RAIN tags are the items that are attached to the “thing” that needs to be identified. The tag is made from an integrated circuit (tag chip) and an antenna mounted on a substrate.
Tag chips are made by several companies and they offer a variety of different features. The basic feature set is common to all chips, but the standard that defines the air interface (how a tag chip talks to a reader) has many option in it that a manufacturer can chose to implement or not. Options include security, file management features, user memory, and the ability to add “battery assist”.
The most common form factor for a tag is a paper label, but there are many other form factors available, as well as different configurations of the various form factors.
Tags antennas are designed to be used in specific applications – for example, a tag may be deigned to be used on a bottle of shampoo. This tag will be specially designed and tuned to consider the properties of the shampoo and the effect that it has on radio waves. Other examples might be a tag to be used on a metal object, or on a bottle of water. Size is also a factor when designing a tag. A tag that must be read at large distances will typically be larger than one that is only read close by.
Other form facts may include:
- A hard shell around the tag chip and antenna for a more rugged application.
This form factor may or may not include adaptions to allow the tag to be mounted on metal surfaces
- Flexible shells to allow attachment to curved surfaces while still affording the extra protection of a shell
- Embedded in a plastic surround such as an ID card
- As part of a thread used in the manufacture of garments etc.