KR20110013870A - Rf tag, method for detection of rf tag and rf system including the same - Google Patents

Abstract

PURPOSE: An RF tag, a detecting method thereof, and an RF system therefor are provided to exactly distinguish the existence of a tag located in an RF range, thereby reducing the power consumption of a reader. CONSTITUTION: An analog block(120) generates operation power based on an RF reception signal transmitted from a reader. A digital block(110) generates a response signal based on the RF reception signal. The digital block outputs the response signal to the reader through the analog block and an RF tag informs the reader of the existence in RF coverage range of the reader. The digital block includes a signal generating unit which generates response data and encoder/decoder which outputs the response signal based on the response data.

Description

Rf tag, method for detecting same, and rf system for same

An embodiment of the present invention relates to a technique for detecting an RF tag, and more particularly, to an RF tag capable of outputting a detection response signal, a detection method thereof, and an RF system therefor.

In general, RFID (radio frequency identification) system can be divided into an inductively coupled method and an electromagnetic wave method according to a wireless access method.

The mutual induction method is used in a short range (within 1 m) RFID system, and the RF signal receiver (eg, reader) and the RF signal transmitter (eg, RF tag) communicate wirelessly using a coil antenna.

The mutually induced RF tag is a passive tag. In other words, all the energy required for the operation of the IC chip of the RF tag is supplied from a reader.

The reader outputs a magnetic field signal, such as an RF signal, within its RF range, and the tag located within the RF range generates power to operate the tag using the RF signal output from the reader. At this time, the reader detects a tag by detecting a current change due to mutual inductance with a tag within an RF range, that is, an amplitude change of the RF signal, and performs RF communication with the tag. To this end, the reader includes a current measurement element.

However, in the tag detection method of the above-described reader, the reader always outputs an RF signal, thereby increasing power consumption of the reader. In addition, when the amplitude of the RF signal is changed due to the influence of the surrounding environment, the reader indicates a result of detecting the tag even if the tag does not exist in the RF range. This causes malfunction of the reader and reduces the reliability of the RF system.

An object of the present invention is to provide an RF tag capable of outputting a detection response signal.

Another object of the present invention is to provide an RF tag detection method.

Another object of the present invention is to provide an RF system including an RF tag.

The RF tag according to an embodiment of the present invention for solving the above problems, generates a response signal based on the analog block and the RF received signal to generate an operating power based on the RF received signal transmitted from the reader, It includes a digital block that outputs the response signal to the reader through the analog block to indicate the presence or absence within the RF range.

According to another aspect of the present invention, there is provided a method of detecting an RF tag, the method including generating an operating power source of an RF tag based on an RF received signal transmitted from a reader, and operating the RF tag by the operating power source. The method may include generating a response signal responsive to the RF received signal and transmitting a response signal to the reader to indicate the presence or absence of an RF tag within the RF range of the reader.

The RF system according to an embodiment of the present invention for solving the another problem, the RF communication with the reader in the RF range and the reader for performing RF communication by detecting at least one RF tag located in the RF range It includes an RF tag.

According to an embodiment of the present invention, an RF tag, a detection method thereof, and an RF system therefor may accurately determine whether a tag is located within an RF range without changing the hardware of the reader, and may reduce power consumption of the reader. In addition, it is effective to build a reliable RF system because it is not affected by the surrounding environment.

In order to fully understand the present invention, the operational advantages of the present invention, and the objects achieved by the embodiments of the present invention, reference should be made to the accompanying drawings which illustrate embodiments of the present invention and the contents described in the accompanying drawings.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 is a schematic block diagram of a tag according to an embodiment of the present invention, FIG. 2 is a flowchart of an RF communication operation between a tag and a reader shown in FIG. 1, and FIG. 3 is a DS signal of a tag shown in FIG. 1. Figure 1 shows an example.

Referring to FIG. 1, the tag TAG 100 may include an analog block 110, a digital block 120, and a memory 130. According to an embodiment, the tag 100 illustrated in FIG. 1 may be a passive RF tag that operates by generating a tag operation power from an RF received signal RX output from an external device, for example, a reader (not shown). Can be. However, the present invention is not limited thereto, and according to an exemplary embodiment, the tag 100 may be an active RF tag in which a power generation device such as a battery (not shown) is embedded.

The analog block 110 includes a modulator / demodulator (MOD / DEMOD) 111, a clock generator (CLK Generator) 113, an operation power generator (RECT) 115, and a reset signal generator (POR) 117. It may include.

