RFID TRANSPONDER USING AMBIENT RADIATION

• US 20110148580A1
• Filed: 12/22/2009
• Published: 06/23/2011
• Est. Priority Date: 12/22/2009
• Status: Active Grant

• Current Assignee: RadioFIDO LLC
• Original Assignee: BAE Systems Information and Electronic Systems Integration Incorporated (BAE Systems Plc)
• Inventors: Brommer, Karl D., Sutphin, Eldon M., Brittain, Candice L.
• Granted Patent: US 8,373,543 B2
• Time in Patent Office: Days
• US Class Current: 340/10.1
• 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 19/0723 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: H04Q 2213/13095 PIN / Access code, authentication

Abstract

A tag operates in an environment where transmitted interrogators are not possible or desired. High-efficiency diode rectifiers and low-power oscillators are used in combination with an energy storage element and hysteretic switch. The combination of multi-diode rectifier, low power tunnel diode oscillator, energy storage element and hysteretic switch allow for nanowatt levels of received RF power to be stored to produce micro-watts of RF transmit power. The device trickle charges off of ambient RF radiation until enough energy is stored for transmission.

Claims

1. A transponder apparatus operating from ambient radiation comprising:

a rectifier to at least partially rectify said ambient radiation;

an energy storage element storing at least some energy of said rectified ambient radiation;

a switch controlling output of at least some energy of said energy storage element; and

an oscillator generating a signal for transmission.

2. The apparatus of claim 1 wherein said transponder is a Radio Frequency IDentification (RFID) tag.

3. The apparatus of claim 1 wherein said transponder is a sensor.

4. The apparatus of claim 1 wherein said rectifier is a multi-diode rectifier.

5. The apparatus of claim 4 wherein said multi-diode rectifier comprises Schottky diodes.

6. The apparatus of claim 4 wherein said multi-diode rectifier comprises sixteen diodes.

7. The apparatus of claim 1 wherein said energy storage element comprises a low current charging path.

8. The system of claim 1 wherein said energy storage element further comprises a low current charging path comprising a battery whereby a low duty cycle mode of operation is provided.

9. The apparatus of claim 1 wherein said switch is a hysteretic switch.

10. The apparatus of claim 1 wherein said oscillator is a low-power oscillator.

11. The apparatus of claim 1 wherein said oscillator comprises a sensor.

12. The apparatus of claim 11 wherein said sensor is a capacitive sensor.

13. The apparatus of claim 12 wherein said sensor is a Micro-Electro-Mechanical Systems (MEMS) capacitive sensor.

14. The apparatus of claim 1 wherein said oscillator comprises an inductor, a Micro-Electro-Mechanical Systems (MEMS) sensor, and a tunnel diode.

15. A method for transponding using ambient radiation comprising:

receiving said ambient radiation;

rectifying energy from said ambient radiation;

storing said rectified energy from said received ambient radiation;

switching power of said stored rectified energy;

modulating said power; and

transmitting said modulated power.

16. The method of claim 15 wherein said step of rectifying comprises full wave rectification.

17. The method of claim 15 wherein said step of switching comprises hysteretic switching.

18. The method of claim 15 wherein said step of modulating comprises a low power oscillator.

19. The method of claim 15 wherein said step of oscillating comprises sensing a capacitance.

20. A Radio Frequency IDentification (RFID) tag sensor system operating from ambient radiation comprising:

a rectifier to at least partially rectify said ambient radiation, wherein said rectifier comprises sixteen Schottky diodes;

an energy storage element storing at least some energy of said rectified ambient radiation, wherein said energy storage element comprises a low current charging path comprising a battery whereby a low duty cycle mode of operation is provided;

a switch controlling output of at least some energy of said energy storage element, wherein said switch is an active hysteretic switch; and

an oscillator generating a signal for transmission, wherein said oscillator comprises an inductor, a Micro-Electro-Mechanical Systems (MEMS) capacitive sensor, and a tunnel diode.