Abstract:
An RFID device, and more particularly to a RFID device which can be used in both a tag mode and a reader mode. There is provided an RF antenna transmitting and receiving wireless signals; a tuning circuit as a frequency filtering circuit connected to the RF antenna; a memory storing data; and a wireless communication card including antenna connection terminals connected to the RF antenna.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application claims the benefit of Korean Application No. 10-2009-0013484, filed Feb. 18, 2009, in the Korean Intellectual Property Office, the disclosure of which is incorporated herein by reference. 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     Aspects of the present invention relate to a near field communication device, and more particularly to an RFID communication device using a frequency of 13.56 MHz. 
     2. Description of the Related Art 
     Radio frequency identification (RFID) is a non-contact type automatic identification technique in which an RFID tag attached to an identification object and operated in a passive mode and an RFID reader operated in an active mode communicate with each other through transmission and reception of signals using a radio frequency in order to automatically identify an object using wireless radio waves. Since the RFID technique can overcome shortcomings of an existing automatic identification technique such as a barcode and an optical character identification technique, it is being applied to credit cards. 
     A credit card with an existing RF function is designed to be used only in passive mode using a frequency of 13.56 MHz. Induction currents generated by a radio wave emitted from an RF reader activate an RF chip mounted on a credit card so that communication is made between the credit card and the RF reader. Since a credit card with an existing RF function inevitably needs a reader for communication, its use is limited and can be improved. 
     SUMMARY OF THE INVENTION 
     Aspects of the present invention have been made in view of the above noted circumstance and provide a Radio Frequency Identification (RFID) communication device including a card enabling communication without a reader. 
     Aspects of the present invention also provide an RFID communication device operated in a passive or active mode. 
     Aspects of the present invention also provide an RFID communication device facilitating use of data. 
     In accordance with an aspect of the present invention, there is provided an RFID communication device comprising a wireless communication card including an RF antenna transmitting and receiving wireless signals; a tuning circuit as a frequency filtering circuit connected to the RF antenna; a memory storing data; and antenna connection terminals connected to the RF antenna. The wireless communication card may further include a rechargeable secondary battery, which includes a bare cell, two charge/discharge terminals connected to the bare cell, and a protection circuit controlling charge and discharge of the bare cell. The number of antenna connection terminals may be three and one of the antenna connection terminals may be shared with the one of the charge/discharge terminals. 
     The tuning circuit may be a 13.56 MHz frequency filtering circuit. 
     The RFID communication device may include a communication controller chip supporting both an RFID tag mode and a reader mode and may further include a wireless communication controller set connected to the wireless communication card. 
     The communication controller chip of the wireless communication controller set may be a near field communications (NFC) chip. 
     The wireless communication controller set may further include a matching circuit as a frequency filtering circuit connecting the antenna connection terminals of the wireless communication card and the communication controller chip. 
     The wireless communication card may further include a secondary battery for providing power to the wireless communication controller set. 
     The wireless communication controller set may further include an output unit outputting data stored in the memory of the wireless communication card. 
     The wireless communication controller set may further include a power source therein. 
     The wireless communication card may further include a controller unit controlling the memory. 
     In accordance with another aspect of the present invention, there is provided a credit card including an RF antenna transmitting and receiving wireless signals; a tuning circuit as a frequency filtering circuit connected to the RF antenna; a memory storing data; a controller unit controlling the tuning circuit and the memory; and antenna connection terminals connected to the RF antenna. 
     Various types of RFID communications can be enabled and data can be easily confirmed by providing the antenna connection terminal connected to the RF antenna and the wireless communication memory card for storing data. 
     Further, the wireless communication controller set supporting both an RFID tag mode and a reader mode is coupled to the wireless communication card in order to operate in both passive and active modes. 
     Moreover, usage time for RFID communication can be prolonged by providing the wireless communication card with a secondary battery supplying power to the wireless communication controller set coupled to the wireless communication card. 
     Additional aspects and/or advantages of the invention will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the invention. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       These and/or other aspects and advantages of the invention will become apparent and more readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings of which: 
         FIG. 1  is a block diagram illustrating an RFID communication device according to an embodiment of the present invention; and 
         FIG. 2  is a block diagram illustrating a circuit of a wireless communication card illustrated in the  FIG. 1 . 
     
    
    
     DETAILED DESCRIPTION OF THE EMBODIMENTS 
     Reference will now be made in detail to the present embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to the like elements throughout. The embodiments are described below in order to explain the aspects of the present invention by referring to the figures. 
     Herein, when a first element is described as being connected to a second element, the first element may be not be only directly connected to the second element but may also be indirectly connected to the second element via a third element. 
       FIG. 1  is a block diagram illustrating an RFID communication device according to an embodiment of the present invention.  FIG. 2  is a view illustrating a circuit of a wireless communication card illustrated in the  FIG. 1 . 
