KR20090083868A - Apparatus and method for sensing grouped rfid tags using multiple antenna - Google Patents

Abstract

An apparatus and a method for sensing grouped RFID tags using multiband antenna are provided to group RFID tags of scattered all over the separated space or wide region to sense the RFID with multiband antenna. Connection apparatuses(210, 230, 250, 270) are connected to a plurality of antennas(221, 241, 261, 281), which are covering a plurality of regions, and reproduces the signals of the antennas. An RFID(Radio Frequency ID) reader(200) distinguishes the region via connected the apparatus, and senses the RFID tag equipped within the region. A controller is connected to the RFID reader to recognize the RFID tag and controls the connection apparatus.

Description

Apparatus and method for sensing grouped RFID tags using multiple antenna}

The present invention relates to an apparatus and method for detecting and identifying a target object, and more particularly, to an object having a Radio Frequency Identification (RFID) tag and interspersed in each separated space or large area by region. An apparatus and method for detecting a radio frequency identification tag by grouping the sensing and tracking the movement.

In general, a satellite positioning system (GPS) or a wireless mobile communication system is used as a technique for identifying a desired position of a desired object in a wide area. The satellite navigation system is easy to provide location and time information of the vehicle outdoors, and is particularly useful for identifying a stationary object. In addition, the mobile communication system can determine the location by installing only the base station not only outdoors but also indoors or underground.

However, in the satellite navigation system, the accuracy of positioning is remarkably inferior in indoor and underground where the receiver is expensive and the satellite signal cannot be received, and the mobile communication system is cheaper than the satellite navigation system, but the location information is the radius of the base station. There is a problem that the error range is large and the loss of data is relatively large.

As a technology for solving the problems of the prior art, a contactless radio frequency tag system has been developed that can be used simply and semi-permanently in a limited area such as an apartment building premises or an underground parking lot. A radio frequency tag system (hereinafter referred to as 'RFID') tag system attaches or mounts an RFID tag having a small antenna to an object whose location is to be tracked, and is received from the RFID tag in response to a signal transmitted from the RFID reader. The signal detects the position of the object and tracks its movement. This RFID tag system is very useful in that it is robust, can be reused repeatedly, and can transmit and receive a lot of information quickly and accurately without contact.

However, an RFID tag system using a high-frequency radio signal in the 900MHz band usually has a limitation of recognition distance due to its frequency characteristics, and the transmission output is induced by noise of the receiver in the RFID reader to further reduce the reception distance. Moreover, wireless signals can be shielded or disconnected in limited areas such as apartment buildings or underground parking lots where RFID tag systems are mainly used, and a large number of RFID tags can be used to detect RFID tags mixed in separate spaces and large areas. The disadvantage is that they require a leader and still cost a lot of installation.

The present invention has been made to solve the above problems of the prior art, the RFID tag of the object scattered in each separated space or a large area by using multiple antennas to detect the group of RFID tag It provides a sensing device and method.

The present invention also provides an apparatus and method for detecting an RFID tag, which prevents a transmission output for detecting RFID tags from acting as a noise of a receiver and improves a reception distance.

In order to achieve the above object, a sensing apparatus of an RFID tag according to the present invention includes a plurality of connection devices 210 and 230 connected to a plurality of antennas respectively covering a plurality of areas, respectively, to reproduce signals of the antennas. 250 and 270, an RFID reader 200 connected to the connection device and identifying the areas and controlling the connection device to detect a radio frequency identification tag provided in the areas, and connected to a rear end of the RFID reader. And a bias tee 202 for transmitting power and RF signals simultaneously, and an amplifier module 203 connected to a rear end of the bias tee for bidirectionally amplifying the RF signal with a predetermined gain.

In addition, the RFID tag detection method according to the invention, receiving the tag information from the RFID tag provided in the object in the area by any one of a plurality of antennas each covering a plurality of areas, and the tag And transmitting the information by adding area information of the antenna that has received the tag information and time information when the tag information is received.

As described above, the present invention enables the RFID tag mixed in a separated space or a large area to be detected by using a few RFID readers, thereby reducing the equipment and installation cost due to the RFID readers, and the transmission output is the receiving end. It is possible to solve the problem of the loss of the received signal by acting as the noise of the signal, and to amplify the bidirectional signal in the transmission and reception path, thereby extending the received signal, thereby increasing the actual receiving distance.

Hereinafter, with reference to the accompanying drawings will be described in detail the operating principle of the preferred embodiment of the present invention. In describing the present invention, when it is determined that the detailed description of the related known function or configuration may unnecessarily obscure the subject matter of the present invention, the detailed description may be omitted.

The present invention relates to an apparatus and a method for detecting an RFID tag provided in an object to be detected, and in particular, by detecting a group of RFID tags mixed in a wide space by using a plurality of RFID readers and a plurality of antennas. will be. To this end, the present invention provides a multi-antenna connection device that can be connected to a plurality of antenna array using the antenna terminal provided in the RFID reader. In addition, the present invention further comprises a bias-tee to simultaneously transmit a power supply and a radio frequency (RF) signal on only one line, and include a bidirectional signal amplifying means for reproducing a high frequency (hereinafter referred to as 'RF') signal. And recovery function.

