RFID Education

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RFID 101

What is RFID?

RFID stands for Radio Frequency IDentification.


The new RAIN RFID standard is also an acronym (RAdio frequency IdentificatioN) designed to help consumers better link the possibilities and capabilities of RFID with Cloud Computing based applications, which is usually where the data resides.


How does RFID work?

At the highest level RFID works by powering an RFID Tag, usually by the RFID readers signal once it comes into close enough proximity, so that the tag is able to send it's unique identification number to the reader. This unique identification number can then be cross checked in a sub-system to see what asset or person is being identified.

RFID Diagram

The more technical answer is that RFID transmits data through electromagnetism. Small, electrically-charged particles interact with each other, creating an electromagnetic field. This field is made up of different waves of photons; the collection of waves from lowest to highest frequency is what we call the electromagnetic spectrum.

Every day, you use several devices that rely on communicating through the generation of waves in the electromagnetic spectrum. For example, radio stations use transmitters to generate waves sending music to the receiver in your car radio. RFID uses this same principal to send information between the tag and the reader.


What uses are there for RFID?

The two broad uses for RFID are 1- Access control, and 2- Asset Tracking.

Chances are you already use RFID and didn't know it. - Contactless payment and transit/toll systems use RFID to identify who you are and process your transaction or allow you through the toll gate.

  • Passive RFID tags in retail products assist in loss prevention and enable emerging business methods, like consumer self-checkout.
  • Hospitals use RFID to improve efficiency, provide better patient care and reduce the risk of spreading an infection.
  • Manufactures embed RFID tags into their products to track each stage of production and ensure quality

This is just a few real world examples, the application of RFID is near limitless.


What is the maximum read distance of RFID?

RFID is a group of technology, usually identified by the frequency or "wave" they use. The maximum distance is determined by;

  • The frequency of the RFID system
  • The individual RFID reader
  • The antenna being used
  • Characteristics of the RFID tag
  • The thickness and material the tag is attached to
  • How the tag is attached
  • The environment the system is being used in

...to name the major factors. This complexity is why specifications usually show the "free air" read distance. The performance when the environment is free of any other electrionics and there is nothing between the tag and the reader. This is why a specification that says 5 meters, but didn't account for the factors listed above, may only give you 1 meter in practise.

Generally speaking, RFID tag maximum read distances are as follows:

125 kHz and 134.2 kHz
Maximum 30 cm (1 foot) or less
Usually 10 cm (4 inches)
It is possible to get longer read distances, but these cases need individual assessment.

13.56 MHz
Maximum 1.5 meters (5 feet)
Usually under 1 meter (3 feet)
To obtain more than 1 meter you need a reader with output over 1 watt.

433 MHz
Maximum 500 meters (1,500 feet)
Usually 60 meters (200 feet)
We've obtained reads over 1 kilometer using highly sensitive antennas.

860 ~ 960 MHz
Maximum 16 meters (53 feet)
Usually 1-2 meters (6 feet)
Specific use tags may be tuned to work at either 860MHz or 902 MHz.

Maximum 100 meters (325 feet)
Usually 50 meters (160 feet)
An emerging standard.
NOTE: 2.45GHz RFID is not the same as WiFi enabled Internet-of-Things devices which also work on the 2.4GHz band.


What is the maximum transmit power?

This is country specific and in some cases further regulated by the region or city. This list is by no means the full list of all of the different frequency regulations. To ensure your compliance with local regulations make sure that you review the current standards prior to purchasing your readers.


Maximum Transmit Power

125 kHz & 134.2 kHz 72 dBμA/m
13.56 MHz 60 dBμA/m
433 MHz 0.1 Watts
860 - 960 MHz Download the GS1 Regulations Outline
2.4 - 2.483 GHz 4 W indoor
0.5 W EIRP outdoor
5.725 - 5.875 GHz 4 W USA/Canada
0.5 W Europe

How do I learn more?

We offer a FREE RFID basics course which is broken down into 6 lessons that can be completed in about 30 minutes. You get one lesson per day delivered to your email for a week, which will give you the essential knowledge you need to ensure your new RFID system meets your expectations. Sign up below.

Free RFID Course

The SkyRFID Basic Course consists of 6 lessons via email.



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