     Referring to  FIG. 1 , an RFID communication device  100  includes a wireless communication card  200 , and a wireless communication controller set  300 . 
     Referring to  FIGS. 1 and 2 , the wireless communication card  200  is a credit card, and includes an RF antenna  210 , three antenna connection terminals  220   a,    220   b,  and  220   c,  a tuning circuit  230 , a memory  240 , a controller  250 , and a secondary battery  260 . The wireless communication card  200  communicates with an external RFID tag  10  or an RFID reader  20 , and stores data into a memory  240 . 
     The RF antenna  210  selectively identifies a radio wave having a frequency of 13.56 MHz from among radio waves radiated in the air for RFID communication. In active mode the RF antenna  210  transmits RF communication data to the outside in active mode. The RF antenna  210  is a general loop antenna used for both passive and active mode. 
     The three antenna connection terminals  220   a,    220   b,  and  220   c  are connected to the RF antenna  210 , and are exposed to the outside of the wireless communication card  200 . The three antenna connection terminals  220   a,    220   b,  and  220   c  support both active and passive modes. The three antenna connection terminals  220   a,    220   b,  and  220   c  are made of a conductive material and are located in parallel to be exposed to a short edge of the wireless communication card  200 . The location of the three antenna connection terminals  220   a,    220   b , and  220   c  may vary according to the structure of the wireless communication card  200 . 
     The tuning circuit  230  is electrically connected to the three antenna connection terminals  220   a,    220   b,  and  220   c  respectively, and is electrically connected to the RF antenna  210 . The tuning circuit  230  filters a frequency of 13.56 MHz. The tuning circuit  230  is a general circuit used for RFID communication. 
     Basic data about RFID and diverse data are stored in the memory  240 . For instance, when the RFID communication device  100  is used as a transportation card, detailed data about means of transportation, sections of a line, fares, and transportation time may be stored in the memory  240 . The memory  240  is a non-volatile memory such as a flash memory, wherein data stored therein are not erased even when power is not supplied to it. 
     The controller  250  is electrically connected to the RF antenna  210  and the memory  240 . The controller  250  transmits data stored in memory  240  to the outside through the RF antenna  210 , or stores data received by the RF antenna  210  in the memory  240 . When the controller  250  is in passive mode, it is operated by currents induced by radio waves emitted from the RFID reader  20 . When the controller  250  is in active mode, it is operated by power provided by a wireless communication controller set  300  received through the RF antenna  210 . The controller  250  is provided in the form of an integrated circuit (IC) chip. Although a controller  250  is provided in the embodiment of the present invention, it may not be included in another embodiment of the present invention. In the absence of a controller  250 , the memory  240  may be controlled by a microcontroller unit (MCU)  330  mounted on the wireless communication controller set  300 . In this case, the memory  240  may be connected to the MCU  330  of the wireless communication controller set  300  through the antenna connection terminals  220   a ,  220   b,  and  220   c.    
     The secondary battery  260  includes a bare cell  261 , a protection circuit  262 , and two charge/discharge terminals  263  and  220   c.  The secondary battery  260  supplies power to the wireless communication controller set  300 . 
     Although not illustrated in detail, the bare cell  261  is an electrical energy source, and may include an electrode assembly (not shown) and a pouch (not shown) surrounding the electrode assembly (not shown). The electrode assembly may include a first electrode plate (not shown), a second electrode plate (not shown), and a separator (not shown). The electrode assembly may have a form of a plate in which the separator is located between the first electrode plate and the second electrode plate. The electrode assembly is sealed by the pouch (not shown) together with a polymeric electrolyte. Although not illustrated, the bare cell  261  includes a positive electrode terminal and a negative electrode terminal connected to the protection circuit  262 . 
     The protection circuit  262  is electrically connected between the two charge/discharge terminals  263  and  220   c,  and controls charge and discharge of the bare cell  261 . The protection circuit  262  includes a charge/discharge controller chip  262   a  and a switching device  262   b.  The charge/discharge controller chip  262   a  monitors data about the voltage and charge/discharge current of the bare cell  261 , and outputs control signals to protect the bare cell  261  from over-charge, over-discharge, and over-currents. The switching device  262   b  is located on a path of charge/discharge currents of the bare cell  261  and sets the direction of currents so that either a charge or a discharge operation is possible according to the control signal of the charge/discharge controller chip  262   a.  Although not illustrated, the switching device  262   b  may include a charge FET and a discharge FET connected in series. The charge FET is turned on and the discharge FET is turned off in order to allow the switching device  262   b  to flow only charging currents of the switching device  262   b.  On the other hand, the charge FET is turned off and the discharge FET is turned on in order to allow the switching device  262   b  to flow only discharging currents during the discharging operation of the switching device  262   b.  Although not illustrated, the protection circuit  262  may include other electronic circuit devices such as a resistor, a capacitor, and a thermal fuse. 
