A sinusoidal carrier has amplitude of 20V and a frequency of 30kHz. It is amplitude modulated by a sinusoidal voltage of amplitude 3V and frequency 2kHz.Modulated voltage is developed across 50ohm R

Welcome back.

and 2 others joined a min ago.

5.5kviews

written 8.6 years ago by

teamques10 ★ 69k

• modified 4.1 years ago

i. Write the equation for modulated wave

ii. Plot the modulated wave showing maxima and minima of waveform

iii. Determine the modulation index

iv. Draw spectrum of modulated wave

principles of communication network

ADD COMMENT EDIT

1 Answer

303views

written 8.6 years ago by

teamques10 ★ 69k

Given: $E_C= 20V , f_C = 30 kHz , E_m= 3V , f_m=2 kHz ,R = 50Ω$

Modulation index:

enter image description here

Equation of modulated wave:

enter image description here

Spectrum of AM wave:

Various spectral components are as follows:

Carrier: $f_C=30$ kHz
USB :( $f_C+ f_m$)=32 kHz
LSB: ( $f_C- f_m$)=28 kHz

Amplitude of these spectral components are as follows:

Carrier:

$E_C$= 20V

LSB and USB :

m $E_C$/2 =$\frac{0.15*20}{2} = 1.5V$

enter image description here

Maxima and minima:

enter image description here

ADD COMMENT EDIT

Community

Content

Company