What is RFID?

Radio Frequency Identification or RFID is a technology used for contactless automatic information identification and collection. RFID has two types: Active and Passive. This article will mainly discuss Passive RFID. There are three frequencies where Passive RFID operates: Low Frequency(LF) 125Khz, High Frequency(HF) 13.56Mhz, and Ultra-High Frequency(UHF) 860Mhz – 960Mhz. RFID is mainly composed of three components: RFID Reader, RFID Antenna, and RFID Tag. 

The three frequencies mentioned are covered by its own regulatory standards:

  • Low Frequency(LF) – ISO 18000-2
  • High Frequency(HF) – ISO 14443 / ISO 15693 / ISO 18000-3
  • Ultra-High Frequency(UHF) – ISO 18000-6B / ISO 18000-6C (GS1)

UHF RFID operates between 860Mhz – 960Mhz depending on the country due to different regulatory standards placed by each country/region.

How RFID works?

The RFID Reader emits radio waves through the RFID Antenna to power up the RFID Tag to read or write data of the RFID Tag. Conventional RFID Tags has a unique ID that is issued by the manufacturer which means there is no RFID Tag with the same ID in the entire world. Memory of the RFID tag varies depending on the frequency it operates and the IC or chip it uses. It can be noted that liquid and metal can cause great interference on RFID Technology especially in UHF.

Reading Distance 

  • Low Frequency(LF) – up to 30 centimeters
  • High Frequency(HF) – up to 1 meter
  • Ultra-High Frequency(UHF) – up to 16 meters

Reading distance is decided by the combination of RFID Reader, RFID Antenna, and RFID Tags used. Proper reading area is obtained by selecting the right combination of the three main components such as the Output Power of the RFID Reader, the type of Antenna to be used, and the RFID Tag’s sensitivity. It is a common misconception that buying the best or most expensive components is enough to get the best performance. REMINDER: Proper calibration is the most important factor in implementing an RFID system.

Where is RFID used?

Low Frequency(LF) are commonly used in access control and animal tracking due to its higher tolerance towards liquids compared to HF and UHF.

High Frequency(HF) are mostly used in access control, payments, data transfer, etc. Examples of these are: Passports, Credit Cards, Subway/Metro Cards. HF is chosen due to its high security memory structure and communication protocol.

Ultra-High Frequency(UHF) are applied in car parking management, inventory/warehouse management, production management, etc. UHF applications are gaining more support due to its ability to read at a distance and read multiple tags at a time. 

Watch out for next month’s Journal on Knowing more about the RFID Process.

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