How Passive RFID Works
Many commonly used RFID tags are passive, meaning they do not contain their own battery or power source.
Instead, the reader provides the energy required during the reading process. When the tag enters the reader’s usable reading area, it receives energy from the reader and responds with its stored digital information.
The reader decodes that response into usable data, such as a unique identification number, which can then be passed to software, databases or other systems.
The Basic Parts of an RFID System
A typical passive RFID system includes:
RFID Tag
Contains an electronic chip and antenna used to store and communicate identification data.
RFID Reader and Antenna
The reader controls communication with the RFID tag. Depending on the system, the antenna may be integrated into the reader or connected separately.
Software / System
Information captured by the reader is passed into software, a database or another connected system where it can be displayed, recorded or used.
In simple terms:
- RFID Tag
- Reader
- Software / System
RFID Is Not One Single Technology
The most commonly used RFID frequency groups are Low Frequency (LF), High Frequency (HF) and Ultra High Frequency (UHF).
Each has different characteristics and is established in different applications.
| Frequency group | Frequency | Characteristics |
|---|---|---|
| LF | 125 kHz (industrial use) / 134.2 kHz (animal use) | LF RFID generally provides relatively short reading distances and is well established in industrial identification and electronic animal identification. |
| HF | 13.56 MHz | HF RFID is used in applications including contactless systems, access and industrial identification, and NFC (Near-Field Communication). |
| UHF | 860–960 MHz | UHF RFID can provide short- and longer-range reading capability, higher data-transfer rates and multi-tag identification in appropriate systems. |
Start With the Application
There is no single “best” RFID frequency.
The right technology depends on what needs to be identified, the required reading distance, whether one or multiple tags need to be read, the operating environment, the systems the RFID data must work with, and any standards or approvals that apply.
A technology that is appropriate for one application may be unsuitable for another.
Understand the requirement first, then select the technology.
Why Standards Matter
RFID tags and readers need a common way to communicate and interpret information.
Standards define aspects of how RFID data is communicated and encoded, helping compatible tags, readers and systems work together consistently.
The standards that matter depend on the application. This is particularly important where identification information must be recognised across different organisations, systems or locations.