Basic mathematics Notice the 4rft term this is twice the frequency of the original signal and by averaging the product over a period long compared to 1/f, this will average to zero The remaining terms are the cosine and sine of the phase This is an example of the " modulation theorem"of fourier transforms 02/25/02 12.540Lec0602/25/02 12.540 Lec 06 16 Basic mathematics • Notice the 4 πft term: this is twice the frequency of the original signal and by averaging the product over a period long compared to 1/f, this will average to zero • The remaining terms are the cosine and sine of the phase • This is an example of the “modulation theorem” of Fourier transforms