Unfortunately it's also a spectacularly perishable food, and just a day or two in your refrigerator -- or an unplanned stop on your way home from the store -- can spoil your meal. You can often detect bad fish easily by smell or touch, but that's not always the case.nfortunately it's also a spectacularly perishable food, and just a day or two in your refrigerator -- or an unplanned stop on your way home from the store -- can spoil your meal. You can often detect bad fish easily by smell or touch, but that's not always the case.
In analog frequency modulation, such as FM radio broadcasting of an audio signal representing voice or music, the instantaneous frequency deviation, the difference between the frequency of the carrier and its center frequency, is proportional to the modulating signal.
Frequency is the rate of recurrence of a cyclic or periodic event. In physics, you can observe periodicity in rotations, oscillations, and waves. For an analog or digital waveform, you can invert the signal period to obtain the frequency.The smaller the period, the higher the frequency and vice versa.This is illustrated in Figure 1, with the top waveform having the lowest frequency and the bottom waveform having the highest frequency.or an analog or digital waveform, you can invert the signal period to obtain the frequency. The smaller the period, the higher the frequency and vice versa. This is illustrated in Figure 1, with the top waveform having the lowest frequency and the bottom waveform having the highest frequency.