Notes on Near-Field Communications (NFC) and Radio Frequency Identification (RFID) Technology

Introduction

• Overview of NFC and RFID technologies
• Maxim as a leader in the development of these technologies
• Aim: Understand how NFC and RFID work, their applications, advantages, and disadvantages

Definitions

NFC (Near Field Communication)

• Subcategory of RFID
• Defined by specific standards for operating frequency, modulation, power, range, and bitrate
• Focused on secure operations (e.g., payments, access control)

RFID (Radio Frequency Identification)

• System using radio waves to read/capture information from a tag attached to an object or person
• Tags can be read from a distance and do not require direct line of sight

Wireless Communication Technologies

• NFC and RFID are part of wireless communication technologies
• Information is transmitted without physical contact or wired connections
• Utilizes electromagnetic waves:
  • Transmitter modulates information onto a carrier
  • Receiver demodulates carrier to recover information

RFID System Components

• Typical RFID system components:
  • Antenna
  • Receiver
  • Transmitter (tag/transponder)
  • Modulator
  • Demodulator
• Terminology may differ (e.g., "reader" instead of "receiver")

Differences Between NFC and RFID

• Range: NFC operates at short distances (less than 10 cm); RFID can operate up to several meters (passive) or kilometers (active)
• Security: NFC is more secure due to its short range; suitable for payments and access control
• Cost and Robustness: Passive tags are cheaper and more robust; active tags have batteries but larger memory and longer read distances

Types of Tags

• Passive Tags: No energy source; harvest energy from RF carrier
• Active Tags: Contain batteries; longer range and larger memory storage
• Semi-Passive Tags: Use battery for logic but harvest energy for communication

Frequency Ranges and Applications

Low Frequency (< 135 kHz)

• Applications: Waste sorting, medical ID, alarm systems

High Frequency (13.56 MHz) - NFC

• Applications: Contactless payment cards, mobile wallets, public transport ticketing, healthcare applications

UHF (433 MHz and 900 MHz)

• Applications: Shipping container tracking, manufacturing

Microwave Region (2.45 GHz and 5.8 GHz)

• Applications: Automatic highway toll systems

Potential Applications of RFID

• Vehicle tracking, factory automation, access control, animal tracking
• Enhances management visibility in manufacturing processes

Medical Applications for RFID

• Implanting passive RFID tags in patients for medication tracking
• Emerging trend in hospitals for patients with specific conditions

NFC Applications

• Well-suited for close-proximity communications
• Examples: Payment systems, exchanging contact information, access control
• Increasing adoption of contactless payments

Security Aspects of NFC

• NFC as a smart electronic key for secure access
• Implementing strong cryptographic systems for data exchange

Tag Forms and Reader Variations

• Common tag forms: flat square tags, paper tags, encapsulated tags
• Reader forms: anti-theft systems, portable payment terminals, peer-to-peer communication devices

Technical Details of RFID

• Operate primarily in ISM bands (license-free)
• Frequencies are divided into inductive (low frequency) and radiative (high frequency)
• Most RFID systems operate in the near field, using inductive coupling

Modulation Techniques

• Pulse interval encoding, amplitude shift keying (ASK)
• Different representation schemes possible for data encoding

Conclusion

• Summary of how NFC and RFID work, key applications, and potential
• More information available on Maxim Integrated's website under embedded security and NFC/RFID products

Additional Resources

• For further study, explore online resources regarding RFID system performance and antenna placement.