In this note, we are going to learn about a topic called “What is Modulation?” and 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 –
- Amplitude Modulation or AM: The amplitude (signal strength) of the carrier wave varies in proportion to the information being transmitted.
- Frequency Modulation or FM: The frequency of the carrier wave varies according to the information signal.
- Phase Modulation or PM: The phase of the carrier wave is changed in response to the information stream.
Need for Modulation
Here are we listed need for this technique –
- Modulation enables signal transmission over great distances with minimal data loss.
- Different signals can be sent simultaneously without interference by modifying the carrier frequency.
- Modulated signals can be used to minimize noise and interference. For example, FM is less sensitive to amplitude noise than AM.
- Modulation allows the signal to be adjusted to the medium’s needs.
- 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.
- Multiple signals can be broadcast over the same channel by using separate carrier frequencies.