the rotation, the polarization changes by repeating circular polarization → elliptical polarization → linear polarization → elliptical polarization → circular polarization →. In either case, an electric field component parallel to the wireless IC tag 8 is generated, and the wireless IC tag 8 operates. In addition, since there is no radio wave radiation to the ground conductor 2 side of the radio wave polarization conversion resonant reflector 10, the metal-compatible wireless IC tag device 50 can be configured such that the ground conductor 2 side is a mounting surface for an object. In addition, this means that the radio wave polarization conversion resonant reflector 10 according to the present embodiment has the following actions depending on the appropriate mounting position of the wireless IC tag 8 in addition to the reflection by the planar circuit resonance. Means.
(A) The incident linearly polarized radio signal is converted into a circularly polarized wave or an elliptically polarized radio signal and reflected to the radio IC tag 8.
(B) The incident circularly or elliptically polarized radio signal is converted into a linearly polarized radio signal and reflected to the radio IC tag 8.
(C) A linearly polarized radio signal from the radio IC tag 8 is converted into a circularly polarized wave or an elliptically polarized radio signal and reflected.
(D) If the wireless IC tag 8 emits a circularly or elliptically polarized wireless signal, the circularly or elliptically polarized wireless signal from the wireless IC tag 8 is converted into a linearly polarized wireless signal. Convert and reflect.
The radio wave polarization conversion resonant reflector 10 may not convert the polarization, but it is included in the action.

  In the formation of the metal-compatible wireless IC tag device 50 shown in each of the above examples, the wireless IC tag 8 with respect to the patch conductor 3 of the radio wave polarization conversion resonant reflector 10 is the end of the central portion of each side of the patch conductor 3. It is preferable that the straight line connecting the center O and the linear polarization axis of the wireless IC tag 8 be arranged in parallel. In addition, since the interval and the arrangement positional relationship between the patch conductor 3 and the wireless IC tag 8 differ depending on the tag antenna system of the wireless IC tag 8, the connection method of the IC, the casing, and the like, the optimal position is determined experimentally. This is one of the features that can be easily adjusted because the radio wave polarization conversion resonant reflector 10 and the wireless IC tag 8 are separated. Furthermore, there is a specific effect that a radio wave polarization conversion resonant reflector 10 suitable for one radio IC tag 8 can be used to obtain a radio wave polarization conversion characteristic suitable for the application.

Second embodiment.
FIG. 7 is a plan view showing a configuration of a metal-compatible wireless IC tag device 50A according to the second embodiment of the present invention. FIG. 8 is a longitudinal sectional view taken along line DD ′ of FIG. FIG. 9 is a plan view showing the configuration and operation of the wireless IC tag 8 of FIGS. The metal-compatible wireless IC tag device 50A according to the second embodiment includes a radio wave polarization conversion resonant reflector 10A. As shown in FIGS. 7 and 8, the metal-compatible wireless IC tag device 50 according to the first embodiment. The following points are different.
(1) Instead of the square patch conductor 3, a circular patch conductor 3A was used.
(2) A resonance axis RA11 having the same length as the diameter of the patch conductor 3A is provided at a position corresponding to the resonance axis RA1 in FIG.
(3) A resonance axis RA12 having substantially rectangular notches 3c and 3d at both ends thereof and having a length shorter than the diameter of the patch conductor 3A is provided at a position corresponding to the resonance axis RA2 in FIG.
(4) The wireless IC tag 8 is mounted such that its longitudinal direction includes the center O and is along the −Y axis.

  In FIG. 7, the shape of the patch conductor 3A has a lower resonance frequency fl at the resonance axis RA11 and a higher resonance frequency fh at the resonance axis RA12, and the communication frequency f0 as in the first embodiment. , And the phase of the communication frequency f0 is substantially 45 degrees from the resonance frequency fh by the resonance phase characteristic by the resonance axis RA12. It is set so as to move forward only.

  In FIG. 9, for example, the wireless IC tag 8 shows an example in which a C-shaped antenna is used by bending both ends of a half-wavelength dipole antenna 8b on a dielectric substrate 8c into a U-shape for the purpose of miniaturization. In this wireless IC tag 8, when the current flowing through the antenna 8b is bent in a U-shape, the direction is partially reversed, and the electric field component radiated therefrom also generates a backward component, and radio wave radiation from the entire antenna 8b. Is smaller than that of a linear dipole antenna, and the gain is lowered. However, a radiation electric field component En that is orthogonal to the electric field Et in the longitudinal direction of the antenna 8b is also generated, and there is an application that is suitable as the wireless IC tag 8. Similarly, the dipole antenna 8b may be folded back on both surfaces of the dielectric substrate 8c using both surfaces of the dielectric substrate 8c. In addition, as the wireless IC tag 8, various devices can be applied as long as they have at least one linearly polarized electric field radiation component.

Third embodiment.
FIG. 10 is a plan view showing a configuration of a metal-compatible wireless IC tag device 50B according to the third embodiment of the present invention. The metal-compatible wireless IC tag device 50B according to the third embodiment includes a radio wave polarization conversion resonant reflector 10B, and differs from the metal-compatible wireless IC tag device 50 according to the first embodiment in the following points.
(1) A strip-shaped slot 3S including the center O of the square patch conductor 3B and having a longitudinal direction in the direction of the azimuth angle θ = 45 degrees is formed in the patch conductor 3B.
(2) In order to determine one arrangement position of the wireless IC tag from the patch conductor 3B in the + X-axis direction, a protruding portion 3e protruding in a rectangular shape is formed.
(3) The wireless IC tag 8 is preferably mounted so that the longitudinal direction thereof is along the + X axis, for example, as indicated by a position 8A.

