The Fourier series of a periodic signal f(t) is given by
f(t) =Equation 1.1
For a square wave this reduces to
f(t) =Equation 1.2
(For the purpose of this discussion we assume a 50% duty cycle with rise and a fall times tending to “0”.)
As can be seen, this is a series of sinusoids of the odd harmonics of the fundamental frequency ω0 and can be depicted in the frequency domain as shown above in Figure 1.
These energy peaks are the elements that compliance engineers battle.