img
Question:
Published on: 22 December, 2024

The maximum deviation allowed in an FM broadcast system is 75 kHz. If the modulating signal is a single tone sinusoid of 10 kHz, find the bandwidth of the FM signal. What will be the change in the bandwidth, if the modulating frequency is double? Determine the bandwidth when modulating signal amplitude is also double.

Answer:

Given that ∆f=75KHz and fm=10KHz

According to the Carson’s thumb rule the bandwidth

BW=2(∆f+fm )=2(75+10)=170KHz

The frequency deviation ∆f=kf Am

Then Bandwidth BW=2(kf Am+fm )

Modulation index β=∆f/fm =75/10=7.5

If the modulating frequency is double then the bandwidth

BW=2(∆f+2×fm )=2(75+2×10)=190KHz

Hence the frequency band (BW) is enhanced by (190-170)=20KHz

 

If the signal amplitude is doubled with normal modulating frequency then

BW=2(2kf Am+fm )

BW=2(2∆f+fm )=2(2×75+10)=320KHz

The bandwidth is enhanced by (320-170)=150KHz

Subjects
Power Electronics Power System I Electrical Engineering Management Basic Electrical Engineering Analog Communication Radio Frequency and Microwave Engineering
Trending

For a broadcast super heterodyne AM receiver having no RF amplifier, the loaded quality factor Q of the antenna coupling circuit is 100. Now if the intermediate frequency is 455 KHz, then determine the image frequency and its rejection ratio at an incoming frequency of 1 MHz.
View : 773
22 December, 2024

Find the Fourier transform of the following:

Fig. 1
View : 787
22 December, 2024

What is angle modulation?
View : 796
21 June, 2022

Explain with suitable block diagram the generation of FM signal using Armstrong method.
View : 1213
22 December, 2024

A carrier signal \(A_ccos\omega_ct\) is amplitude modulated by a message signal \(A_mcos\omega_mt\), where \(A_m<A_c\)

  • Write down the expression for the modulated signal
  • Write down the expression for carrier component and side band components.
  • Draw the phasor diagram of the modulated signal.
View : 759
22 December, 2024
Random questions
About
MindStudy is a preparation hub for all the students. The goal is to make it easier for pupils to get better grades on exams. We have a list of questions with the best answer for each. Professors, Teachers, and Faculty members from a variety of universities, schools, and institutions throughout the world prepare the Q&A.
Contacts
Shunya Intelliware Solution
Kolkata, WB
Mail us at: info@mindstudy.in

Follow us on:
Streams
Top Subjects
Data Structures & Algorithm Database Management System Software Engineering Compiler Design Mobile computing Design and Analysis of Algorithm C Programming and Practices Computer Graphics and Multimedia Basic Electrical Engineering Radio Frequency and Microwave Engineering Analog Communication Electrical Engineering Management Concrete Technology Design of Reinforced Concrete Structures Power Electronics Irrigation Engineering Surveying Power System I
MindStudy © Copyright 2022, All rights reserved.
Home About Contact