Frequency modulation

Carrier frequency is defined as the frequency of a carrier wave, measured in cycles per second, or Hertz, that is modulated to transmit signals .

The satellites continuously broadcast electromagnetic signals in the L-band, which is used for radio communication. The relationship between the wavelength (λ), the speed of light (c), and the frequency (f) is λ = c/f .

For the transmission of audio signals at distant places , the high frequency carrier waves are used, because these frequency carrier waves travel through space or medium with the speed of light and they are not obstructed by earth’s atmosphere.

Frequency Modulation, FM. When the audio signal is modulated onto the radio frequency carrier , the new radio frequency signal moves up and down in frequency. The amount by which the signal moves up and down is important. It is known as the deviation and is normally quoted as the number of kilohertz deviation.