RFID - Radio Frequency Identification

RFID ( Radio Frequency Identification ) is an 

emerging technology for the purpose of tracking and 

identification of objects.

RFID technology has two parts :-

1. Tag
2. Interrogator ( Reader )

Important Points

•  The tag consist of a microchip and an antenna coiled around it  
• The microchip is used to store a unique identity and other information 
• The interrogator emits radio waves to activate the tag

OPERATION

   

When an RFID tag is passed through an electromagnetic zone that is produced

 by the interrogator, it detects the activation signal. The reader ( interrogator )

decodes the data encoded in the tag for processing.

CLASSIFICATION

RFID tags are classified into two based on the power source

1. Active tags :- contains internal power source
2. Passive tags :- depends upon the power of the radio waves

 Another classification is based on the programming

1. Class 0 :- Pre-programmed
2. Class 1 :- Can be programmed once
3. Class 2 :- Can be programmed many

RF Frequencies used

1. Low frequency:    125 - 134.2 KHz
2. High frequency:   13.56 MHz
3. UHF :                    2.4 - 2.5 GHz