Ask Questions, Get Answers

Want to ask us a question? Click here
Browse Questions
Home  >>  JEEMAIN and AIPMT  >>  Physics  >>  Class12  >>  Communication Systems
0 votes

A transmitter puts out a total power of 25 Watts of 30% AM signal. Calculate how much power is contained in each of the sidebands and the fraction of power in the carrier.

Can you answer this question?

1 Answer

0 votes
The total power in an AM signal when the carrier power and the percentage of modulation are known is $P_T = P_c \big ( 1 + \large\frac{m^2}{2}$$\big )$
$\Rightarrow 25 = P_c \big ( 1 + \large\frac{0.3^2}{2}$$\big )$
$\Rightarrow P_c = \large\frac{25}{1.045}$$ = 23.92\;W$
The total power in both side bands $ = 25 - 23.92 = 1.08\;W$
The power in each side band is half of this $ = 0.54\;W$
$\Rightarrow$ The fraction of the power in the carrier is $\large\frac{23.92}{25} $$= 0.957$
answered Jul 12, 2014 by balaji.thirumalai

Related questions

Ask Question
student study plans
JEE MAIN, CBSE, NEET Mobile and Tablet App
The ultimate mobile app to help you crack your examinations
Get the Android App