RFID Fast Hop Frequency Hopping

• US 20090257473A1
• Filed: 04/15/2008
• Published: 10/15/2009
• Est. Priority Date: 04/15/2008
• Status: Abandoned Application

• Current Assignee: Round Rock Research LLC
• Original Assignee: Keystone Technology Solutions, LLC
• Inventors: Tuttle, John R.
• Application Number:
  US12/103,318
• Publication Number:
  US 20090257473A1
• Time in Patent Office: Days
• US Class Current: 375/132
• CPC Class Codes: H04B 1/713 using frequency hopping
• CPC Class Codes: H04Q 2213/13095 PIN / Access code, authentication

Abstract

Methods and apparatus, including computer program products, for RFID fast hop frequency hopping. A method including transmitting from a radio frequency identification (RFID) interrogator a continuous wave un-modulated radio frequency (RF) signal from a frequency synthesizer based on digital waveform reconstruction with Direct Memory Access (DMA), the continuous wave un-modulated RF signal conforming to a fast hop frequency hopping protocol in which each hop of a plurality of hops spans at least one bit but less than the totality of bits to be sent from a single RFID device data in a single communications session.

Claims

1. A method comprising:

transmitting from a radio frequency identification (RFID) interrogator a continuous wave un-modulated radio frequency (RF) signal from a frequency synthesizer based on digital waveform reconstruction with Direct Memory Access (DMA), the continuous wave un-modulated RF signal conforming to a fast hop frequency hopping protocol in which each hop of a plurality of hops spans at least one bit but less than the totality of bits to be sent from a single RFID device data in a single communications session.

2. The method of claim 1 further comprising:

sending one or more commands to cause a RFID device to reply; and

transmitting a continuous wave un-modulated RF signal conforming to the fast hop frequency hopping protocol while listening for a RFID device response.

3. The method of claim 2 further comprising:

receiving a RFID device response; and

reporting the RFID device response to a computer coupled to the RFID interrogator.

4. The method of claim 3 in which receiving comprises:

tracking data returned from the RFID device during a hop; and

reconstructing the returned data after RF signal transmission is completed.

5. The method of claim 1 wherein the fast hop frequency hopping protocol comprises:

frequency hops occurring at rates of up to 10 MHz to 50 MHz for operation complying with 900 MHz Part 15 rules; and

frequency hops occurring up to 100 MHz for operation complying with 2.45 GHz Part 15 rules.

6. A method comprising:

transmitting from a radio frequency identification (RFID) interrogator a continuous wave un-modulated radio frequency (RF) signal from a frequency synthesizer based on digital waveform reconstruction with a Digital to Analog Converter (DAC), the continuous wave un-modulated RF signal conforming to a fast hop frequency hopping protocol in which each hop of a plurality of hops spans at least one bit but less than the totality of bits to be sent from a single RFID device data in a single communications session.

7. The method of claim 6 further comprising:

sending one or more commands to cause a RFID device to reply; and

transmitting a continuous wave un-modulated RF signal conforming to the fast hop frequency hopping protocol while listening for a RFID device response.

8. The method of claim 7 further comprising:

receiving a RFID device response; and

reporting the RFID device response to a computer coupled to the RFID interrogator.

9. The method of claim 8 in which receiving comprises:

tracking data returned from the RFID device during a hop; and

reconstructing the returned data after RF signal transmission is completed.

10. The method of claim 6 wherein the fast hop frequency hopping protocol comprises:

frequency hops occurring at rates of up to 10 MHz to 50 MHz for operation complying with 900 MHz Part 15 rules; and

frequency hops occurring up to 100 MHz for operation complying with 2.45 GHz Part 15 rules.

11. The method of claim 6 wherein the DAC is a Fixed DAC, a Binary Weighed DAC, a R-2R DAC, a Thermometer coded DAC, a Segmented DAC or a Hybrid DAC.

12. A radio frequency identification (RFID) interrogator comprising:

a microcontroller coupled to a radio frequency (RF) transmitter and a RF receiver;

an antenna coupled to the RF transmitter and RF receiver; and

the microcontroller causing the RF transmitter to transmit a continuous wave un-modulated radio frequency (RF) signal from a frequency synthesizer based on digital waveform reconstruction with Direct Memory Access (DMA), the continuous wave un-modulated RF signal conforming to a fast hop frequency hopping protocol in which each hop of a plurality of hops spans at least one bit but less than the totality of bits to be sent from a single RFID device data in a single communications session.

13. The RFID interrogator of claim 12 wherein the fast hop frequency hopping protocol comprises:

frequency hops occurring at rates of up to 10 MHz to 50 MHz for operation complying with 900 MHz Part 15 rules; and

frequency hops occurring up to 100 MHz for operation complying with 2.45 GHz Part 15 rules.

14. A radio frequency identification (RFID) interrogator comprising:

a microcontroller coupled to a radio frequency (RF) transmitter and a RF receiver;

an antenna coupled to the RF transmitter and RF receiver; and

the microcontroller causing the RF transmitter to transmit a continuous wave un-modulated radio frequency (RF) signal from a frequency synthesizer based on digital waveform reconstruction with a Digital to Analog Converter (DAC), the continuous wave un-modulated RF signal conforming to a fast hop frequency hopping protocol in which each hop of a plurality of hops spans at least one bit but less than the totality of bits to be sent from a single RFID device data in a single communications session.

15. The RFID interrogator of claim 14 wherein the DAC is a Fixed DAC, a Binary Weighed DAC, a R-2R DAC, a Thermometer coded DAC, a Segmented DAC or a Hybrid DAC.

16. The RFID interrogator of claim 14 wherein the fast hop frequency hopping protocol comprises:

frequency hops occurring at rates of up to 10 MHz to 50 MHz for operation complying with 900 MHz Part 15 rules; and

frequency hops occurring up to 100 MHz for operation complying with 2.45 GHz Part 15 rules.