  In FIG. 10, a rectangular patch conductor 3B is formed with a slot 3S at the center so that the longitudinal direction thereof is the azimuth angle θ = 45 degrees, whereby the azimuth angle θ = ± 45 in the patch conductor 3B. The plane circuit resonance is set at the two resonance frequencies fl and fh described above with two axes orthogonal to each other in the degree direction. Note that the resonance phase setting conditions are the same as in the first embodiment. Further, the wireless IC tag 8 may be disposed in parallel with the straight line connecting the end of the patch conductor 3B and the center O so that the electric field axis of the linearly polarized wave is not limited to the position 8A in FIG. It may be at position 8B or 8C. At the position 8B, the wireless IC tag 8 is mounted along the −Y axis. At the position 8C, the wireless IC tag 8 is mounted along the diagonal line of the patch conductor 3B.

Fourth embodiment.
FIG. 11 is a plan view showing a configuration of a metal-compatible wireless IC tag device 50C according to the fourth embodiment of the present invention. The metal-compatible wireless IC tag device 50C according to the fourth embodiment includes a radio wave polarization conversion resonant reflector 10C, and is different from the metal-compatible wireless IC tag device 50 according to the first embodiment in the following points.
(1) The patch conductor 3C has a rectangular shape, and the short side direction and the long side direction are set as resonance axes, respectively, and the lengths of these two resonance axes are set to resonate in a planar circuit at resonance frequencies fh and fl, respectively. Is done. Note that the resonance phase setting conditions are the same as in the first embodiment.
(2) The wireless IC tag 8 is mounted along the diagonal line of the patch conductor 3C, for example, as shown in FIG.

Fifth embodiment.
FIG. 12 is a plan view showing the configuration and operation of a metal-compatible wireless IC tag device 50D according to the fifth embodiment of the present invention. FIG. 13 is a longitudinal sectional view taken along line EE ′ of FIG. 12 and a side view of the interrogator 20, showing the positional relationship and operation between the metal-compatible wireless IC tag device 50 D of FIG. 12 and the interrogator 20.

The metal-compatible wireless IC tag device 50D according to the fifth embodiment includes a radio wave polarization conversion resonant reflector 10D, and differs from the metal-compatible wireless IC tag device 50 according to the first embodiment in the following points.
(1) A square patch conductor 3D having no notch is provided. Here, each side of the patch conductor 3D is parallel to the X-axis or the Y-axis, and the patch conductor 3D passes through the center O and passes along the X-axis to the resonance axis RA21 connecting both ends of the patch conductor 3D, and the center. A resonance axis RA22 that passes through O and connects both ends of the patch conductor 3D along the Y axis is provided.
(2) The right end portion of the resonance axis RA21 and the lower end portion of the resonance axis RA22 are connected, and the phase adjusting strip conductor 11 having a predetermined length described later is formed on the dielectric substrate 1. Here, the strip conductor 11 and the ground conductor 2 formed via the dielectric substrate 1 constitute a phase adjustment transmission line which is a microstrip line.

  In FIG. 12, the patch conductor 3 </ b> D preferably has a length of each side that is approximately half of the guide wavelength λg in consideration of the dielectric substrate 1, or an odd multiple thereof, and has a resonance axis RA <b> 21 having the length. , RA22 so that planar circuit resonance occurs at the resonance frequency f0. Further, the length of the strip conductor 11 is preferably set to approximately 1/4 of the guide wavelength λg considering the dielectric substrate 1 or an odd multiple thereof. Further, the wireless IC tag 8 is disposed and mounted on the patch conductor 3D, for example, preferably parallel to the X axis or the Y axis.

  14 to 16 are plan views showing the operation when the wireless IC tag 8 is placed on the patch conductor 3D shown in FIGS. Next, referring to FIG. 12 to FIG. 16, the operation of the radio wave polarization conversion resonant reflector 10D that converts a circularly polarized radio signal into a linearly polarized radio signal and reflects it, and the radio IC tag 8 are mounted. The operation of the metal-compatible wireless IC tag device 50D will be described below.

  In FIG. 13, an interrogator 20 disposed in front of the radio wave polarization conversion resonant reflector 10D (right side in FIG. 13) transmits a circularly polarized radio signal toward the radio wave polarization conversion resonance reflector 10D. Here, as shown in FIG. 12, the wireless IC tag 8 is arranged along the X axis including the center O of the patch conductor 3D. When the electric field component of the rotating circularly-polarized radio signal transmitted from the interrogator 20 is Ec, the circularly-polarized radio signal is two linearly-polarized radio signals whose orthogonal phase differences are different by 90 degrees. Thus, the electric field components of the two decomposed radio signals can be expressed as Eca and Ecb, where the electric field component Ecb is a left-handed circularly polarized wave whose phase is advanced by 90 degrees from the electric field component Eca.

  First, re-radiation from the patch conductor 3D when the two linearly polarized radio signals are incident on the radio wave polarization conversion resonant reflector 10D will be described. Considering the electric field components Ecb and Eca separately, the operation of the electric field component Ecb will be described first. 12 and 13, the electric field component Ecb is incident so as to be parallel to the Y axis of the patch conductor 3 </ b> D, and undergoes planar circuit resonance along the resonance axis RA22. Thereby, a current Icb parallel to the Y axis flows on the patch conductor 3D as shown in FIG. As a result, the current Icb flows to the patch conductor 3D through the strip conductor 11 and the end portions on the X-axis side of the patch conductor 3D. Therefore, since the phase adjustment transmission line including the strip conductor 11 has a length of ¼ of the guide wavelength λg, for example, it is orthogonal to Icb on the patch conductor 3D and only 90 degrees from the current Icb in the X-axis direction. A current Icb (-90 °) whose phase is delayed (the phase display here is a phase based on the current Icb, and so on). The current Icb (−90 °) indicates that the phase is delayed by 90 degrees from the current Icb. Therefore, as shown in FIG. 14, currents Icb and Icb (−90 °) orthogonal to each other flow on the patch conductor 3D.

