Radio frequency identification system using multiple band transmission
A radio frequency identification (RFID) system employs multiple band transmission to prevent signal collision. The system includes a plurality of RFID tag groups and at least one RFID reader. Each RFID tag group includes at least one RFID tag. The RFID tags of the same RFID tag group are operated for radio frequency transmission in the same transmission frequency band, and those of different RFID tag groups are operated for radio frequency transmission in different transmission frequency bands. When the RFID reader simultaneously receives radio frequency signals issued from RFID tags of different RFID tag groups, since they are transmitted in different transmission frequency bands, signal collision among the RFID tags of the RFID tag groups can be avoided.
1. A radio frequency identification system that employs multiple band transmission to prevent tag signal collision, comprising:
a plurality of RFID tag groups, each comprising a plurality of RFID tags each containing tag information, the RFID tags of each RFID tag group being set to operate in a respective predetermined transmission frequency band; and
at least one RFID reader, which comprises a single multiple-band radio frequency transmission/reception module operating only in the predetermined transmission frequency bands for transmitting/receiving the tag information of the RFID tags of the RFID tag groups,
wherein the predetermined frequency bands are separated only by a safety frequency margin and wherein each RFID tag has an operating frequency which is not used by any other RFID tag.
2. The radio frequency identification system as claimed in claim 1 , wherein the RFID tag comprises a microprocessor that is connected to a memory unit and a radio frequency transmission/reception module.
3. The radio frequency identification system as claimed in claim 2 , wherein the microprocessor of the RFID tag is connected to a power supply unit that supplies electrical power desired by the RFID tag.
4. The radio frequency identification system as claimed in claim 1 , wherein the tag information comprises a tag identification code and tag identification data.
5. The radio frequency identification system as claimed in claim 4 , wherein the tag identification data comprises one of available tag power, tag mode, data of firmware version, data of software version, transmission bandwidth, transmission power, data of authenticity, tag owner, and data of group to which the tag belongs or a combination thereof.
6. The radio frequency identification system as claimed in claim 1 , wherein the RFID reader comprises a connection interface that connects a controller host.