Software-defined multi-mode RFID read devices
Devices and methods for reading multiple types of RFID tags having different frequencies and/or encoding schemes are disclosed. One or more search signals covering a plurality of RFID bands are transmitted. A presence indication of an RFID tag in one of the plurality of RFID bands is detected. An interrogating signal having a carrier frequency tuned to a frequency at which the presence indication is detected is transmitted. A tag response signal comprising tag information associated with the RFID tag is received. A digital response signal based on the tag response signal is digital signal processed to obtain the tag information.
1. A radio frequency identification (RFID) device, comprising:
an antenna;
a memory that stores sets of information each comprising a respective encoding scheme for a particular type of RFID tag; and
a processor configured to:
operate the antenna to transmit a broadband signal covering an entire bandwidth of an RFID band;
select a target frequency in an RFID band based on a first response from an RFID tag;
operate the antenna for communications with the RFID tag using the encoding scheme for that type of RFID tag; and
filter and demodulate a second response from the RFID tag based on the encoding scheme in the memory for the RFID tag.
2. The RFID device of claim 1 , wherein the processor is further configured to decode the demodulated and filtered second response to obtain tag information encoded in the second response.
3. The RFID device of claim 1 , wherein the processor is further configured to operate the antenna to transmit an interrogating signal comprising a carrier signal having the selected target frequency.
4. The RFID device of claim 1 , further comprising a second antenna.
5. The RFID device of claim 4 , wherein the processor is configured to transmit an interrogating signal with one of the first and second antennas, the first antenna associated with the RFID band and the second antenna associated with a different RFID band.
6. The RFID device of claim 1 , wherein the memory is updatable for storing a new encoding scheme for a new type of RFID tag, and wherein the processor is configured to operate the antenna to communicate with the new type of RFID tag upon storing of the new encoding scheme in the memory.
7. The RFID device of claim 1 , wherein each set of information further comprises a respective RFID frequency band for the particular type of RFID tag.
8. A method of operating a radio frequency identification (RFID) device, the method comprising:
storing, in memory of the RFID device, a plurality of sets of information each comprising a respective encoding scheme for a particular type of RFID tag;
operating, by a processor of the RFID device, an antenna of the RFID device to transmit a broadband signal covering an entire bandwidth of an RFID band;
selecting, by the processor, a target frequency in an RFID band based on a first response from an RFID tag;
operating, by the processor, an antenna of the RFID device for communications with the RFID tag using the encoding scheme stored in the memory for that type of RFID tag; and
filtering and demodulating a second response from the RFID tag based on the encoding scheme in the memory for the RFID tag.
9. The method of claim 8 , further comprising decoding, with the processor, the demodulated and filtered second response to obtain tag information encoded in the second response.
10. The method of claim 8 , further comprising operating, by the processor, the antenna to transmit an interrogating signal comprising a carrier signal having the selected target frequency.
11. The method of claim 8 , further comprising operating, by the processor, one of first and second antennas according to the target frequency, the first antenna associated with the RFID band and the second antenna associated with a different RFID band.
12. The method of claim 8 , further comprising:
storing an additional encoding scheme for a new type of RFID tag in the memory; and
operating, with the processor, the antenna to communicate with the new type of RFID tag upon storing of the additional encoding scheme in the memory.
13. The method of claim 8 , further comprising, storing, in the memory, a respective RFID frequency band for each type of RFID tag.
14. A radio frequency identification (RFID) device, comprising:
an antenna;
a memory that stores sets of information each comprising a respective target frequency for a particular type of RFID tag; and
a processor configured to:
operate the antenna to transmit a broadband signal covering an entire bandwidth of an RFID band;
select a current target frequency in an RFID band from the stored target frequencies based on a first response from an RFID tag;
operate the antenna for communications with the RFID tag using the target frequency for that type of RFID tag; and
filter and demodulate a second response from the RFID tag.
15. The RFID device of claim 14 , wherein the processor is further configured to decode the demodulated and filtered second response to obtain tag information encoded in the second response.
16. The RFID device of claim 14 , wherein the processor is configured to transmit an interrogating signal from one of first and second antennas, the first antenna associated with the RFID band and the second antenna associated with a different RFID band.
17. The RFID device of claim 16 , further comprising an antenna selection switch coupled to an output of a modulator of the RFID device and a first input of a demodulator of the RFID device, and configured to be selectably coupled to one of the first and second antennas.
18. The RFID device of claim 14 , wherein the memory is updatable for storing a new target frequency for a new type of RFID tag, and wherein the processor is configured to operate the antenna to communicate with the new type of RFID tag upon storing of the new target frequency in the memory.