JKTechnics From design to implementation

Introduction of Radio Frequency Identification (RFID)

Radio Frequency Identification (RFID) is a form of wireless communication that uses electromagnetic coupling to uniquely identify objects or persons. It uses radio frequency to search, identify, track, and communicate with items and people.

RFID is a technology that uses electromagnetic fields to automatically identify and track tags attached to objects. These tags contain electronically stored information that can be read from several meters away without requiring direct line-of-sight. It is widely used in inventory management, asset tracking, access control, and supply chain logistics due to its efficiency.

It is a method used to track or identify an object by radio transmission. Data is digitally encoded in an RFID tag and read by a reader. Unlike traditional barcodes or QR codes, RFID tags can be read without line-of-sight and can be active or passive.

Types of RFID

There are many kinds of RFID, each with different characteristics. Most RFID tags have no power source; all energy is supplied by readers. This is called passive RFID. Active RFID uses a tag with its own power source.

• UHF RFID (Ultra-High Frequency): Used in logistics and shipping (902–928 MHz). Tags reflect signals using backscatter, enabling several-meter read ranges.
• HF RFID (High-Frequency): Operates at 13.56 MHz. Used in passports, contactless cards, books. Range ≤ 1 meter.

Passive RFID

Passive tags have no power source; they use energy from the reader. Frequencies include:

• 125–134 kHz (LF)
• 13.56 MHz (HF)
• 856–960 MHz (UHF)
• No embedded power
• Used for tracking inventory
• Unique identification number
• Sensitive to interference

Active RFID

Active tags have an internal battery that emits signals. They provide long ranges and can support sensors.

• Embedded power for long-distance communication
• Unique identification number
• Can include sensors (temperature, motion, etc.)
• Perform better than passive tags near metal

Other forms of RFID include LF RFID (Low Frequency), an early technology used for tracking.

Working Principle of RFID

RFID uses radio waves for Automatic Identification and Data Capture (AIDC). An antenna converts power into radio waves, enabling communication between the reader and the tag. The reader retrieves information, reads or writes data, and communicates with a host system. A reader contains a processor, memory, transmitter, and receiver.

Working of RFID System

An RFID system consists of three components: a scanning antenna, a transceiver, and a transponder. When combined, the antenna and transceiver form the RFID reader. Readers can be fixed or portable and transmit signals to activate tags.

The transponder is part of the tag. Read range varies by tag type, reader, frequency, and environmental interference. Tags with stronger power sources provide longer ranges.