Going Beyond the Limitation of RFID

New Advances in RFID Help Food Traceability talks about the current constraints of RFID tags (UHF RFID, active tags, …) and about the ongoing developments to go beyond the limitations.

The limitations of Active tags vs. Passive tags

True, longer range has always been available if there is a battery in the RFID tag, and this is a viable solution for vehicles and trailers. However, these so called active tags have limited life and they are expensive, relatively large and with more parts to go wrong. That has meant that UHF (Ultra-high frequency) passive tags have been standardized for pallets and cases of food and other produce at the behest of leading US and European retailers and the US Military.

The limitations of Passive tags

UHF RFID can behave very unpredictably when water or metal is nearby, let alone in the way. As Hong Kong Airport (tagging baggage) and Metro (trailing tagging of food) have found, sometimes the proximity of water or metal can prevent any reads taking place. At other times, things can be unexpectedly and annoyingly sensed 50 meters away, creating confusion about what one is sensing. In Europe, the problems of UHF are compounded by the Military and other vested interests preventing UHF radio regulations permitting higher power and wider bandwidth and this is greatly restricting range and control of interference between readers in trials of pallet and case tagging of food.

Now, the improvement of HF RFID include:

• New ways of extending the range of HF RFID, sometimes even to ten meters.
• Password protected HF tags of controllable range, more tolerant of water and metal than those at UHF.
• RFID devices that work well with difficult substances and RFID which is even sterilization tolerant.
• Use of Surface Acoustic Wave chips to replace the silicon chips in RFID tags