Solution
Robert answered on
Dec 22 2021
RMIT University
School of Electrical and Computer Engineering
EEET2369 – Signals and Systems
Assignment #2
Lecturer: Dr. Katrina Neville
Student Name: …….. Student Number: 3261851
Submission Due Date: …….
Design of Nulling Filters:
A simple nulling filter is designed that removes a single frequency [1]. MATLAB functions
are used to design a nulling filter that filters out a single frequency. That frequency is selected
ased on the 5
th
number in the student number. The student‟s number is 3261851. The fifth
digit in this number is „8‟. Therefore the nulling filter should be able to filter out the 8
th
frequency in the table, which is 0.8π.
Nulling filter that filters out a single frequency is a notch filter. The notch filter is
characterized by the sharp attenuation dip in frequency domain. This filter type is generally
used to remove a distu
ance of a known na
ow band frequency [2].
The simplest possible general nulling filter can have as few as three coefficients [1][2]. If
̂ is the desired nulling frequency, then the difference equation for the filter is given below
, - , - ( ̂ ) , - , -
It has a zero in its frequency response at ̂
Since the filter designed should eliminate the frequency 0.8π, then the difference equation for
the filter is
, - , - ( ) , - , -
which will have a zero in its frequency response at
The impulse response of the filter is
, - , - , - , -
The Z-Transform for the filter is
, - , - ( ) , - , -
, - , - , - , -
, - , - , -
, -
, -
, -
, -
, -
[
]
, -
, -
[
]
There are two zeros and two poles for the filter. The two zeros are at -0.8050±0.5933i and
two poles at origin.
The pole zero plot of the system obtained by using the matlab function zplane() is shown
elow.
The frequency response of the filter obtained by using the matlab function freqz() is shown
elow.
The description of a system in terms of its poles and zeros is an extremely useful abstraction
of a system. The poles represent the roots of the feedback part of the transfer function of a
system. For a stable system the poles should have a magnitude of less than one and lie inside
the unit circle. The...