Components of an RFID System:
The tag is a cheap device that that consists of a microchip and an antenna. The microchip can store up to as much as two kilobytes of data. It can store important information like, date of manufacture, product shipment, expiration date etc. It is generally a serial code that is unique to every tag. An RFID system can have more than one tag. The cost of a tag depends on its frequency (a tag of higher frequency has a longer antenna coil and hence costs more), capacity to store information and design of antenna. Active tags are more expensive than passive tags. While a passive tag can cost only around 20 cents, an active one can cost up to 50 dollars. (Active and passive systems will be discussed further)
The interrogator has one or more antennas that gives out radio signals and receives signals from the tag. It activates the tag so that it can read and write to it. When the tag is in the electromagnetic zone of the reader, it gets activated by the signal sent by the reader. The reader decodes the information sent by the tag and the data is then transferred to a computer to be processed. A reader can have an internal or external antenna. They also have input/output ports to connect external devices like USB, Wi-Fi or Ethernet. Readers can cost anywhere from $500 to $3000 depending on their capabilities. Readers that have anti-collision capabilities (i.e. able to read data from multiple tags simultaneously) and can read tags of different frequencies are generally more expensive.
Middleware and Servers:
Middleware is the software used to communicate between the RFID reader and the computer or other applications. It takes raw data from the reader and converts it into useful information. It sends the right information to the right application in a multi-tag system. For example, the software will confirm that a parcel has arrived; it will then send an email to the retailer that it has been shipped. Middleware costs...