Why Is Our RFID Toll-Collection System Receiving Signals from the Wrong Lanes?

I am working on a toll-collection project as a technical support engineer in the Philippines' toll expressway industry. I'd like to ask about our current RFID issues encountered at site. Our setup is this: In a toll plaza, we have 10 lanes that are using RFID readers and antennas. The lanes are separated by a toll island, where the tollbooth and TCS equipment are located. Now our problem is this: The RFID antenna receives or reads tag signals coming from an adjacent or different lane. We tried lowering the power and angle, but the problem still occurs. What would be the best solution for this? Thanks.

—Marc

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Marc,

I talked to an engineer about your challenge. There are a variety of approaches to prevent stray reads across multiple lanes. You should be using vertically polarized RFID antennas, which would put out an RF beam front to rear of the car, or into the lane. If you are using a circular polarized RFID antenna, this creates a rounded RFID field and can cover lanes to the left or right. You would definitely not want to be using horizontally polarized RFID antennas. There are a variety of ways to block the spilling of RF signals between lanes on toll roads, and if the antenna polarization is not the problem, a shield would help, typically with metal that reflects signals back into the lane.

Claire Swedberg
Senior Editor
RFID Journal