taajuussignaalin

Taajuussignaali refers to a signal whose information is encoded in its frequency. Unlike amplitude modulation where the strength of the signal is varied, or phase modulation where the timing is shifted, frequency modulation (FM) alters the signal's frequency. The instantaneous frequency of the carrier wave deviates from its center frequency in proportion to the instantaneous amplitude of the modulating signal. This means that a higher amplitude in the message signal will cause a greater shift in the carrier frequency, and a lower amplitude will cause a smaller shift.

Frequency modulation is widely used in various applications, most notably in radio broadcasting (FM radio). Its robustness against noise and interference makes it superior to amplitude modulation in many scenarios. When a noisy signal is received, the amplitude variations caused by noise are largely ignored by the FM receiver, as it primarily focuses on the frequency changes. This results in a clearer audio output compared to AM radio, especially in areas with significant electrical interference.

Beyond radio, frequency modulation finds applications in telecommunications, such as in mobile phone systems and satellite communications, as well as in musical instrument synthesizers and certain types of data transmission. The fundamental principle remains the same: information is conveyed by systematically changing the frequency of a carrier wave. The rate of these frequency changes corresponds to the frequency of the message signal, while the extent of the frequency deviation corresponds to the amplitude of the message signal.