1 illustrates a connection structure of a sensing device according to a first embodiment of the present invention. As shown in the drawing, first to Nth connection devices 210, 230, 250, and 270 are sequentially connected to an RFID reader 200. And a bias-tee 202 for supplying power and an amplifier module 203 for bidirectionally amplifying an RF signal between the RFID reader and the first connection device. Antenna groups 220, 240, 260, and 280 composed of a plurality of antenna elements are connected to each connection device 210, 230, 250, and 270, respectively. 224, 242 to 244, 262 to 264, and 282 to 284 are detected.

The first to Nth connection devices 210, 230, 250, and 270 are connected to themselves, respectively, and receive antenna tap information in the first to Nth areas 220, 240, 260, and 280 grouped with the RFID reader 200. To send). Then, the RFID reader 200 adjusts the RF output by matching the overall impedance according to the antenna tap information.

The bias-tee 202 supplies power to the first to Nth connectors 210, 230, 250, and 270 and the amplifier module 203, and at the same time, the first to Nth connectors 210, 230, and 250. , 270 transmits and receives an RF signal to and from the RFID reader 200, and also transmits a control signal to the first to Nth connection devices 210, 230, 250, and 270 through the same line. The present invention has the advantage that can be simultaneously transmitted or received by a power supply, a 900MHz band RF signal, and a control signal through a single line by such a bias-tee.

The amplifier module 203 amplifies and transmits an RF signal with a predetermined gain between the first to Nth connection devices 310, 330, 350, and 370 and the RFID reader 300 to secure data reliability, It is for widening the area to be covered. Such an amplifier module is illustrated as being provided between the bias-tee and the first connector in FIG. 1, but the present invention is not limited thereto, and the first to Nth connectors may be connected to any of the paths that follow. It can also be connected between each connecting device and the antenna. In addition, the amplifier module may be provided with two or more to increase the area covered by the present invention, it may be omitted if a sufficient RF signal can be obtained.

Referring to FIG. 1, antennas 221, 241, 261, and 281 connected to the connection devices 210, 230, 250, and 270 are respectively located in the plurality of regions 220, 240, 260, and 280 that are separated from each other. And each of the antennas has a unique area index corresponding to that area. In the first embodiment of the present invention, it is shown that one antenna is connected to each connection device, but in reality, two to more antennas are used depending on the structure and the topographical characteristics of the corresponding areas and the number of antenna connection taps provided. Up to 10 antennas can be connected. Here, each of the regions means a range within a limit in which signals of each antenna are transmitted and received.

The connecting devices 210, 230, 250, and 270 are connected to the RFID reader 200 through an RF line, and the RFID reader acquires tag information of RFID tags located in the areas. The RFID tag is provided in objects to be detected and transmits a response signal including its own tag information in response to a signal transmitted from antennas in the area. The tag information may include a state of the opening / closing of the door or the switch and the detection of the pressure according to the type or use of the object to which the RFID tag is attached.

In FIG. 1, first to Nth connection devices are hierarchically connected using an uplink terminal. Here, the hierarchically connected means that the lower connection device is connected to the RFID reader through the upper connection device. However, the present invention is not limited thereto, and the first to Nth connection devices may be radially distributed around the RFID reader, and each connection device may be directly connected to the RFID reader.

Meanwhile, in FIG. 1, the RFID tags are installed in windows, doors, gas valves, electrical switches, and the like to transmit / receive status information about opening / closing to tag information, or installed on floors or walls to provide tag information about pressure information. Can be sent on. In other cases, the RFID tags may be used for checking the storage of valuables and the like or for identifying the location of a desired object. The tag information is collected by the RFID reader 200 and reported to a controller (not shown). The controller is connected to the RFID reader, collects, manages and analyzes the tag information, and notifies an emergency alarm to a user's mobile phone or terminal which is set in advance when deemed necessary.

2 is a block diagram of a connection device according to the first embodiment of FIG. 1. As shown, the first connector 210 receives RF signals from the bias-tee 202 and the amplifier module 203 and branches the signals by the first directional coupler 211 to the second connector 230. ) And the first antenna 221. Similarly, the second connector 230 receives the RF signal from the first connector 210 and branches the signal by a second directional coupler (not shown) to connect the third connector 250 and the second antenna. To 241. In FIG. 2, the RFID tag information detected by the first antenna 221 is transmitted to the RFID reader 200, and the same applies to the second to Nth antennas.

3 is a view showing a connection structure according to a second embodiment of the present invention. As shown in FIG. 3, the basic configuration is the same as that of the first embodiment of FIG. 1, and each connection device 410, 430, 450, 470 is shown. ) Is connected to a plurality of antennas (three in the second embodiment of the present invention). That is, in FIG. 3, two or more antennas 421 to 423, 441 to 443, 461 to 463, and 481 to 483 are provided for each connection device 410, 430, 450, and 470. The number of such antennas can be further extended.

