KR100434824B1 - Apparatus for identification of dual-band radio frequency - Google Patents

Abstract

Combining the advantages of the magnetic field coupling type wireless recognition device and the electromagnetic field coupling type wireless recognition device, the driving power is supplied to the tag with low frequency energy of the magnetic field coupling type, and the data of the tag and the reader are microwaved with the electromagnetic field coupling type. By transmitting, the sensing distance can be improved, and the data can be transmitted at high speed, thereby enabling high speed recognition.

The reader includes a loop antenna for transmitting magnetic energy to a tag, a microstrip patch antenna for transmitting predetermined data to the tag, a microstrip patch antenna for receiving response data transmitted from the tag, and a The terminal is configured to provide a magnetic field energy to the loop antenna, provide predetermined data to the transmitting microstrip patch antenna, and transmit the received data, and receive the response data received by the receiving microstrip patch antenna, and the tag is transmitted by the reader. A loop antenna for receiving the magnetic field energy, a control circuit unit operating a current generated when the loop antenna of the tag receives the magnetic field energy as an operating power source, and generating response data according to the received data; Receives predetermined data and inputs it to the control circuit A receiving microstrip patch antenna and a transmitting microstrip patch antenna for transmitting response data generated by the control circuit unit to the reader.

Description

Apparatus for identification of dual-band radio frequency

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a radio frequency identification device in which a tag receives a magnetic field energy transmitted by a reader and uses the tag as an operating power source, and the reader and the tag transmit predetermined data to each other. The present invention relates to a dual-band wireless recognition device which improves detection distance by combining a combination recognition wireless recognition device and an electromagnetic coupling device wireless recognition device, and enables a reader and a tag to transmit data at high speed.

The wireless recognition device is a wireless transceiver that consists of a reader, which is an interrogator body, and a tag that is a transponder that is carried by a user or attached to an object, and operates at a low frequency of 133 GHz or 13.56 MHz frequency band. Coupling wireless recognition devices and electromagnetic coupling wireless communication devices operating in microwave bands of several hundred MHz are known.

As shown in FIG. 1, the reader 100 includes a loop antenna 101, a rectifier circuit, a modulator, a demodulator, a power supply circuit, a central processing unit, and the like. The tag 150 includes a loop antenna 151, a control circuit unit 153 including an ID (identification) storage circuit, a diode rectification and detection circuit, a diode modulator circuit, and the like.

In the conventional magnetic recognition device of the conventional magnetic coupling method having such a configuration, the terminal 103 of the reader 100 transmits magnetic field energy and predetermined data to the tag 150 through the loop antenna 101, and the tag 150. The loop antenna 151 receives the magnetic field energy transmitted by the loop antenna 101 of the reader 100 to generate driving power, and the control circuit unit 153 operates its ID as the generated driving power. Data is transmitted to the reader 100 through the loop antenna 151.

At this time, since the current of the loop antenna 151 generated as the loop antenna 151 of the tag 150 receives the magnetic field energy is very weak, the operating power supplied to the control circuit unit 153 is weak. The sensing distance that the 100 can recognize the tag 150 is very short, and the operating frequency is several kHz to several MHz, and the data transmission speed is low.

That is, in the magnetic recognition method of the magnetic field coupling method using a low frequency band, the contactless communication between the reader 100 and the tag 150 is caused by the change of the magnetic field formed by the current flowing through each of the loop antennas 101 and 151. As a matter of fact, the present invention does not correspond to a radio recognition apparatus using a radio propagation method. In addition, the magnetic field coupling type wireless recognition device using the low frequency band has been used as a wireless recognition device of the no battery tag 150, which is mainly battery-free, and the sensing distance should be almost close.

On the other hand, the electromagnetic recognition device of the electromagnetic coupling method is a radio frequency communication, a radio frequency transmission principle used in radar, etc. as applied to the reader 200, as shown in Figure 2, the terminal 201, the transmission microstrip patch An antenna 203 and a receiving microstrip patch antenna 205, and the tag 250 includes a control circuit section 251, a transmitting microstrip patch antenna 253 and a receiving microstrip patch antenna 255. It consists of.

In the conventional electromagnetic recognition device having the above configuration, the tag 250 reflects the microwave electromagnetic signal transmitted from the reader 200, and the reader 200 receives the reflected signal similar to the principle of the radar. It works.

