In practice, both amplitude modulation (AM) and frequency modulation (FM) are used for communication purposes, but they have different applications and characteristics that make them suitable for different situations.
AM waves are primarily used for long-distance radio broadcasting. They are advantageous for this purpose due to the following reasons:
Signal Propagation: AM waves can propagate over long distances because they can travel farther and are less affected by obstacles and atmospheric conditions. The lower frequency range of AM signals allows them to diffract around objects and travel through buildings, making them suitable for long-range communication.
Simple Reception: AM signals are relatively easy to receive and demodulate. The process of demodulating an AM signal involves extracting the audio or information signal by detecting the variations in the amplitude of the carrier wave. This simplicity makes AM receivers less complex and more affordable.
On the other hand, FM waves are commonly used in applications such as commercial FM radio broadcasting, two-way radio communications, and high-fidelity audio transmission. FM offers several advantages in these scenarios:
Noise Resistance: FM signals are less susceptible to amplitude variations or noise interference compared to AM signals. Since the information in FM is encoded in the frequency variations of the carrier wave, changes in amplitude do not affect the demodulated signal as much. This makes FM more resilient to atmospheric disturbances and electrical noise, resulting in higher audio quality and clearer reception.
Bandwidth Efficiency: FM signals occupy a larger bandwidth compared to AM signals. This increased bandwidth allows for the transmission of a wider range of audio frequencies, resulting in higher fidelity and better sound quality. It is particularly beneficial for applications like music broadcasting or high-quality audio transmission.
In summary, AM waves are well-suited for long-distance radio broadcasting due to their ability to propagate over long distances and their simple reception process. FM waves, on the other hand, are advantageous in applications where noise resistance and higher fidelity are important, such as FM radio broadcasting and high-quality audio transmission. Both modulation techniques have their respective strengths and find applications in different areas of communication.