The demodulator / demodulator 111 demodulates an RF received signal received through the antenna 140 from the reader, for example, the first RF signal RX to generate a demodulated signal RS, and generates the demodulated signal RS in response to the demodulated signal RS. The response signal, for example, the second response signal TS2, may be modulated to generate an RF transmission signal, for example, the second RF signal TX. The second RF signal TX may be transmitted to the reader through the antenna 140.

The clock generator 113 may generate a clock signal CLK in response to the first RF signal RX, and output the generated clock signal CLK to the digital block 120.

The operation power generator 115 may generate an operation power of the tag 100 in response to the first RF signal RX.

The reset signal generator 117 may generate a reset signal RST and output the generated reset signal RST to the digital block 120.

The digital block 120 may include an encoder / decoder (ENCODER / DECODER) 121 and a signal generator (RF DETECT) 125.

The encoder / decoder 121 encodes a demodulated signal RS output from the modulator / demodulator 111 of the analog block 110 to determine a command signal included in the demodulated signal RS, or the signal generator 125 ) May generate a response signal, for example, a first response signal TS1.

The encoder / decoder 121 receives data such as first data DATA1 from the memory 130 or encodes a demodulated signal such as second data according to a determination result of the command signal included in the demodulation signal RS. DATA2 may be output to the memory 130. The first data DATA1 may include ID information of the tag 100 or a plurality of data.

The encoder / decoder 121 may generate a second response signal TS2 by decoding the first data DATA1, and the second response signal TS2 may be a modulator / demodulator 111 of the analog block 110. Can be output.

The signal generator 125 may generate the response data DS based on the first RF signal RX or the signal generated by the first RF signal RX. For example, the signal generator 125 generates an operating power of the tag 100 from the operating power generator 115 by the first RF signal RX transmitted from the reader to the tag 100. Operate to generate response data DS. The response data DS may be output to the encoder / decoder 121.

The memory 130 may store the first data DATA1 or the second data DATA2 transmitted from the encoder / decoder 121.

Hereinafter, the operation of the tag 100 described above with reference to FIG. 2 will be described.

1 and 2, the reader may output a first RF signal RX in order to detect at least one tag 100 located in an RF range (S10).

When the tag 100 is located within the RF range of the reader, the tag 100 is modulated by the first response signal TS1 in response to the first RF signal RX output from the reader. ) Can be printed. The reader may detect the tag 100 by the second RF signal TX output from the tag 100 (S20).

For example, the tag 100 may generate an operating power that may operate the tag 100 based on the first RF signal RX. In other words, the operating power generator 115 of the tag 100 generates and outputs operating power from the first RF signal RX, and the tag 100 is powered by the generated operating power. Can be turned on.

In addition, the reset signal RST output from the reset signal generator 117 of the tag 100 may reset the digital block 120, and the tag 100 may be in a standby state.

The signal generator 125 of the tag 100 may generate and output response data DS. The encoder / decoder 121 may output the first response signal TS1 including the response data DS.

The response data DS may be generated using a protocol of the type shown in FIG. 3. For example, the first response signal TS1 may include a preamble signal, a start of bit (SOB) signal, a start of frame (SOF) signal, an end of bit (EOB) signal, and an end signal. It may be generated using a protocol that includes an End Of Frame (EOF) signal. According to an embodiment, the response data DS may be generated as a signal of any one bit or one byte.

Referring back to FIGS. 1 and 2, the modulator / demodulator 111 modulates the first response signal TS1 output from the encoder / decoder 121 to generate the second RF signal TX, and the antenna 140. ) May transmit the second RF signal TX to the reader.

Accordingly, the reader may detect the tag 100 located in the RF range according to the second RF signal TX transmitted from the tag 100. When the tag 100 is detected, the reader and the tag 100 may perform RF communication (S40).

For example, the first RF signal RX output from the reader may include a command signal of the reader. The demodulator / demodulator 111 of the tag 100 may demodulate the first RF signal RX to generate a demodulated signal RS including a command signal.

The encoder / decoder 121 may determine the command signal of the reader by encoding the demodulated signal RS. The encoder / decoder 121 may generate a second response signal TS2 including the first data DATA1 according to the determination result. The first data DATA1 included in the second response signal TS2 may include ID information or a plurality of data of the tag 100.

The modulator / demodulator 111 modulates the second response signal TS2 output from the encoder / decoder 121 to generate a second RF signal TX, and through the antenna 140, the second RF signal TX. Can be sent to the reader.

