JP2003124841A - System and device for radio communication - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a system and a device for radio communication which can make a communication distance longer than before. SOLUTION: This radio communication system is equipped with a 1st radio communication device which makes radio communication with an opposite 2nd radio communication device by using a 1st frequency and a radio wave radiation device which radiates a radio wave of 2nd frequency and is characterized in that the 1st radio communication device uses the energy of the radio wave of 2nd frequency as the energy for the radio communication with the 2nd radio communication device. The radio communication device of this invention corresponds to the 1st radio communication device mentioned above.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wireless communication system and a wireless communication device, for example, a communication system including a non-contact type IC tag or a resonance tag, or a non-contact type I.
It can be applied to a C tag and a resonance tag.

[0002]

2. Description of the Related Art Today, non-contact 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.

For example, in an IC tag that does not have a built-in battery,
The tag reader applies an alternating magnetic field to the coil formed on the substrate and utilizes the electromotive force generated in the coil to obtain the energy required for the IC chip in the tag. In the IC tag, based on the energy obtained here,
It creates its own power source and wirelessly returns the data recorded in the IC chip to the tag reader.

[0004]

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, it is necessary to give a large amount of energy to the ID tag from the tag reader. That is, since the 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 from the ID tag to the tag reader, I
Since the D tag operates with the energy obtained from the tag reader, the communication distance is likely to be short, and if the communication distance between the ID tag and the tag reader is to be extended, the communication from the ID tag to the tag reader is performed. Distance is important,
As a result, the tag reader must give a great deal of energy to the ID tag.

However, the frequency and output level of the wireless communication device are regulated by law, and it is necessary for the ID tag and the tag reader to meet the regulation conditions. Cannot supply energy.

For example, a wireless communication device which does not require a user's license has an electric field strength of 500 μV / m at a distance of 3 m.
(322 MHz or less) or a device with power output of 10 mW or less. Even in the latter allowable condition that is large in terms of electric power, I
The D tag side can receive a small amount of energy, a few cm
It becomes impossible to communicate with the tag reader just by leaving.

This problem can be solved if the high-power radio station can be approved, but it is difficult under the current circumstances where the radio wave usage density is increasing. Further, even if possible, it takes a lot of time for procedures and the like, so there is a high possibility that the chance of system construction is missed, and the cost also becomes large.

The present invention has been made in view of the above points, and an object of the present invention is to provide a wireless communication system and a wireless communication device capable of further extending a communication distance between wireless communication devices.

[0009]

In order to solve the above problems, a wireless communication system of the present invention according to claim 1 uses a first frequency to wirelessly communicate with an opposing second wireless communication device. Wireless communication device and a radio wave emitting device that emits a radio wave of a second frequency, wherein the first radio communication device transfers the energy of the radio wave of the second frequency to the second radio wave. It is characterized by being used for energy for wireless communication with a communication device.

A radio communication system of the present invention according to claim 2 is
In the present invention of claim 1, the first wireless communication device comprises a communication means for performing a communication process at a first frequency, and a second means.
The second frequency tuning means for tuning and capturing the radio wave of the frequency and the energy supply means for introducing the received electric energy captured by the second frequency tuning means to the communication means.

A radio communication system according to the present invention of claim 3 is
In the present invention of claim 2, the energy supplying 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. It is characterized by

A radio communication system according to the present invention of claim 4 is
In the present invention according to claim 2, the energy supply means rectifies and stores the electric signal of the second frequency captured by the second frequency tuning means, and supplies the stored electric energy to the transmission means. And

A wireless communication system according to the present invention of claim 5 is
In the present invention according to any one of claims 1 to 4, the first wireless communication device is a non-contact type IC tag or a resonance tag.

The radio communication apparatus according to the present invention of claim 6 is the first
For wirelessly communicating with an opposing wireless communication device using the frequency of 1., and tuning the communication means for performing communication processing at the first frequency and the radio wave of the second frequency radiated by the radio wave radiating device. A second frequency tuning means for capturing and this second frequency tuning means
Energy introducing means for introducing the received electric energy captured by the frequency tuning means into the communication means.

