Basic Principle Of RFID System

The basic working principle of an RFID system is that a reader/writer sends a specific frequency RF signal through a transmitting antenna. When an electronic tag enters an effective working area, an induced current is generated, thereby obtaining energy to be activated, allowing the electronic tag to transmit its encoded information through a built-in antenna; The receiving antenna of the reader/writer receives the modulated signal sent from the tag and transmits it to the reader/writer signal processing module through the modulator of the antenna. After being demodulated and decoded, the effective information is transmitted to the background host system for relevant processing; The host system recognizes the identity of the tag based on logical operations, performs corresponding processing and control for different settings, and ultimately sends a signal to control the reader to complete different read and write operations.
From the perspective of communication and energy sensing between electronic tags and readers, RFID systems can generally be divided into inductive coupling (magnetic coupling) systems and electromagnetic backscatter coupling (electromagnetic coupling) systems. Inductively coupled systems are coupled by high-frequency alternating magnetic fields in space, based on the law of electromagnetic induction; Electromagnetic backscatter coupling, or radar principle model, refers to the reflection of electromagnetic waves emitted when they encounter a target, while carrying back target information, based on the spatial propagation law of electromagnetic waves.
Inductive coupling is generally suitable for short range RFID systems operating at medium and low frequencies; Electromagnetic backscatter coupling is generally suitable for long-distance RFID systems with high-frequency and microwave operating frequencies.