周期矩形脉冲信号傅立叶级数分析，体现脉冲宽度不变，周期变化时的频域特点-periodic rectangle pulse signal FS analysis, presents its frequency domain characteristics when pulse width does not change, while the circle changes.

矩形周期脉冲信号FS分析，体现周期不变脉冲宽度改变时的频域特点-periodic rectangle pulse FS analysys. this time the circle does not change, while the pulse width changes.