Why Frequency Domain ? Ans: Fourier Analysis
Can write any periodic function g(t) with period T as:
- g(t) = 1/2 c + ? an sin (2?nft) + ? bn cos (2?nft)
- f = 1/T is the fundamental frequency
- an and bn amplitudes can be computed from g(t) by integration
You find the component frequencies of sinusoids that it consists of…
- The range of frequencies used = “frequency spectrum”
- Digital (DC, or baseband) signals require a large spectrum
- Techniques like amplitude, frequency or phase modulation use a sinusoidal carrier and a smaller spectrum
- The width of the spectrum (band) available: “bandwidth”