Sensitive Passive Radio Frequency Identification (RFID) Tag Development

Passive radio frequency identification (pRFID) transponders (tags) are relatively less expensive than active RFID (aRFID) tags, and the absence of a battery makes them attractive for applications where very long life is important. Passive tags derive their power from the RF field, and this power diversion significantly reduces the power received by the interrogator (reader), rendering this tag type the last choice when reader power is limited and the required range is large. In these cases, an alternative to a battery-powered tag that has mostly been confined to research environments is to power it with an external energy source such as light, magnetic fields, or acoustic energy. In the case of tagging ordnance, the acoustic and inductive powering are not attractive because the high amount of power required is unsafe. Light powered tags, on the other hand, have the potential to safely power the tag. Such a tag would contain, in addition to the circuitry and antenna, a solar cell to harness power from ambient light sources. This research program will examine the feasibility of this approach to making pRFID tags to be used for Naval ordnance.