FM SpectraMay get negative frequency components:amplitudefrequencythese fold up with change of sign?amplitudefrequency
FM Spectra • May get negative frequency components: • these fold up with change of sign:
FM SpectraWith larger modulation index (1), we get moresidebands with larger amplitudes (i.e.,spectrum gets brighter)May get negative amplitude partials:fromnegativeBessel valuesJ,(I)fromoddleftsidebands＊ （-1)iJ-i(I)= J; (I)0.750.500.25-0.250.500.75-1.007891011121314151617131920124hanonic numte
FM Spectra • With larger modulation index (I), we get more sidebands with larger amplitudes (i.e., spectrum gets brighter). • May get negative amplitude partials: • from negative Bessel values Jn(I) • from odd left sidebands J-i(I) = Ji(I) * (-1)i