AM radio, also known as amplitude modulation radio, refers to a type of broadcasting system that uses amplitude modulation to transmit radio waves. The term "AM" stands for amplitude modulation, which is a modulation technique where the amplitude of the carrier wave is varied in proportion to the waveform being transmitted.
AM radio operates in the frequency range of 530 kHz to 1700 kHz in the United States, and the range may slightly vary in different countries. It utilizes a medium wave frequency band to transmit audio signals, allowing for the communication and relay of information, news, music, and entertainment to a wide range of listeners.
AM radio works by encoding the audio signal onto the carrier wave in the form of varying amplitudes, which can be then detected by receivers. The receivers have the ability to demodulate the signal, separating the audio content from the carrier wave, thus producing sound.
Due to the nature of AM radio transmission, it is susceptible to various types of interference, such as electrical noise, atmospheric conditions, and other radio-frequency signals. As a result, the overall quality of AM radio broadcasts is generally lower compared to FM (frequency modulation) radio, which is characterized by a higher frequency range and better audio fidelity.
Although AM radio has faced challenges and declining popularity with the advent of FM and digital broadcasting, it still plays a significant role in providing a means of communication and entertainment to numerous listeners worldwide.
