Learn about the function and construction of RFID tags and how screen printing and other imaging methods are used to produce these devices.
By Wim Zoomer
RFID technology provides an automatic means of delivering data about a product or account without direct contact between the RFID label, tag, or card and the reading device. RFIDs react to magnetic radiation by returning data to the reading device about the product or card to which they're attached. Additionally, the data stored on some RFID tags can be updated or changed. While RFIDs are unlikely to completely replace all barcodes and similar systems, they are poised to become the dominant form of product identification in the future.
The makeup of an RFID tag is basically the same whether it is used as a label that is affixed to a product or embedded in a credit or banking card. The tag contains an RFID transponder, which consists of a chip attached to an antenna. The antenna is actually a simple coil, generating magnetic induction or an electric voltage.
The data exchange between the RFID tag and the antenna of the reader/writer takes place without direct contact between the reader and the tag. The reader/writer is connected to a computer. The following is a step-by-step description of how RFID technology works:
1. The passive RFID tag is moved within the electromagnetic field of a reader.
2. The tag receives a signal from the reader, which activates the tag.
3. The tag responds by transmitting to the reader data saved on the transponder's chip.
4. The reader passes on the received data to the main computer. The reader also may provide the tag with new data, overwrite existing data, or deactivate the tag.
One considerable advantage of the RFID tag over a barcode is that the tag can be read without being in the line of sight of the reading device. Unlike the barcode, no human assistance is required to position an RFID tag so that it can be read—the process of reading the tags can be executed automatically.
Another advantage of RFID tags is that the chip on an RFID transponder is a dynamic data carrier, meaning that data can be both be read from and written to the chip. And because the data are exchanged via electromagnetic radiation, multiple RFID tags can be read simultaneously.
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