What is Modulation? - Explained

What is Modulation? - Explained
Illustration of Modulation Signals. Image by Internet.

Modulation is a technique that use to improve the quality of signal and to take the signal much far from the transmitting location. A typical and a usual radio frequency wave cannot travel far from it's transmitting location due to the less power that they carry in the original signals.

A stronger and powerful radio frequency modulated with the original radio frequency is a modulation. Which means the stronger and powerful radio frequency acting as a carrier wave for the original radio frequency.

Modulation is used in almost all the radio frequency transmission and in electromagnetic wave transmission. Modulation is used from the early stage to transmit frequency to a far distance from the transmitting location. 

Electromagnetic waves or the Radio waves can be categorized into two different parts by analyzing the core characteristics. The analog and digital, Each type of signals needs unique way to modulate the signal types.

There are three types of popular modulation techniques that has been invented to different purposes and needs of the commercial and military activities.


1. Frequency Modulation (FM)

Frequency modulation or the FM is a commonly used modulation technique in the world for analog signal modulation. What happens inside the frequency modulation is, the instances of the initial signal or the frequency is encoded with a carrier wave which is stronger and powerful than the initial pure signal or the radio wave.

Frequency Modulation
Illustration of Frequency Modulation. Image by Internet.

Commercially the Frequency modulation is done for radio broadcasting in almost all the countries in the world to offer a better coverage for the receivers.

Though the modulation technique is used to send signals far from the initial point, Frequency modulated signals can't be used as in the state because the original signal is modulated with the carrier signal.

To use the frequency modulated signal it require to decode the encoded signals which has been received to receiver. There are electronic components which can dump the carrier wave use the pure signal wave or the radio wave to use in original applications.

2. Amplitude Modulation (AM)

Amplitude Modulation is also known as AM and it's used to transmit data by modulating the original signal with a carrier wave or a signal. Amplitude modulation is different from the frequency modulation.

Amplitude Modulation
Illustration of Amplitude Modulation. Image by Internet.

Unlike the frequency modulation, in amplitude modulation uses carrier wave to modulate the amplitude of the wave. AM or the amplitude modulation is used in radio broadcasting from a long time period but due to the energy consumption and due to energy loss the amplitude modulation wasn't became a favorite modulation technique.

Amplitude modulation is used in the loudspeakers. The analog voice signal which is emitted by the human's mouth directly to the microphone is amplified by using the amplitude modulation and emitted out by using the speakers. The human voice will receive a louder voice by using the amplitude modulation and by the loud speaker.

3. Digital Modulation

Digital modulation is mostly used modulation technique though it's not popular as FM or AM. Digital Modulation is a digital signal which is in binary, modulated with a analog carrier wave. In digital modulation from the point where it's receiving, the device's receiving module captures the digital signal and demodulating the wave and dumping the carrier wave and using the original message which is transmitted.

Digital Amplitude Modulation
Illustration of Digital Amplitude Modulation. Image by Internet

Digital modulation is used in wide range of applications in the world. From the smart phone that we use, WiFi access point, Laptop, tablet PC, to Connected IoT devices and smart vehicles do use digital modulation to receive and transmit data.

In commercial level, satellites, air planes, cargo ships, passenger ships uses modulation techniques for navigation.