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| Frequency Modulation |
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| In frequency modulation, the frequency of the carrier wave is modified in accordance with the amplitude of the modulating wave. |
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| The amplitude of the carrier remains unchanged at all times. In other words, the amplitude of the modulated wave remains the same as the amplitude of the carrier wave. The frequency of the carrier is made to fluctuate symmetrically above and below its unmodulated frequency. As an example, a carrier frequency, of 1000kHz may be caused to swing between 925kHz and 1075kHz or any other amount chosen in accordance with the signal voltage. |
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| In frequency modulation, the deviation of the carrier frequency from its average value is proportional to the instantaneous amplitude of the modulating signals. When the signal voltage is zero, the carrier frequency is unchanged. When the signal approaches its positive peaks, the carrier frequency is increased to maximum as indicated by the closely spaced cycles. However, during the negative peaks of signals, the carrier frequency is reduced to minimum as shown by widely spaced cycles. |
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