In this case, the tag 250 modulates the carrier frequency signal of the reader 200 according to the ID data information of the tag 250 to back scatter the reader 200, and the reader 200 modulates the reflected signal. Demodulate the ID information of the tag. In addition, the signal transmitted by the reader 200 and the tag 250 is a microwave band signal, and the data transmission speed is high, and the size of the transmission data may be large, and the sensing distance is also described with the magnetic recognition method of the magnetic coupling method. Otherwise increases significantly.

However, the tag 250 is not suitable as a passive type (no battery) because the output of the reader 200 must be very large in order to rectify the RF wave received at a long distance and use it as an operating power source.

In addition, the operating frequency of the electromagnetic recognition type wireless recognition device is more than several hundred MHz, and mainly uses UHF band of 800∼900MHz band, ISM (Industrial, Scientific, Medical) band of 2.4㎓ and 5.8㎓, and has long sensing distance. Therefore, it is mainly attached to vehicles, objects, etc., and is widely used in logistics distribution, factory automation, vehicle recognition, and highway electronic toll collection (ETC).

The magnetic recognition device of the magnetic field coupling method and the wireless recognition device of the electromagnetic field coupling method differ only in a transmission field and operate on the same principle. That is, the readers 100 and 200 continue to transmit the CW signal, and the tags 150 and 250 reach the low power save mode by the RF power detection circuit when they reach within the communication area with the readers 100 and 200. In the sleep mode (wake mode) is switched to the normal operation mode (wake-up) to transmit the data indicating the presence of the reader (100, 200). When the readers 100 and 200 receive the presence data of the tags 150 and 250 transmitted by the tags 150 and 250, the reader 100 and 200 transmits an RF signal to the tags 150 and 250 instructing the recognition transmission. The tags 150 and 250 detect and demodulate the RF signal of the received recognition transmission command through the Schottky diode, and then transmit ID data stored in the internal digital circuit to the reader 100 or 200.

At this time, the reader 100 or 200 irradiates CW or non-modulated waves to the tags 150 and 250 to receive the information reflected back from the tags 150 and 250. In this case, the ID data of the tags 150 and 250 causes the encoder and the switch driver to load-switch the antenna state of the tags 150 and 250 to another state. As a result, the weak signals reflected from the tags 150 and 250 are modulated. The modulated signals are received by the readers 100 and 200 and sensed by the terminals 101 and 201.

In this manner, the readers 100 and 200 and the tags 150 and 250 communicate with each other using only RF signals generated by the readers 100 and 200 without the transmitters provided in the tags 150 and 250 themselves.

That is, the retroreflective signal of the recognition data ID is received by the loop antenna 101 or the microstrip patch antenna 205 of the readers 100 and 200, and the RF signal modulated by the retroreflected signal by the ID data is read by the reader ( Demodulated by the radio signal block detection circuits 100 and 200, the data is transmitted to the digital circuit unit. The digital circuit unit decodes ID data and is displayed through an external connection device.

In order to achieve mutual RF communication by the simple tags 150 and 250, some constraints are required in the communication circuit structure. That is, in order to simply configure the receiving circuit of the tags 150 and 250, the transmission method of the readers 100 and 200 is typically an amplitude shift keying method. In addition, a simple switching circuit is used in the modulation circuit of the tags 150 and 250 to avoid complexity.

Therefore, a Schottky diode circuit is used for the reception detection circuit of the tag, and a pin diode or a transistor switch circuit is used for the modulation circuit.

The readers 100 and 200 are usually connected to and operated by a computer, and control the wireless recognition device reader system by operating software according to the application purpose.

In such a wireless recognition device, the conventional magnetic field coupling type wireless recognition device is a principle applied to most low frequency wireless recognition devices. As a result, power energy and data transmission are caused by a current flowing through the loop antennas 101 and 151. The principle of operation is the same as that of an inductive transformer because it is transmitted as the magnetic energy that is formed. In other words, the power energy generated by the loop antenna 101 of the reader 100 by the driving current forms a magnetic field, and the change of the magnetic field is applied to the loop antenna 151 of the tag 150 located in the region of the magnetic field. The current by is induced and the power by the induced current is used as the operating power source. That is, the tag 150 receives the minimum power required for the operation from the reader 100. In addition, the tag 150 operated by the power received from the reader 100 transmits its own data to the reader 100 by the same principle. The current flowing through the loop antenna 151 of the tag 150 is very high. Because of the weak current, the distance that the tag 150 can transmit data to the reader 100 is very close.

