Radio Frequency Identification (RFID) is a non-contact technology which works on radio frequency to achieve auto-identification and data-gathering of a tagged object.

 

RFID transmissions mainly operate in three primary frequency ranges:

• LF ( Low-Frequency ): 125 - 134 kHz
• HF ( High-Frequency ): 13.56 MHz
• UHF ( Ultra High-Frequency ) : 433, and 860-960 MHz

 

 

1. Low Frequency RFID

 

The Low Frequency (LF) is between 30 kHz and 300 kHz with long wavelengths of around 2,400 meters. Because there are multiple types of signals communicating on this frequency, LF RFID systems typically operate between 125 and 134 kHz. The large wave size allows LF waves to penetrate metal and water, which is unique to this band.

 

LF RFID communicates in a similar way to HF or NFC RFID in that it uses electromagnetic coupling to send and receive signals. Although LF RFID has a long wavelength, its reading range is shorter than both HF and UHF RFID – only a couple centimeters and ideally up to about 50 centimeters, which due to dependence on magnetic coupling.

 

LF tags have relatively slow reading rates because of the low data transmission rate is very low and it takes longer for the RFID reader to receive and decode the tag’s signal.

 

Key features:

 

• Only a small amount of data can be stored on the RFID tags.
• LF RFID systems have a shorter reading range than both HF and UHF RFID.
• LF RFID tags are usually smaller than other types of RFID tags.
• LF RFID tags work well in close proximity to liquids and metals.
• LF RFID tags require less energy to operate.

 

Applications:

 

Animal Tracking (pet tagging and livestock identification )

Access Control

Car Key-Fob

Applications with Liquids and Metals

 

Read more about LF125KHz RFID Reader Module

 

 

2. High Frequency RFID

 

The High Frequency (HF) band extends from 3 MHz to 30 MHz and the wavelength of HF wave is much shorter than low frequency (LF) wave.

 

High frequency, which similar to the low frequency, uses magnetic coupling to communicate between the tags and the RFID reader/RFID antenna. HF waves are able to pass through most materials except for water and high density metals. Thin metals, like aluminum, which tagged with HF RFID tags still can function normally.

 

HF RFID tags usually have a general reading range of a few centimeters up to about a meter in length depending on the setup of the system.

 

Read more about HF13.56MHz RFID Reader Module

 

 

HF RFID standards and their common applications:

 

ISO 14443 (type A and type B)

 

Thanks to their high security features (encryption) and short reading distance, which is good for privacy, HF ISO14443 RFID tags offer guarantees best for embedding into smart cards, high security payments solutions, access control and other applications where require higher security.

 

Card types commonly used including:

ISO14443A: MIFARE® Classic 1K/4K, MIFARE Ultralight® / Ultralight®C, MIFARE DESFire®EV1/EV2 ISO14443B: SRI4K, SRIX4K, AT88RF020, 66CL160S, SR176

 

ISO 15693 (ISO 18000-3 Mode 1)

 

HF ISO15693 RFID tags mainly feature low manufacturing cost with good memory capacity, good functioning with liquids and metals, and reading distance from 1 cm up to about 1 meter. HF ISO 15693 RFID tags are commonly used in access control, ticketing, retail logistics, library management, item tracking and so on.

 

Card types: ICODE SLI, ICODE SLI-S, Tag-it HF-1 Plus, EM4135

 

ISO 18092 NFC

 

Within the high frequency band of the RF spectrum, near-field communication (NFC) is a communication protocol approved by the International Organization of Standardization (ISO 14443 & ISO 18000-3). Because NFC is a global communication standard, it is regulated to operate on a single frequency - 13.56 MHz, which makes NFC easily adaptable for hundreds of applications.

 

The NFC Forum has mandated four tag types to be operable with NFC devices. This is the backbone of interoperability between different NFC tag providers and NFC device manufacturers to ensure a consistent user experience.

 

The operation specifications for the NFC Forum Type 1/2/3/4 Tags provide the technical information needed to implement the reader/writer and associated control functionality of the NFC device to interact with the tags. Type 1/2/3/4 Tags are all based on existing contactless products and are commercially available.

 

Read more about NFC Tag Type Technical Specifications or NFC Reader Module

 

 

3. Ultra High Frequency RFID

 

In the Ultra High Frequency (UHF) band, where RFID tags work according to the principle of electromagnetic coupling, currently the most popular technology is based on ISO 18000-6C protocol,  common as EPC Class 1 Gen 2 (Gen 2 for short). The EPC 1 Class 1 Gen 2 standard was proposed by the private organization EPC global and adopted by the International Organization for Standards ISO 18000-6C in 2006.

 

The majority of UHF RFID systems use the 860 to 960 MHz frequency range and it is commonly known as 915 MHz Ultra High Frequency. However, the spectrum for North America is actually 902-928 MHz, while most of Europe is standardized on 865.5 to 867.5 MHz.

 

Compared with LF and HF RFID tags, UHF RFID tags have a much longer reading distance. There are two types of RFID in the Ultra High Frequency band - Passive RFID and Active RFID.

 

Passive UHF RFID

 

Passive UHF RFID tags are powered by UHF RFID reader that emits an electromagnetic field. Passive UHF tags can be detected from an average distance of about 5 - 6 meters, but larger UHF tags can achieve more than 25 meters under ideal conditions. Passive UHF is typically used in applications such as race timing, warehouse management, supply chain tracking, asset tracking, etc.

 

Active UHF RFID

 

Active UHF RFID tags are powered by an internal battery to continuously broadcast their own signals via BLE (Bluetooth Low Energy) or WiFi. There are three main frequencies used by active systems - 433 MHz, 915MHz and 2.45 GHz.

 

In the RFID system which uses an active beacon tag, the tag will send out its specific information every 3-5 seconds, and their signal is readable up to several hundreds meters away.

 

Active UHF RFID is very common in the oil and gas industry, vehicle tracking and electronic tolling.

Read more about Passive tag and Active tag

 

Read more about UHF 915MHz RFID Reader