Contents
1
2
3
4
5
6
7
8
9
index
Modules
Demos
Solved Problems
Antenna Properties
Module 9.3:
Dish Antenna
Given:
A parabolic dish antenna of diameter
d
1
operating at frequency
f
1
.
Q1.
If the antenna is operated at a higher frequency, namely
f
2
=10
f
1
, how will the antenna beamwidth and directivity change?
(a) Beamwidth will:
Increase by a factor of 10.
Increase by a factor of 100.
Not change.
Decrease by a factor of 10.
Decrease by a factor of 100.
(b) Directivity will:
Increase by a factor of 10.
Increase by a factor of 100.
Not change.
Decrease by a factor of 10.
Decrease by a factor of 100.
Q2.
If the frequency is increased from
f
1
to
f
2
=10
f
1
and simultaneously the antenna is reduced in size to a new diameter
d
2
=
d
1
/10, what will become of the beamwidth and directivity?
(a) Beamwidth will:
Increase by a factor of 10.
Increase by a factor of 100.
Not change.
Decrease by a factor of 10.
Decrease by a factor of 100.
(b) Directivity will:
Increase by a factor of 10.
Increase by a factor of 100.
Not change.
Decrease by a factor of 10.
Decrease by a factor of 100.
Proceed to Module 9.4
Contents
1
2
3
4
5
6
7
8
9
index
Modules
Demos
Solved Problems
Fawwaz T. Ulaby,
Fundamentals of Applied Electromagnetics.
Prentice Hall, Upper Saddle River, New Jersey, 2001. Copyright © 2001 Prentice Hall.