For reference, since the wireless recognition device using the low frequency operates according to the principle described above, the sensing distance or the data transmission distance is several centimeters or less, which is almost a contact type, thereby limiting its utility.

Herein, the reason why the sensing distance is limited will be described. In the inductive method, energy is transmitted by magnetic field coupling between the reader 100 and the tag 150. The intensity of the magnetic field transmitted is the loop antenna 101 of the reader 100. The intensity of the magnetic field decreases in proportion to the distance of 1 / d ³ (where d is the distance between the reader 100 and the tag 150) and 1 / d ⁴ according to the alignment direction of the and tags 150. Since the attenuation of the magnetic field signal, that is, the loss in free space, is very large, compared to the case of electromagnetic wave attenuation by 1 / d ² , the magnetic field signal driven by the weak radio wave of the tag 150 is a leader. To transmit to the loop antenna 101 of (100), the transmission magnetic field attenuation is so large that the sensing distance is limited. The power density of the no-power tag 150 that receives the transmit power of the reader 100 to obtain driving energy is determined by the size of the loop antenna 151 and the number of turns. flux). The magnetic coupling method using the low frequency is widely used in the passive tag 150 because the output of the reader is capable of transmitting a higher power than the microwave band radio waves with high frequency in the FCC (Federal Communications Commission).

In addition, the magnetic coupling type wireless recognition device has a low data transmission rate because of low frequency. Therefore, the magnetic coupling tag 150 is suitable as a simple memory device recognition card, but lacks practicality due to a slow detection speed for use in a large contactless smart card in the future, and the magnetic field is shielded by a conductor such as a printed circuit board (PCB). There is a problem that the operating range is limited and the non-contact detection function is lowered depending on the detection direction.

In addition, the electromagnetic recognition device of the electromagnetic coupling method is an RF propagation method, which is applied to the RF propagation principle in a radio communication radar. That is, the tag 250 reflects the microwave electromagnetic field signal transmitted by the reader 200, and is similar to the radar principle of receiving the reflected signal by the reader 200.

When the tag 250 modulates and reflects the carrier frequency signal of the reader 200 according to the ID data, the reader 200 demodulates the modulated and reflected signal to decode the ID data of the tag 250. In this case, the RF frequency is a microwave band signal, the data transmission rate is high, and the free space loss of the radio waves reflected from the tag 250 is also proportional to the square of the distance unlike the magnetic coupling device of the magnetic field coupling method (1 / d ^2). The sensing distance is long because it is attenuated.

However, in the electromagnetic recognition device of the electromagnetic coupling method, when the sensing distance is far, the output of the reader 200 must be very large so that the tag 250 can be used as an operating power by rectifying the RF radio wave received at a long distance. It is not suitable for use in a wireless recognition device using a passive tag 250 that does not use power.

That is, the wireless recognition device of the microwave frequency band has the advantage of high data transmission speed and long sensing distance, but has a disadvantage that it is difficult to operate as a passive tag wireless recognition device that does not use a battery in the tag 250.

This is limited by the use of high power due to the safety regulations of RF radio waves, and in order to use it in a wireless card that a person carries, the output of the reader 200 of 10 ㎽ or less corresponding to a weak radio wave is generally low. The tag 250 or card had a problem that it is impossible to generate sufficient power energy required to drive its own electronic circuit.

Accordingly, an object of the present invention is to combine the advantages of the magnetic field coupling type wireless recognition device and the electromagnetic field coupling type wireless recognition device to supply the driving power to the tag with low frequency energy of the magnetic field coupling method, the data of the tag and the reader is electromagnetic coupling The present invention provides a dual band wireless recognition apparatus for transmitting microwaves.

In general, the electromagnetic coupling wireless recognition device is regulated by the power management law, and it is proved that it is not suitable for the safety regulations of the human body to convert the reader's microwave into the driving power of the passive tag. In fact, in order for the tag to receive, rectify and use the output of microwaves as a power source, a high power of more than hundreds of microwatts is required in the reader.

Therefore, the dual band wireless recognition apparatus of the present invention supplies the operating power to the magnetic coupling using a loop antenna like the magnetic coupling type of the magnetic field coupling method, and the data of the reader and the tag is the same as the magnetic recognition type of the magnetic field coupling type. Microwaves allow each other to transmit via a microstrip patch antenna.

