RFID tags are made of three different components: integrated circuit (IC),
antenna, and substrate, as shown in Figure 3-1. A tag manufacturer typically
does not make all three components in-house. The IC is typically designed
and made by a semiconductor manufacturer, while an antenna is usually designed
and made by a tag manufacturer. Tags are available in various sizes, designs,
and formfactors, and they can be customized for a particular application.
Unless you need a very large number of tags, you should try to use stock tags because
customized tags can be very expensive.