  Next, the operation of another linearly polarized electric field component Eca that forms a circularly polarized radio signal will be described with reference to FIG. The linearly polarized electric field component Eca parallel to the X-axis in FIG. 15 is incident on the patch conductor 3D and undergoes planar circuit resonance along the resonance axis RA21. As a result, as shown in FIG. 15, a current Ica parallel to the electric field component Eca is generated. Incidentally, since the phase of the electric field component Eca is delayed by 90 degrees compared to the electric field component Ecb described above, the phase of the current Ica is also delayed by 90 degrees compared to the current Icb. Therefore, the current Ica can be expressed as Ica = Icb (−90 °). The electric field components Eca and Ecb are assumed to have the same absolute value. On the other hand, the current Ica = Icb (−90 °) flows through the phase adjustment transmission line including the strip conductor 11 and also flows in the Y-axis direction of the patch conductor 3D. However, since the length of the phase adjustment transmission line is λg / 4, for example, there is a delay of 90 degrees. Therefore, the current flowing in the Y-axis direction of the patch conductor 3D is further delayed by 90 degrees from the current Ica, and as a result, the current can be expressed as Icb (−180 °). The circularly polarized radio signal has the above two electric field components transmitted at the same time, so that the current flowing through the patch conductor is synthesized. That is, the current in the Y-axis direction of the patch conductor 3D is canceled because the phase differs by 180 degrees, and only the current in the X-axis direction (2Ica) is generated as shown in FIG. The radiation electric field generated by the current (2Ica) is a linearly polarized radio signal that changes in the X-axis direction. Therefore, the wireless IC tag 8 having a linearly polarized antenna arranged in parallel with the X-axis direction in front of the patch conductor 3D matches the linearly polarized wireless signal from the patch conductor 3D with the electric field axis direction. Communication is possible by effectively receiving a radio signal from the patch conductor 3D.

  Further, the radio signal returned from the wireless IC tag 8 and modulated in accordance with the tag information is subjected to polarization conversion by the operation opposite to the above operation, and then the circularly polarized radio signal is returned to the interrogator 20. . Therefore, the radio wave polarization conversion resonant reflector 10D converts the circularly polarized radio signal into a linearly polarized radio signal and executes the reverse process. Further, since the ground conductor 2 is formed on the back surface of the radio wave polarization conversion resonant reflector 10D, it is possible to prevent radio wave radiation to the back of the back surface and attach the surface side to any object including a metal body. it can.

  In the above embodiment, the example of the left-handed circularly polarized wave is described, but the same applies to the right-handed circularly polarized wave. In that case, the optimum position of the wireless IC tag 8 on the patch conductor 3D is preferably arranged along the Y-axis direction orthogonal to the above-described X-axis direction. In FIG. 12, the dotted line indicates the arrangement in that case.

First modified example of the fifth embodiment.
FIG. 17: is a top view which shows the structure and operation | movement of the metal corresponding | compatible radio | wireless IC tag apparatus 50E which concern on the 1st modification of the 5th Embodiment of this invention. 18 is a longitudinal sectional view taken along line FF ′ in FIG. 17 and a side view of the interrogator 20, showing the positional relationship and operation between the metal-compatible wireless IC tag device 50E in FIG. 17 and the interrogator 20. In the first modification, the metal-compatible wireless IC tag device 50E includes the radio wave polarization conversion resonant reflector 10E, and the operation when a linearly polarized radio signal arrives from the interrogator 20 will be described below.

  In FIG. 18, it is assumed that the electric field Ei of the radio signal of linear polarization from the interrogator 20 varies in the vertical direction of FIG. When the radio wave polarization conversion resonant reflector 10E is not present, the linearly polarized radio signal Ei from the interrogator 20 is orthogonal to the radio IC tag 8, so that even if the signal intensity is relatively high, the radio IC tag 8 Inoperable.

  Next, when the radio wave polarization conversion resonant reflector 10E is arranged behind the wireless IC tag 8 with respect to the transmission signal from the interrogator 20, the linearly polarized radio signal from the interrogator 20 is an orthogonal radio. The IC tag 8 does not act directly, and reaches the radio wave polarization conversion resonant reflector 10E. The electric field component Ei of the radio signal from the interrogator 20 undergoes planar circuit resonance by the resonance axis RA22 parallel to the Y axis, and as a result, the current Ira along the Y axis parallel to the electric field Ei is formed on the square patch conductor 3E. Is generated. Here, the current Ira flows into the end on the + X-axis side of the patch conductor 3E via the phase adjustment transmission line including the strip conductor 11, flows in the X-axis direction in the patch conductor 3E, and the current along the X-axis is Let Irb. Here, if the line length of the strip conductor 11 is λg / 4, for example, the currents Ira and Irb are orthogonal to each other on the patch conductor 3E, and the current Irb is a current delayed by 90 degrees compared to the current Ira. The current flowing on the patch conductor 3E radiates an electric field component parallel thereto. Assuming that the radiated electric fields for the currents Ira and Irb are electric field components Era and Erb, respectively, the electric field component Erb is an electric field component whose phase is delayed by 90 degrees with respect to the electric field component Era. As a result, the combined electric field component Ec by the two electric field components Era and Erb is circularly polarized and re-radiated from the patch conductor 3E while rotating. Therefore, since the rotating electric field component has an electric field component parallel to the dipole antenna of the wireless IC tag 8 arranged in front of the rotating electric field component, the wireless IC tag 8 receives the wireless signal and starts.

