JP3965038B2 - Wireless communication system and wireless communication device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a wireless communication system and a wireless communication apparatus, and can be applied to, for example, a communication system including a non-contact type IC tag or a resonance tag, or a non-contact type IC tag or a resonance tag.
[0002]
[Prior art]
Nowadays, contactless ID tags such as IC tags and resonance tags are used in wireless communication systems for various purposes such as article management, personal identification, and theft prevention.
[0003]
For example, in an IC tag that does not contain a battery, a tag reader applies an alternating magnetic field to a coil formed on the substrate, and an energy required for the IC chip in the tag is obtained by using an electromotive force generated in the coil. Have gained. The IC tag creates its own power source based on the energy obtained here, and wirelessly returns the data recorded in the IC chip to the tag reader.
[0004]
[Problems to be solved by the invention]
By the way, in order to extend the communication distance between an ID tag such as an IC tag or a resonance tag and a tag reader, a large amount of energy must be given from the tag reader to the ID tag. In other words, since a tag reader having a power source performs a transmission operation to the ID tag from the tag reader to the ID tag, a certain communication distance can be secured, but an ID tag is obtained from the tag reader from the ID tag to the tag reader. The transmission distance is likely to be shortened due to the transmission operation with high energy, and when trying to extend the communication distance between the ID tag and the tag reader, the communication distance in communication from the ID tag to the tag reader becomes important. The tag reader must give a lot of energy to the ID tag.
[0005]
However, the use frequency and output level of the wireless communication device are regulated by law, and the ID tag and tag reader must satisfy the specified conditions, and the tag reader supplies more energy than the predetermined value to the ID tag. Can not do it.
[0006]
For example, a wireless communication device that does not require a license is a device whose electric field intensity at a distance of 3 m is 500 μV / m (322 MHz or less) or whose power is 10 mW or less. Even in the latter permissible condition, which is large in terms of power, the ID tag side can receive a small amount of energy, and communication with the tag reader becomes impossible only a few centimeters away.
[0007]
This problem can be solved if it can be approved by a high-power radio station, but it is difficult in the present situation where the use density of radio waves is increasing. In addition, even if possible, it takes a period of procedures, etc., so there is a high possibility that a system construction opportunity will be missed, and the cost will increase.
[0008]
The present invention has been made in consideration of the above points, and an object of the present invention is to provide a wireless communication system and a wireless communication apparatus that can further extend the communication distance between the wireless communication apparatuses.
[0009]
[Means for Solving the Problems]
In order to solve such a problem, the wireless communication system of the present invention according to claim 1 includes a first wireless communication device that wirelessly communicates with a second wireless communication device that is opposed by using a first frequency, and a second wireless communication device. A radio wave radiation device that radiates a radio wave of a frequency, wherein the first radio communication device is a communication unit that performs communication processing at a first frequency, and a second radio frequency radio wave that is tuned and captured. Two-frequency tuning means and energy supply means for supplying the received electrical energy captured by the second frequency tuning means to the communication means, wherein the energy supply means is a second frequency captured by the second frequency tuning means. An electrical signal having a frequency of 1 is converted into an electrical signal having a first frequency and supplied to the communication means, and the first wireless communication device converts the energy of the radio wave having the second frequency to the second frequency. With wireless communication devices Characterized by utilizing the energy for the wireless communication.
[0013]
According to a second aspect of the present invention, there is provided a wireless communication system according to the first aspect of the present invention, wherein the first wireless communication device is a non-contact IC tag or a resonance tag.
[0014]
According to a third aspect of the present invention, there is provided a wireless communication apparatus according to the present invention, which wirelessly communicates with a facing wireless communication apparatus using a first frequency, a communication means for performing communication processing at the first frequency, and a radio wave a second frequency tuning means for emitting device tunes capturing a radio wave of a second frequency radiated, the received electrical energy the second frequency tuning means has captured the energy introduction means for introducing into said communication means possess, The energy supply means converts the electric signal of the second frequency captured by the second frequency tuning means into an electric signal of the first frequency and supplies the electric signal to the communication means .
[0017]
According to a fourth aspect of the present invention, there is provided the wireless communication apparatus according to the third aspect of the present invention, wherein the wireless communication apparatus is a non-contact IC tag or a resonance tag.
