Home Internet of Things Aerospace Apparel Energy Defense Health Care Logistics Manufacturing Retail

Ask The Experts Forum

BlogsAsk The Experts ForumIs It Possible to Determine How Far a Passive or Active RFID Tag Is from a Reader?

Is It Possible to Determine How Far a Passive or Active RFID Tag Is from a Reader?

Posted By RFID Journal, 12.01.2016

For instance, if a tag were placed somewhere within a room, would a reader be able to tell where or how far away it was?

—Master

———

Master,

This is a question we are often asked. Conventional passive low-frequency (LF), high-frequency (HF) and ultrahigh-frequency (UHF) systems are designed to tell you when a tag is inside a read field. They do not tell you that a tagged item is, say, 3 feet from the back wall of a room and 4 feet from the left wall. There are passive UHF solutions that used phased-array antennas to determine a tag's location; these are accurate to within about 10 square feet (0.9 square meter).

Active tags transmit a signal, and several readers might pick it up. Software can then triangulate on the signal and use time of arrival, angle of arrival and other techniques to determine the tag's location. These are also accurate to within about 10 feet.

If you require greater location accuracy than this, I would suggest an active ultra-wideband (UWB) system. UWB technologies employ a variety of frequencies to overcome the problem of the same frequency signal reflecting off surfaces and arriving at different times, which makes it difficult to pinpoint a tag's location. UWB systems are accurate to within about 10 centimeters (3.9 inches).

—Mark Roberti, Founder and Editor, RFID Journal

USER COMMENTS

ROCCO EMELIO 2017-01-17 10:04:11 AM
can these be used to send me a signal (over a LAN/WAN) when an item or items are removed from a hotel room?

Login and post your comment!

Not a member?

Signup for an account now to access all of the features of RFIDJournal.com!

Next Post
Is There Any Sort of RFID Learning Kit A...
Previous Post
Do You Know of Any Companies That Make G...
PREMIUM CONTENT
Case Studies Features Best Practices How-Tos
RFID JOURNAL EVENTS
Live Events Virtual Events Webinars
ASK THE EXPERTS
Simply enter a question for our experts.
TAKE THE POLL
JOIN THE CONVERSATION ON TWITTER
Loading
RFID Journal LIVE! RFID in Health Care LIVE! LatAm LIVE! Brasil LIVE! Europe RFID Connect Virtual Events RFID Journal Awards Webinars Presentations
© Copyright 2002-2017 RFID Journal LLC.
Powered By: Haycco