To this end, the dual-band wireless recognition apparatus of the present invention is a reader that transmits energy and transmits predetermined data to receive response data, and generates and operates a power source with energy transmitted by the reader and transmits the data to the data transmitted by the reader. A radio answering device comprising a tag for transmitting response data to a reader, the reader comprising: a loop antenna for transmitting magnetic energy to the tag, a transmission microstrip patch antenna for transmitting predetermined data to the tag; A microstrip patch antenna for receiving the response data transmitted by the tag, magnetic field energy transmitted by the loop antenna, and providing predetermined data to the microstrip patch antenna for transmission to transmit the data; Enter the response data received by the strip patch antenna. The tag comprises a loop antenna for receiving magnetic energy transmitted by the reader, and a current generated by the loop antenna receiving magnetic energy as an operating power source, and response data according to the received data. A control circuit section for generating a signal; a receiving microstrip patch antenna for receiving and inputting predetermined data transmitted from the reader; and a transmission microstrip patch for transmitting response data generated by the control circuit section to the reader. It is characterized by consisting of an antenna.

Each of the reader and the tag transmitting microstrip patch antenna and the receiving microstrip patch antenna are provided in two or more in parallel, and each of the loop antennas of the reader and the tag includes a microstrip patch antenna, a terminal, and a control circuit unit. It is installed to wrap all or separated from the microstrip patch antenna and the terminal and the control circuit.

The magnetic energy is transmitted at 125 GHz or 13.56 MHz, and the microstrip patch antennas transmit and receive data in microwave in a UHF band, 2.4 GHz, 5.8 GHz or other frequency band, and the terminal transmits an oscillation signal. And an oscillator for applying magnetic energy to the loop antenna of the reader.

1 is a view showing a conventional magnetic recognition method of the magnetic field coupling method,

2 is a view illustrating a conventional electromagnetic recognition method of a wireless recognition device.

3 is a view showing an embodiment configuration of a dual-band wireless recognition device of the present invention,

4 is a diagram showing the configuration of another embodiment of a dual band wireless recognition apparatus of the present invention.

* Description of the symbols for the main parts of the drawings *

300: reader 301, 351: loop antenna

303, 355: receiving microstrip patch antenna

305, 357: microstrip patch antenna for transmission

350: tag 353: control circuit

359: oscillator

Hereinafter, a dual band wireless recognition apparatus of the present invention will be described in detail with reference to the accompanying drawings.

3 is a diagram illustrating an embodiment of a dual band wireless recognition device of the present invention. Here, reference numeral 300 denotes a reader and reference numeral 350 denotes a tag.

The reader 300 includes a loop antenna 301 for transmitting magnetic energy to the tag 350, a transmission microstrip patch antenna 303 for transmitting predetermined data to the tag 350, and the tag. A receiving microstrip patch antenna 305 for receiving the response data transmitted by the 350, and a magnetic field energy transmitted by the loop antenna 301 to the tag 350, and providing the transmitting microstrip patch antenna ( The terminal 307 receives predetermined data from the tag 350 and transmits the predetermined data to the tag 350 and receives the response data received by the receiving microstrip patch antenna 305 from the tag 350. The terminal 307 includes an oscillator 309 for generating a low frequency oscillation signal of 125 Hz or 133 Hz and applying the generated oscillation signal to the loop antenna 301 to transmit magnetic field energy. The loop antenna 301 is installed to surround the transmission microstrip patch antenna 303 and a receiving microstrip patch antenna (305).

The tag 350 may include a loop antenna 351 for receiving magnetic field energy transmitted by the loop antenna 301 of the reader 300 and supplying operating power, and the loop antenna 351 for receiving magnetic field energy. The control circuit unit 353 for operating the current generated according to the operating power and generating response data according to the received data, and receives the predetermined data transmitted from the reader 300 to the control circuit unit 353. A reception microstrip patch antenna 355 and a transmission microstrip patch antenna 357 for transmitting response data generated by the control circuit unit 353 to the reader 300, and the loop antenna 351 The reception microstrip patch antenna 355 and the transmission microstrip patch antenna 357 are formed to surround.

In the dual band wireless recognition apparatus of the present invention configured as described above, the reader 300 includes a terminal 307 for outputting microwaves of low power, a transmission microstrip patch antenna 303 and a reception microstrip patch antenna 305, An oscillator 309 and a loop antenna 301 for generating a low frequency signal are combined to supply energy of the operating power to the tag 350.

