Smallest Gen2 compatible RFID tag which is just 125 x 245μm.
RFID chips or RFID tags are labels that can exchange data with a reader using radio frequency (RF) signals. It consists of a built-in antenna and an integrated circuit for processing data. The antenna can send and receive radio waves, while the IC does the job of modulating and demodulating the radio signals, as well as processing and storing data.
All RFID tags are classified by their generation and class. Current Generation-2 RFID tags offer significant advantages over Generation-1 tags such as faster read speeds, precise performance with anti-collision protocols, improved security, interoperability and easier physical deployment of multiple readers.
Paul Franzon, a professor of electrical engineering at North Carolina State University presented a 125 x 245μm Gen-2 RFID chip at the IEEE International Conference on RFID. It has -2 dBm sensitivity in the 860-960MHz band. According to Paul, the small size is due to the standard cell-based digital implementation using dual-phase RF-only logic approach, near-threshold voltage operation and the elimination of area intensive, complex, and less scalable rectifiers, storage capacitors, and power management units used in conventional RFID tags.
“The size of an RFID tag is largely determined by the size of its antenna, not the RFID chip,” said Franzon. “But the chip is the expensive part. Being so small in practical terms, this means that we can manufacture RFID tags for less than one cent each if we’re manufacturing them in volume”.
The researchers are now trying to commercialize the chip. Further information can be found in the IEEE conference paper ‘A 125μm×245μm Mainly Digital UHF EPC Gen2 Compatible RFID tag in 55nm CMOS process’.