Recognition Systems | IGCSE Information and Communication Technology Preparation - Year 11 PDF Download

Recognition Systems

How does RFID work?

• RFID Tags:
  • RFID, or Radio Frequency Identification, is a technology for identifying and tracking objects using radio waves. It relies on RFID tags, which hold data about the objects they're attached to.
• Components of RFID Tags:
  • RFID tags contain two main components: an integrated circuit (IC) and an antenna. The IC stores and processes information, while the antenna receives and transmits signals.
• Passive RFID Tags:
  • These tags don't have their own power source. Instead, they harness energy from RFID readers' radio waves.
  • When a reader emits radio waves, the passive tag's antenna picks them up.
  • The antenna converts the waves into electrical energy, powering the IC.
  • The IC then sends stored information back to the reader via the antenna.
• Active RFID Tags:
  • Active tags have their own power source, usually a battery, making them more powerful and capable of longer-range communication.
  • They emit a signal that the reader detects, without needing the reader's signal to activate.
• Radio Waves:
  • Both passive and active RFID systems use radio waves for communication.
  • Readers transmit radio waves, which interact with the tag's antenna (in passive tags) or directly with active tags' signals.
  • Different frequencies (LF, HF, UHF) impact reading distance, data transfer speed, and penetration capabilities.
• Antennas:
  • Antennas play a crucial role in tag-reader communication.
  • In passive tags, the antenna receives reader signals, powers the IC, and transmits tag information back.
  • In active tags, the antenna emits signals carrying tag information to the reader.
• Communication with RFID Reader:
  • The reader sends out radio waves, captured by the tag's antenna or interacting with active tags' signals.
  • Information from the tag's IC is transmitted back to the reader through the antenna, enabling object identification and tracking.

What is Near Field Communication (NFC)?

This technology facilitates close-range communication between two devices, usually within a few centimeters of each other. It's the same technology enabling contactless payments where you tap your phone or card on a payment terminal.

• Two Modes of Operation: NFC operates in two modes: reader/writer mode, used for reading tags in NFC posters, for instance, and peer-to-peer mode, utilized for data exchange between two NFC devices.
• Power Source: NFC devices can be either passive or active. Active devices, such as smartphones, have the capability to both send and receive data. On the other hand, passive devices like NFC tags lack their own power source and can only transmit data when near an active device.
• Communication: Communication between NFC devices occurs via radio waves. When two NFC devices come into proximity, one emits radio waves that the other can detect, enabling the exchange of information.
• Usage: NFC facilitates various functionalities, such as making payments at stores by tapping a phone on the terminal, sharing files by bringing two phones close together, and using a phone as a bus or train ticket.
• Security: NFC is generally considered secure due to its short-range nature. However, it's essential to recognize that any wireless communication might potentially be intercepted. Therefore, it's crucial to use NFC only for secure transactions with trusted devices.