For example, a 13.56 MHz signal is a frequency used in a magnetic recognition method using a low frequency magnetic coupling method, and the energy delivered to the tag 350 is not RF radio wave, but magnetic energy due to magnetic coupling, which is a voltage by a transformer or It is the same principle as power transformer operation. That is, in the passive tag 350 in the magnetic field region formed by the current flowing through the loop antenna 301 of the reader 300, the control circuit unit 353 rectifies the current by the magnetic field energy induced in the loop antenna 351. Then, the required voltage is generated and used as an operating power source.

As described above, when the operating power is supplied to the tag 350, the terminal 307 and the control circuit unit 353 transmit the microstrip patch antennas 303 and 357 for transmission and the microstrip patch antennas for reception 305 and 355. By transmitting the predetermined data between each other to recognize.

Since the dual band wireless recognition apparatus of the present invention supplies the operating power required for the dual band tag 350 with the low frequency magnetic field energy of the reader 300, the radio wave output regulation of the reader 300 is limited to the supply of the operating power. In addition, since the terminal 307 and the control circuit unit 353 use microwaves, the real reflection of the recognition information, that is, the transmission of data, has a long sensing distance even when the output of the reader 300 is low.

In addition, the reader 300 includes a plurality of microstrip patch antennas 303 and a microstrip patch antenna 305 for reception in parallel, in parallel, so as to smoothly transmit data with the tag 350 at a distance. It is preferable.

4 is a diagram showing the configuration of another embodiment of a dual band wireless recognition apparatus of the present invention. As shown therein, another embodiment of the present invention is a structure in which the low frequency loop antennas 301 and 351 and the high frequency microstrip patch antennas 303 and 305 and 355 and 357 are separated.

In this structure, the tag 350 is only separated in a layout, so there is no big difference, but in actual operation, the tag 350 has a big difference, and the low frequency coil loop antenna 301 of the reader 300 supplies power energy at a separate location. The tag 350 receiving the power energy has a structure in which driving power is generated to communicate with the reader 300 of the weak RF propagation output. That is, the inductive magnetic field energy generating device is shown in the same manner as the antenna board such as the reader 300 in FIG.

This embodiment of FIG. 4 suggests that a wireless recognition device of a small, low power reader 300 having a sensing distance and a sensing speed equivalent to that of a conventional high power microwave recognition device can be realized.

As described in detail above, the present invention provides a sensing distance as a low-frequency reader supplies operating power to a tag by using a loop antenna, and a microwave-roar reader and a tag transmit predetermined data to each other using a microstrip patch antenna. It is improved and data transfer speed is high, so high speed recognition is possible.

Claims (5)

Wireless reader consisting of a tag that transmits energy and transmits predetermined data to receive response data, and a tag that generates power by operating the energy transmitted by the reader and transmits response data according to the data transmitted by the reader to the reader. In the response device, The leader; A loop antenna for transmitting magnetic energy to the tag; A transmission microstrip patch antenna for transmitting predetermined data to the tag; A receiving microstrip patch antenna for receiving response data transmitted by the tag; And A terminal for providing magnetic field energy transmitted by the loop antenna and providing and transmitting predetermined data to the transmitting microstrip patch antenna, and receiving response data received by the receiving microstrip patch antenna, The tag; A loop antenna for receiving magnetic energy transmitted by the reader; A control circuit unit operating a current generated as the loop antenna receives magnetic field energy as an operating power source and generating response data according to the received data; A reception microstrip patch antenna for receiving predetermined data transmitted from the reader and inputting the data to the control circuit unit; And And a transmission microstrip patch antenna for transmitting the response data generated by the control circuit unit to the reader. 2. The apparatus of claim 1, wherein each of the transmitting microstrip patch antennas and the receiving microstrip patch antennas of the reader and the tag; Dual band wireless recognition device characterized in that two or more are provided in parallel. 2. The antenna of claim 1, wherein each of the loop antennas of the reader and the tag; Dual band wireless recognition device, characterized in that installed to surround the microstrip patch antenna. 2. The antenna of claim 1, wherein each of the loop antennas of the reader and the tag; Dual band wireless recognition device, characterized in that is installed separately from the microstrip patch antenna. The terminal of claim 1, wherein the terminal; And an oscillator configured to oscillate and apply an oscillation signal to the loop antenna of the reader to transmit magnetic field energy.