DEVICE FOR WIRELESS OPERATION AND METHOD FOR OPERATING THE DEVICE

• US 20090207037A1
• Filed: 09/03/2007
• Published: 08/20/2009
• Est. Priority Date: 09/01/2006
• Status: Active Grant

• Current Assignee: Leptonradio AB
• Original Assignee: Leptonradio AB
• Inventors: Bilstrup, Urban, Wiberg, Per-Arne
• Granted Patent: US 8,368,514 B2
• Time in Patent Office: Days
• US Class Current: 340/693.300
• CPC Class Codes: G06K 19/0705 the battery being connected to a power saving arrangement
• 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

Abstract

An electronic device and a method of operating the device. The device receives a first signal having a first frequency and a predetermined signal strength and retransmits a signal after a latency period and during a time period. The device comprises an oscillation circuit operating in a sub-threshold area in a meta-stable, first mode of operation. When the first signal is received, the oscillation circuit is trigged and passes to an active mode in a second mode of operation, wherein the circuit oscillates. Finally, the device is reset to the first mode of operation. The device may have an identity, which is used for the purpose of the system, which may be an RFID system.

Claims

1. A method of operating an electronic device, comprising:

initially operating the device in a meta-stable, first mode of operation;

operating the device in an oscillating, second mode of operation, wherein the device oscillates at a predetermined oscillation frequency;

transferring the device from said first mode of operation to said second mode of operation by means of a signal having a predetermined signal frequency and power level and being input to an input terminal of the device;

terminating the second mode of operation and transferring said device to said meta-stable, first mode of operation.

2. The method according to claim 1, wherein said transferring of the device from said first mode of operation to said second mode of operation takes place after a latency period after inputting said signal.

3. The method according to claim 1, wherein said signal is a signal received by an antenna.

4. The method according to claim 1, wherein said signal frequency is offset from the oscillation frequency of the device.

5. The method according to claim 1, wherein the device is in a sub-threshold area of operation in the meta-stable, first mode of operation.

6. The method according to claim 1, wherein the oscillation frequency is adjustable.

7. the method according to claim 1, further comprising:

activation of a control circuit at the transferring from the first mode of operation to the second mode of operation.

8. An electronic device, comprising:

an amplification member and a filter member connected to form an oscillation circuit,

a bias circuit for maintaining the oscillation circuit in an inactive, meta-stabile, first mode of operation, having low power dissipation,

an input circuit for inputting a signal to said amplification member for transferring said device into a second mode of operation, wherein the device oscillates at a predetermined oscillation frequency;

a reset circuit for resetting said device to said first mode of operation.

9. The device according to claim 8, wherein said input circuit comprises an antenna.

10. The device according to claim 8, wherein the filter member comprises at least one inductor and at least one capacitor.

11. The device according to claim 8, wherein said filter member is adjustable.

12. The device according to claim 8, further comprising a control circuit adapted to be activated at the transferring from said first mode to said second mode.

13. The device according to claim 12, wherein said control circuit controls the reset circuit.

14. The device according to claim 12, wherein at least a second electronic device is connected to the control circuit.

15. The device according to claim 14, wherein said second electronic device has a different oscillation frequency than the first electronic device.

16. The device according to claim 11, wherein the device is used in an article surveillance system comprising a reader and several identification tags.