1. What is an RFID tag ?
 
An RFID tag is a label that has an RFID inlay inserted between the label facestock and liner.
 
2. What are the components of an RFID tag ?
 
An RFID tag has a protective and printable facestock, a layer of adhesive, then the RFID inlay, another layer of adhesive, and finally a removable liner.
 
The RF inlay provides the RFID functionality. The inlay consists of a carrier sheet that holds a RF antenna, to which is bonded a tiny microchip.
 
The liner and facestock are typically made of paper, but may also be made from other materials such as plastic films.
 
The selection of materials determines how well the tag will survive and whether it will be compatible with printers, applicators and other system hardware. Material selection may also have to accommodate FDA regulations. In addition, there are mechanical considerations, such as selecting an adhesive that will ensure the tag will remain adhered to the carton.
 
3. How is an RFID tag encoded ?
 
RFID tag can be encoded with a stand-alone reader / antenna setup. However, in a typical real-world application that function is accomplished within an RFID-enabled printer.
 
4. What is the difference between active, semi-passive and passive tags ?
 
Active tag broadcasts under its own power, using an onboard battery. As a result, It has very long reading distance. It is more expensive than passive tag, so it is normally used to tag very high-value items.
 
Semi-passive tag is a small and light-weight hybrid of active and passive tag. It generally uses a battery to power the electronic logic (like active tag), but can also transmit data using power generated from RFID readers (like passive tag).
 
Passive tag is the most economical RFID tag and the most common tag used in supply chain applications. It has no onboard battery like active tag, because it gets power from RFID readers. The RFID reader sends electromagnetic waves to the tag's antenna. Using energy from these waves, passive tag broadcasts a signal back to the reader.