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− | Table of Z Transform Pairs and Properties | + | Table of (double-sided) Z Transform Pairs and Properties |
click [[Collective_Table_of_Formulas|here]] for [[Collective_Table_of_Formulas|more formulas]] | click [[Collective_Table_of_Formulas|here]] for [[Collective_Table_of_Formulas|more formulas]] | ||
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− | + | ! style="background: none repeat scroll 0% 0% rgb(238, 238, 238);" colspan="3" | (double-sided) Z Transform and its Inverse | |
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− | ! style="background: none repeat scroll 0% 0% rgb(238, 238, 238);" colspan="3" | | + | |
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| align="right" style="padding-right: 1em;" | (Double-side) Z Transform | | align="right" style="padding-right: 1em;" | (Double-side) Z Transform | ||
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! style="background: none repeat scroll 0% 0% rgb(238, 238, 238);" colspan="6" | Z Transform Properties | ! style="background: none repeat scroll 0% 0% rgb(238, 238, 238);" colspan="6" | Z Transform Properties | ||
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+ | ! colspan="6" | Below <math>x[n]</math>, <math>x_1[n]</math> and <math>x_2[n]</math> are DT signals with z-transforms <math>X(z)</math>, <math>X_1(Z)</math> and <math>x_2[n]</math> | ||
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| align="right" style="padding-right: 1em;" | | | align="right" style="padding-right: 1em;" | |
Revision as of 16:22, 3 March 2015
Table of (double-sided) Z Transform Pairs and Properties
click here for more formulas
(double-sided) Z Transform and its Inverse | |||||
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(Double-side) Z Transform | $ X(z)=\mathcal{L}(x[n])=\sum_{n=-\infty}^{\infty}x[n]z^{-n} $ | (info) | |||
Inverse Z Transform | $ x[n]=\mathcal{L}^{-1}(X(z))=\frac{1}{2\pi j}\oint_{c}X(z)z^{n-1}dz $ | (info) |
Z Transform Pairs | |||||
---|---|---|---|---|---|
Signal $ x[n] $ | Transform $ X(z) $ | ROC | |||
Unit impulse signal | $ \delta[n]\ $ | $ 1\ $ | $ All\ z\ $ | ||
Unit step signal | $ u[n]\ $ | $ \frac{1}{1-z^{-1}} $ | $ |z| > 1\ $ | ||
$ -u[-n-1]\ $ | $ \frac{1}{1-z^{-1}} $ | $ |z| < 1\ $ | |||
Shifted unit impulse signal | $ \delta[n-m]\ $ | $ z^{-m}\ $ | $ All\ z,\ except\ $ | ||
$ 0\ (if\ m>0)\ or\ $ | |||||
$ \infty \ (if\ m<0)\ $ | |||||
$ \alpha^{n}u[n]\ $ | $ \frac{1}{1-\alpha z^{-1}} $ | $ |z| > | \alpha |\ $ | |||
$ -\alpha^{n}u[-n-1]\ $ | $ \frac{1}{1-\alpha z^{-1}} $ | $ |z| < | \alpha |\ $ | |||
$ n\alpha^{n}u[n]\ $ | $ \frac{\alpha z^{-1}}{(1-\alpha z^{-1})^{2}} $ | $ |z| > | \alpha |\ $ | |||
