Høyfrekvens

Høyfrekvens refers to a range of electromagnetic waves with frequencies higher than those typically associated with audible sound and lower than infrared radiation. This frequency spectrum falls within the radio wave portion of the electromagnetic spectrum, specifically between approximately 3 megahertz (MHz) and 30 MHz.

The properties of high-frequency waves allow them to travel long distances. They can bounce off the ionosphere, a layer of charged particles in Earth's upper atmosphere, enabling global communication. This phenomenon, known as skywave propagation, is crucial for shortwave radio broadcasting.

Historically, high-frequency radio played a vital role in international communication, maritime and aeronautical navigation, and military communications before the advent of satellite technology. While its prominence has diminished in some areas, it remains important for specific applications. These include amateur radio (ham radio), emergency communications where infrastructure may be damaged, and certain military and government operations.

The allocation and use of high-frequency bands are regulated internationally by organizations like the International Telecommunication Union (ITU) to prevent interference between different services and users. Different frequency sub-bands within the high-frequency range are designated for specific purposes, such as broadcasting, mobile communications, and scientific research.