What chips or tags do I need?
Let’s start with the type of radio frequency identification technology. There are many different types of RFID systems, and the right one depends on the nature of the objects you want to track and the distance over which you plan to track them. If you wish to monitor large items over long distances—say, 500 to 1,000 meters (1,640 to 3,280 feet)—then you will probably require active RFID technology. If, however, you want to track smaller objects over shorter distances—7 to 9 meters (20 to 30 feet), for instance—then you can use a passive ultrahigh-frequency (UHF) RFID system. If you simply need to read a tag from a few inches away via a smartphone, then you can utilize passive high-frequency (HF) technology.
Your question suggests that you are trying to pick a passive UHF RFID chip and tag (I infer this because there is more variety among tags in this category than any other). Different chips have different features. If you need security, you might want to choose NXP Semiconductors’ DNA chip, which supports encryption (see NXP Releases IC for Secure Encrypted UHF Reads). If you want to protect your customers’ privacy, perhaps Impinj’s Monza chips, which support public and private modes of operation, would be best (see New Impinj Chip Promises Higher Sensitivity, Read Range and Flexibility). And if you need to store a lot of data on the tag, perhaps you should choose a high-memory model from Tego, Fujitsu, MAINtag or Marubeni Chemix (see A Flurry of High-Memory Tags Take Flight).
When choosing a tag with one of the above chips in it, you will need to consider a number of factors. The first issue is the environment in which the tag will be used. Will it be exposed to high levels of heat, pounding, chemicals or other abuse? If so, you will need to choose a tag encased in an appropriate shell that would protect it from being damaged.
You will also need to consider the material on which the tag will be placed. If an ordinary passive UHF label is placed on a metal object, the metal will detune the tag, making it difficult or impossible to read that tag. You would thus require a special on-metal tag. Other materials, including glass, water, carbon fiber and wet wood, can all impact a tag’s performance. These materials require special passive UHF tags.
RFID Journal has produced a report titled “How to Choose the Right RFID System: A Step-by-Step Guide,” which walks companies through the process of choosing the right type of RFID solution and the appropriate tags. You might find this useful for your purposes.
—Mark Roberti, Founder and Editor, RFID Journal