RFID Passive Tags

Passive tags receive energy from the radio waves of the RFID reader's interrogation. Active tags have a battery and can be read from a greater distance, up to hundreds of meters. The tag does not require a line of sight with the reader, so it can be embedded in the object being tracked. RFID is a method of automatic identification and data capture (AIDC). RFID tags have many applications in various industries. For example, an RFID tag on a car during production can track its progress along the assembly line, RFID-tagged drugs can be monitored in warehouses, and RFID microchips in animals and pets can identify them. Tags can also speed up checkout and prevent theft in stores. However, RFID tags also raise serious privacy concerns, as they can be attached to money, clothes, and belongings, or implanted in animals and people, and read without consent. These concerns led to the development of standards that address privacy and security issues. A passive RFID system consists of three main components: an RFID reader or interrogator, an RFID antenna, and RFID tags. Passive RFID tags have only two components: the tag's antenna and the microchip or integrated circuit (IC). Passive tags wait for a signal from an RFID reader. The reader sends energy to an antenna, which converts it into RF waves that radiate into the surrounding area. The RFID tags capture the energy through their internal antennas and send it to the IC. The RF energy activates the IC, which modulates the energy with the information stored in its memory bank and sends it back through the tag's antenna. The reader receives the modulated RF energy from the tag. High Temperature RFID Tags – Some industries, such as healthcare, pharmaceutical, and manufacturing, need to track how many times their instruments go through harsh autoclaves. There are special passive RFID tags that can endure extreme temperatures and suit those kinds of applications and more. Rugged RFID Tags – Outdoor environments or tough warehouses require tags that can resist snow and ice, dust and debris, or even the crushing force of a tractor wheel. For these applications, a very rugged passive tag is essential to make the application work. Size – Some applications have specific size constraints when tracking small or large items. Size is one of the most important questions to answer when choosing an RFID tag because there are many different sizes available. Item Materials – If an application involves tracking metal assets, UHF metal-mount tags are usually the only way to get a reliable tag read with a decent read range. These tags are specially designed to overcome the problems UHF RFID faces around metal. Embeddable RFID Tags – If tagging an item is a problem for some applications due to significant wear and tear, embeddable tags can fit in small crevices and be covered with epoxy so the RFID tag is protected. To learn more about how to embed RFID tags, read our article: Embeddable RFID Tags - What do I Need to Know. A close-up of a can A roll of Passive RFID inlays Inlays are usually the cheapest RFID tags, costing as low as $0.12 per tag in high volumes, but the price does not affect the performance. These inlays are grouped into three main types: Dry Inlays – An RFID microchip (IC) and antenna attached to a material or substrate called a web. These inlays look like they have been laminated and come standard without adhesive. Wet Inlays – An RFID microchip (IC) and antenna attached to a material, usually PET or PVT, with an adhesive backing. Most