AM/FM is an acronym that stands for "amplitude modulation/frequency modulation," referring to the two main methods of radio broadcasting modulation. It is used to describe the dual reception capabilities of radio receivers, commonly found in cars and portable devices, allowing users to tune in to both AM and FM radio stations.
AM, or amplitude modulation, is a modulation technique that alters the amplitude of the carrier wave in accordance with the amplitude variations of the audio signal being transmitted. AM broadcasting typically operates in a frequency range of 535 to 1705 kHz, providing greater coverage over longer distances and better penetration through obstacles like buildings and hills.
FM, or frequency modulation, is a modulation technique that instead modulates the frequency of the carrier wave based on the audio signal. FM broadcasting typically operates in a higher frequency range of 88 to 108 MHz, providing better sound quality and resistance to noise interference compared to AM.
The AM/FM radio receiver allows users to select between these two modulation methods, tuning in to a wide variety of radio stations broadcasting on different frequencies. It is equipped with the necessary circuitry and controls to detect and demodulate both AM and FM signals, enabling the user to access a diverse range of programming, including news, music, talk shows, sports, and more.
In summary, AM/FM denotes the capability of a radio receiver to receive and decode both amplitude modulation (AM) and frequency modulation (FM) radio frequencies, offering users the flexibility to select and enjoy broadcasts in both modulation formats.
The abbreviation "AM/FM" stands for "Amplitude Modulation" and "Frequency Modulation", referring to the two primary methods of radio broadcasting. Regarding their etymology:
1. Amplitude Modulation (AM): The term "amplitude" refers to the measure of the maximum extent of a vibration or oscillation, while "modulation" indicates the process of varying a parameter of a periodic wave. In the context of radio broadcasting, amplitude modulation involves varying the amplitude of the carrier wave in correspondence with the audio signal being transmitted. The term "amplitude modulation" was coined to describe this technique.
2. Frequency Modulation (FM): The term "frequency" denotes the rate at which a vibration or oscillation occurs, while "modulation" refers to varying a parameter of a periodic wave as mentioned earlier. In FM radio broadcasting, the frequency of the carrier wave is modulated according to the audio signal.