RFID systems are now all around us, and their applications are well-known across industries. RFID tags are a vital part of any RFID system, and it is crucial to get an understanding of how they work and what they are made of. It is quite popular that RFID tags communicate with raiders through EM waves that induce power on passive tags and provide backscatter coupling. This article breaks down what RFID tags are made of.
Key components in an RFID Tag
Any RFID tag has three major components in it. The first is the Integrated Circuit (IC) of the RFID chipset. The second is the radio antenna, and the last one is the substrate. These three add up to the creation of any RFID tag. These three components can be supplied from different sources when a tag is being manufactured.
Here, we will dive deeper into all three critical components:
RFID IC chipset
An Integrated Circuit (IC) is the central part of the solution, as this semiconductor piece acts as a logical unit and data storage for any RFID application. A small IC can comprise a microcontroller with several thousands of transistors and serve to control powering RFID tags. This power to operate them may be received from an RFID reader device or a dedicated battery (for active RFID tags).
The IC is responsible for implementing the communication protocol, and it also helps modulate RF waves for encoding and decoding between the tag and the reader. Tags can vary based on the IC and be read-only type, write-once type, or rewritable. These ICs also carry EEPROM to store information without a power supply. For example, it allows users to store a unique identifier, a password, or any such information. ICs that can operate at a lesser power would be able to work farther from an RFID reader.
For their manufacturing, these semiconductor ICs on each wafer are sliced from silicon wafers and then attached with an RFID tag antenna. Smaller-sized ICs are costlier as they require precision to assemble them with the RFID antenna.
RFID Tag Antenna
RFID tag’s communication range depends on its antenna. The antenna is the largest among RFID tag components, and it connects to the IC. The antenna acts as a receiver of RFID reader signals, and the same EM waves act as a power supply for passive tags, so the tags then reflect the signal back to the interrogator for detection. However, the antenna just facilitates the EM transmission for active RFID tags.
Made from a flexible or rigid material, the substrate is basically responsible for holding the components of the RFID tag. The substrate basically has the antenna printed on top of it, and the antenna is then attached to the IC. It can be made of flexible plastic 100 to 200 nm or even other materials such as PVS, polymer, polyesters, and even paper, among others.
A substrate is responsible for making a sturdy build, providing an antenna surface, protecting against the environment, and giving stability during application. As such, it is important that the substrate does not affect the antenna performance.