  In response to this, the wireless IC tag 8 digitally modulates the wireless carrier wave according to the tag information, and returns the wireless signal to the interrogator 20 via the radio wave polarization conversion resonant reflector 10E. Here, in the radio wave polarization conversion resonant reflector 10E, an operation reverse to the above is executed, and the interrogator 20 is returned with the same linear polarization as the radio signal transmitted from the interrogator 20. The interrogator 20 digitally demodulates the radio signal from the radio IC tag 8 to extract tag information. When the direction of the linearly polarized radio signal from the interrogator 20 is fixed, for example, in a direction parallel to the Y-axis direction, the radio signal can be rotated around the center O of the patch conductor 3E from the position of the radio IC tag 8 in FIG. For example, although the effect of the above-described circular polarization becomes small, an electric field component parallel to the radiation axis of the wireless IC tag 8 is generated, so that the wireless IC tag 8 is activated. Further, since there is no radio wave radiation to the ground conductor 2 side of the radio wave polarization conversion resonant reflector 10E, the radio IC tag 8 is realized as a metal-compatible radio IC tag device 50E with the ground conductor 2 side mounted on the object. it can.

Second modification of the fifth embodiment.
FIG. 19 is a plan view showing the configuration and operation of a metal-compatible wireless IC tag device 50F according to a second modification of the fifth embodiment of the present invention. In the modification, the metal-compatible wireless IC tag device 50F includes a radio wave polarization conversion resonant reflector 10F, and in comparison with the fifth embodiment, instead of the square patch conductor 3D, resonance axes orthogonal to each other. This is that a circular patch conductor 3F having RA21 and RA22 is formed, and other configurations and operational effects are the same as those of the fifth embodiment and the first modification thereof.

Sixth embodiment.
FIG. 20 is a plan view showing the configuration and operation of a metal-compatible wireless IC tag device 50G provided with a radio wave polarization conversion resonant reflection device 10G according to the sixth embodiment of the present invention. FIG. 21 is a longitudinal sectional view taken along line GG ′ of FIG. The metal-compatible wireless IC tag device 50G according to the sixth embodiment includes a radio wave polarization conversion resonant reflection device 10G, which is on the dielectric substrate 1 as compared with the metal-compatible wireless IC tag device 50 according to the first embodiment. 1 includes two patch conductors 3P and 3Q having the same configuration as the patch conductor 3 in FIG. 1, and the two patch conductors 3P and 3Q have an electrical length of λg / 2 (an odd multiple of λg / 2). It is characterized by being connected by a connection transmission line which is a microstrip line including the strip conductor 12.

  In FIG. 20, the patch conductor 3P has notches 3pa and 3pb, and has resonance axes RA31 and RA32 orthogonal to each other. The patch conductor 3Q has notches 3qa and 3qb, and has resonance axes RA41 and RA42 orthogonal to each other. An end in the + X-axis direction of the patch conductor 3P and an end in the −X-axis direction of the patch conductor 3Q are connected by a connection transmission line including the strip conductor 12. Here, the wireless IC tag 8 is disposed, for example, on the patch conductor 3P and along the X-axis direction, and is disposed so that the radiation electric field axis of the antenna of the wireless IC tag 8 is parallel to the X-axis direction.

  The radio wave polarization conversion and reflection processing by the patch conductors 3P and 3Q configured as described above is the same as that of the first embodiment, but the circularly polarized radio signal from the interrogator 20 is the patch conductor 3P. A current for radiating a linearly polarized radio signal is generated on 3Q. At this time, the substantial propagation gain can be further increased by the two patch conductors 3P and 3Q. The operation will be described in detail below.

  In FIG. 20, when a circularly polarized radio signal is incident on the radio wave polarization conversion resonant reflection device 10G, the patch conductors 3P, 3Q are provided on the two patch conductors 3P, 3Q as described with reference to FIG. A current that induces linear polarization is induced. In the patch conductor 3P, the current Ia flows on the patch conductor 3P in the direction of the arrow, and the current also flows on the patch conductor 3Q connected to the patch conductor 3P via the strip conductor 12. On the other hand, a similar current Ib is generated in the patch conductor 3Q, and also flows through the strip conductor 12 to the patch conductor 3P. By the way, since the line length of the connection transmission line that connects the patch conductor 3P and the patch conductor 3Q is substantially a half wavelength, the current flowing through the connection transmission line is reversed, and further, the current flows into the patch conductor 3Q or 3P on the other side. Is reversed. Therefore, the currents Ia and Ib become in-phase currents on the other side patch conductors 3Q or 3P and strengthen each other. As a result, the radio signal re-radiated on any one of the patch conductors 3P and 3Q is strengthened and gives a stronger radio signal to the radio IC tag 8 disposed on the upper part. Therefore, in this embodiment, the communication distance can be made longer than in the first embodiment.

  In the above embodiment, an example using two patch conductors 3P and 3Q has been shown. However, a radio wave polarization conversion resonant reflector in which another patch conductor is further added may be formed by the same method. That is, a connection having a plurality of patch conductors or a plurality of radio wave polarization conversion resonant reflectors and having a line length that is an odd multiple of 1/2 of the in-tube wavelength of the communication frequency in the connection transmission line The plurality of patch conductors or radio wave polarization conversion resonant reflectors are connected by transmission lines so that all the radio wave polarization conversion resonance reflectors are connected to at least any other radio wave polarization conversion resonance reflector. Connect to each other. Also in this case, since there is a ground conductor on the back side of the patch conductors 3P and 3Q, a metal-compatible wireless IC tag is obtained. When the number of patch conductors is increased, the aperture area increases, so that the substantial propagation gain can be increased.

