MIT's RFID field probe

The Auto-ID Labs of the Massachusetts Institute of Technology, Cambridge, MA, has developed an inexpensive field probe that emulates an RFID tag but yields much more robust information than simple trial-and-error, pass or fail testing.

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Started in early 2004, the project resulted in a Class 1 Generation 1 RFID field probe last March that continues to be improved upon.

The field probe, which measures 9’’x3’’, integrates an Electronic Product Code RFID tag emulator and a sensor probe. The device is capable of reporting various sensor values continuously. The latest version provides both visual and audio feedback of the RFID field strength.

What it has

The device features a semi-passive tag, power level detector, and on-board battery. The battery permits the unit to send information at conditions below threshold levels that would activate typical tags.

Operating in the 900 to 950 MHz range, the device can be reconfigured to match different antenna designs. It works in conjunction with 3-D modeling software that provides a graphical rendering of the field strength—a visualization of the electromagnetic performance of a real-world RFID system, according to research assistant Rich Redemske.

What it does

The RFID field probe can be used to help determine the best positioning for tags on a case as well as the “sweet spot” for antenna positioning to yield the highest number of good reads. It can also gauge interference from competing RF signals in the environment. In short, the field probe is a useful, multipurpose diagnostics tool.

The field probe is built using parts that cost less than $20. The team has developed more than 100 of the field probes, and it’s working on a fourth generation of the device that should be available mid-year that will emulate a Generation 2 EPC Protocol.

Currently, to have access to the field probe and other related developments at the Auto-ID Labs, companies must be sponsors of the program—a $50ꯠ annual fee.

RFID Antenna asked if the Auto-ID Labs would provide field probes for sale. If such an effort made sense, department head Daniel Engels said it would involve a third-party vendor. They were also asked about any options for short-term contracted projects for companies that weren’t sponsors.

“That’s a great and interesting idea,” says Engels. “It’s something we would be capable of doing, once we are set up administratively.” He can be reached at the contact information below.

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