Structure and Components of an RFID System

An RFID system comprises two main components: the transponder (RFID tag) and the reader.

Transponder

The transponder contains the following parts:

• Antenna: Receives the radio waves from the reader.
• Transceiver: Manages data reception and transmission.
• Integrated Circuit (IC, chip): Outputs pre-stored information.
• Memory: Stores the information to be transmitted.

Reader

The reader emits radio waves that the transponder picks up along with the stored information. It translates these signals into data that is processed by software. The reader is equipped with an antenna and a high-frequency module enabling communication.

How RFID Technology Works

RFID communication is based on electromagnetic waves generated by the reader. The primary steps in the process are:

1. Signal transmission: The reader sends an electromagnetic signal to request data from the transponder.
2. Power supply: The transponder draws energy from these waves and activates transmission, requiring only a few millivolts.
3. Data transfer: The transponder modulates the voltage field between it and the reader to transmit the requested information.
4. Data evaluation: The reader interprets the signals and forwards the data to the connected software.

RFID Frequency Bands and Characteristics

RFID systems use various frequency bands, each with specific benefits depending on the application:

1. Low Frequency (LF): 125 kHz – Previously used in industrial environments, now mainly for animal identification. Range up to 10 cm, highly resistant to metal and moisture.
2. High Frequency/Near Field Communication (HF/NFC): 13.56 MHz – Universal, with a range up to 1 meter. Common in cashless payment, retail, and access control.
3. Ultra High Frequency (UHF): 865-869 MHz (Europe/ETSI), 902-928 MHz (USA/Asia/FCC) – High range up to 50 meters. Often used for pallet and container management (pooling) and product tracking.
   

Power Supply: Active vs. Passive Transponders

There are two main types of RFID transponders:

• Passive transponders: Powered by the radio waves from the reader, cost-effective, and smaller but with shorter range. Ideal as cost-effective and easy-to-process labels.
• Active transponders: Have an internal power source (battery), achieving greater range (up to 100 meters). Suitable for applications requiring long-distance coverage, such as vehicle identification. They are more expensive and require battery disposal, a disadvantage compared to passive tags.

Application Scenarios and Customization Options

RFID systems can be customized for different industries and needs. Depending on the requirements, they can be optimized for range, transmission speed, memory capacity, and cost. For instance, read-only tags are often used in logistics and can only be read after initial programming, while read-and-write tags in industrial settings allow data updates.

Advantages of RFID Technology

RFID technology offers numerous benefits, especially in industry and logistics:

• Contactless identification: No direct line of sight needed between the reader and tag.
• Fast data exchange: High transmission rates enable efficient workflows.
• Automation potential: RFID systems enhance warehouse management and process optimization, supporting Industry 4.0.
  

FAQ About RFID Technology

What is an RFID system?
An RFID system consists of a reader and a transponder that exchange data through electromagnetic waves.

What are the advantages of RFID over other technologies?
RFID allows for fast, contactless object identification without direct line of sight and offers higher data transmission rates than barcodes.

Where is RFID used?
Primarily in logistics, retail, the automotive industry, and pharmaceuticals for object identification and management.