That is, the tag 100 generates a first response signal TS1 indicating that the tag 100 is located within the RF range of the reader in response to the first RF signal RX output from the reader, and outputs the first response signal TS1 to the reader. The second response signal TS2 may be generated and output to the reader according to the determination result of the command signal included in the first RF signal RX.

According to an embodiment, the tag 100 outputs the first response signal TS1 and the second response signal TS2 to the reader at the same time, or first outputs the first response signal TS1 to the reader as described above. After that, the second response signal TS2 may be output.

When the RF communication between the reader and the tag 100 is terminated, the reader may stop the output of the first RF signal RX (S30), and thus the tag 100 may be powered off.

The leader enters the standby mode (S50), and waits for a predetermined time. The latency of the reader may be approximately 500 ms, but is not limited. After the waiting time passes, the reader may again output the first RF signal RX to detect a tag located within the RF range (S10).

On the other hand, if the tag 100 is not located within the RF range of the reader, for example, if the reader does not detect the tag 100, the reader may stop the output of the first RF signal RX (S30), and the standby mode It may enter into (S50). After the waiting time passes, the reader may again output the first RF signal RX to detect a tag located within the RF range (S10).

4 is a schematic block diagram of an RF system including the tag shown in FIG.

1 and 4, the RF system 200 may include a reader 210 and a tag 100.

The reader 210 may output the first RF signal RX to detect at least one tag 100 located in the RF range 220. The reader 210 based on the second RF signal TX including the first response signal TS1 or the second response signal TS2 output by the tag 100 in response to the first RF signal RX. RF communication with the tag 100 may be performed.

The tag 100 generates a second RF signal TX including the first response signal TS1 or the second response signal TS2 in response to the first RF signal RX output from the reader 210. You can print The tag 100 has been described in detail with reference to FIG. 1.

Although the present invention has been described with reference to one embodiment shown in the drawings, this is merely exemplary, and those skilled in the art will understand that various modifications and equivalent other embodiments are possible therefrom. Therefore, the true technical protection scope of the present invention will be defined by the technical spirit of the appended claims.

BRIEF DESCRIPTION OF THE DRAWINGS In order to better understand the drawings cited in the detailed description of the invention, a brief description of each drawing is provided.

1 is a schematic block diagram of a tag according to an embodiment of the present invention.

2 is a flowchart of an RF communication operation between a tag and a reader illustrated in FIG. 1.

3 is a diagram illustrating an example of a DS signal of a tag illustrated in FIG. 1.

4 is a schematic block diagram of an RF system including the tag shown in FIG.

Claims (10)

An analog block for generating an operating power source based on the RF received signal transmitted from the reader; And And a digital block generating a response signal based on the RF received signal and outputting the response signal to the reader through the analog block to indicate whether the response signal exists within the RF range of the reader. The method of claim 1, wherein the digital block, A signal generator for generating response data based on the signal generated by the RF received signal; And An encoder / decoder for generating a response signal based on the response data and outputting the generated response signal to the reader as an RF transmission signal through the analog block. The method of claim 1, wherein the analog block, A demodulator / demodulator for demodulating the RF received signal to generate a demodulated signal or modulating the response signal to generate the RF transmitted signal; An operation power generator configured to generate an operation power of the RF tag based on the RF received signal; And And a reset signal generator configured to generate a reset signal based on the RF received signal. The method of claim 3, And the digital block generates and outputs the response signal after being reset by the reset signal. According to claim 1, The RF tag further includes a memory storing ID information or a plurality of data of the tag, And the digital block generates the response signal including the ID information or the plurality of data of the tag stored in the memory. According to claim 1, The RF tag is a passive RF tag. Generating an operating power source for the RF tag based on the RF received signal transmitted from the reader; Generating a response signal in response to the RF received signal when the RF tag is operated by the operating power source; And And transmitting the response signal to the reader to indicate the presence or absence of the RF tag within the RF range of the reader. 8. The method of claim 7, The generating of the response signal may include generating response data based on a signal generated by the RF received signal and generating the response signal based on the response data. 8. The method of claim 7, And the reader detects the RF tag from the response signal to perform RF communication or operate in a standby mode without outputting the RF received signal. A reader for detecting at least one RF tag located within an RF range and performing RF communication; And An RF tag for performing the RF communication with the reader within the RF range, The RF tag, An analog block for generating an operating power source based on the RF received signal transmitted from the reader; And And a digital block generating a response signal based on the RF received signal and outputting the response signal to the reader through the analog block to indicate the presence or absence of a tag within the RF range of the reader.

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