A rectangular pulse and a rectangular pulse with first pulse differentiated and the spectrum is the spectrums of pulse multiplied by the angular frequency.

• 一方波及一方波，其前一脉波之微分。验证其频谱为原本频谱乘以频域之角频率，但微分定理对于不连续脉波只有低频部份有较精准之近似。