Types of Radio Transmission

First of all, in order to transmit radio waves, a transmitter and receiver are needed. A radio wave acts as the carrier of the information through encoded waves or a process called modulation. Modulation is the variation of a property of an electromagnetic wave or signal, such as its amplitude, frequency, or phase.

The two main types of radio transmission are amplitude modulation (AM) and frequency modulation (FM). The older broadcasting method and most popular method, frequency modulation (FM) minimizes noise and provides greater reliability. Both AM and FM process sounds into patterns, that are always varying, of electrical signals. They closely resemble sound waves. In an AM transmission the carrier wave has a constant frequency, but the strength of the wave varies. The FM transmitter is just the opposite; the wave has constant amplitude but a varying frequency.

Usually the radio is used in the transmission of sound; such as voices and music. The sound is converted into electrical signals by a microphone. Then the signals are amplified, and transmitted. Once the carrier is amplified it can be applied to an antenna. The antenna converts the electrical signals into electromagnetic waves and sends them out or they can also be received. The receiving antennas change it back to the form of electrical signals, and then feed it to another receiver.