Low frequency
Low frequency
Low frequency refers to electromagnetic radiation or electronic signals with a frequency below 30 kilohertz, characterized by long wavelengths and weaker propagation properties compared to higher frequencies. It is typically used in applications such as radio navigation, induction heating, and medical imaging.
What does Low frequency mean?
Low frequency (LF) refers to electromagnetic radiation or sound waves with frequencies ranging from 30 Hz to 300 kHz. In the electromagnetic Spectrum, LF occupies the band between the medium frequency (MF) and very low frequency (VLF) ranges, While in acoustics, LF covers the bass and sub-bass frequency bands.
ELF waves (Extra Low Frequency) are lower frequencies than LF, ranging from 3 Hz to 30 Hz. VLF waves (Very Low Frequency) are higher frequencies than LF, ranging from 3 kHz to 30 kHz.
LF waves propagate relatively long distances, allowing them to penetrate materials and travel around obstacles. They are used in various applications, including communication, navigation, and scientific research.
Applications
Communication: LF waves are used in long-range communication systems because they can penetrate obstacles and travel over long distances. They are used in maritime and aviation navigation, military communication, and emergency broadcasting.
Navigation: LF waves are used in navigation systems to provide precise location information. The Global Navigation Satellite System (GNSS) uses LF signals to determine position and time, as do various other navigation systems.
Scientific Research: LF waves are used in various scientific research applications. For example, geophysicists use LF waves to study the Earth’s structure, while biologists use them to examine the effects of electromagnetic fields on living organisms.
History
The use of LF waves dates back to the early days of radio communication. In the 19th century, researchers began experimenting with using LF waves for long-distance communication. In 1899, Guglielmo Marconi used LF waves to send a Wireless signal across the Atlantic Ocean.
During the 20th century, LF waves were used in a wide range of communication systems, including long-range radio broadcasting, maritime navigation, and military communication. Today, LF waves are still used in various applications, but they have largely been replaced by higher-frequency technologies for communication purposes.