In this note, we are going to learn about a topic called What is Modulation and the Need for Modulation in Communication Engineering. Welcome to Poly Notes Hub, a leading destination for engineering notes for diploma and degree engineering students.

Author Name: Arun Paul.

What is Modulation?

Modulation is a technique used in communications to send a signal (such as a voice, music, or data) via a medium (such as radio waves or electrical cables). The information is encoded by changing a carrier signal (a high-frequency signal).

Types of Modulation

There are three types of modulation in communication systems:

1. Amplitude Modulation or AM: The amplitude (signal strength) of the carrier wave varies in proportion to the information being transmitted.
2. Frequency Modulation or FM: The frequency of the carrier wave varies according to the information signal.
3. Phase Modulation or PM: The phase of the carrier wave is changed in response to the information stream.

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Need for Modulation in Communication Systems

Here are we listed need for this technique:

1. Modulation enables signal transmission over great distances with minimal data loss.
2. Different signals can be sent simultaneously without interference by modifying the carrier frequency.
3. Modulated signals can be used to minimize noise and interference. For example, FM is less sensitive to amplitude noise than AM.
4. Modulation allows the signal to be adjusted to the medium’s needs.
5. The antenna size is inversely proportional to the transmitted signal frequency. High-frequency carrier signals obtained through modulation enable the use of relatively sized antennas for successful transmission and reception.
6. Multiple signals can be broadcast over the same channel by using separate carrier frequencies.