傅立叶变换是信号与系统分析中的基本时间—频率变换工具,本文从傅立叶变换的定义出发,对实、复时间信号的傅立叶变换及其幅频特性函数和相频特性函数的奇偶虚实性做详细的推导与论述,其结果不仅有助于我们进一步理解信号的时域与频域之间的联系,而且在信号分析中得到广泛应用。 Fourier transform is the basic time-frequency transform tool in signal and system analysis. In this paper, the definition of Fourier transform is used to detail the Fourier transform of real and complex time signals, and the odd-even realities of the amplitude-frequency and phase-frequency characteristic functions The results not only help us to further understand the relationship between the signal time-domain and frequency-domain, but also widely used in signal analysis.