Seventh embodiment.
FIG. 22 is a plan view showing the configuration and operation of a metal-compatible wireless IC tag device 50H according to the seventh embodiment of the present invention. FIG. 23 is a longitudinal sectional view taken along line HH ′ of FIG. The metal-compatible wireless IC tag device 50H according to the seventh embodiment includes a radio wave polarization conversion resonant reflector 10H, and is characterized in that it does not have the ground conductor 2 by itself as compared with the above embodiment.

  22 and FIG. 23, a radio wave polarization conversion resonant reflector 10H in which, for example, a circular patch conductor 3F is formed on a dielectric substrate 1 and a wireless IC tag 8 is formed via a tag mounting base 9 is provided. The back surface of the dielectric substrate 1 is directly attached to the surface of the metal plate 13. Here, the surface of the metal plate 13 operates as a ground conductor of the radio wave polarization conversion resonant reflector 10H, and becomes a metal-compatible wireless IC tag by the same operation as described above. The radio wave polarization conversion resonant reflector 10H can be formed more easily because it does not have a ground conductor by itself.

Eighth embodiment.
FIG. 24 is a back view showing the configuration and operation of the metal-compatible wireless IC tag device 50I according to the eighth embodiment of the present invention. 25 is a longitudinal sectional view taken along line II ′ of FIG. FIG. 24 shows the back surface of the radio wave polarization conversion resonant reflector 10I. In the eighth embodiment, the metal-compatible wireless IC tag device 50I includes a radio wave polarization conversion resonant reflector 10I.

  24 and 25, in the radio wave polarization conversion resonant reflector 10I, a dielectric thin film 1A is formed instead of the dielectric substrate 1, and a circular patch conductor 3F is formed on the dielectric thin film 1A, for example. As shown in FIG. 25, the patch conductor 3F of the radio wave polarization conversion resonant reflector 10I is placed on the lower side and attached to the dielectric wall 14 having the metal plate 13 (operating as a ground conductor) on one side. The patch conductor 3F of the radio wave polarization conversion resonant reflector 10I is covered and protected by the dielectric thin film 1A, and the dielectric thin film 1A can be used as a display surface for various labels, for example. The wireless IC tag 8 is attached to the surface. Since the radio wave polarization conversion resonant reflector 10I can be formed of a thin film, it has a specific effect that it can be easily applied to a circular object or the like.

Ninth embodiment.
FIG. 26 is a plan view showing the configuration and operation of a metal-compatible wireless IC tag device 50J according to the ninth embodiment of the present invention. 27 is a longitudinal sectional view taken along line JJ ′ of FIG. In the ninth embodiment, the metal-compatible wireless IC tag device 50J includes a radio wave polarization conversion resonant reflector 10J.

  In the ninth embodiment, the patch conductor 3 having the same shape as that of the first embodiment is formed of a conductive thin film such as a copper plate or an aluminum foil. An adhesive for attaching the patch conductor 3 to the object may be used in combination. The present embodiment can be applied to the dielectric wall 14 having the metal plate 13A on the back surface. In ordinary electronic devices and information devices, a plastic housing with a metal coating on the inside is often used to suppress unnecessary radiation of electromagnetic waves. In this case, the coated metal part is used as the ground conductor of the radio wave polarization conversion resonant reflector 10J, and the radio wave polarization conversion resonance reflector 10J composed of only the patch conductor 3 is formed outside the housing case. The wireless IC tag 8 can be installed via the tag mounting base 9. For example, in FIG. 27, the dielectric wall 14 is a wall surface of a housing such as plastic, and a patch conductor is disposed on the outside thereof, and the wireless IC tag 8 is mounted. If there is no conductor such as the metal plate 13A on the dielectric wall 14, a metal or the like may be provided inside the housing. Furthermore, when the thickness of the dielectric wall 14 is insufficient, a dielectric spacer 17 shown in FIGS. 33 and 34, which will be described later, may be used.

  In the ninth embodiment, the rectangular patch conductor 3 having a notch is used. However, the present invention is not limited to this, and a patch conductor having a circular shape, an elliptical shape, or other shapes may be used.

Tenth embodiment.
FIG. 28 is a perspective view showing the configuration and operation of a metal-compatible wireless IC tag device 50K according to the tenth embodiment of the present invention. FIG. 29 is an enlarged view showing details of the metal-compatible wireless IC tag device 50K of FIG. In this embodiment, as shown in FIGS. 28 and 29, the radio wave polarization conversion resonant reflector 10K is mounted and disposed on the dielectric wall 16 of the packaging box 15.

  30 to 34 are longitudinal sectional views showing configurations of first to fifth examples 50K-1 to 50K-5 of the metal-compatible wireless IC tag device 50K according to the tenth embodiment. Here, the first to fifth embodiments 50K-1 to 50K-5 of the metal-compatible wireless IC tag device 50K include radio wave polarization conversion resonant reflectors 10K-1 to 10K-5, respectively.

  FIG. 30 showing the first embodiment 50K-1 of the metal-compatible wireless IC tag device 50K is an integral formation in which the ground conductor 2 is formed on one side of the dielectric substrate 1 and the patch conductor 3 is formed on the other side. This is an example in which a radio wave polarization conversion resonant reflector 10K-1 is mounted on a dielectric wall 16 and a wireless IC tag 8 is installed. Since the radio wave polarization conversion resonant reflector 10K-1 has the ground conductor 2, the wireless IC tag 8 can be mounted on any object as it is without being limited to the packing box 15, and the metal-compatible wireless IC tag device 50K-1 can be formed. .

  In FIG. 31 illustrating a second embodiment 50K-2 of the metal-compatible wireless IC tag device 50K, the ground conductor is not formed on the dielectric substrate 1, but the ground conductor 2A is formed inside the dielectric wall 16. It is an example. The radio wave polarization conversion resonant reflector 10K-2 is attached to the dielectric wall 16 of the packing box 15, the ground conductor 2A is provided inside the dielectric wall 16, and the patch conductor 3 is wirelessly connected via the tag mounting base 9. The IC tag 8 is mounted and arranged. Thereby, it becomes the metal corresponding | compatible radio | wireless IC tag apparatus 50K-2, and the substantial propagation gain of the radio | wireless IC tag 8 can be increased.

