Jump to content
Main menu
Main menu
move to sidebar
hide
Navigation
Main Page
Help
Browse
Cookbook
Wikijunior
Featured books
Recent changes
Random book
Using Wikibooks
Community
Reading room forum
Community portal
Bulletin Board
Help out!
Policies and guidelines
Contact us
Search
Search
Appearance
Donations
Create account
Log in
Personal tools
Donations
Create account
Log in
Pages for logged out editors
learn more
Contributions
Discussion for this IP address
Contents
move to sidebar
hide
Beginning
1
Fourier Transform
2
Inverse Fourier Transform
3
Table of Fourier Transforms
Toggle the table of contents
Engineering Handbook/Mathematics/Fourier Transformation
Add languages
Add links
Book
Discussion
English
Read
Edit
Edit source
View history
Tools
Tools
move to sidebar
hide
Actions
Read
Edit
Edit source
View history
General
What links here
Related changes
Upload file
Special pages
Permanent link
Page information
Cite this page
Get shortened URL
Download QR code
Sister projects
Wikipedia
Wikiversity
Wiktionary
Wikiquote
Wikisource
Wikinews
Wikivoyage
Commons
Wikidata
MediaWiki
Meta-Wiki
Print/export
Create a collection
Download as PDF
Printable version
In other projects
Appearance
move to sidebar
hide
From Wikibooks, open books for an open world
<
Engineering Handbook
|
Mathematics
Fourier Transform
[
edit
|
edit source
]
F
(
j
ω
)
=
F
{
f
(
t
)
}
=
∫
−
∞
∞
f
(
t
)
e
−
j
ω
t
d
t
{\displaystyle F(j\omega )={\mathcal {F}}\left\{f(t)\right\}=\int _{-\infty }^{\infty }f(t)e^{-j\omega t}dt}
Inverse Fourier Transform
[
edit
|
edit source
]
F
−
1
{
F
(
j
ω
)
}
=
f
(
t
)
=
1
2
π
∫
−
∞
∞
F
(
j
ω
)
e
j
ω
t
d
ω
{\displaystyle {\mathcal {F}}^{-1}\left\{F(j\omega )\right\}=f(t)={\frac {1}{2\pi }}\int _{-\infty }^{\infty }F(j\omega )e^{j\omega t}d\omega }
Table of Fourier Transforms
[
edit
|
edit source
]
This table contains some of the most commonly encountered Fourier transforms.
Time Domain
Frequency Domain
x
(
t
)
=
F
−
1
{
X
(
ω
)
}
{\displaystyle x(t)={\mathcal {F}}^{-1}\left\{X(\omega )\right\}}
X
(
ω
)
=
F
{
x
(
t
)
}
{\displaystyle X(\omega )={\mathcal {F}}\left\{x(t)\right\}}
1
X
(
j
ω
)
=
∫
−
∞
∞
x
(
t
)
e
−
j
ω
t
d
t
{\displaystyle X(j\omega )=\int _{-\infty }^{\infty }x(t)e^{-j\omega t}dt}
x
(
t
)
=
1
2
π
∫
−
∞
∞
X
(
ω
)
e
j
ω
t
d
ω
{\displaystyle x(t)={\frac {1}{2\pi }}\int _{-\infty }^{\infty }X(\omega )e^{j\omega t}d\omega }
2
1
{\displaystyle 1\,}
2
π
δ
(
ω
)
{\displaystyle 2\pi \delta (\omega )\,}
3
−
0.5
+
u
(
t
)
{\displaystyle -0.5+u(t)\,}
1
j
ω
{\displaystyle {\frac {1}{j\omega }}\,}
4
δ
(
t
)
{\displaystyle \delta (t)\,}
1
{\displaystyle 1\,}