According to a seventh aspect of the present invention, there is provided the wireless communication device according to the sixth aspect, wherein the energy supply means receives the electric signal of the second frequency captured by the second frequency tuning means as the first signal. It is characterized in that it is converted into an electric signal of a frequency and supplied to the communication means.

According to an eighth aspect of the present invention, there is provided the wireless communication device according to the sixth aspect, wherein the energy supply means rectifies and stores the electric signal of the second frequency captured by the second frequency tuning means. The stored electrical energy is supplied to the communication means.

A ninth aspect of the present invention is the wireless communication device according to the sixth or seventh aspect, wherein the wireless communication device is a non-contact type IC tag or a resonance tag.

[0018]

BEST MODE FOR CARRYING OUT THE INVENTION (A) First Embodiment Hereinafter, a first embodiment in which a wireless communication system and a wireless communication device according to the present invention are applied to an IC tag communication system and an IC tag.
Embodiments will be described in detail with reference to the drawings.

FIG. 1 is a block diagram showing the overall configuration of the IC tag communication system of the first embodiment.

In FIG. 1, an IC tag communication system 1 of the first embodiment comprises an IC tag 2 which is a first wireless communication device and a tag reader 3 which is a second wireless communication device, and further energy transmission. A device 4 is provided.

The IC tag 2 has an internal structure shown in FIG. 2 which will be described later, and performs signal communication with the tag reader 3 via the radio wave of the first frequency f1 as in the conventional case. It is something to do.

The IC tag 2 of the first embodiment obtains energy required for communication with the tag reader 3 mainly from a radio wave having a second frequency f2, which is radiated by the energy transmitting device 4. It is a thing.

The tag reader 3 is the same as the conventional one, and transmits, for example, an inquiry radio wave having the first frequency f1 to the IC tag 2 and includes data stored in the IC tag 2. A response radio wave having a frequency f1 of 1 is captured and the above data is captured.

As described above, the energy transmitter 4 supplies the IC tag 2 with the energy required for the IC tag 2 to communicate with the tag reader 3 via the radio wave having the second frequency f2. It is a thing.

Here, the energy transmitting device 4 may be configured as a dedicated device of the system, and uses a wireless communication device for another communication system that emits a radio wave having the second frequency f2. be able to.

For example, a Dopa service radio provided by NTT DoCoMo, Inc. can be used as the energy transmission device 4. The Dopa service is a data communication system that uses the radio wave band of a mobile phone and charges for data packets transmitted and received. The Dopa radio is
It has a transmission output of 0.8 W like a mobile phone, and communicates with 80 times as much energy as the allowable power of 10 mW in the low power radio as described above. For this reason, energy can be supplied to the IC tags 2 located almost anywhere in the country unless the conditions are bad such as underground, inside a building where the building is standing upright, or in a room.

FIG. 2 is a block diagram showing an internal configuration example of the IC tag 2 of the first embodiment.

In FIG. 2, the IC tag 2 of the first embodiment uses an antenna section 21, a communication section 22, a control section 23, and a memory 24 as communication means, and a tuning acquisition section 25 and a memory 24 as second frequency tuning means. It has a frequency converter 26 as an energy supply means.

The antenna section 21 is formed of only a coil or a resonance circuit configuration of a coil and a capacitor, and captures the inquiry radio wave of the first frequency f1 from the tag reader 3, The obtained inquiry electric signal is given to the communication unit 22, or the response electric signal of the first frequency f1 from the communication unit 22 is emitted as a response radio wave.

The communication unit 22 demodulates the inquiry electric signal from the antenna unit 21 to give inquiry data to the control unit 23, modulates the response data from the control unit 23, and outputs the response electric signal to the antenna unit 21. To give to.

The control unit 23 decodes the question data from the communication unit 22, reads the data stored in the memory 24, if applicable, and gives it to the communication unit 22 as response data.

The memory 24 stores data unique to the IC tag 2 and the like, and as described above, the data is appropriately read by the control section 23.

The IC tag 2 as described above has a tuning acquisition section 25 and a frequency conversion section 26 in addition to the general structure.

The tuning acquisition unit 25 has, for example, a resonance circuit configuration of a coil and a capacitor, and the energy transmission device 4
The radio wave having the second frequency f2 emitted by is captured, converted into an electric signal (sinusoidal electric signal), and given to the frequency conversion unit 26.

