Question 1

What is RFID?

Accepted Answer

Radio-Frequency Identification (RFID) is a generic term for technologies that use radio waves to automatically identify people or objects. The most common approach stores a serial number — and sometimes additional information — on a microchip attached to an antenna. Together the chip and antenna are called a tag. The antenna lets the chip transmit identifying information to a reader, which converts the reflected radio waves into digital data for downstream systems.

Question 2

How does an RFID system work?

Accepted Answer

An RFID system consists of a tag (a microchip with an antenna) and a reader (an interrogator with its own antenna). The reader emits electromagnetic waves; the tag's antenna is tuned to receive them. A passive tag draws power from the field, the chip modulates the waves sent back to the reader, and the reader converts the response into digital data.

Question 3

What is the difference between low, high and ultra-high frequencies?

Accepted Answer

Just like a radio, RFID tags and readers need to be tuned to the same frequency. The most common bands are low frequency (around 125 kHz), high frequency (13.56 MHz) and ultra-high frequency or UHF (850–900 MHz). Microwave (2.45 GHz) is used in some applications. Radio waves behave differently at each frequency, so the band must match the application.

Question 4

How do I know which frequency is right for my application?

Accepted Answer

Low-frequency tags are cheaper, use less power and penetrate non-metallic substances well — ideal for short-range scanning of objects with high water content (like fruit). UHF offers better range and faster data transfer but uses more power, struggles with metal and liquid, and is more directional. UHF is often the right choice for scanning cartons through a warehouse bay door. A consultant, integrator or experienced vendor can help match frequency to use case.

Question 5

What is the difference between active and passive tags?

Accepted Answer

Active tags have a battery powering the chip and broadcasting a signal — like a cell phone to a base station. Passive tags have no battery and draw power from the reader. Semi-passive tags use a battery for the chip but still rely on backscatter to communicate. Active and semi-passive tags suit long-range tracking of high-value goods, but cost a dollar or more each. Passive UHF tags can be produced for under 50 cents in volume — short of active tag range, but far more economical for item-level use.

Question 6

What is automatic identification?

Accepted Answer

Automatic identification (auto-ID) is the broad term for technologies that help machines identify objects. It's often paired with automatic data capture — getting information into a computer without manual entry. The goal is fewer errors, higher efficiency and more time for value-adding work. Auto-ID includes barcodes, smart cards, voice recognition, biometrics, OCR and RFID.

Question 7

What is an Electronic Product Code (EPC)?

Accepted Answer

The Electronic Product Code was developed by the Auto-ID Center as a successor to the barcode. It's a numbering scheme designed to identify products as they move through the global supply chain — the basis of EPC RFID standards.

Question 8

What is the read range for a typical RFID tag?

Accepted Answer

Read range depends on frequency, reader power and interference. In general: low-frequency tags read at a foot or less; high-frequency tags around three feet; UHF tags 10–20 feet. Active tags with batteries can extend range to 300 feet or more — used for assets like railway cars.

Question 9

What RFID standards are most widely used in open, global supply chains?

Accepted Answer

Passive UHF RFID is preferred for open, global supply chains thanks to longer read distances and faster data transfer. The standards have been developed over many years by a broad stakeholder community facilitated by GS1 — the global, not-for-profit standards organisation headquartered in Brussels.

Question 10

Who do I contact in New Zealand for independent advice and guidance on RFID?

Accepted Answer

The New Zealand RFID Pathfinder Group was established in 2006 to provide independent advice and guidance on all things RFID. Get in touch via our contact page and we'll connect you with the right experts.

FAQs

Still got a question?

Stay across NZ RFID research and events