In bipolar modulation, with a carrier symmetric about zero and of amplitude Cm, how does the normalised PWM output behave?
Correct answer B. Switches between −1/2 and +1/2
Explanation
In bipolar modulation the output never rests at zero; it swings between equal positive and negative levels, which for a half-bridge normalised to the DC bus are −1/2 and +1/2.
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