AUTONOMOUS BATTERY-FREE MICROWAVE FREQUENCY COMMUNICATION SYSTEM

• US 20110260839A1
• Filed: 04/22/2011
• Published: 10/27/2011
• Est. Priority Date: 04/27/2010
• Status: Active Grant

• Current Assignee: Apple Inc.
• Original Assignee: Passif Semiconductor Corp. (Apple Inc.)
• Inventors: Berny, Axel D., Cook, Benjamin W., Trachewsky, Jason A.
• Granted Patent: US 8,797,146 B2
• Time in Patent Office: Days
• US Class Current: 340/10.4
• CPC Class Codes: G06K 19/0708 the source being electromagnetic or magnetic
• 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

Abstract

An autonomous battery-free microwave frequency communication device which includes a capacitance, at least one antenna, a microwave energy harvesting system, a microwave frequency transceiver, and a control system. The energy harvesting system is configured to harvest and store microwave energy received via the antenna onto the capacitance. The transceiver is empowered by energy stored on the capacitance, and is configured to autonomously generate a microwave frequency carrier and to autonomously transmit information using the microwave frequency carrier according to a predetermined communications protocol via the antenna. The control system is empowered by energy stored on the capacitance, and is configured to provide information for transmission. Energy may be harvested from various communication forms, such as wireless network protocols or cellular communications. The frequency band from which energy is harvested may differ from the frequency band used for communications. The energy storage enables autonomous communications with external devices according to common or standard wireless communication protocols.

Claims

1. An autonomous battery-free microwave frequency communication device, comprising:

a capacitance;

at least one antenna;

a microwave energy harvesting system which is configured to harvest and store microwave energy received via said at least one antenna onto said capacitance;

a microwave frequency transceiver empowered by energy stored on said capacitance, which is configured to use a portion of energy stored on said capacitance to autonomously generate a microwave frequency carrier and to autonomously transmit information using said microwave frequency carrier according to a predetermined communications protocol via said at least one antenna; and

a control system empowered by energy stored on said capacitance, which is configured to provide said information for transmission.

2. The autonomous battery-free microwave frequency communication device of claim 1, wherein said microwave energy harvesting system is configured to detect and convert microwave energy comprising a communication packet transmitted by an external device and received by said at least one antenna.

3. The autonomous battery-free microwave frequency communication device of claim 1, wherein said microwave energy received via said at least one antenna comprises microwave energy in a first microwave frequency band, and wherein said microwave frequency transceiver is configured to transmit information according to said predetermined communications protocol in a second microwave frequency band which is different from said first microwave frequency band.

4. The autonomous battery-free microwave frequency communication device of claim 1, wherein said at least one antenna comprises at least one common antenna which is coupled to and used by both said microwave energy harvesting system and said microwave frequency transceiver.

5. The autonomous battery-free microwave frequency communication device of claim 1, wherein said microwave energy harvesting system is adapted to receive and convert microwave energy comprising at least one of Wi-Fi communications, cellular uplink communications, and Bluetooth communications.

6. The autonomous battery-free microwave frequency communication device of claim 1, wherein said at least one antenna comprises at least one first antenna coupled to said microwave energy harvesting system for energy harvesting and at least one second antenna coupled to said microwave frequency transceiver for communications.

7. The autonomous battery-free microwave frequency communication device of claim 1, wherein said microwave frequency transceiver comprises:

a frame generation circuit configured to generate a data frame formatted according to said predetermined communications protocol using energy stored on said capacitance;

a microwave frequency carrier generation circuit configured to generate said microwave frequency carrier according to said predetermined communications protocol using energy stored on said capacitance;

a modulator circuit configured to modulate said data frame on said microwave frequency carrier according to said predetermined communications protocol using energy stored on said capacitance to provide modulation information; and

a transmitter circuit configured to transmit said modulation information via said at least one antenna according to said predetermined communications protocol using energy stored on said capacitance.

8. The autonomous battery-free microwave frequency communication device of claim 1, wherein said microwave frequency transceiver comprises:

a receiver circuit configured to receive modulated information via said at least one antenna according to said predetermined communications protocol using energy stored on said capacitance;

a microwave frequency carrier generation circuit configured to generate said microwave frequency carrier according to said predetermined communications protocol using energy stored on said capacitance;

a demodulator circuit configured to demodulate said received modulated information using said microwave frequency carrier according to said predetermined communications protocol using energy stored on said capacitance to provide a received data frame; and

a frame processing circuit configured to process said received data frame formatted according to said predetermined communications protocol using energy stored on said capacitance.