$ -n\alpha^{n}u[-n-1]\ $ | $ \frac{\alpha z^{-1}}{(1-\alpha z^{-1})^{2}} $ | $ |z| < | \alpha |\ $ | |||
Single-side cosine signal | $ [\cos{\omega_{0}n}]u[n]\ $ | $ \frac{1-[\cos{\omega_{0}}]z^{-1}}{1-[2\cos{\omega_{0}}]z^{-1}+z^{-2}} $ | $ |z| > 1\ $ | ||
Single-side sine signal | $ [\sin{\omega_{0}n}]u[n]\ $ | $ \frac{1-[\sin{\omega_{0}}]z^{-1}}{1-[2\cos{\omega_{0}}]z^{-1}+z^{-2}} $ | $ |z| > 1\ $ | ||
$ [r^{n}\cos{\omega_{0}n}]u[n]\ $ | $ \frac{1-[r\cos{\omega_{0}}]z^{-1}}{1-[2r\cos{\omega_{0}}]z^{-1}+r^{2}z^{-2}} $ | $ |z| > r\ $ | |||
$ [r^{n}\sin{\omega_{0}n}]u[n]\ $ | $ \frac{1-[r\sin{\omega_{0}}]z^{-1}}{1-[2r\cos{\omega_{0}}]z^{-1}+r^{2}z^{-2}} $ | $ |z| > r\ $ |
Z Transform Properties | |||||
---|---|---|---|---|---|
Below $ x[n] $, $ x_1[n] $ and $ x_2[n] $ are DT signals with z-transforms $ X(z) $, $ X_1(Z) $ and $ x_2[n] $ | |||||
Signal $ x[n] $ | Transform $ X(f) $ | ROC | |||
$ x[n]\ $ | $ X(z)\ $ | $ R\ $ | |||
$ x_{1}[n]\ $ | $ X_{1}(z)\ $ | $ R_{1}\ $ | |||
$ x_{2}[n]\ $ | $ X_{2}(z)\ $ | $ R_{2}\ $ | |||
Linearity | $ ax_{1}[n]+bx_{2}[n]\ $ | $ aX_{1}(z)+bX_{2}[z]\ $ | $ At\ least\ the\ intersection\ of\ R_{1}\ and\ R_{2}\ $ | ||
Time shifting | $ x[n-n_{0}]\ $ | $ z^{-n_{0}}X(z)\ $ | $ R,\ except\ for\ the\ possible\ addition\ $ | ||
$ or\ deletion\ of\ the\ origin\ $ | |||||
Scaling in the z-domain | $ e^{j\omega_{0}n}x[n]\ $ | $ X(e^{j\omega_{0}}z)\ $ | $ R\ $ | ||
$ z_{0}^{n}x[n]\ $ | $ X(\frac{z}{z_{0}})\ $ | $ z_{0}R\ $ | |||
$ a^{n}x[n]\ $ | $ X(a^{-1}z)\ $ | $ Scaled\ version\ of\ R\ $ | |||
$ (i.e.,\ |a|R=\ the\ set\ of\ points\ {|a|z}\ for\ z\ in\ R)\ $ | |||||
Time reversal | $ x[-n]\ $ | $ X(z^{-1})\ $ | $ R^{1/k}\ (i.e.,\ the\ set\ of\ points\ z^{1/k},\ $ | ||
$ where\ z\ is\ in\ R)\ $ | |||||
Time expansion | $ x^{(k)}= \begin{cases} x[r], &n=rk \\ 0, &n\neq rk \end{cases} $ | $ X(z^{k})\ $ | $ R^{1/k}\ (i.e.,\ the\ set\ of\ points\ z^{1/k},\ $ | ||
$ where\ z\ is\ in\ R)\ $ | |||||
Conjugation | $ x^{*}[n]\ $ | $ X^{*}(z^{*})\ $ | $ R\ $ | ||
Convolution | $ x_{1}[n]*x_{2}[n]\ $ | $ X_{1}(z)X_{2}(z)\ $ | $ At\ least\ the\ intersection\ of\ R_{1}\ and\ R_{2}\ $ | ||
First difference | $ x[n]-x[n-1]\ $ | $ (1-z^(-1))X(z)\ $ | $ At\ least\ the\ intersection\ of\ R\ and\ |z|>0\ $ | ||
Accumulation | $ \sum_{k=-\infty}^{n}x[k]\ $ | $ \frac{1}{(1-z^(-1))}X(z)\ $ | $ At\ least\ the\ intersection\ of\ R\ and\ |z|>1\ $ | ||
Differentiation in the z-domain | $ nx[n]\ $ | $ -z\frac{dX(z)}{dz}\ $ | $ R\ $ |
Other Z Transform Properties | |
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Initial Value Theorem | $ If\ x[n]=0\ for\ n<0,\ then\ x[0]=\lim_{z\rightarrow \infty}X(z)\ $ |
Go to Relevant Course Page: ECE 438