1. Department of Microelectronics,
Indian Institute of Information Technology, Allahabad
SUBMITTED BY:
Prashant singh(imi2011003)
Rahul Patidar(imi2011011)

2.  Introduction
 Classification
 Types
 Structures
 Digital Vs Analog filters
 Refrences

3.  Electronic circuits which perform signal processing functions,
remove unwanted frequency component, to enhance wanted ones,
or both.
 Digital filter-Performs mathematical operations on a
sampled,discrete time signal to reduce or enhance certain aspects
of that signal.
 Filters generally do not add frequ-
ency components to a signal.
 Boost or attenuate selected frequ-
ency regions.
Digital Filtering

4.  Magnitude response consideration.
 Four basic types of ideal filters with magnitude responses as shown
below
π
1
ω
0 ωc–ωc
HLP(e jω
)
− π π
ω
0 ωc–ωc
1
HHP (e jω
)
− π
π− π
ω
11–
–ωc1 ωc1–ωc2 ωc2
HBP (e jω)
− π π
ω
1
–ωc1 ωc1–ωc2 ωc2
HBS(e jω
)

5.  Depending on the form of the filter equation
(a) Linear filters versus nonlinear filters.
(b) Time-invariant filters versus time-varying filters.
(c) Adaptive filters versus non-adaptive filters.
(d) Recursive versus non-recursive filters.
 Depending on the structure of implementation
(a) Direct-form, cascade-form, parallel-form and lattice structures.

6.  A class of linear filters whose behavior does not change over time
- Linearity implies that the filter meets the scaling and superposition properties.
 Two types
1.FIR filter
-Operate only on previous values of the input
2.IIR filter
-Operates on previous values of input & output both

7.  A recursive filter has feedback from
output to input, and in general
its output is a function of the previous
output samples and the present and
past input samples

8.  A non recursive filter has no feedback from output to input, and
in general its output is a function of the present and past input
samples

9.  Direct Form
Direct Filter Structure

10.  Cascade Form
Cascade Filter Structure

11.  Parallel Form
Parallel Form Structure

12. DIGITAL
High Accuracy
Linear Phase (FIR Filters)
Flexible, Adaptive Filtering
Possible
Easy to Simulate and Design
Computation Must be Completed
in
Sampling Period - Limits Real
Time Operation
Requires High Performance
ADC,DAC & DSP
ANALOG
Less Accuracy–Component Tolerances
Non-Linear Phase
Adaptive Filters Difficult
Difficult to Simulate and
Design
Analog Filters Required at High
Frequencies and for Anti-
Aliasing Filters
No ADC, DAC, or DSP Required

13.  Introduction to Speech Processing | Ricardo Gutierrez-Osuna | CSE@TAMU, chapter 10 of [Taylor, TTS synthesis, 2009].
 An Introduction to Digital Filters,application note,january1999, Intersil and Design is a trademark of Intersil Corporation. |
Copyright©Intersil Corporation 2000
 Digital Filters and Z Transforms,Copyright © Richard C. Bailey and David M. Harrison, 1998, 1999
 http://en.wikipedia.org/wiki/Digital_filter