  FIG. 32 illustrating a third embodiment 50K-3 of the metal-compatible wireless IC tag device 50K is an example using a radio wave polarization conversion resonant reflector 10K-3 made up of only the patch conductor 3. The radio wave polarization conversion resonant reflector 10K-3 made of the patch conductor 3 is attached from the outside of the dielectric wall 16 of the packing box 15, and the ground conductor 2A made of a metal film or the like is formed on the inside. Here, the wireless IC tag 8 is mounted on the patch conductor 3. The radio wave polarization conversion resonant reflector 10K-3 made of the patch conductor 3 can be easily formed by forming the ground conductor 2A by a printing technique or the like when the packaging box 15 is manufactured. In addition, as described above, if there is a metal foil of the ground conductor 2A inside the wall surface of the packing box 15 or the container, the patch conductor 3 is attached to the outer wall, and the radio wave polarization conversion resonant reflector on which the wireless IC tag 8 is mounted. It is only necessary to install 10K-3. Thereby, the metal-compatible wireless IC tag device 50K-3 can be formed.

  FIG. 33 illustrating a fourth embodiment 50K-4 of the metal-compatible wireless IC tag device 50K shows a method in which the dielectric spacer 17 is used in the radio wave polarization conversion resonant reflector 10K-4. For example, if the thickness of the dielectric wall 16 is very thin, a sufficient effect may not be obtained as the radio wave polarization conversion resonant reflector 10K-4. In this case, the effect can be enhanced by inserting the dielectric spacer 17 between the ground conductor 2 </ b> B and the patch conductor 3 and increasing the thickness of the dielectric wall 16. The dielectric spacer 17 may be used on the front side of the dielectric wall 16. Thereby, the metal-compatible wireless IC tag device 50K-4 can be formed, and since this is not affected by the electrical influence on the back surface, it has good propagation characteristics regardless of the contained articles in the packing box 15.

  FIG. 34 showing a fifth embodiment 50K-5 of the metal-compatible wireless IC tag device 50K shows the radio wave polarization conversion resonant reflector 10K-5 in order to reduce the protrusion of the dielectric wall 16 to the outside. In this example, the polarization conversion resonant reflector 10K-5 is provided inside the dielectric wall 16, and the wireless IC tag 8 is mounted and installed via the dielectric wall 16 and the tag mounting base 9. Thereby, the metal-compatible wireless IC tag device 50K-5 can be formed.

  Next, experiments and results obtained by the inventors will be described below.

  FIG. 35 is a plan view showing the azimuth angle φ of the wireless IC tag 8 when the maximum communication distance of the independent wireless IC tag 8 according to the comparative example is measured facing the antenna 20A of the interrogator 20. FIG. FIG. 36 is a plan view showing the azimuth angle φ when the maximum communication distance of the metal-compatible wireless IC tag device 50K according to the first embodiment is measured. FIG. 37 is a graph showing the maximum communication distance with respect to the azimuth angle φ, which is the experimental result of the inventors of FIGS. 35 and 36. In FIG. 35, the azimuth angle φ of the independent wireless IC tag 8 is clockwise when viewed from above. Also in FIG. 36, the same applies to the metal-compatible wireless IC tag device 50 in which the wireless IC tag 8 is placed on the patch conductor 3.

  FIG. 37 shows an example of an experimental result in a state in conformity with an actual use form for showing the operation and effect of the metal-compatible wireless IC tag device 50 using the radio wave polarization conversion resonant reflector 10 according to the first embodiment. It is. In the experiment, as an independent wireless IC tag 8, a 2.45 GHz band wireless IC tag in which a tag IC was mounted on a general dipole antenna and molded with a dielectric was used. Further, a left-handed circularly polarized wave that is highly practical for tag communication is transmitted from the antenna 20A of the interrogator 20, and the radio IC tag 8 is opposed to the antenna 20A of the interrogator 20 in consideration of the degree of freedom in the tag mounting direction. And measured the maximum communication distance. The metal-compatible wireless IC tag device 50 may be attached to any object. However, since the wireless IC tag 8 itself is affected by the attached object, it is attached to the surface of a foam material and a similar experiment is performed as a comparative example. . In addition, the radio wave polarization conversion resonant reflector 10 used in the metal-compatible wireless IC tag device 50 uses, for example, a 3 mm thick foam material plate as the dielectric substrate 1 to form the patch conductor 3 and the ground conductor 2 with a thin copper plate. is doing. The interrogator 20 and the metal-compatible wireless IC tag device 50 are opposed to each other, and the maximum communication distance is measured while rotating the metal-compatible wireless IC tag device 50 in the same manner as the independent wireless IC tag 8.

  According to the measurement results, as apparent from FIG. 37, the maximum communication distance of the metal-compatible wireless IC tag 50 using the radio wave polarization conversion resonant reflector 10 is about the communication distance of the wireless IC tag 8 alone. It has doubled. This effect is obtained by converting the circularly polarized wave into a linearly polarized wave by the radio wave polarization converting resonant reflector 10 and efficiently supplying a radio signal to the radio IC tag. It is analyzed that the electric field enhancement of the radio signal due to the resonance effect of 3 dB is improved by 3 dB. The fluctuation of the maximum communication distance accompanying the rotation of the wireless IC tag 8 is mainly due to the axial ratio of the antenna 20A of the interrogator 20.

