Can I Use a Tiny RFID Chip to Track an Object from 50 Yards Away?

Published: October 15, 2012

Is there a radio frequency identification chip available that can provide this function, and also fit inside a cylinder measuring 9.3 millimeters (0.4 inch) or less? Also, do I need an antenna of some sort to track the chip at this distance? If so, what would be the cheapest option?

—Luke

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Luke,

Unfortunately, there is no low-cost RFID solution that can do what you ask. Passive ultrahigh-frequency (UHF) transponders must harvest energy from a reader in order to reflect back a signal to that reader. With a tag less than 9 millimeters in size, the antenna would be very small and have a read range of probably only a foot or so.

Even with an eight-inch antenna, passive UHF tags can be read from a distance of 10 to 30 feet, so 150 feet would require a phased-array antenna system, which would be fairly expensive. Such systems are most cost-effective in determining a tagged object’s location within a large warehouse, factory, lay-down yard or other large facility.

—Mark Roberti, Founder and Editor, RFID Journal