9. The autonomous battery-free microwave frequency communication device of claim 1, wherein said predetermined communications protocol comprises either one of a Wi-Fi communications protocol and a Bluetooth communications protocol.

10. The autonomous battery-free microwave frequency communication device of claim 1, wherein said control system comprises:

a controller configured to processes information received by said microwave frequency transceiver and to generate information to be transmitted by said microwave frequency transceiver; and

a non-volatile memory coupled to said controller.

11. The autonomous battery-free microwave frequency communication device of claim 1, wherein said microwave energy harvesting system transfers and stores microwave energy received via said at least one antenna onto said capacitance during a first time period, and wherein said microwave frequency transceiver autonomously transmits information during a second time period which is mutually exclusive relative to said first time period.

12. A method of performing autonomous communications by a battery-free device, comprising:

receiving microwave energy via at least one antenna;

harvesting the received microwave energy and storing harvested energy on a storage capacitance;

generating at least one data frame formatted according to a first communications protocol using energy stored on the storage capacitance;

generating a microwave frequency carrier using energy stored on the storage capacitance;

modulating the microwave frequency carrier with the data frame using energy stored on the storage capacitance to provide a modulated information; and

transmitting the modulated information via the at least one antenna using energy stored on the storage capacitance.

13. The method of claim 12, wherein said receiving microwave energy comprises receiving microwave energy on a plurality of directional antennas.

14. The method of claim 12, wherein said receiving microwave energy comprises receiving the microwave energy on at least one first antenna provided for energy harvesting, and wherein said transmitting the modulated information comprises transmitting the modulated information on at least one second antenna provided for communications.

15. The method of claim 12, further comprising:

said receiving microwave energy comprising receiving at least one microwave modulated data frame;

demodulating the microwave modulated data frames using the microwave frequency carrier and using energy stored on the capacitance to provide at least one received data frame; and

processing the at least one received data frame according to the first communications protocol to retrieve transmitted information using energy stored on the capacitance.

16. The method of claim 12, wherein said receiving microwave energy comprises receiving microwave communications in a first microwave frequency band, and wherein said transmitting the modulated information comprises transmitting the modulated information in a second microwave frequency band which is different from the first microwave frequency band.

17. The method of claim 12, wherein said receiving microwave energy, harvesting the received microwave energy and storing harvested energy comprises receiving microwave energy, harvesting the received microwave energy and storing harvested energy during a first time period, and wherein said transmitting the modulated information comprises transmitting the modulated information during a second time period which is mutually exclusive relative to the first time period.

18. The method of claim 12, further comprising:

said receiving microwave energy comprising receiving microwave modulated data frames;

processing the microwave modulated data to retrieve the received data using energy stored on the storage capacitance.

19. The method of claim 13, further comprising using the received data to generate at least a portion of the modulated sequence.

20. The method of claim 12, wherein said receiving microwave energy comprises receiving a data frame formatted according to the first protocol and modulated onto a microwave frequency carrier.

21. The method of claim 12, wherein said receiving microwave energy comprises receiving a data frame formatted according to a second protocol and modulated onto a microwave frequency carrier.

22. A wireless radio frequency tag device, comprising:

a physical article configured for a predetermined purpose; and

an autonomous battery-free microwave frequency communication device embedded on said physical article to enhance said predetermined purpose, comprising;

a capacitance;

at least one antenna;

a microwave energy harvesting system which is configured to harvest and store microwave energy received via said at least one antenna onto said capacitance;

a microwave frequency transceiver empowered by energy stored on said capacitance, which is configured to use a portion of energy stored on said capacitance to autonomously generate a microwave frequency carrier and to autonomously transmit information using said microwave frequency carrier according to a predetermined communications protocol via said at least one antenna; and

a control system empowered by energy stored on said capacitance, which is configured to provide said information for transmission, wherein said information is associated with said predetermined purpose, and wherein said control system comprises a memory for storing data associated with said predetermined purpose.

23. The wireless radio frequency tag device of claim 22, wherein said physical article comprises a wristband.

24. The wireless radio frequency tag device of claim 23, wherein said data includes medical information associated with a person wearing said wristband.

25. The wireless radio frequency tag device of claim 22, wherein said physical article comprises an advertisement flyer, and wherein said information and data is associated with at least one commercial enterprise.

26. The wireless radio frequency tag device of claim 22, wherein said physical article comprises a physical card, and wherein said information and data is associated with commercial transaction information.