One practical application of amplitude modulated (AM) waves in wireless communication systems is in the transmission of audio signals over long distances. AM is commonly used in broadcasting applications, such as AM radio stations. Here's how it works:
Modulation: In an AM system, the audio signal (e.g., voice or music) is used to modulate the amplitude of a high-frequency carrier wave. The carrier wave is typically in the radio frequency (RF) range, allowing for efficient transmission over long distances.
Transmission: The modulated AM signal is transmitted through antennas, which radiate the signal as electromagnetic waves. The AM signal can travel long distances without significant loss of signal strength.
Reception: At the receiver end, antennas receive the transmitted signal. The receiver extracts the modulated signal and demodulates it to recover the original audio signal.
The practical benefits of using AM in wireless communication systems are as follows:
Long-distance coverage: AM signals can propagate over long distances due to their ability to utilize the Earth's ionosphere for signal reflection. This characteristic makes AM suitable for long-range broadcasting, allowing a single transmitter to reach a wide geographic area.
Cost-effectiveness: Compared to other modulation techniques, AM is relatively simple and cost-effective to implement. This factor played a significant role in the widespread adoption of AM radio broadcasting in the early days of wireless communication.
Compatibility: AM receivers are widely available and relatively inexpensive. This compatibility has contributed to the continued use of AM broadcasting, particularly in areas with limited access to alternative communication technologies.
However, it's important to note that AM has certain limitations, such as lower audio fidelity and vulnerability to noise and interference. Therefore, other modulation techniques like frequency modulation (FM) and digital modulation schemes are often preferred for higher-quality audio transmission and data communication in modern wireless systems.