  As described above, according to the embodiment of the present invention, a characteristic planar radio wave polarization conversion resonant reflector 10 and a normal small-sized wireless IC tag 8 are arranged in front of it. Then, based on the specific positional relationship between the wireless IC tag 8 and the radio wave polarization conversion resonant reflector 10, the incoming wireless signal is subjected to polarization conversion, the re-radiation electric field axis and the radiation electric field axis of the wireless IC tag 8 are combined, and wireless An effective radio signal is given to the IC tag 8. The wireless IC tag 8 is detachable, and by changing the arrangement relationship thereof, it is possible to effectively cope with different polarized waves. Further, the plane power circuit resonance of the radio wave polarization conversion resonant reflector 10 increases the signal power density and gives a stronger wireless signal to the wireless IC tag 8. Thereby, the propagation gain related to the wireless IC tag 8 is substantially increased, and communication over a longer distance becomes possible. The wireless IC tag 8 disposed on the radio wave polarization conversion resonant reflector 10 has a smaller shielding effect against incoming waves as the area ratio of the wireless IC tag 8 occupied on the wireless IC tag 8 is smaller than the area of the patch conductor 3. Therefore, the effect of improving the communication capability of the small wireless IC tag 8 can be greatly obtained. Further, by installing the radio wave polarization conversion resonant reflector 10 behind the small wireless IC tag 8, a metal-compatible wireless IC tag device 50 that can be mounted on any object including a metal body very important for the wireless IC tag 8. Can be realized. Furthermore, in particular, it is possible to provide an optimum means for circular polarization communication that increases the degree of freedom of attachment of the wireless IC tag 8 and wireless communication. One normal wireless IC tag 8 can obtain a suitable form and performance by using various radio wave polarization conversion resonant reflectors 10 in the process of production, distribution, distribution, repair, disposal, etc. Therefore, the use range of the wireless IC tag 8 can be widened, and the economical wireless IC tag 8 can be realized.

  The radio wave polarization conversion resonant reflector according to the present embodiment can be formed independently. However, if the outer wall is incorporated in an article such as a packing box or various equipment housings in advance, for example, a small and thin wireless By simply mounting the IC tag 8 on the wall surface, the propagation gain is substantially increased, and the wireless IC tag device 50 is simple and highly practical. By using the metal-compatible wireless IC tag device 50, a high-performance system suitable for the application can be realized as an RFID system. In the future, the devices according to the embodiments of the present invention can be used in the same manner as other wireless communication devices are miniaturized.

  In the above embodiment, the one-layer dielectric substrate 1 is used. However, the present invention is not limited to this, and a two-layer or more dielectric substrate or dielectric may be used.

