A “chipless RFID” tag refers to a system that uses RF energy to communicate data without relying on a silicon microchip to store a serial number in the transponder. Some chipless tags are made from plastic or conductive polymers instead of traditional silicon-based microchips. Other types use materials that reflect a portion of the radio waves back to the reader. A computer analyzes the reflected waves, creating a unique pattern that serves as a “fingerprint” to identify the tagged object. Some companies are experimenting with embedding RF-reflecting fibers into paper to prevent unauthorized photocopying of documents. Additionally, specialized inks that reflect certain radio frequencies can be used, for example, to tattoo animals with chipless RFID transponders for identification.

RFID tags can be categorized as read-write, read-only, or “write once, read many” (WORM).

• Read-write tags allow you to add or overwrite data when the tag is within range of a reader. While the serial number typically cannot be changed, additional data blocks can be written to or locked for permanent storage.
• Read-only tags have pre-programmed information stored during the manufacturing process, which cannot be altered afterward.
• WORM tags allow a serial number to be written once, and this information cannot be modified afterward.

There isn’t a “typical” RFID tag, as read ranges vary significantly based on whether the tag is active or passive.

• Active RFID tags have longer read ranges, often exceeding 300 feet, since they broadcast their own signal.
• Passive RFID tags depend on several factors including operating frequency, reader power, and interference. In general:
  • Low-frequency (LF) and high-frequency (HF) tags are read within 3 feet (1 meter).
  • Ultra-high-frequency (UHF) tags have a read range of 10 to 20 feet.
  • Specialized readers with phased array antennas can extend the read range of passive tags to 60 feet or more.

There are many RFID vendors, each with expertise in different areas. Some specialize in active RFID tags, while others focus on passive tags. Vendors may concentrate on specific frequency ranges, such as ultra-high frequency (UHF) systems, or offer low-, high-, and UHF options. Among them, JIA RFID is recognized as one of the top global vendors, providing high-quality RFID products across various categories.

While it is true that RFID can face challenges with metal and water, low- and high-frequency (LF and HF) tags tend to perform better in such environments. For instance, low-frequency RFID tags can be embedded in metal auto parts to track them. At ultra-high frequencies (UHF), radio waves tend to bounce off metal and are absorbed by water, making passive UHF tags less effective for tracking metal products or those with high water content. However, recent advancements in RFID technology have led to the development of specialized UHF tags that can overcome these obstacles. Additionally, there are strategies for tagging metal or liquid-based products to ensure reliable read performance.

The goal of the RFID industry is to reach a point where large-scale production drives down the cost of silicon-based RFID tags that can store unique serial numbers to around 5 cents per tag. While costs have been steadily decreasing over recent years, further price reductions are expected as adoption and production volumes increase.

The durability of an RFID tag varies depending on whether it is active or passive.

• Active RFID tags rely on batteries, and once the battery is depleted, the tag becomes unusable. The lifespan of an active tag depends on the battery capacity and application conditions—longer read distances can drain the battery faster. However, many active tags are designed with long-life batteries to extend their operational durability.

• Passive RFID tags offer significantly longer lifespans, making them a cost-effective investment for RFID systems. For example, Pepperl+Fuchs manufactures passive RFID tags designed for harsh industrial environments, capable of over 100,000 write cycles. FRAM-based tags can be rewritten almost indefinitely. Additionally, some tags come in robust metal housings that can withstand temperatures as high as 220°C. Others are encased in durable plastic, offering resistance to water, chemicals, transformer oil, petrol, and heating oil. Tags with high IP ratings further demonstrate their ability to withstand tough industrial conditions, ensuring long-term reliability.