Open In App

Difference between Amplitude Modulation and Frequency Modulation

Last Updated : 16 May, 2024
Improve
Improve
Like Article
Like
Save
Share
Report

Difference between AM and FM: Amplitude Modulation (AM) and Frequency Modulation (FM) are two essential techniques used in analog communication systems to convey information, such as audio signals, using radio waves. While both approaches accomplish the same purpose of modulating a carrier signal to encode information, they differ in how they modulate the carrier signal and the properties of the modulated signals they generate. Learn more about Difference between Amplitude Modulation and Frequency Modulation in this article

What is Amplitude Modulation?

Amplitude modulation is a modulation in which the amplitude of the carrier wave changes according to the instantaneous amplitude of the modulating signal, keeping phase and frequency constant. The amplitude of the carrier wave is modified in order to send the data or information. It can transmit over long distances, and has a large range. Its modulation index varies from 0 to 1. In amplitude modulation, the frequency and phase remain the same.

What is Frequency Modulation?

Frequency Modulation is a modulation in which the frequency of the carrier wave changes according to the instantaneous amplitude of the modulating signal keeping phase and amplitude as constant. The frequency of the carrier wave is modified in order to send the data or information. It cannot transmit over long distances, have a smaller range. Its modulation index is always greater than one. In frequency modulation amplitude and phase remain the same.

Difference between Amplitude Modulation and Frequency Modulation

The difference between amplitude modulation and frequency modulation is tabulated below:

Amplitude Modulation Frequency Modulation
In amplitude modulation, the frequency and phase remain the same.  In frequency modulation amplitude and phase remain the same.
Its modulation index varies from 0 to 1. Its modulation index is always greater than one.
It has only two sidebands. It has an infinite number of sidebands.
It has simple circuit. It has complex circuit.
The amplitude of the carrier wave is modified in order to send the data or information. The frequency of the carrier wave is modified in order to send the data or information.
It requires low bandwidth in the range of 10 kHz. It requires high bandwidth in the range of 200 kHz.
In AM received signal is of low quality. In FM received signal is of high quality.
It works in a frequency range of 535 to 1705 Kilohertz (KHz). It works in a frequency range of 88 to 108 Megahertz (MHz).
 It operates in the medium frequency (MF) and high frequency (HF).  It operates in the very high frequency.
It has poor sound quality. It has better sound quality.

Applications of AM and FM

Amplitude Modulation (AM) and Frequency Modulation (FM) are two fundamental techniques used in analog and digital communication systems. There applications are mentioned below:

Applications of Amplitude Modulation

  • AM modulation is commonly used to broadcast radio signals, particularly for AM radio stations.
  • AM is extensively utilized in shortwave radio communication, especially for multinational broadcasts.
  • AM is utilized in aviation communication systems, including air traffic control and aircraft-to-aircraft communication.
  • AM modulation is used in two-way radio communication systems such as Citizen Band (CB) radios, Emergency Communication Systems, and Walkie-Talkies.

Applications of Frequency Modulation

  • FM modulation is commonly utilized in commercial radio broadcasting, particularly among FM radio stations.
  • FM modulation is used in mobile communication systems, including analog FM-based mobile networks and digital systems.
  • FM modulation is widely utilized in wireless microphone systems designed for live events, broadcasting, and recording.
  • FM modulation is utilized in radio navigation systems, such as VHF Omni-directional Range (VOR) and Instrument Landing System (ILS), which are used for aircraft navigation.

Also, Check

FAQs on Difference between AM and FM

Which is better amplitude modulation or frequency modulation?

Frequency modulation is better as the sound received through it is better in quality but travel short distance

Why is FM better than AM?

FM is better because it produces better sound quality due to higher bandwidth

Where do we use AM and FM?

We use AM in TV signals and FM for radio and audio signals

Do cell phones use AM or FM?

Most of the current generation mobile phones use FM

Why AM has more noise as compared to FM?

AM has more noise as compared to FM because it has lower bandwidth and noise is added during signal transmission


Similar Reads

Difference between Amplitude Modulation and Phase Modulation
Prerequisite - Modulation 1. Amplitude Modulation : Amplitude Modulation is a modulation in which the amplitude of the carrier wave changes according to the instantaneous amplitude of the modulating signal keeping phase and frequency as constant. The amplitude of the carrier wave is modified in order to send the data or information. It can transmit
2 min read
Difference between Frequency Modulation and Phase Modulation
Prerequisite - Modulation 1. Frequency Modulation: Frequency Modulation is a modulation in which the frequency of the carrier wave changes according to the instantaneous amplitude of the modulating signal keeping phase and amplitude constant. The frequency of the carrier wave is modified in order to send the data or information. It cannot transmit
2 min read
Amplitude Modulation - Definition, Types, Expression
Amplitude Modulation or AM, is a modulation technology mainly used for radio carrier wave-based message transmission which modifies the carrier wave's amplitude (signal intensity) in accordance with the message signal, such as an audio signal, i.e., a modulating signal. In this article, we will learn what amplitude modulation is, its definition, hi
17 min read
Difference between Pulse Code Modulation (PCM) and Delta Modulation (DM)
PCM stands for Pulse Code Modulation and DM stands for Delta Modulation. PCM is basically used for reworking analog to digital signals and DM is a conversion technique between analog and digital signals. In this article, we will discuss these two topics and also see the differences between these PCM and DM. Pulse Code Modulation (PCM)Pulse Code Mod
3 min read
Difference between Delta Modulation (DM) and Differential Pulse Code Modulation (DPCM)
Delta Modulation (DM): Delta modulation is associated with analog-to-digital and digital-to-analog signal conversion techniques. Delta modulation is utilized to appreciate high signal-to-noise magnitude relation. It uses one-bit PCM code to appreciate the digital transmission of the analog signal. With delta modulation, rather than transmitting a c
2 min read
Difference Between Amplitude and Frequency
Amplitude and frequency are fundamental concepts in the study of periodic motion. While both describe characteristics of oscillatory phenomena, they represent distinct aspects of the motion. Amplitude refers to the maximum displacement of a wave or oscillating object from its equilibrium position that reflects its intensity or strength. On the othe
6 min read
Amplitude, Time Period and Frequency of a Vibration
Sound is a form of energy generated by vibrating bodies. Its spread necessitates the use of a medium. As a result, sound cannot travel in a vacuum because there is no material to transfer sound waves. Sound vibration is the back and forth motion of an entity that causes the sound to be made. That is often referred to as oscillatory motion. What are
5 min read
Frequency Modulation
Frequency Modulation or FM is a method of encoding information on one carrier wave by changing the wave carrier frequency. Frequency Modulation technology is used in the fields of computing, telecommunications, and signal processing. In frequency modulation, the frequency of the carrier wave is changed according to the frequency of the modulating s
10 min read
Amplitude Formula
The largest deviation of a variable from its mean value is referred to as amplitude. It is the largest displacement from a particle's mean location in to and fro motion around a mean position. Periodic pressure variations, periodic current or voltage variations, periodic variations in electric or magnetic fields, and so on all have amplitudes. Ampl
5 min read
Difference Between Frequency and Relative Frequency
Frequency and relative frequency are two fundamental concepts in statistics. They describe how often values or categories appear in a dataset, and what proportion of the dataset they represent.  In this article, we will discuss the difference between frequency and relative frequency, and how to calculate them. FrequencyFrequency is the number of ti
6 min read