The frequency conversion unit 26 converts the electric signal having the second frequency f2 into an electric signal having the first frequency f1 and supplies the electric signal to the communication unit 22.

Here, the communication section 22 holds the electric signal having the first frequency f1 from the antenna section 21 by resonance so that it can be used for transmission (the antenna section 2).
1 coil may be a functional element for resonance), and the frequency conversion unit 26 adjusts the phase to the electric signal of the first frequency f1 in the resonance state by itself, for example, by the PLL function or the like. The electric signal of the first frequency f1 is superimposed.

The communication section 22 also has a function of supplying operating power to the control section 23 and the memory 24 (for example, a function of converting to DC power), but the first section after the above-mentioned superimposition is performed.
The operating power is supplied from the electric signal of the frequency f1.

The IC chip of 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 may be installed. It may be mounted, and further, the capacitor element of the antenna unit 21 and the communication unit 2
2, the control unit 23, the memory 24, the capacitor element of the tuning acquisition unit 25, and the frequency conversion unit 26 may be mounted.

Elements (for example, coil elements) in the antenna section 21 which are not provided inside the IC chip and IC
Elements (for example, coil elements) in the tuning capture unit 25 that are not provided inside the chip may be separately provided on the front and back surfaces of the substrate of the IC tag 2, and may be located on the same surface of the substrate of the IC tag 2. The IC tag 2 may be provided separately, or may be provided on the same surface of the substrate of the IC tag 2 with an insulating layer interposed therebetween.

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 by the energy transmitting device 4, and then the second frequency thereof. The electric signal having f2 is converted into a signal having the first frequency f1, and the electric signal having the first frequency f1 from the tag reader 3 is captured and superimposed on the electric signal, which is used at the time of transmission and incorporated. It forms the operating power supply required by each part.

Using the energy of the radio wave of the second frequency f2 radiated by the energy transmitting device 4 as described above, I
The C tag 2 executes communication with the tag reader 3.

According to the IC tag communication system 1 and the IC tag 2 of the first embodiment described above, the IC tag 2 uses the energy of the radio wave of the second frequency f2 radiated by the energy transmitting device 4 as a tag reader. The communication distance can be made longer than that of the conventional one because the communication is performed with the communication terminal 3.

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 in the opposite direction, and the communication distance from the IC tag 2 to the tag reader 3 is the communication distance in consideration of bidirectional communication. The IC tag 2 to the tag reader 3 Being able to increase the communication distance to is very effective.

Further, as exemplified in the above description, when the device existing in the whole country is used as the energy transmitting device 4, even if the IC tag 2 is located at any position in the whole country, the above effect can be enjoyed. You can

(B) Second Embodiment Next, a second embodiment in which the wireless communication system and the wireless communication device according to the present invention are applied to an IC tag communication system and an IC tag.
Embodiments will be described in detail with reference to the drawings.

The overall configuration of the IC tag communication system of the second embodiment can also be represented by FIG. 1 according to the first embodiment.

However, in the second embodiment, the internal structure of the IC tag (the reference numeral 2A is used in the second embodiment) is different from that of the first embodiment.

FIG. 3 is a block diagram showing the internal structure of the IC tag 2A of the second embodiment. The same or corresponding parts as those of FIG. 2 according to the first embodiment are designated by the same or corresponding reference numerals. Is shown.

In the IC tag 2A of the second embodiment, the receiver 22R and the transmitter 22S that communicate with the tag reader 3 are clearly separated. Receiver 22R
Is for demodulating the interrogation electric signal from the antenna section 21 and providing interrogation data to the control section 23.
2S modulates response data from the control unit 23 and gives a response electric signal to the antenna unit 21.

Here, an electric signal (for example, a sine wave electric signal) having the first frequency f1 from the frequency converter 26 is given to the transmitter 22S, and the transmitter 22S
Modulation processing is performed using this electric signal as a carrier wave.

The receiving unit 22R (or the control unit 23)
However, it constantly monitors the arrival of the interrogation electric signal, detects the arrival thereof, and only when the transmission operation is necessary, for example, for a predetermined period, stops its own operation and operates the transmission unit 22S. You may do it.

