بخش دوم. spectrum (or Fourier spectrum) of x( t ). magnitude spectrum of x(t), phase spectrum...
-
Upload
alicia-stevens -
Category
Documents
-
view
243 -
download
0
Transcript of بخش دوم. spectrum (or Fourier spectrum) of x( t ). magnitude spectrum of x(t), phase spectrum...
![Page 1: بخش دوم. spectrum (or Fourier spectrum) of x( t ). magnitude spectrum of x(t), phase spectrum of x(t).](https://reader030.fdocuments.net/reader030/viewer/2022012406/5697bfc71a28abf838ca7e02/html5/thumbnails/1.jpg)
دوم بخش
![Page 2: بخش دوم. spectrum (or Fourier spectrum) of x( t ). magnitude spectrum of x(t), phase spectrum of x(t).](https://reader030.fdocuments.net/reader030/viewer/2022012406/5697bfc71a28abf838ca7e02/html5/thumbnails/2.jpg)
spectrum (or Fourier spectrum) of x( t ).magnitude spectrum of x(t),
phase spectrum of x(t).
![Page 3: بخش دوم. spectrum (or Fourier spectrum) of x( t ). magnitude spectrum of x(t), phase spectrum of x(t).](https://reader030.fdocuments.net/reader030/viewer/2022012406/5697bfc71a28abf838ca7e02/html5/thumbnails/3.jpg)
![Page 4: بخش دوم. spectrum (or Fourier spectrum) of x( t ). magnitude spectrum of x(t), phase spectrum of x(t).](https://reader030.fdocuments.net/reader030/viewer/2022012406/5697bfc71a28abf838ca7e02/html5/thumbnails/4.jpg)
![Page 5: بخش دوم. spectrum (or Fourier spectrum) of x( t ). magnitude spectrum of x(t), phase spectrum of x(t).](https://reader030.fdocuments.net/reader030/viewer/2022012406/5697bfc71a28abf838ca7e02/html5/thumbnails/5.jpg)
THE FREQUENCY RESPONSE OF CONTINUOUS-TIME LTI SYSTEMS
frequency response of the system
Example:
و سیستم ویژه تابع بینیم می هم باز شد گفته هم قبال که H(w0)همانطورآنست ویژه مقدار
![Page 6: بخش دوم. spectrum (or Fourier spectrum) of x( t ). magnitude spectrum of x(t), phase spectrum of x(t).](https://reader030.fdocuments.net/reader030/viewer/2022012406/5697bfc71a28abf838ca7e02/html5/thumbnails/6.jpg)
Example:
Example:
![Page 7: بخش دوم. spectrum (or Fourier spectrum) of x( t ). magnitude spectrum of x(t), phase spectrum of x(t).](https://reader030.fdocuments.net/reader030/viewer/2022012406/5697bfc71a28abf838ca7e02/html5/thumbnails/7.jpg)
Example:
![Page 8: بخش دوم. spectrum (or Fourier spectrum) of x( t ). magnitude spectrum of x(t), phase spectrum of x(t).](https://reader030.fdocuments.net/reader030/viewer/2022012406/5697bfc71a28abf838ca7e02/html5/thumbnails/8.jpg)
Example:
![Page 9: بخش دوم. spectrum (or Fourier spectrum) of x( t ). magnitude spectrum of x(t), phase spectrum of x(t).](https://reader030.fdocuments.net/reader030/viewer/2022012406/5697bfc71a28abf838ca7e02/html5/thumbnails/9.jpg)
![Page 10: بخش دوم. spectrum (or Fourier spectrum) of x( t ). magnitude spectrum of x(t), phase spectrum of x(t).](https://reader030.fdocuments.net/reader030/viewer/2022012406/5697bfc71a28abf838ca7e02/html5/thumbnails/10.jpg)
Fourier Transform Applications
![Page 11: بخش دوم. spectrum (or Fourier spectrum) of x( t ). magnitude spectrum of x(t), phase spectrum of x(t).](https://reader030.fdocuments.net/reader030/viewer/2022012406/5697bfc71a28abf838ca7e02/html5/thumbnails/11.jpg)
FILTERING
Ideal Low-Pass Filter (LPF)
Ideal High-Pass Filter (HPF)
(LPF) (HPF)
