英语翻译1.简谐信号是最简单和最重要的周期信号.任意一个周期信号可以用简谐信号来表达,两者之间联系的桥梁是傅里叶级数,所以傅里叶级数是周期信号分析的理论基础.2.一个在时域上显得很复杂的信号,将其变换或映射到频域（包括s和z域）,就能够分解为非常简单的基本信号形式,进行分析和求解.3.频谱是由不连续的谱线组成,每条谱线代表一个谐波分量.这种频谱称为离散频谱.谱线之间的间隔等于基波频率w的整数倍.即频谱中的每一条谱线只能出现在基波频率w的整数倍上,各谐波的频率nw都是基波频率的整数倍.

1.Simple harmonics signal is simplest and the most important cyclicalsignal.Wilfully a cyclical signal may use simple harmonics signal toexpress,two between relates the bridge is the fourier's series,therefore the fourier's series is the cycle signal analysingrationale.
2.Appears the very complex signal in the time domain,or maps itstransformation the frequency range (including s and the z territory),can decompose into the extremely simple elementary signal form,carries on the analysis and the solution
3.The frequency spectrum is composed by not the continual spectral line,each spectral line represents a harmonic component.This kind offrequency spectrum is called the separate frequency spectrum.Betweenthe spectral line gap is equal to base frequency w the integralmultiple.Namely in the frequency spectrum each spectral line only canappear in the base frequency w integral multiple,various overtonesfrequency nw all is the base frequency integral multiple.