Further, the operating power source for the control section 23 and the memory 24 may be such that the receiving section 22R obtains from the received energy of the interrogation electric signal from the antenna section 21 (hence the energy of the radio wave from the tag reader 3). Well (FIG. 3 shows this case), the frequency converter 26 and the transmitter 22
S may be obtained from the received energy of the electric signal from the tuning acquisition unit 25 (hence, the energy of the radio wave from the energy transmission device 4).

Also according to the IC tag communication system 1 and the IC tag 2A of the second embodiment, the IC tag 2A uses the energy of the radio wave of the second frequency f2 radiated by the energy transmitting device 4 to cause the tag reader 3 to operate. Since it is transmitted to, the communication distance can be made longer than the conventional one.

(C) Third Embodiment Next, a third embodiment in which the wireless communication system and the wireless communication device according to the present invention are applied to an IC tag communication system and an IC tag.
Embodiments will be described in detail with reference to the drawings.

The overall configuration of the IC tag communication system of the third embodiment can also be represented by FIG. 1 according to the first embodiment.

However, in the third embodiment, the internal structure of the IC tag (the reference numeral 2B is used in the third embodiment) is different from that of the first embodiment.

FIG. 4 is a block diagram showing the internal structure of the IC tag 2B of the third embodiment. The same or corresponding parts as in FIG. 2 according to the first embodiment are designated by the same or corresponding reference numerals. Is shown.

The IC tag 2B of the third embodiment is a frequency conversion unit 2 of the first embodiment as an energy supply means.
Instead of 6, the rectification power storage unit 27 is provided.

The rectification power storage unit 27 rectifies and stores the electric signal of the second frequency f2 from the tuning and capturing unit 25, and supplies the stored electric energy as DC power to the communication unit 22. It should be noted that the power may be supplied as a power source for operating the control unit 23 and the memory 24. The power storage function unit in the rectification power storage unit 27 may be a secondary battery or the like, but in consideration of downsizing of the IC tag 2B, a capacitor is preferably used.

Similarly to the first embodiment, the communication section 22 of the third embodiment holds the received electric signal of the first frequency f1 for a certain period of time by the resonance function and uses it as the carrier wave for the transmission operation. To do. 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 of the first frequency f1 held by the resonance operation.

For example, as the resonance structure, not only the passive elements of the coil and the capacitor but also the active element such as the transistor in addition to the coil and the capacitor is applied, and the rectifying power storage unit 27 is used as the power source for the active element. The DC electric power from the electric power source is used to increase the power of the electric signal of the first frequency f1 held by the resonance operation.

The electric signal of the first frequency f1 with such increased power is modulated as a carrier wave and converted into a transmission signal.

Also according to the IC tag communication system and the IC tag 2B of the third embodiment, the IC tag 2B uses the energy of the radio wave of the second frequency f2 radiated by the energy transmitting device 4 to the tag reader 3. I will send it
The communication distance can be made longer than the conventional one.

(D) Fourth Embodiment Next, a fourth embodiment in which the wireless communication system and the wireless communication device according to the present invention are applied to an IC tag communication system and an IC tag.
Embodiments will be described in detail with reference to the drawings.

The overall configuration of the IC tag communication system according to the fourth embodiment can also be represented by FIG. 1 according to the first embodiment.

However, in the fourth embodiment, the internal structure of the IC tag (the reference numeral 2C is used in the fourth embodiment) is different from that of the above-described embodiments.

FIG. 5 is a block diagram showing the internal structure of the IC tag 2C according to the fourth embodiment. The same or corresponding portions as those in FIGS. It is shown with reference numerals.

The IC tag 2C of 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 of the second embodiment. The rectification power storage unit 27 uses the second frequency f from the tuning acquisition unit 25.
The electric energy obtained by rectifying and accumulating the electric signal No. 2 is supplied to the transmitting unit 22 as DC power. It should be noted that the power may be supplied as a power source for operating the control unit 23 and the memory 24.

The transmitting unit 22 uses the electric energy from the rectifying power storage unit 27 to perform a transmitting operation and increases the transmitting power as compared with the conventional IC tag.