![Page 12: بخش دوم. spectrum (or Fourier spectrum) of x( t ). magnitude spectrum of x(t), phase spectrum of x(t).](https://reader030.fdocuments.net/reader030/viewer/2022012406/5697bfc71a28abf838ca7e02/html5/thumbnails/12.jpg)
Ideal Bandpass Filter
(BPF)
(BPF)
Ideal Bandstop Filter
(BSF)
(BSF)
![Page 13: بخش دوم. spectrum (or Fourier spectrum) of x( t ). magnitude spectrum of x(t), phase spectrum of x(t).](https://reader030.fdocuments.net/reader030/viewer/2022012406/5697bfc71a28abf838ca7e02/html5/thumbnails/13.jpg)
Sampling Systems
![Page 14: بخش دوم. spectrum (or Fourier spectrum) of x( t ). magnitude spectrum of x(t), phase spectrum of x(t).](https://reader030.fdocuments.net/reader030/viewer/2022012406/5697bfc71a28abf838ca7e02/html5/thumbnails/14.jpg)
![Page 15: بخش دوم. spectrum (or Fourier spectrum) of x( t ). magnitude spectrum of x(t), phase spectrum of x(t).](https://reader030.fdocuments.net/reader030/viewer/2022012406/5697bfc71a28abf838ca7e02/html5/thumbnails/15.jpg)
The extremely useful sampling theorem, also known as the Nyquist theorem, or the Shannon theorem, gives a sufficient condition to recover a continuous-time signal from its samples
The Sampling Theorem
Ideal lowpass filter usedto recover the continuous-time signalfrom the impulse train sampled signal.
![Page 16: بخش دوم. spectrum (or Fourier spectrum) of x( t ). magnitude spectrum of x(t), phase spectrum of x(t).](https://reader030.fdocuments.net/reader030/viewer/2022012406/5697bfc71a28abf838ca7e02/html5/thumbnails/16.jpg)
Sampling Using a Sample-and-Hold Operator
sample-and-hold (SH)
Simplified sample-and-hold circuit
![Page 17: بخش دوم. spectrum (or Fourier spectrum) of x( t ). magnitude spectrum of x(t), phase spectrum of x(t).](https://reader030.fdocuments.net/reader030/viewer/2022012406/5697bfc71a28abf838ca7e02/html5/thumbnails/17.jpg)
The theoretical representation of a sample-and-hold shown in following Figure consists a) sampling operation (multiplication by an impulse train), b) followed by filtering with a linear time-invariant (LTI) system of impulse response h0(t),
which is a unit pulse of duration equal to the sampling period Ts.
Note that the sample and-hold operator is sometimes called zero-order-hold (ZOH), although here we call zero-order-hold only the LTI system block with impulse response h0(t) in following Figure .
Effect of sample-and-hold operator on an input signal
![Page 18: بخش دوم. spectrum (or Fourier spectrum) of x( t ). magnitude spectrum of x(t), phase spectrum of x(t).](https://reader030.fdocuments.net/reader030/viewer/2022012406/5697bfc71a28abf838ca7e02/html5/thumbnails/18.jpg)
ZOH systemیادآوریضرب ZOHدیدیم شامل
فیلتری از عبور و ضربه قطاربود مستطیلی ضربه پاسخ با
حوزه در آن مفهوم کهمی بررسی را فرکانس
کنیم:
بازسازی برای فیلتر این معکوسلذا است نظر مورد سیگنال
: یابیم می آنرا معکوس
![Page 19: بخش دوم. spectrum (or Fourier spectrum) of x( t ). magnitude spectrum of x(t), phase spectrum of x(t).](https://reader030.fdocuments.net/reader030/viewer/2022012406/5697bfc71a28abf838ca7e02/html5/thumbnails/19.jpg)
Signal reconstruction from the output of the sample-and-hold
Frequency response of the reconstruction filter.