1 is a plan view showing a configuration of a radio wave polarization conversion resonant reflector 10 according to a first embodiment of the present invention. It is a longitudinal cross-sectional view about the A-A 'line | wire of FIG. It is a top view which shows the structure and operation | movement of the metal corresponding | compatible radio | wireless IC tag apparatus 50 by which the radio | wireless IC tag 8 is mounted on the radio wave polarization conversion resonant reflector 10 of FIG. FIG. 4 is a longitudinal sectional view taken along line B-B ′ in FIG. 3 and a side view of the interrogator 20, showing an arrangement relationship and operation between the metal-compatible wireless IC tag device 50 in FIG. 3 and the interrogator 20. It is a top view which shows the structure and operation | movement of the metal corresponding | compatible radio | wireless IC tag apparatus 50 which concern on the modification of the 1st Embodiment of this invention. FIG. 6 is a longitudinal sectional view taken along line C-C ′ in FIG. 5 and a side view of the interrogator 20, showing a positional relationship and operation between the metal-compatible wireless IC tag device 50 in FIG. 5 and the interrogator 20. It is a top view which shows the structure of 50 A of metal corresponding | compatible radio | wireless IC tag apparatuses which concern on the 2nd Embodiment of this invention. It is a longitudinal cross-sectional view about the D-D 'line | wire of FIG. It is a top view which shows the structure and operation | movement of the radio | wireless IC tag 8 of FIG.7 and FIG.8. It is a top view which shows the structure of the metal corresponding | compatible radio | wireless IC tag apparatus 50B which concerns on the 3rd Embodiment of this invention. It is a top view which shows the structure of 50 C of metal corresponding | compatible radio | wireless IC tag apparatuses which concern on the 4th Embodiment of this invention. It is a top view which shows the structure and operation | movement of metal corresponding | compatible radio | wireless IC tag apparatus 50D which concern on the 5th Embodiment of this invention. FIG. 13 is a longitudinal sectional view taken along line E-E ′ of FIG. 12 and a side view of the interrogator 20, showing the arrangement relationship and operation between the metal-compatible wireless IC tag device 50 </ b> D of FIG. 12 and the interrogator 20. FIG. 13 is a plan view showing a first operation when the wireless IC tag 8 is placed on the patch conductor 3D of FIG. It is a top view which shows the 2nd operation | movement when the radio | wireless IC tag 8 is mounted on the patch conductor 3D of FIG. It is a top view which shows the 3rd operation | movement when the radio | wireless IC tag 8 is mounted on the patch conductor 3D of FIG. It is a top view which shows the structure and operation | movement of the metal corresponding | compatible radio | wireless IC tag apparatus 50E which concern on the 1st modification of the 5th Embodiment of this invention. FIG. 18 is a longitudinal sectional view taken along line F-F ′ in FIG. 17 and a side view of the interrogator 20, showing the arrangement relationship and operation between the metal-compatible wireless IC tag device 50 </ b> E in FIG. 17 and the interrogator 20. It is a top view which shows the structure and operation | movement of the metal corresponding | compatible radio | wireless IC tag apparatus 50F which concern on the 2nd modification of the 5th Embodiment of this invention. It is a top view which shows the structure and operation | movement of the metal corresponding | compatible radio | wireless IC tag apparatus 50G provided with the radio wave polarization conversion resonant reflection apparatus 10G which concerns on the 6th Embodiment of this invention. It is a longitudinal cross-sectional view about the G-G 'line | wire of FIG. It is a top view which shows the structure and operation | movement of the metal corresponding | compatible radio | wireless IC tag apparatus 50H which concern on the 7th Embodiment of this invention. It is a longitudinal cross-sectional view about the H-H 'line | wire of FIG. It is a back view which shows the structure and operation | movement of the metal corresponding | compatible radio | wireless IC tag apparatus 50I which concern on the 8th Embodiment of this invention. FIG. 25 is a longitudinal sectional view taken along line I-I ′ of FIG. 24. It is a top view which shows the structure and operation | movement of the metal corresponding | compatible radio | wireless IC tag apparatus 50J which concern on the 9th Embodiment of this invention. It is a longitudinal cross-sectional view about the J-J 'line | wire of FIG. It is a perspective view which shows the structure and operation | movement of the metal corresponding | compatible radio | wireless IC tag apparatus 50K which concern on the 10th Embodiment of this invention. It is an enlarged view which shows the detail of the metal-compatible radio | wireless IC tag apparatus 50K of FIG. It is a longitudinal cross-sectional view which shows the structure of 1st Example 50K-1 in the metal corresponding | compatible radio | wireless IC tag apparatus 50K which concerns on 10th Embodiment. It is a longitudinal cross-sectional view which shows the structure of 2nd Example 50K-2 in the metal corresponding | compatible radio | wireless IC tag apparatus 50K which concerns on 10th Embodiment. It is a longitudinal cross-sectional view which shows the structure of 3rd Example 50K-3 in the metal corresponding | compatible radio | wireless IC tag apparatus 50K which concerns on 10th Embodiment. It is a longitudinal cross-sectional view which shows the structure of 4th Example 50K-4 in the metal corresponding | compatible radio | wireless IC tag apparatus 50K which concerns on 10th Embodiment. It is a longitudinal cross-sectional view which shows the structure of 5th Example 50K-5 in the metal corresponding | compatible radio | wireless IC tag apparatus 50K which concerns on 10th Embodiment. It is a top view which shows azimuth angle (phi) of the wireless IC tag 8 when the maximum communication distance of the wireless IC tag 8 which concerns on a comparative example is measured. It is a top view which shows azimuth angle (phi) of the metal corresponding | compatible radio | wireless IC tag apparatus 50 when the maximum communication distance of the metal corresponding | compatible radio | wireless IC tag apparatus 50 which concerns on 1st Embodiment is measured. FIG. 37 is a graph showing the maximum communication distance with respect to the azimuth angle φ, which is an experiment result of the inventors of FIGS. 35 and 36. FIG. It is a top view which shows the structure of the general independent radio | wireless IC tag 8 which concerns on a prior art. It is a block diagram which shows the structure of tag IC8a of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Dielectric substrate, 1A ... Dielectric thin film, 2, 2A, 2B ... Ground conductor, 3, 3A, 3B, 3C, 3D, 3E, 3F, 3P, 3Q ... Patch conductor, 3S ... Slot, 3a, 3b, 3c, 3d, 3pa, 3pb, 3qa, 3qb ... notch, 3e ... protrusion, 8 ... wireless IC tag, 8a ... tag IC, 8b ... dipole antenna, 8c ... dielectric substrate, 9 ... tag mounting base, 10, 10A, 10B, 10C, 10D, 10E, 10F, 10H, 10I, 10K, 10K-1, 10K-2, 10K-3, 10K-4, 10K-5 ... Radio wave polarization conversion resonant reflector, 10G ... Radio wave polarization Wave conversion resonant reflection device, 11 ... phase adjusting strip conductor, 12 ... connection strip conductor, 13, 13A ... metal plate, 14 ... dielectric wall, 15 ... packing box, 16 ... dielectric plate, 17 ... dielectric spacer, 20 ... Interrogator 20A ... antenna, 30 ... asynchronous MPU, 31 ... nonvolatile memory, 32 ... power regeneration circuit, 33 ... high frequency communication circuit, 34 ... external communication port, 50, 50A, 50B, 50C, 50D, 50E, 50F, 50G, 50H , 50I, 50J, 50K-1, 50K-2, 50K-3, 50K-4, 50K-5 ... Metal-compatible wireless IC tag devices, RA1, RA2, RA11, RA12, RA21, RA22, RA31, RA32, RA41, RA42: Resonance axis.

Claims (1)

A wireless IC tag having a linearly polarized field emission component;
A dielectric having first and second surfaces substantially parallel to each other;
A ground conductor provided on the first surface of the dielectric;
Provided on the second surface of the dielectric, open at both ends of the first and second resonance axes orthogonal to each other, and predetermined first and second at the first and second resonance axes, respectively. A radio wave conversion resonant reflector comprising a patch conductor that resonates in a planar circuit at a resonance frequency of
The wireless IC tag is attached to the radio wave conversion resonant reflector so that the direction of the linearly polarized field emission component of the radio IC tag and one resonance axis of the radio wave conversion resonant reflector substantially coincide with each other. On the second surface of the dielectric or on the patch conductor;
As a received wave having a communication frequency that is one of the first resonance frequency, the second resonance frequency, and the frequency between the first resonance frequency and the second resonance frequency. The incident first radio signal is caused to resonate in a planar circuit by the patch conductor, converted to a second radio signal, reflected by the radio IC tag, and a third radio signal having the communication frequency from the radio IC tag. A metal-compatible wireless IC tag device, wherein the patch conductor is made to resonate in a planar circuit, is converted into a fourth wireless signal, and is reflected as a transmission wave.

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