RFID tag can be grouped into passive, semi-passive and active.
Passive Tag
Tags that are energized by readers electromagnetic field.
They are low cost & small size because no batteries are needed.
Passive tags are classified into 3 types:-
- Class 0:- are read only tags with simple 1D number. The id is typically a manufacture programmed 64 or 96 bit number which can be EPC & cannot be modified.
- Class 1:- are read/write passive tags that can be written once, either by the manufacture or the user.
- Class 2:- are read/write passive tags that can be written several times and has additional features like data
logging, cryptography may be included
Semi - Passive Tag
Semi - Passive tags generally use energy from batteries to work in addition to radio frequency transmission as passive tags.
- Class 3:- with extra energy the tags can increase their reading distance range as well as providing new functionalities eg:- Sensor.
- Active Tag
Active tags provided with batteries allowing the tag generate its own radio frequency signal.
They might also include additional feature like sensors, encryptions & data processing among other functionalities.
- Class 4 :- Provide communication functionalities with other active tags &have the same features as class 3.
- Class 5:- have reader capabilities enabling them to communicate with all types of tags.
![enter image description here](https://i.imgur.com/7MAnFUa.png)