[0018]
DETAILED DESCRIPTION OF THE INVENTION
(A) First Embodiment Hereinafter, a first embodiment in which a wireless communication system and a wireless communication apparatus according to the present invention are applied to an IC tag communication system and an IC tag will be described in detail with reference to the drawings.
[0019]
FIG. 1 is a block diagram showing the overall configuration of the IC tag communication system of the first embodiment.
[0020]
In FIG. 1, an IC tag communication system 1 of the first embodiment includes an IC tag 2 that is a first wireless communication device and a tag reader 3 that is a second wireless communication device, and further includes an energy transmission device 4. Prepare.
[0021]
The IC tag 2 has an internal configuration shown in FIG. 2 to be described later, and performs signal communication with the tag reader 3 via a radio wave of the first frequency f1 as in the conventional case. is there.
[0022]
The IC tag 2 according to the first embodiment is obtained mainly from energy required for communication with the tag reader 3 from a radio wave having a second frequency f2 radiated by the energy transmission device 4. .
[0023]
The tag reader 3 is the same as the conventional one, for example, a first frequency including data stored in the IC tag 2 by transmitting an interrogation radio wave having the first frequency f1 to the IC tag 2 The response radio wave having f1 is captured and the data is captured.
[0024]
As described above, the energy transmission device 4 supplies the energy required by the IC tag 2 for communication with the tag reader 3 to the IC tag 2 via the radio wave having the second frequency f2. .
[0025]
Here, the energy transmission device 4 may be configured as a dedicated device of the system, and a wireless communication device for another communication system that radiates a radio wave having the second frequency f2 can be used. .
[0026]
For example, a wireless device for Dopa service provided by NTT Docomo Corporation can be used as the energy transmission device 4. The Dopa service is a data communication system that uses the mobile phone's radio wave band and charges according to the transmitted and received data packets. The Dopa radio has a transmission output of 0.8 W, similar to a mobile phone, and communicates with 80 times the energy compared to the allowable power of 10 mW in the low power radio as described above. For this reason, energy can be supplied to the IC tag 2 located almost anywhere in the country unless it is a bad condition such as the basement, the inner part where the building is standing up, or the room.
[0027]
FIG. 2 is a block diagram illustrating an internal configuration example of the IC tag 2 according to the first embodiment.
[0028]
2, the IC tag 2 according to the first embodiment includes an antenna unit 21, a communication unit 22, a control unit 23, and a memory 24 as communication units, and a tuning acquisition unit 25 and energy supply unit as second frequency tuning units. The frequency converter 26 is included.
[0029]
The antenna unit 21 is formed of only a coil or a resonance circuit configuration of a coil and a capacitor, and is obtained by capturing the interrogation radio wave of the first frequency f1 from the tag reader 3. An inquiry electric signal is given to the communication unit 22 or a response electric signal of the first frequency f1 from the communication unit 22 is radiated as a response radio wave.
[0030]
The communication unit 22 demodulates the interrogation electrical signal from the antenna unit 21 and provides the interrogation data to the control unit 23, or modulates the response data from the control unit 23 and provides the response electrical signal to the antenna unit 21. To do.
[0031]
The control unit 23 decodes the question data from the communication unit 22 and, if applicable, reads the data stored in the memory 24 and gives it to the communication unit 22 as response data.
[0032]
The memory 24 stores data unique to the IC tag 2 and the data is appropriately read out by the control unit 23 as described above.
[0033]
The IC tag 2 as described above includes a tuning acquisition unit 25 and a frequency conversion unit 26 in addition to a general configuration.
[0034]
The tuning capturing unit 25 has, for example, a resonance circuit configuration of a coil and a capacitor, captures a radio wave having the second frequency f2 radiated from the energy transmission device 4, and converts it into an electrical signal (sine wave electrical signal). This is given to the frequency converter 26.
[0035]
The frequency conversion unit 26 converts the electrical signal having the second frequency f2 into an electrical signal having the first frequency f1 and gives it to the communication unit 22.
[0036]
Here, the communication unit 22 holds the electric signal having the first frequency f1 from the antenna unit 21 by resonance so that it can be used for transmission (the coil of the antenna unit 21 is a functional element for resonance). For example, the frequency converter 26 uses the PLL function or the like to match the phase of the electrical signal of the first frequency f1 in the resonance state with the electrical signal of the first frequency f1 from itself. Superimpose.
[0037]
The communication unit 22 also has a function of supplying operation power such as the control unit 23 and the memory 24 (for example, a function of converting to DC power), but the electric signal of the first frequency f1 after being superimposed as described above. Supply operating power from.
