Battery-assisted backscatter RFID transponder

• US 20060001528A1
• Filed: 06/30/2005
• Published: 01/05/2006
• Est. Priority Date: 07/01/2004
• Status: Abandoned Application

• Current Assignee: PowerID Ltd.
• Original Assignee: PowerID Ltd.
• Inventors: Nitzan, Zvi, Guri, Gaby, Lavee, Doron
• Application Number:
  US11/169,728
• Publication Number:
  US 20060001528A1
• Time in Patent Office: Days
• US Class Current: 340/10.330
• CPC Class Codes: G06K 19/0702 the arrangement including a battery
• CPC Class Codes: G06K 19/0705 the battery being connected to a power saving arrangement
• CPC Class Codes: G06K 19/0707 the arrangement being capable of collecting energy from external energy sources, e.g. thermocouples, vibration, electromagnetic radiation G06K19/0702 takes precedence
• CPC Class Codes: G06K 19/0712 the arrangement being capable of triggering distinct operating modes or functions dependent on the strength of an energy or interrogation field in the proximity of the record carrier active means for hindering electromagnetic reading or writing G06K19/07336
• 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: G06K 19/07749 the record carrier being capable of non-contact communication, e.g. constructional details of the antenna of a non-contact smart card
• CPC Class Codes: H01Q 1/2225 used in active tags, i.e. provided with its own power source or in passive tags, i.e. deriving power from RF signal
• CPC Class Codes: H01Q 1/38 formed by a conductive layer on an insulating support patch antennas H01Q9/0407; microstrip dipole antennas H01Q9/065; microstrip slot antennas H01Q13/106; transmission line microstrip antennas H01Q13/206; manufacturing reflecting surfaces using insulating material for supporting the reflecting surface H01Q15/142
• CPC Class Codes: H01Q 9/16 with feed intermediate between the extremities of the antenna, e.g. centre-fed dipole H01Q9/44 takes precedence

Abstract

A radio frequency transponder includes at least one battery, which is coupled to provide electrical power for operating the transponder and at least one antenna, which is configured to receive and backscatter RF interrogation radiation from an interrogation device. An integrated circuit is arranged to store a code including information and, powered only with energy provided by the battery, to vary a radiation characteristic of the antenna responsively to the code so as to modulate the information onto the backscattered radiation.

Claims

1. A radio frequency (RF) transponder, comprising:

an antenna, which is arranged to receive first RF radiation carrying signals from an interrogation device and to transmit second RF radiation responsively to the first RF radiation;

a battery, which is coupled to provide electrical power for operating the transponder; and

an integrated circuit (IC), which is operative in accordance with a reader-talks-first (RTF) protocol, and which is configured to detect a presence of the first RF radiation, to analyze the signals carried by the first RF radiation, to progressively activate components of the transponder responsively to the analyzed signals, so as to reduce an energy consumption from the battery, to assess a relevance of the first RF radiation to the transponder based on the analyzed signals, and to enable the transponder to transmit the second RF radiation based on the relevance.

2. The transponder according to claim 1, wherein the IC is configured to assess the relevance of the first RF radiation by performing at least one of detecting a pattern in the first RF radiation and determining addressing information in the first RF radiation.

3. The transponder according to claim 1, wherein the IC is arranged, responsively to the relevance of the first RF radiation, to perform at least one of rejecting RF radiation not generated by an RF reader and rejecting RF radiation not addressed to the transponder.

4. The transponder according to claim 1, wherein the IC is arranged to evaluate one or more timeout conditions and to deactivate predetermined components of the transponder responsively to the timeout conditions after having detected the presence of the first RF radiation.

5. The transponder according to claim 1, wherein the IC comprises a battery status indicator, which is arranged to indicate an availability of sufficient electrical power from the battery, and wherein the IC is arranged to draw electrical power from the first RF radiation responsively to a reported unavailability of battery power as determined by the battery status indicator.

6. The transponder according to claim 1, and comprising at least one sensor, wherein the IC is arranged to receive an indication of a local condition in a vicinity of the transponder from the at least one sensor.

7. The transponder according to claim 1, and comprising an energy conversion circuit, which is arranged to draw excess power from the interrogation radiation, when excess power is available, and to perform at least one of powering the IC and charging the battery using the drawn excess power.

8. The transponder according to claim 1, wherein the IC is arranged to decode and react to interrogation data carried by the interrogation radiation, the interrogation data comprising at least one of a command relating to an operation of the transponder and data to be written to the transponder.

9. A method for reducing energy consumption from a battery in

a radio-frequency (RF) transponder operating in accordance with a reader-talks-first (RTF) protocol, comprising:

detecting a presence of RF radiation at the transponder;

analyzing signals carried by the detected RF radiation;

progressively activating components of the transponder responsively to the analyzed signals, so as to reduce the energy consumption;

assessing a relevance of the RF radiation to the transponder based on the analyzed signals; and

based on the relevance, enabling the transponder to react to the RF radiation.

10. The method according to claim 9, wherein analyzing the signals comprises at least one of detecting a pattern in the RF radiation and determining addressing information in the RF radiation.

11. The method according to claim 9, wherein assessing the relevance comprises at least one of rejecting RF radiation not generated by an RF reader and rejecting RF radiation not addressed to the transponder.

12. The method according to claim 9, and comprising evaluating one or more timeout conditions so as to activate predetermined components of the transponder responsively to the analyzed signals.

13. The method according to claim 9, further comprising, drawing electrical power from the RF radiation and powering the transponder with the drawn power when the battery is unable to provide sufficient electrical power for operating the transponder.

14. An energy saving circuit for reducing energy consumption from a battery in a radio-frequency (RF) transponder, comprising:

a state machine, which is arranged to detect a presence of RF radiation at the transponder, to analyze signals carried by the detected RF radiation, to progressively activate components of the transponder responsively to the analyzed signals so as to reduce the energy consumption, to assess a relevance of the RF radiation to the transponder based on the analyzed signals, and, based on the relevance, to enable the transponder to react to the RF radiation; and

one or more timeout circuits, which are arranged to evaluate timeout conditions so as to activate predetermined components of the transponder responsively to the analyzed signals.

15. The circuit according to claim 14, wherein the state machine is arranged to assess the relevance by performing at least one of detecting a pattern in the RF radiation and determining addressing information in the RF radiation.

16. The circuit according to claim 14, wherein the state machine is arranged to perform at least one of rejecting RF radiation not generated by an RF reader and rejecting RF radiation not addressed to the transponder.