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信号与系统

说明

先开个坑()

常用表格

Laplace变换表

时域信号 \(f(t)\) 拉普拉斯变换 \(F(s)\) 收敛域 (ROC)
\(\delta(t)\) \(1\) 全平面
\(u(t)\) \(\frac{1}{s}\) \(\Re(s) > 0\)
\(e^{-at}u(t)\) \(\frac{1}{s+a}\) \(\Re(s) > -a\)
\(t \cdot u(t)\) \(\frac{1}{s^2}\) \(\Re(s) > 0\)
\(\frac{t^n}{n!} u(t)\) \(\frac{1}{s^{n+1}}\) \(\Re(s) > 0\)
\(\cos(\omega t)u(t)\) \(\frac{s}{s^2 + \omega^2}\) \(\Re(s) > 0\)
\(\sin(\omega t)u(t)\) \(\frac{\omega}{s^2 + \omega^2}\) \(\Re(s) > 0\)
\(e^{-at}\cos(\omega t)u(t)\) \(\frac{s+a}{(s+a)^2 + \omega^2}\) \(\Re(s) > -a\)
\(e^{-at}\sin(\omega t)u(t)\) \(\frac{\omega}{(s+a)^2 + \omega^2}\) \(\Re(s) > -a\)

Z变换表

时域序列 \(x[n]\) Z 变换 \(X(z)\) 收敛域 (ROC)
\(\delta[n]\) \(1\) 全平面
\(u[n]\) \(\frac{1}{1 - z^{-1}}\) \(\|z\| > 1\)
\(a^n u[n]\) \(\frac{1}{1 - a z^{-1}}\) \(\|z\| > \|a\|\)
\(n u[n]\) \(\frac{z^{-1}}{(1 - z^{-1})^2}\) \(\|z\| > 1\)
\(n a^n u[n]\) \(\frac{a z^{-1}}{(1 - a z^{-1})^2}\) \(\|z\| > \|a\|\)
\(\cos(\omega n)u[n]\) \(\frac{1 - \cos\omega \, z^{-1}}{1 - 2\cos\omega \, z^{-1} + z^{-2}}\) \(\|z\| > 1\)
\(\sin(\omega n)u[n]\) \(\frac{\sin\omega \, z^{-1}}{1 - 2\cos\omega \, z^{-1} + z^{-2}}\) \(\|z\| > 1\)
\(a^n \cos(\omega n)u[n]\) \(\frac{1 - a\cos\omega \, z^{-1}}{1 - 2a\cos\omega \, z^{-1} + a^2 z^{-2}}\) \(\|z\| > \|a\|\)
\(a^n \sin(\omega n)u[n]\) \(\frac{a\sin\omega \, z^{-1}}{1 - 2a\cos\omega \, z^{-1} + a^2 z^{-2}}\) \(\|z\| > \|a\|\)