[0038]
The IC chip in the IC tag 2 may be equipped with the communication unit 22, the control unit 23, and the memory 24, and the communication unit 22, the control unit 23, the memory 24, and the frequency conversion unit 26. Furthermore, the capacitor element of the antenna unit 21, the communication unit 22, the control unit 23, the memory 24, the capacitor element of the tuning capturing unit 25, and the frequency conversion unit 26 may be mounted.
[0039]
In addition, an element (for example, a coil element) in the antenna unit 21 that is not provided in the IC chip and an element (for example, a coil element) in the tuning capturing unit 25 that is not provided in the IC chip are provided on the front and back surfaces of the substrate of the IC tag 2. It may be provided separately, or may be provided on the same surface of the substrate of the IC tag 2 by changing its position, and further laminated on the same surface of the substrate of the IC tag 2 via an insulating layer. It may be provided.
[0040]
In the IC tag communication system 1 of the first embodiment as described above, the IC tag 2 tunes and captures the radio wave of the second frequency f2 radiated from the energy transmission device 4, and has the second frequency f2. The electric signal is converted into a signal having the first frequency f1, and superimposed on the electric signal obtained by capturing the radio wave of the first frequency f1 from the tag reader 3 and used at the time of transmission, and each internal part is required. The operation power supply is formed.
[0041]
The IC tag 2 communicates with the tag reader 3 using the energy of the radio wave of the second frequency f2 radiated by the energy transmission device 4 as described above.
[0042]
According to the IC tag communication system 1 and the IC tag 2 of the first embodiment, the IC tag 2 communicates with the tag reader 3 using the energy of the radio wave of the second frequency f2 radiated by the energy transmission device 4. Therefore, the communication distance can be made longer than the conventional one.
[0043]
Incidentally, since the tag reader 3 having a power source is the transmission source from the tag reader 3 to the IC tag 2, the communication distance is longer than the communication distance of communication in the reverse direction, and the communication distance from the IC tag 2 to the tag reader 3 However, this is a communication distance in consideration of bidirectional communication, and it is very effective to increase the communication distance from the IC tag 2 to the tag reader 3.
[0044]
Further, as exemplified in the above description, when an apparatus existing throughout the country is used as the energy transmission apparatus 4, the above-described effect can be enjoyed even if the IC tag 2 is located at any position in the country.
[0045]
(B) Second Embodiment Next, a second embodiment in which the wireless communication system and the wireless communication apparatus according to the present invention are applied to an IC tag communication system and an IC tag will be described in detail with reference to the drawings.
[0046]
The overall configuration of the IC tag communication system of the second embodiment can also be represented in FIG. 1 according to the first embodiment.
[0047]
However, the second embodiment is different from the first embodiment in the internal configuration of the IC tag (the reference numeral 2A is used for the second embodiment).
[0048]
FIG. 3 is a block diagram showing an internal configuration of the IC tag 2A according to the second embodiment. The same and corresponding parts as those in FIG. 2 according to the first embodiment are denoted by the same and corresponding reference numerals. ing.
[0049]
In the IC tag 2A of the second embodiment, the receiving unit 22R and the transmitting unit 22S that perform communication with the tag reader 3 are clearly separated. The receiving unit 22R demodulates the interrogation electric signal from the antenna unit 21 and gives the interrogation data to the control unit 23. The transmission unit 22S modulates the response data from the control unit 23 and outputs the response electric signal. Is given to the antenna unit 21.
[0050]
Here, the transmission unit 22S is provided with an electrical signal (for example, a sine wave electrical signal) having the first frequency f1 from the frequency conversion unit 26, and the transmission unit 22S performs modulation processing using this electrical signal as a carrier wave. To do.
[0051]
Note that the reception unit 22R (or the control unit 23) constantly monitors the arrival of the inquiry electric signal, detects the arrival of the inquiry electric signal, and only when the transmission operation is necessary, for example, for a predetermined period of time. The operation may be stopped and the transmission unit 22S may be operated.
[0052]
Further, the operation power source of the control unit 23 and the memory 24 may be obtained by the reception unit 22R from the reception energy of the interrogation electric signal from the antenna unit 21 (accordingly, the radio wave energy from the tag reader 3) (see FIG. 3 indicates this case), and the frequency conversion unit 26 and the transmission unit 22S may obtain from the reception energy of the electric signal from the tuning acquisition unit 25 (therefore, the energy of the radio wave from the energy transmission device 4). good.