In FIG. 3, the RFID tag information detected by the antenna 1-1 421 is transmitted to the RFID reader 200, and similarly the RFID tag information detected by the antenna 1-2 422 or the antenna 1-K 423. Also transmitted to the RFID reader 200, the same works for the other antennas 441 to 443, 461 to 463, and 481 to 483.

4 is a block diagram of an amplifier module according to the present invention. In FIG. 4, the amplifier module transmits the input downlink signal to the power amplifier 602 and outputs an uplink signal from the low noise amplifier 604 and a downlink from the first shuffler. A second power amplifier 602 that amplifies the link signal and delivers the downlink signal received from the power amplifier, and transmits the input uplink signal to the low noise amplifier 604. And a low noise amplifier 604 that amplifies an uplink signal from the second shuffler and transmits the uplink signal to the first shuffler. The first and second circulators, the power amplifier, and the low noise amplifier are included. It is preferable that is comprised integrally.

5 is a signal flow diagram illustrating communication between an RFID reader and a controller in accordance with the present invention. In FIG. 5, when there is no event, as shown in process S110, the RFID reader 200 and the controller 201 perform a keeping alive check to determine whether there is an error in communication with each other. When the RFID tag is detected by any one of the plurality of antennas as in step S120, and a response signal is transmitted to the RFID reader 200 through the connection device, the RFID reader 200 is controlled by the controller 201. Send event information to.

The controller 201 is to process the RFID tag information detected by the RFID reader by communicating with the RFID reader 200 and is not related to the function of controlling the operation of the connection device. That is, the present invention does not require the function of controlling the operation of the connecting device by using the directional couplers as in the above-described embodiment.

Meanwhile, in the detailed description of the present invention, specific embodiments have been described, but various modifications are possible without departing from the scope of the present invention. Therefore, the scope of the present invention should not be limited to the described embodiments, but should be defined not only by the scope of the following claims, but also by those equivalent to the scope of the claims.

1 is a view showing a connection structure according to a first embodiment of the present invention.

2 is a block diagram of a connection device according to the first embodiment of FIG.

3 is a view showing a connection structure according to a second embodiment of the present invention.

4 is a block diagram of an amplifier module according to the invention.

5 is a signal flow diagram illustrating communication between an RFID reader and a controller in accordance with the present invention.

* Explanation of symbols for the main parts of the drawings

200: RFID reader 202: bias-tee

203: Amplifier Module

210, 230, 250, 270: first to Nth connection device

211: first directional coupler

220, 240, 260, 280: first to Nth regions

221, 241, 261, 281: first to Nth antennas

601: first shuffler 602: power amplifier

603: second shuffler 604: low noise amplifier

Claims (7)

In the sensing device of the RFID tag, At least one connection device connected to a plurality of antennas respectively covering a plurality of regions, for reproducing the signals of the antennas; At least one RFID reader connected to the connection device to identify the areas and sense an RFID tag provided in the areas; A bias-tee connected to a rear end of the RFID reader and simultaneously transmitting power and RF signals; An amplifier module connected to a rear end of the bias tee to bidirectionally amplify an RF signal with a predetermined gain; And a controller connected to the RFID reader to recognize the RFID tag and to control the connection device. The method of claim 1, wherein the amplifier module, A first shuffler which transfers the input downlink signal to the power amplifier and outputs an uplink signal from the low noise amplifier; A power amplifier for amplifying a downlink signal from the first shuffler and transferring the downlink signal to a second shuffler; A second shuffler for outputting a downlink signal received from the power amplifier and transferring the input uplink signal to a low noise amplifier; And a low noise amplifier for amplifying an uplink signal from the second shuffler and transferring the uplink signal to the first shuffler. In the sensing device of the RFID tag, A plurality of connecting devices connected to a plurality of antennas respectively covering a plurality of areas, and connected to each other to reproduce signals of the antennas; At least one RFID reader connected to the connecting devices to identify the areas and sense an RFID tag provided in the areas; A bias-tee connected to a rear end of the RFID reader and simultaneously transmitting power and RF signals; An amplifier module selectively connected between the plurality of connection devices to bidirectionally amplify an RF signal with a predetermined gain; And a controller connected to the RFID reader to recognize the RFID tag and to control the connection devices. The method of claim 1 or 2, wherein the amplifier module, At least one sensing device of the RFID tag, characterized in that connected between each connecting device and the antenna. The method of claim 1, wherein the connection device, Receiving an RF signal and a control signal by the directional coupler for branching the signals transmitted to each of the connecting device and the antenna connected to the rear end of the RFID tag detection device. In the method for detecting an RFID tag, Receiving tag information from an RFID tag provided in an object in the areas by any one of a plurality of antennas respectively covering a plurality of areas; And transmitting the tag information, area information of the antenna that has received the tag information, and time information when the antenna receives the tag information to an RFID reader. The method of claim 6, wherein the receiving of the tag information comprises: And transmits a transmission signal for detecting the RFID tag by the plurality of antennas, and receives a response signal including the tag information from one of the plurality of antennas in response to the transmission signal. RFID tag detection method.

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