High frequency electromagnetic fields

High frequency electromagnetic fields are used for speech and data transmission in mobile communication. Normally these fields are radiated by an antenna. In free space they propagate with the speed of light and thereby transmit energy and information on large distances.

High frequency fields cover the frequency range from 100 kHz to 300 GHz of the electromagnetic spectrum. The unit for the physical quantity frequency is called hertz (Hz), 1 Hz is equivalent to one oscillation per second. Frequency and wavelength of electromagnetic fields are linked by the speed of the travelling wave. The higher the frequency is, the shorter is the wavelength and vice versa. Far away from a radiating antenna the two components of the electromagnetic fields, the electric field and the magnetic field, are closely connected through the wave impedance of free space.