[0053]
Also by the IC tag communication system 1 and the IC tag 2A of the second embodiment, the IC tag 2A transmits to the tag reader 3 using the energy of the radio wave of the second frequency f2 radiated by the energy transmission device 4. Therefore, the communication distance can be made longer than the conventional one.
[0054]
(C) Third Embodiment Next, a third embodiment in which the wireless communication system and the wireless communication apparatus according to the present invention are applied to an IC tag communication system and an IC tag will be described in detail with reference to the drawings.
[0055]
The overall configuration of the IC tag communication system of the third embodiment can also be represented in FIG. 1 according to the first embodiment.
[0056]
However, the third embodiment is different from that of the first embodiment in the internal configuration of the IC tag (reference numeral 2B is used for the third embodiment).
[0057]
FIG. 4 is a block diagram showing the internal configuration of the IC tag 2B of the third embodiment. The same and corresponding parts as those in FIG. 2 according to the first embodiment are indicated by the same and corresponding reference numerals. ing.
[0058]
The IC tag 2B of the third embodiment is provided with a rectification power storage unit 27 instead of the frequency conversion unit 26 of the first embodiment as an energy supply unit.
[0059]
The rectifying power storage unit 27 rectifies and accumulates the electric signal of the second frequency f2 from the tuning capturing unit 25 and supplies the accumulated electric energy to the communication unit 22 as DC power. In addition, you may supply as operation | movement power supply of the control part 23 or the memory 24. FIG. The power storage function unit in the rectifying power storage unit 27 may be a secondary battery or the like, but in consideration of the miniaturization of the IC tag 2B, one using a capacitor is preferable.
[0060]
Similarly to the first embodiment, the communication unit 22 of the third embodiment also holds the received electrical signal of the first frequency f1 for a certain amount of time by the resonance function and uses it as a carrier wave for transmission operation. is there. The communication unit 22 of the third embodiment uses the DC power from the rectifying power storage unit 27 to increase the power of the electric signal having the first frequency f1 that is held by the resonance operation.
[0061]
For example, as a resonance configuration, not only the coil and capacitor passive elements but also those having an active element such as a transistor in addition to the coil and capacitor are applied, and a direct current from the rectifying power storage unit 27 is used as a power source for the active element. Using the electric power, the electric signal of the first frequency f1 held by the resonance operation is increased.
[0062]
The electric signal of the first frequency f1 with such increased power is modulated as a carrier wave and converted into a transmission signal.
[0063]
Since the IC tag communication system and the IC tag 2B of the third embodiment also transmit the IC tag 2B to the tag reader 3 using the energy of the radio wave of the second frequency f2 radiated by the energy transmission device 4. The communication distance can be made longer than the conventional one.
[0064]
(D) Fourth Embodiment Next, a fourth embodiment in which the wireless communication system and the wireless communication apparatus according to the present invention are applied to an IC tag communication system and an IC tag will be described in detail with reference to the drawings.
[0065]
The overall configuration of the IC tag communication system of the fourth embodiment can also be represented in FIG. 1 according to the first embodiment.
[0066]
However, in the fourth embodiment, the internal configuration of the IC tag (the reference numeral 2C is used for the fourth embodiment) is different from that of the above-described embodiment.
[0067]
FIG. 5 is a block diagram showing the internal configuration of the IC tag 2C according to the fourth embodiment. The same and corresponding parts as those in FIGS. As shown.
[0068]
The IC tag 2C according to the fourth embodiment is provided with a rectifying power storage unit 27 similar to that described in the third embodiment, instead of the frequency conversion unit 26 according to the second embodiment. The rectifying power storage unit 27 supplies the electric energy obtained by rectifying and accumulating the electric signal of the second frequency f2 from the tuning capturing unit 25 to the transmitting unit 22 as DC power. In addition, you may supply as operation | movement power supply of the control part 23 or the memory 24. FIG.
[0069]
The transmission unit 22 performs a transmission operation using the electrical energy from the rectifying power storage unit 27 and increases the transmission power compared to the conventional IC tag.