5
δ
(
t
−
c
)
{\displaystyle \delta (t-c)\,}
e
−
j
ω
c
{\displaystyle e^{-j\omega c}\,}
6
u
(
t
)
{\displaystyle u(t)\,}
π
δ
(
ω
)
+
1
j
ω
{\displaystyle \pi \delta (\omega )+{\frac {1}{j\omega }}\,}
7
e
−
b
t
u
(
t
)
(
b
>
0
)
{\displaystyle e^{-bt}u(t)\,(b>0)}
1
j
ω
+
b
{\displaystyle {\frac {1}{j\omega +b}}\,}
8
cos
ω
0
t
{\displaystyle \cos \omega _{0}t\,}
π
[
δ
(
ω
+
ω
0
)
+
δ
(
ω
−
ω
0
)
]
{\displaystyle \pi \left[\delta (\omega +\omega _{0})+\delta (\omega -\omega _{0})\right]\,}
9
cos
(
ω
0
t
+
θ
)
{\displaystyle \cos(\omega _{0}t+\theta )\,}
π
[
e
−
j
θ
δ
(
ω
+
ω
0
)
+
e
j
θ
δ
(
ω
−
ω
0
)
]
{\displaystyle \pi \left[e^{-j\theta }\delta (\omega +\omega _{0})+e^{j\theta }\delta (\omega -\omega _{0})\right]\,}
10
sin
ω
0
t
{\displaystyle \sin \omega _{0}t\,}
j
π
[
δ
(
ω
+
ω
0
)
−
δ
(
ω
−
ω
0
)
]
{\displaystyle j\pi \left[\delta (\omega +\omega _{0})-\delta (\omega -\omega _{0})\right]\,}
11
sin
(
ω
0
t
+
θ
)
{\displaystyle \sin(\omega _{0}t+\theta )\,}
j
π
[
e
−
j
θ
δ
(
ω
+
ω
0
)
−
e
j
θ
δ
(
ω
−
ω
0
)
]
{\displaystyle j\pi \left[e^{-j\theta }\delta (\omega +\omega _{0})-e^{j\theta }\delta (\omega -\omega _{0})\right]\,}
12
rect
(
t
τ
)
{\displaystyle {\mbox{rect}}\left({\frac {t}{\tau }}\right)\,}
τ
sinc
(
τ
ω
2
π
)
{\displaystyle \tau {\mbox{sinc}}\left({\frac {\tau \omega }{2\pi }}\right)\,}
13
τ
sinc
(
τ
t
2
π
)
{\displaystyle \tau {\mbox{sinc}}\left({\frac {\tau t}{2\pi }}\right)\,}
2
π
rect
(
ω
τ
)
{\displaystyle 2\pi {\mbox{rect}}\left({\frac {\omega }{\tau }}\right)\,}
14
(
1
−
2
|
t
|
τ
)
rect
(
t
τ
)
{\displaystyle \left(1-{\frac {2|t|}{\tau }}\right){\mbox{rect}}\left({\frac {t}{\tau }}\right)\,}
τ
2
sinc
2
(
τ
ω
4
π
)
{\displaystyle {\frac {\tau }{2}}{\mbox{sinc}}^{2}\left({\frac {\tau \omega }{4\pi }}\right)\,}
15
τ
2
sinc
2
(
τ
t
4
π
)
{\displaystyle {\frac {\tau }{2}}{\mbox{sinc}}^{2}\left({\frac {\tau t}{4\pi }}\right)\,}
2
π
(
1
−
2
|
ω
|
τ
)
rect
(
ω
τ
)
{\displaystyle 2\pi \left(1-{\frac {2|\omega |}{\tau }}\right){\mbox{rect}}\left({\frac {\omega }{\tau }}\right)\,}
16
e
−
a
|
t
|
,
ℜ
{
a
}
>
0
{\displaystyle e^{-a|t|},\Re \{a\}>0\,}
2
a
a
2
+
ω
2
{\displaystyle {\frac {2a}{a^{2}+\omega ^{2}}}\,}
Notes:
sinc
(
x
)
=
sin
(
π
x
)
/
(
π
x
)
{\displaystyle {\mbox{sinc}}(x)=\sin(\pi x)/(\pi x)}
rect
(
t
τ
)
{\displaystyle {\mbox{rect}}\left({\frac {t}{\tau }}\right)}
is the rectangular pulse function of width
τ
{\displaystyle \tau }
u
(
t
)
{\displaystyle u(t)}
is the Heaviside step function
δ
(
t
)
{\displaystyle \delta (t)}
is the Dirac delta function
This box:
view
•
talk
•
edit
Category
:
Book:Engineering Handbook