If the transmitting unit 22 includes an oscillating unit having a first frequency f1 using an active element such as a transistor and modulates the oscillating signal as a carrier wave, it can be used as an operating power source for the active element or the like. The transmission power can be increased by using the DC power from the rectified power storage unit 27. Further, the transmission power can be increased by providing an amplifier circuit that amplifies the modulated electric signal by using the electric energy from the rectifying power storage unit 27.

Also according to the IC tag communication system and the IC tag 2C of the fourth embodiment, the IC tag 2C uses the energy of the radio wave of the second frequency f2 radiated by the energy transmitting device 4 to the tag reader 3. I will send it
The communication distance can be made longer than the conventional one.

(E) Other Embodiments In each of the above embodiments, the tuning acquisition unit 25, the frequency conversion unit 26, and the rectifying power storage unit 27 are shown to be constantly operating. When the control unit 23 or the like detects that the radio wave from the tag reader 3 is received, the frequency conversion unit 26, the rectification power storage unit 27, and the like may be controlled to operate for a predetermined time, for example.

Further, in each of the above-mentioned embodiments, the communication partner of the IC tag is the tag reader, but it may be a tag writer for transmitting the data stored in the memory 24 to the IC tag, and writing / reading. It may be a tag reader / writer having a function.

Further, in each of the above embodiments, the IC
One type of radio wave having a frequency other than the first frequency f1 used for communication, which allows the tag to take in energy, is shown. However, even if the IC tag takes in energy from two or more types of radio waves. good.

Furthermore, in each of the above embodiments,
Although the present invention is applied to an IC tag communication system and an IC tag, the present invention can be applied to a communication system related to another ID tag such as a resonance tag and its ID tag. The present invention can be applied to a wireless communication system and a wireless communication device according to other than the above. Depending on the applied wireless communication system, the radio energy from the energy transmitting device can be used for the receiving operation.

[0076]

As described above, according to the present invention, the wireless communication device that wirelessly communicates with the opposing wireless communication device using the first frequency has the second frequency emitted by the wireless radio wave emitting device. Since the energy of the radio wave is used as the 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 one. .

[Brief description of 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 showing an internal configuration example of an IC tag according to a second embodiment.

FIG. 4 is a block diagram showing an internal configuration example of an IC tag according to a third embodiment.

FIG. 5 is a block diagram showing 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, opposing wireless communication device) 4) Energy transmission device (radio wave emission device)

Claims (9)

[Claims] 1. A first wireless communication device that wirelessly communicates with a second wireless communication device that opposes using a first frequency, and a wireless radio wave radiating device that radiates a radio wave of a second frequency. The first wireless communication device uses the energy of a wireless radio wave of the second frequency as energy for wireless communication with the second wireless communication device. 2. The first wireless communication device, wherein the first wireless communication device performs communication processing at a first frequency, second frequency tuning means for tuning and capturing a radio wave of a second frequency, and the second frequency. The wireless communication system according to claim 1, further comprising: an energy supply unit that supplies the received electric energy captured by the tuning unit to the communication unit. 3. 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. The wireless communication system according to claim 2. 4. The energy supplying means rectifies and stores the electric signal of the second frequency captured by the second frequency tuning means, and supplies the stored electric energy to the transmitting means. Item 2. The wireless communication system according to Item 2. 5. The first wireless communication device is a non-contact type IC tag or a resonance tag.
The wireless communication system according to any one of 1 to 4. 6. A wireless communication device that wirelessly communicates with an opposing wireless communication device using a first frequency, a communication means for performing communication processing at the first frequency, and a second device radiated by a wireless radio wave radiating device. 2. A wireless communication device comprising: a second frequency tuning means for tuning and capturing a radio wave of the frequency; and an energy supply means for supplying the received electrical energy captured by the second frequency tuning means to the communication means. 7. 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. The wireless communication device according to claim 6. 8. The energy supply means rectifies and stores the electric signal of the second frequency captured by the second frequency tuning means, and supplies the stored electric energy to the communication means. Item 7. The wireless communication device according to Item 6. 9. The wireless communication device according to claim 6, wherein the wireless communication device is a non-contact type IC tag or a resonance tag.