5-20
Figure 5-19.—Distribution of sidebands.
Figure 5-20.—Spectrum distribution for a modulation index of 2.
NEETS, module 12, should be consulted for an in-depth discussion of frequency-modulation
principles.
Q-6.
What happens to an fm signal as you increase the frequency of the modulating signal?
PULSED WAVES
An ideal pulsed radar signal is made up of a train of rf pulses with a constant repetition rate, constant
pulse width and shape, and constant amplitude. To receive the energy reflected from a target, the radar
receiver requires almost ideal pulse radar emission characteristics. By observing the spectra of a pulsed
radar signal, you can easily and accurately measure such characteristics as pulse width, duty cycle, and
