Method and apparatus for stopping power supply in RFID system

• US 8,416,063 B2
• Filed: 10/24/2007
• Issued: 04/09/2013
• Est. Priority Date: 12/08/2006
• Status: Expired due to Fees

• Current Assignee: Electronics and Telecommunications Research Institute
• Original Assignee: Electronics and Telecommunications Research Institute
• Inventors: Jung, Jae-Young, Son, Hae Won, Seo, Jong Hyun, Choi, Su Na, Choi, Gil Young, Pyo, Cheol Sig, Yeo, Jun Ho
• Primary Examiner(s): BROWN, VERNAL U
• Application Number:
  US11/878,000
• Publication Number:
  US 20080136594A1
• Time in Patent Office: 1,994 Days
• Field of Search: 340/10.34, 340/10.33, 340/12.5, 340/13.25, 340/505
• US Class Current: 340/10.34
• CPC Class Codes: G06K 19/0701 at least one of the integrated circuit chips comprising an arrangement for power management
• CPC Class Codes: G06K 19/0723 the record carrier comprising an arrangement for non-contact communication, e.g. wireless communication circuits on transponder cards, non-contact smart cards or RFIDs
• CPC Class Codes: H04W 52/0245 according to signal strength
• CPC Class Codes: Y02D 30/70 in wireless communication networks

Abstract

Provided are a method and apparatus for stopping power supply to a radio frequency identification (RFID) system. The apparatus includes: a power supplier supplying power to a high RFID tag; an input unit rectifying and boosting an input predetermined frequency band signal and outputting a direct-current (DC) voltage signal; a wake-up determiner comparing a voltage of the DC voltage signal output from the input unit with a predetermined reference voltage and outputting a HIGH signal or a LOW signal; and a switch stopping power supply to the high RFID tag if the wake-up determiner outputs the LOW signal.

Claims

1. An apparatus for stopping power supply to a radio frequency identification (RFID) system, the apparatus comprising:

a power supplier configured to supply power to an RFID tag;

an antenna configured to receive an input signal, wherein the input signal comprises a continuous portion and a base band portion in which the base band portion includes a command from an RFID reader;

an input unit coupled to the antenna, wherein the input unit is configured to rectify and boost the continuous portion and to subsequently output a direct-current (DC) signal, wherein the input unit is configured to output the DC signal in a LOW voltage state when the rectified and boosted continuous portion is less than a threshold voltage and the input unit is configured to output the DC signal in a HIGH voltage state when the rectified and boosted continuous portion is greater than the threshold voltage;

a wake-up determiner coupled to the input unit and to a controller, wherein the wake-up determiner is configured to compare the DC signal output from the input unit with a predetermined reference voltage from the controller and the wake-up determiner is configured to output a HIGH signal when either voltage states of the predetermined reference voltage or the DC signal are HIGH, and wherein the wake-up determiner is configured to output a LOW signal when voltage states of both the predetermined reference voltage and the DC voltage signal are LOW;

a demodulator coupled to the input unit and to the controller, wherein the demodulator is configured to read the command in the base band portion of the input signal from the input unit and to transmit the command to the controller;

the controller is configured to execute the command and the controller is configured to change voltage states of the predetermined reference voltage from HIGH to LOW after a clocked time period, and subsequent to when the controller is initially powered up then the controller is configured to change voltage states of the predetermined reference voltage from LOW to HIGH;

a switch coupled to the wake-up determiner, to the power supplier, and to a low voltage output stabilizer, wherein the switch is configured to stop power supply to the RFID tag when the wake-up determiner outputs the LOW signal to the switch and the switch is configured to connect power from the power supplier to the low voltage output stabilizer when the wake-up determiner outputs the HIGH signal; and

the low voltage output stabilizer is configured to subsequently power the controller and the demodulator with a predetermined voltage.

2. The apparatus of claim 1, wherein the wake-up determiner comprises:

a comparator configured to compare the DC signal from the input unit with the predetermined reference voltage from the controller.

