3.4. Input module
3.4.1. RFID device
Fig. 7 illustrates the basic RFID system design based on RFID
tags and the EBox devices. The components of the RFID System are
composed of following components:
3.4.1.1. Tag. The electronic tag ismadeupof coupling elements and
chips, and it stores the formatted information of the vehicles. Each
tag has its unique coding mode to distinguish different vehicles. The
information solidified in the tag basically includes the registration
number. In real usage, a tag should be attached on a vehicle.
3.4.1.2. Antenna. During the radio frequency communication, the
antenna takes charge of transmitting the radio frequency signal
between the tags and the RFID reader. The antenna must be small enough to attach on either the tag or the reader. Meanwhile it can
transmit the max power throughout the tag. Due to the airborne
interface, its polarization almost matches all query signals from
the RFID reader. For the microwave RFID application, the antenna
coupling mode is based on radar model