Arab Academy for Science and Technology & Maritime Transport
College of Engineering & Technology
Department : Electronics & Communication Engineering
Course Title : Introduction to Communication Systems
Course No: EC322
Lecturer
: Communication Dr
TA
:
Sheet # 2 [1/2]
Amplitude Modulation-Part I
1- Consider a message signal
, as shown below, amplitude modulating a carrier to get
DSBTC AM signal. Sketch the modulated signal in case of
modulation and
modulation.
2- For the shown AM wave:
I.
II.
III.
Write the equation of the AM wave.
Sketch the spectrum of AM wave.
Calculate the total power and efficiency.
3- The following unmodulated carrier wave
is to be ordinary AM
modulated by baseband limited signal m(t) having the following spectrum .
I.
II.
III.
Find the modulated wave
and sketch its spectrum.
Find the bandwidth and the RF output power of
from the spectrum and by using the mathematical
formula, comment on the result.
Calculate the efficiency.
4- A broadcasting station is tested using 1KHz tone, If the antenna masts are spread 150 m. The
carrier power = 10 k watt. The efficiency was found to be 50% of the maximum AM
efficiency.
I.
II.
III.
IV.
EC322
What is the carrier frequency?
Find
Find the AM wave.
Find the total power and the BW of the AM wave.
Introduction to Communication Systems
Eng.Mohamed Atef Abbas