3. The apparatus of claim 1, wherein the wake-up determiner comprises an OR gate.

4. The apparatus of claim 1, wherein the base band portion comprises a plurality of commands from the RFID reader.

5. The apparatus of claim 1, further comprising:

an output unit coupled to the controller, to the antenna, and to the input unit, wherein the output unit is configured to output a result of executing the command, wherein when the wake-up determiner outputs the HIGH signal, then the command of the RFID reader is subsequently executed.

6. A method of stopping power supply to a RFID system, the method comprising:

rectifying and boosting a continuous portion from an input signal to output a DC signal wherein when the rectified and boosted continuous portion is less than a threshold voltage then the DC signal is in a LOW voltage state and when the rectified and boosted continuous portion is greater than the threshold voltage then the DC signal is in a HIGH voltage state;

comparing the DC signal with a reference signal such that when voltage states of either the reference signal or the DC signal are HIGH then a HIGH signal is outputted and when voltage states of both the reference signal and the DC signal are LOW then a LOW signal is outputted;

extracting and transmitting a base band portion from the input signal wherein the base band portion comprises commands;

reading the commands in the base band portion;

executing the read commands;

switching power on to a controller and a demodulator with a predetermined voltage from a power supplier in response to a switch receiving the outputted HIGH signal; and

changing the voltage state of the reference signal from HIGH to LOW after a clocked period has expired;

switching off power to the controller and the demodulator of the in response to the LOW signal.

7. The method of claim 6, wherein the base band portion comprises commands of a RFID reader.

8. The method of claim 6, wherein the HIGH signal or the LOW signal are output by an OR logical operator.

9. The method of claim 7, further comprising:

outputting an output signal in response to executing the commands.

10. An apparatus for stopping power supply to a radio frequency identification (RFID) system, the apparatus comprising:

an input unit configured to receive an input signal from an antenna, the input signal comprising a continuous wave portion and a base band portion in which the base band portion includes commands from an RFID reader, wherein the input unit is configured to rectify and boost the continuous portion and to subsequently output a direct-current (DC) signal, wherein the input unit is configured to output the DC signal in a LOW voltage state when the rectified and boosted continuous portion is less than a threshold voltage and the input unit is configured to output the DC signal in a HIGH voltage state when the rectified and boosted continuous portion is greater than the threshold voltage;

a wake-up determiner coupled the input unit and to a controller, wherein the wake-up determiner is configured to compare the DC signal output from the input unit with a predetermined reference voltage from the controller and the wake-up determiner is configured to output a HIGH signal when either voltage states of the predetermined reference voltage or the DC signal are HIGH, and wherein the wake-up determiner is configured to output a LOW signal when voltage states of both the predetermined reference voltage and the DC voltage signal are LOW;

a switch coupled to the wake-up determiner, a power supplier and a low voltage output stabilizer, wherein the switch is configured to disconnect the power supplier from the low voltage output stabilizer when the wake-up determiner outputs the LOW signal to the switch and wherein the switch is configured to connect the power supplier to the low voltage output stabilizer when the wake-up determiner outputs the HIGH signal;

the power supplier coupled to the switch;

the low voltage output stabilizer coupled to the switch, the controller and a demodulator, wherein the low voltage output stabilizer is configured to stabilize power from the power supplier to both the controller and demodulator;

the demodulator coupled to the input unit, the low voltage output stabilizer, and to the controller, wherein the demodulator is configured to read the commands in the base band portion and to transmit the commands to the controller;

the controller coupled to the low voltage output stabilizer, the demodulator, and an output unit, in which the controller is configured to execute the transmitted commands, wherein the controller is configured to change voltage states of the predetermined reference voltage from HIGH to LOW after a clocked time period, and wherein subsequent to when the controller is initially powered up then the controller is configured to change voltage states of the predetermined reference voltage from LOW to HIGH; and

the output unit coupled to the controller, the antenna and the input unit, wherein the output unit is configured to transmit results of the executed commands.

11. The apparatus of claim 10, further comprising a memory coupled to the controller.

12. The apparatus of claim 10, further comprising a high frequency generator coupled to the controller for executing a clock so that the controller changes voltage states of the predetermined reference voltage from HIGH to LOW after the clocked time period.

13. The apparatus of claim 10, further comprising the antenna coupled to the input unit and to the output unit.

14. The apparatus of claim 10, wherein the wake-up determiner comprises an OR gate.