Multi-frequency identification device

Abstract

The present invention comprises a radio frequency identification device that utilizes multiple operating frequencies. In one embodiment of the present invention, one frequency (e.g., an ultra-high frequency such as 915 MHz, 800 MHz, 915 MHz, or microwave frequency such as 2.45 GHz) is used for data transmission, and another frequency (e.g., a low or high frequency such as 13.56 MHz) is used for field penetration. In another embodiment, one frequency is used for reading information received from the multi-frequency identification device, and another frequency is used for writing to the multi-frequency identification device. In an additional embodiment, the multi-frequency identification device utilizes one antenna for all frequencies. In another embodiment, the multi-frequency identification device utilizes two or more antennas for different frequencies, and one common memory. In other embodiments, one or two digital parts, analog parts, antennas, and memories can be used.

What is claimed is: 
     
       1. In vehicle tracking system comprising a reader that operates on multiple frequencies and an RFID tag that operates on multiple frequencies, a method for secure vehicle identification, comprising:
 the tag engaging in a non-secure interaction with the reader over a first frequency;   the tag engaging in a secure interaction with the reader over a second frequency; and   the tag receiving authentication based on the non-secure and secure interaction.   
     
     
       2. The method of  claim 1 , wherein the non-secure interaction comprises a read of the tag. 
     
     
       3. The method of  claim 2 , wherein the first frequency comprises a relatively high frequency, selected such that the read of the tag can be done over a greater distance relative to a distance associated with the interaction using the second frequency. 
     
     
       4. The method of  claim 3 , wherein the first frequency is 915 MHz. 
     
     
       5. The method of  claim 1 , wherein the non-secure interaction comprises a write of the tag. 
     
     
       6. The method of  claim 1 , wherein the secure interaction comprises a write of the tag. 
     
     
       7. The method of  claim 6 , wherein the second frequency comprises a relatively low frequency, relative to a distance associated with the interaction using the first frequency, selected such that the write of the tag can be done more securely over a shorter distance. 
     
     
       8. The method of  claim 7 , wherein the second frequency is 13.56 MHz. 
     
     
       9. The method of  claim 7 , wherein the second frequency is 125 KHz. 
     
     
       10. The method of  claim 1 , wherein the secure interaction comprises a read of the tag. 
     
     
       11. The method of  claim 1 , wherein the secure interaction can be a read or a write of the tag. 
     
     
       12. The method of  claim 1 , wherein the tag is embedded in a license plate. 
     
     
       13. The method of  claim 1 , wherein the tag is attached to a license plate. 
     
     
       14. The method of  claim 1 , wherein the authentication comprises authorization to pass a border. 
     
     
       15. The method of  claim 1 , wherein the non-secure interaction can be a read or a write of the tag. 
     
     
       16. In a vehicle tracking system an RFID system comprising a Radio Frequency Identification (RFID) reader that operates on multiple frequency bands and an RFID transponder that operates on multiple frequency bands, a method for secure vehicle identification, the method comprising:
 the RFID transponder engaging in a non-secure interaction with the reader over a first frequency band, the non-secure interaction comprising a first signal modulation technique;   the RFID transponder engaging in a secure interaction with the reader over a second frequency band, the secure interaction comprising the first signal modulation technique, wherein the second frequency band limits the range of the system to a shorter distance relative to the first frequency band; and   the RFID transponder receiving authentication based on the non-secure and secure interaction.    
     
     
       17. The method of claim 16, wherein the non-secure interaction comprises a read of the RFID transponder.  
     
     
       18. The method of claim 17, wherein the first frequency band comprises a relatively high frequency band, selected such that the read of the RFID transponder can be done over a greater distance relative to a distance associated with the interaction using the second frequency band.  
     
     
       19. The method of claim 18, wherein the first frequency band is 915 MHz.  
     
     
       20. The method of claim 16, wherein the non-secure interaction comprises a write of the RFID transponder.  
     
     
       21. The method of claim 16, wherein the secure interaction comprises a write of the RFID transponder.  
     
     
       22. The method of claim 16, wherein the second frequency band is 13.56 MHz.  
     
     
       23. The method of claim 16, wherein the second frequency band is 125 KHz.  
     
     
       24. The method of claim 16, wherein the secure interaction comprises a read of the RFID transponder.  
     
     
       25. The method of claim 16, wherein the secure interaction can be a read or a write of the RFID transponder.  
     
     
       26. The method of claim 16, wherein the non-secure interaction can be a read or a write of the RFID transponder.  
     
     
       27. The method of claim 16, wherein the secure interaction comprises limiting the distance between the transponder and the reader to less than 3 meters.  
     
     
       28. The method of claim 16, wherein the secure interaction comprises checking and validating at least one key.  
     
     
       29. The method of claim 16, wherein first signal modulation technique is backscatter modulation.