Amplitude modulation (AM) is a modulation technique widely used in various applications. Here are some of the common uses of amplitude modulation:
Broadcast Radio: AM is the modulation scheme used in the broadcasting of AM radio signals. In this application, audio signals are modulated onto a carrier wave using amplitude modulation. The modulated signal is then transmitted through the air and received by AM radios, which demodulate the signal to reproduce the original audio.
Two-Way Radio Communication: AM is employed in two-way radio communication systems, such as aviation communication (AM airband), marine communication, and citizen band (CB) radio. It allows voice communication over long distances and is relatively simple and cost-effective.
Shortwave Broadcasting: AM is also used for shortwave radio broadcasting. Shortwave signals can travel long distances by reflecting off the Earth's ionosphere, making AM an effective modulation technique for international broadcasting.
Amplitude Shift Keying (ASK): ASK is a digital modulation technique that uses amplitude modulation to transmit binary data. It is commonly used in applications like remote control systems, wireless data transmission, and some types of RFID (Radio Frequency Identification) systems.
Radio Altimeters: Amplitude modulation is utilized in radio altimeters, which are devices used in aircraft to measure altitude above the ground. By transmitting and receiving modulated signals and analyzing the reflected signals, radio altimeters provide accurate altitude readings.
Instrumentation and Measurement: In certain cases, amplitude modulation is used in instrumentation and measurement applications. For instance, in amplitude modulation-based fluorometry, fluorescent signals from samples are modulated, and the demodulated signals are analyzed to determine properties like fluorescence lifetime or intensity.
These are just a few examples of the many applications of amplitude modulation. AM's simplicity and ability to carry audio signals over long distances make it suitable for various communication and broadcasting systems.