frekvenciaváltozás

Frekvenciaváltozás, also known as frequency modulation (FM) in English, is a method of encoding information in a carrier wave by varying its frequency. The information signal, or message, is used to modulate the frequency of a carrier wave. The amplitude of the carrier wave remains constant. The rate at which the frequency changes is proportional to the frequency of the message signal, and the extent of the frequency change is proportional to the amplitude of the message signal.

This technique is widely used in radio broadcasting, particularly for FM radio stations, which transmit audio signals. FM offers several advantages over amplitude modulation (AM), including greater immunity to noise and interference. This is because most natural and man-made noise sources tend to affect the amplitude of a radio wave, not its frequency. Therefore, FM receivers can more effectively filter out unwanted noise.

Beyond broadcasting, frequency modulation finds applications in various fields. It is used in telecommunications, such as in some mobile phone systems and cordless phones. In scientific instruments, FM is employed for techniques like frequency-modulated spectroscopy. In audio synthesis, FM synthesis is a powerful method for generating complex and dynamic sounds. The fundamental principle remains the same: using a changing frequency to carry information.