HFBereich

HFBereich, short for Hochfrequenzbereich, refers to the high-frequency portion of the electromagnetic spectrum used in radio communications and electronic systems. In many engineering and technical contexts, HF generally covers frequencies from about 3 MHz to 30 MHz, lying above the medium frequency band and below the very high frequency range. Some regulatory sources may define the boundaries slightly differently, but 3–30 MHz is the widely cited range.

Propagation in the HF range is strongly influenced by ionospheric conditions. HF signals can be reflected by the ionosphere, enabling long-distance, over-the-horizon communication without satellite relays. This skywave propagation makes HF suitable for international broadcasting, amateur radio, maritime and military communications, especially at night or during periods of favorable solar activity.

Equipment and measurement for the HF range require appropriate antennas (such as dipoles, long-wire or loop configurations) and impedance matching networks. Transceivers, receivers, and transmitters operate with filters and modulation schemes adapted to HF bands. Test and measurement gear includes spectrum analyzers, network analyzers, and power meters to characterize performance and emissions.

Applications and regulation: The HF range hosts shortwave broadcasting, amateur radio, and various government and emergency services communications. Radio allocations are governed by international bodies such as the ITU and national regulators, with licensing and restrictions varying by country. Safety considerations include exposure limits for RF energy, as well as electrical safety when operating high-power equipment.