83.1 Discrete-Time Fourier Transform X(eo) is called the magnitude function e(o)is called the phase function Both quantities are again real functions In many applications, the dtft is called the fourier spectrum Likewise, X(ejo)l and e(@) are called the magnitude and phase spectra§3.1 Discrete-Time Fourier Transform • | X(ej) | is called the magnitude function • () is called the phase function • Both quantities are again real functions of  • In many applications, the DTFT is called the Fourier spectrum • Likewise, | X(ej) | and () are called the magnitude and phase spectra