They are 3 types of RFID Frequencies and Frequency refers to the size of the radio waves used to communicate between system components. RFID systems throughout the world operate in low frequency (LF), high frequency (HF), and ultra-high frequency (UHF) bands.
HOW RFID FREQUENCY WORK?
LF, HF, and UHF
Similar to how a radio must be tuned to different frequencies to hear different channels, RFID tags and readers have to be tuned to the same frequency in order to communicate.
There are several different
Low frequency, or LF, (125 – 134 kHz)
High frequency, or HF, (13.56 MHz)
Ultra-high frequency, or UHF, (433, and 860-960 MHz)
FREQUENCY OF OPERATION
125KHZ OR 134KHZ
RANGE: UP TO 10CM
RANGE: UP TO 1M
(ULTRA HIGH FREQUENCY)
860MHZ - 960MHZ
RANGE: 10M TO 15M
RFID IN THE ELECTROMAGNET SPECTRUM
* Less absorption by moisture
* Better omni directional capability
* Less Impact from the presence of metal
* Shorter signal range and slower reading
* Longer reading range
* Higher speed
More interference from metal
OTHER: ULTRASONIC, INFRARED
LF: LOW FREQUENCY
DF: DUAL FREQUENCY
HF: HIGH FREQUENCY
UHF: ULTRA HIGH FREQUENCY
RTLS: REAL TIME LOCATING SYSTEM
UWB: ULTRA WIDE BAND
Radio waves behave differently at the various frequencies,
so it is imperative to select the right frequency for your application
Low-frequency tags have a long wave-length and are better able to penetrate thin metallic substances.
Additionally, LF RFID systems are ideal for reading objects with high-water content, such as fruit or beverages, but the read range is limited to centimeter or inches. Typical LF RFID applications include access control and animal tagging.
High-frequency tags work fairly well on objects made of metal and can work around goods with medium to high water content. Typically, HF RFID systems work in ranges of inches, but they can have a maximum read range of about three feet (1 meter). Typical HF RFID applications include tracking library books, patient flow tracking, and transit tickets.
UHF frequencies typically offer much better read range (inches to 50+ ft. depending on the RFID system setup) and can transfer data faster (i.e. read many more tags per second) than low- and high-frequencies. However, because UHF radio waves have a shorter wavelength, their signal is more likely to be attenuated (or weakened) and they cannot pass through metal or water. Due to their high data transfer rate, UHF RFID tags are well suited for many items at once, such as boxes of goods as they pass through a dock door into a warehouse or racers as they cross a finish line. Also, due to the longer read range, other common UHF RFID applications include electronic toll collection and parking access control.