     The two charge/discharge terminals  263  and  220   c  are connected to the protection circuit  262 . When the two charge/discharge terminals  263  and  220   c  are connected to a charger (not shown), the bare cell  261  is charged under the control of the protection circuit  262 . When an external load such as a wireless communication controller set  300  is connected to the two charge/discharge terminals, power is supplied to the external load under the control of the protection circuit  262 . One of the two charge/discharge terminals  263  and  220   c  is shared and thus is one of the three antenna connection terminals  220   a,    220   b,  and  220   c  so that space for a terminal can be saved. 
     The wireless communication controller set  300  includes a communication controller chip  310 , a matching circuit  320 , an MCU  330 , an output unit  340 , and a power source  350 . The wireless communication controller set  300  controls RFID communication by using the RF antenna  210  of the wireless communication card  200 . The wireless communication controller set  300  may be a mobile communication terminal such as a mobile phone, a mobile computer or a peripheral attachable to a mobile computer, an electronic book, a personal digital assistant, a mobile audio/video device or a similar mobile device. 
     The communication control chip  310  supports both an RFID tag mode as a passive mode and an RFID reader mode as an active mode. In the present embodiment of the present invention, the communication control chip  310  is a near field communication (NFC) chip widely used for near field communication, however aspects of the present invention are not limited thereto. 
     The matching circuit  320  is a frequency filtering circuit connecting the communication control chip  310  and the antenna connection terminals  220   a,    220   b,  and  220   c  of the wireless communication card  200 . The matching circuit  320  includes a plurality of capacitors connected in series or in parallel. 
     The MCU  330  is connected to the communication control chip  310  to control the operation mode of the communication control chip  310 . Selection of the operation mode by a user is transmitted to the communication control chip  310  through the MCU  330  to determine the operation mode of the communication control chip  310 . A user can read and modify the data stored in the memory  240  of the wireless communication card  200  through the MCU  330 . The MCU  330  may be a central processing unit (CPU) provided in a terminal (for example, a mobile phone) used as the wireless communication controller set  300 . 
     The output unit  340  is controlled by the MCU  330  and can provide the data stored in the memory  240  of the wireless communication card  200  to the user. The output unit  340  may be a display device or a speaker unit, and may be a LCD display or a speaker provided in a terminal (for example, a mobile phone) used as the wireless communication controller set  300 . 
     The power source  350  supplies power to the communication controller chip  310 , the MCU  330  and the output unit  340 . The power source  350  may be a secondary battery provided in a terminal (for example, a mobile phone) used as the wireless communication controller set  300 . The power source  350  is connected to the charge/discharge terminals  263  and  220   c  of the wireless communication card  200 . When the power source  350  is fully discharged, the bare cell  261  of the wireless communication card  200  can supply power. Though there is no power source  350  in the wireless communication controller set  300 , RFID communication receives power from the bare cell  261  disposed in the wireless communication card  200 . 
     Hereinafter, the operation of aspects of the present invention will be described in detail with reference to the  FIG. 1 . 
     A user can select a passive mode functioning as an RFID tag or an active mode functioning as an RFID reader through the MCU  330  of the wireless communication controller set  300 . When passive mode is selected, the communication controller chip  310  of the wireless communication controller set  300  is set to passive mode. In this case, the RFID communication device  100  communicates with the RFID reader  20  and functions as a general RFID tag. 
     When active mode is selected, the communication controller chip  310  of the wireless communication controller set  300  is set to active mode. In this case, the RFID communication device  100  communicates with the RFID tag and functions as a general RFID reader. Then, power is supplied to the RFID reader from the power source  350  of the wireless communication controller set  300  or the bare cell  261  of the wireless communication card  200 . 
     In both passive mode and active mode, the history data corresponding to the use of the RFID communication device  100  is stored in the memory  240  of the wireless communication card  200 . For example, when the RFID communication device  100  is used for a transportation card, data about means of transportation, sections of a line, fares, and transportation time may be stored in the memory  240 . Such data can be easily verified through the output unit  340  of the wireless communication controller set  300 . 
     In the present embodiment of the present invention, although the wireless communication card  200  is connected to the wireless communication controller set  300  included in a mobile communication terminal such as a mobile phone for RFID communication, aspects of the present invention are not limited thereto. The wireless communication card  200  may be used as a data storage device. In other words, the wireless communication card  200  may be connected to a personal computer through the antenna connection terminals  220   a,    220   b,  and  220   c  to store new data in the memory  240  or process the data stored in the memory  240 . The wireless communication card  200  may be used as an emergency power source. When the power of a mobile device such as a mobile phone is exhausted, power may be supplied to the mobile device from the bare cell  261  of the wireless communication card  200  by connecting the bare cell  261  to the mobile device. 
     Although a few embodiments of the present invention have been shown and described, it would be appreciated by those skilled in the art that changes may be made in this embodiment without departing from the principles and spirit of the invention, the scope of which is defined in the claims and their equivalents.