WIRELESS ELECTROMAGNETIC PARASITIC POWER TRANSFER

• US 20080036588A1
• Filed: 06/25/2007
• Published: 02/14/2008
• Est. Priority Date: 06/23/2006
• Status: Active Grant

• Current Assignee: Securaplane Technologies, Inc. (Meggitt PLC)
• Original Assignee: Securaplane Technologies, Inc. (Meggitt PLC)
• Inventors: Iverson, Rod, Blair, Harvey, Boost, Michael, Mckernan, Edward, Seitz, Forrest
• Granted Patent: US 7,671,736 B2
• Time in Patent Office: Days
• US Class Current: 340/539.17
• CPC Class Codes: G01D 21/00 Measuring or testing not otherwise provided for
• CPC Class Codes: H02J 50/001 Energy harvesting or scavenging
• CPC Class Codes: H02J 50/10 using inductive coupling
• CPC Class Codes: H02J 50/23 characterised by the type of transmitting antennas, e.g. directional array antennas or Yagi antennas
• CPC Class Codes: H02J 50/40 using two or more transmitting or receiving devices H02J50/50 takes precedence
• CPC Class Codes: H02J 50/80 involving the exchange of data, concerning supply or distribution of electric power, between transmitting devices and receiving devices
• CPC Class Codes: H02J 50/90 involving detection or optimisation of position, e.g. alignment

Abstract

A wireless system including an antenna, an electrical energy storage unit connected to the antenna, the energy storage unit receiving power via electromagnetic coupling of the antenna with an RF field generated by a master unit, and an electronics package. The electronics package is powered by the energy storage unit, and it includes a sensor, a processor that is capable of acquiring data from the sensor, and a transmitter connected to the processor and to the antenna, wherein the energy storage unit is capable of storing sufficient energy to supply power for the processor to format a message containing data acquired from the sensor and for the transmitter to transmit the message wirelessly via the antenna.

Claims

1. A wireless system that, when in operation, is coupled to an RF field transmitted by a power-emitting master unit, the system comprising:

an antenna;

an electrical energy storage unit connected to the antenna, wherein the energy storage unit receives energy via electromagnetic coupling of the antenna with the RF field, at least a part of the received energy being stored in the energy storage unit; and

an electronics package powered solely by the received energy, the electronics package including a sensor, a processor that is capable of acquiring data from the sensor, and a transmitter connected to the processor and to the antenna, wherein the energy storage unit is capable of storing sufficient received energy to supply power for the transmitter to transmit a message wirelessly via the antenna, the message containing data acquired by the processor from the sensor.

2. The wireless system of claim 1, wherein the energy storage unit is capable of storing sufficient energy to further power the processor to perform at least one of the functions of acquiring data from the sensor, formatting a message containing data acquired from the sensor, and shutting the processor down.

3. The wireless system of claim 2 wherein the sensor is an analog sensor and acquiring the data from the sensor includes analog to digital conversion of the data.

4. The wireless system of claim 1, wherein the processor includes instructions in firmware, the instructions implementing a finite state machine when executed on the processor.

5. The wireless system of claim 4, wherein the finite state machine includes a data acquisition state, and a data transmission state.

6. The wireless system of claim 5, wherein the state machine further includes at least one of an RF detection state, a message formatting state, and a system shut-down state.

7. The wireless system of claim 5, wherein the instructions cause the finite state machine to enter the data acquisition state when a level of RF activity in the antenna exceeds a predetermined power-on level.

8. The wireless system of claim 5, wherein the instructions cause the finite state machine to exit the data acquisition state when a level of RF activity in the antenna falls below a predetermined power-off level.

9. The wireless system of claim 1, wherein the system is capable of moving along a path, the path being constrained such that the RF field strength is greater than a threshold RF field strength over substantially all of the path, the threshold RF field strength being determined in part by one or more antenna specifications and by power requirements of the electronics package.

10. The wireless system of claim 9, wherein power-emitting master unit includes an elongated antenna for generating the RF field and the path is a straight line path, the elongated antenna having a length approximately equal to the length of the straight line path.

11. The wireless system of claim 1, wherein the transmitter uses at least one of on-off keying modulation and frequency modulation.

12. The wireless system of claim 1 further comprising a receiver connected to the processor, the receiver being powered by the energy storage unit, the receiver being capable of receiving RF transmitted instructions for execution on the processor.

13. A system comprising:

a master unit including a master unit antenna and a master unit electronics package, the master unit electronics package capable of generating an RF field via the master unit antenna; and

a wireless unit including;

a wireless unit antenna;

an electrical energy storage unit connected to the wireless unit antenna, the electrical energy storage unit receiving power via electromagnetic coupling of the wireless unit antenna with the RF field; and

a wireless unit electronics package powered by the energy storage unit, the wireless unit electronics package including a sensor, a processor capable of acquiring data from the sensor, and a transmitter connected to the processor and to the antenna, wherein the energy storage unit is capable of storing sufficient energy to supply power for the processor to format a message containing data acquired from the sensor and for the transmitter to transmit the message wirelessly via the wireless unit antenna.

14. The system of claim 13, wherein the master electronics package includes a master unit transmitter for transmitting RF via the master antenna and for powering the wireless unit, and a receiver for receiving transmissions from the wireless unit.

15. A method of gathering data in a wireless system, the method comprising:

receiving electrical energy through an antenna in the wireless system that is electromagnetically coupled to an RF signal generated by a master unit;

storing at least a part of the received energy in an energy storage unit connected to the antenna;

powering a processor connected to the energy storage unit to acquire data from a sensor connected to the processor and to the energy storage unit; and

when the RF signal ends, powering a transmitter connected to the processor and to the antenna to transmit via the antenna a message containing the acquired data, the transmission being powered solely by energy stored in the energy storage unit.

16. The method of claim 15 further comprising powering the processor to perform at least one of the functions of acquiring data from the sensor, formatting a message containing data acquired from the sensor, and shutting the processor down, the at least one function being powered solely by energy stored in the energy storage unit.

17. The method of claim 16, wherein acquiring the data from the sensor involves converting the data from analog to digital.

18. The method of claim 15, further comprising executing instructions on the processor for implementing a finite state machine on the processor, the states of the finite state machine including a data acquisition state and a data transmission state.

19. The method of claim 15, wherein the wireless system moves along a path, the path being constrained such that the RF field strength is greater than a threshold RF field strength over substantially all of the path, the threshold RF field strength being determined in part by one or more antenna specifications and by power requirements of the wireless system.

20. The method of claim 19, wherein the master unit includes an elongated antenna for generating the RF field and the path is a straight line path, the elongated antenna having a length approximately equal to the length of the straight line path.