RF-Lucent vs. RF-Opaque: Component Materials in RFID Systems

Whether it’s the object you want tagged or surrounding objects, their material make up can greatly impact the capabilities of an RFID system. Because of this, it’s not only important to design an RFID system, but to build that system to accommodate your unique processes and environment.

There are essentially two categories of materials as it relates to their impact on communication between RFID tags and readers. RF-Lucent materials and RF-Opaque materials. Let’s take a look at each and how they relate to building your RFID system.

What are RF-Lucent materials?

RF-lucent materials have essentially no impact on a system’s ability to transmit radio waves. Materials like fabrics, plastics and cardboard are considered RF-lucent. A tag can be placed directly onto, or even into RF-lucent substrates without impacting the ability of the tag to transmit its data.

What this means to you is that anything made from entirely RF-lucent materials can be tagged, and RF-lucent materials in your surroundings will not interfere with the RFID system’s ability to communicate.

What are RF-Opaque materials?

On the other hand, RF-opaque materials within your tagged items or in your surroundings can interfere with your RFID system. These include materials like water and metals.

The term “opaque” means solid, suggesting an RF-opaque material would block the communication between the RFID tag and reader, however this isn’t entirely the case. Materials are rarely entirely opaque to RFID, and rather than “blocking” the radio waves water will slow down and weaken the transmission, while metals reflect the transmission.

Additionally, certain frequencies are impacted more severely by RF-opaque materials than others. For example, water and metals have a lesser effect on low frequency (LF) tags, however, LF tags typically have a shorter read distance and lower data transfer rate to begin with.

If your system is expected to operate within an environment or on an item containing RF-opaque materials, additional testing will likely be required to tune the process to your needs. Tests will likely involve defining the best tag placement, reader placement, tag frequency and tag application method. The testing required is why it’s important to find an RFID integration partner who will perform an on-site audit and is willing to work with you to build a system that fits your processes and environment.

It’s also important to remember that it takes time to engineer a system to fit your specific requirements. Expect your partner to build and test run several systems, and pilot run the top performing system prior to the official implementation of your solution.

As you now know, materials can greatly affect RFID systems, even without direct contact. That doesn’t have to mean integrating RFID into your processes will be impossible though. In most cases a resolution can be found, but time must be taken and compromises made to find it. This is why it’s critical auditing, testing and pilot runs are performed prior to implementation. Ensure you’re working with an experienced and trustworthy RFID integrator when considering implementing an RFID system into your facility to achieve proper functionality.

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