[0070]
For example, if the transmission unit 22 includes an oscillation unit having a first frequency f1 using an active element such as a transistor and modulates the oscillation signal as a carrier wave, the rectifying power storage unit serves as an operation power supply for the active element or the like. By using the DC power from 27, the transmission power can be increased. In addition, the transmission power can be increased by providing an amplifier circuit that amplifies the modulated electric signal using the electric energy from the rectifying power storage unit 27.
[0071]
Since the IC tag communication system and the IC tag 2C of the fourth embodiment also transmit the IC tag 2C to the tag reader 3 using the energy of the radio wave of the second frequency f2 radiated by the energy transmission device 4. The communication distance can be made longer than the conventional one.
[0072]
(E) Other Embodiments In each of the above embodiments, the tuning acquisition unit 25, the frequency conversion unit 26, and the rectification power storage unit 27 are shown to be constantly operating. 26, the rectifying power storage unit 27, and the like may be controlled so as to operate, for example, for a predetermined time when the control unit 23 detects that the radio wave from the tag reader 3 has been received.
[0073]
In each of the above embodiments, the communication partner of the IC tag is a tag reader. However, the tag writer may transmit data stored in the memory 24 to the IC tag, and has a write / read function. It may be a tag reader / writer.
[0074]
Further, in each of the above embodiments, the IC tag can capture energy, and one type of radio wave having a frequency other than the first frequency f1 used for communication is shown. However, from two or more types of radio waves, The IC tag may take in energy.
[0075]
Furthermore, in each of the above embodiments, the present invention is applied to an IC tag communication system and an IC tag. However, the present invention is applied to a communication system related to another ID tag such as a resonance tag and the ID tag. In addition, the present invention can be applied to a wireless communication system and a wireless communication apparatus other than the ID tag. Depending on the applied radio communication system, the radio wave energy from the energy transmission device can be used for the reception operation.
[0076]
【The invention's effect】
As described above, according to the present invention, a wireless communication device that wirelessly communicates with a facing wireless communication device using the first frequency uses the energy of the second frequency radio wave radiated by the radio wave radiation device. Since it is used for energy for wireless communication with the opposing wireless communication device, it is possible to realize a wireless communication system and a wireless communication device that can increase the communication distance as compared with the conventional case.
[Brief description of the drawings]
FIG. 1 is a block diagram showing an overall configuration of an IC tag communication system according to a first embodiment.
FIG. 2 is a block diagram illustrating an internal configuration example of an IC tag according to the first embodiment.
FIG. 3 is a block diagram illustrating an internal configuration example of an IC tag according to a second embodiment.
FIG. 4 is a block diagram illustrating an internal configuration example of an IC tag according to a third embodiment.
FIG. 5 is a block diagram illustrating an internal configuration example of an IC tag according to a fourth embodiment.
[Explanation of symbols]
1. IC tag communication system (wireless communication system)
2, 2A, 2B, 2C ... IC tag (first wireless communication device, wireless communication device)
3. Tag reader (second wireless communication device, opposite wireless communication device)
4. Energy transmission device (radio wave radiation device)

Claims (4)

A first wireless communication device that wirelessly communicates with a second wireless communication device that is opposed using the first frequency; and a wireless radio wave radiation device that radiates a radio wave of the second frequency,
The first wireless communication device is
Communication means for performing communication processing at a first frequency;
Second frequency tuning means for tuning and capturing radio waves of the second frequency;
Energy supply means for supplying the received electrical energy captured by the second frequency tuning means to the communication means;
The energy supply means converts the electric signal of the second frequency captured by the second frequency tuning means into an electric signal of the first frequency, and supplies the electric signal to the communication means;
A wireless communication system, wherein the first wireless communication device uses energy of a radio wave of the second frequency as energy for wireless communication with the second wireless communication device. The wireless communication system according to claim 1, wherein the first wireless communication device, an IC tag or resonant tag of non-contact type. In a wireless communication device that wirelessly communicates with a facing wireless communication device using a first frequency,
Communication means for performing communication processing at a first frequency;
A second frequency tuning means for tuning and capturing a radio wave of a second frequency radiated by the radio wave radiation device;
Energy supply means for supplying the received electrical energy captured by the second frequency tuning means to the communication means ;
Said energy supply means the second electrical signal having a frequency second frequency tuning means has captured, into an electric signal of a first frequency, non-linear you characterized by supplying to said communication means Communication device. The wireless communication apparatus according to claim 3, wherein the wireless communication apparatus is a non-contact type IC tag or a resonance tag.

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