Engineers Design Smaller, Cheaper RFID Tags

A new technique makes RFID (Radio Frequency Identification) tags less expensive and 25 percent smaller than conventional tags.  Engineering researchers at North Carolina State University shrunk the tags by eliminating the bulky hardware that is typically required in passive RFID systems for converting alternating current (AC) to direct current (DC).

Normally, passive RFID systems use tags that are powered by the electromagnetic energy that is transmitted from an RFID reader. The tag converts the reader’s AC radio signal into DC in order to power the tag’s circuits. Those circuits then bounce the signal back to the reader. This type of system is commonly used for keeping track of objects (like a high-tech bar code), controlling access (such as a badge that unlocks a door), and for logistics (airlines use it to manage luggage).

The NC State team has redesigned the tag by adding additional transistors so the circuit can now operate directly off of AC power. For now, the new “RF-only logic” RFID tags have a shorter range than conventional passive RFID tags. The researchers plan to improve the design and they anticipate the next iteration will have similar range to today’s tags. The research is described in a paper, “Design of a Rectifier-Free UHF Gen-2 Compatible RFID Tag using RF-Only Logic,” which was presented May 5 at the IEEE RFID 2016 conference in Orlando, Florida.

Source: NC State