Difference Between AM and FM

What is AM?

AM radio is a broadcasting technology that was developed in the 1920s. AM works by transmitting an audio signal through the airwaves via an electromagnetic signal. The signal is picked up by a radio receiver, where the audio is amplified and played out loud. For decades, AM radio has been used for various purposes, including broadcasting music, news, and other information.

AM radio was the first type of audible radio signal. It was named after the original method of modulation, known as amplitude modulation. Despite being more than one hundred years old, it remains one of the most widely used forms of radio.

 AM radio has several advantages over other forms of radio, which has helped it to maintain such a large audience. For example, when a person speaks into a microphone, their voice causes the amplitude of the carrier wave to vary. AM radio was the first form of radio broadcast and is still widely used today.

One of the advantages of AM radio is that it is relatively easy to build a transmitter and receiver. This has led to a vast proliferation of AM radio stations worldwide.

Additionally, AM radio signals can travel long distances, which has made it a popular choice for news and another programming that needs to reach a wide area. Another advantage of AM radio is that it is less susceptible to interference than other radio signals.

What is FM?

For the uninitiated, FM radio is a broadcast service that uses frequency modulation to transmit sounds or signals with higher fidelity than AM radio. The concept of FM radio was first patented in the United States by Edwin Armstrong in 1933.

The technology was only used after World War II. Armstrong’s design was based on the principles of amplitude modulation, or AM radio, which had been in use since the early 20th century. However, Armstrong realized that the potential for FM radio was much more significant than AM radio. FM radio has been around for a long time.

It was in the 1950s that FM radio became popular. It is a popular way to listen to music and other audio content. FM radio is broadcast over the airwaves and can be received by an FM radio receiver. FM radio receivers are standard in cars and other vehicles.

One advantage of FM radio is that it has excellent sound quality. This is because FM signals are less likely to be disturbed by other signals and are also less likely to be absorbed by objects. Additionally, FM radio signals can travel further than other signals, which means they can reach more people. This is why FM radio is still used for music and other entertainment broadcasts.

Difference Between AM and FM

It is essential to note the difference between AM and FM when considering the types of waves found in an electromagnetic spectrum.

AM is a type of modulation where the amplitude of the carrier wave is varied by the message signal, while FM is a modulation where the frequency of the carrier wave is varied.

AM radio waves are created using a carrier signal modulated or altered by the audio signal. The carrier signal’s modulation causes the signal’s amplitude, or height, to change. One advantage of FM radio is that it has a higher sound quality than AM radio.

AM and FM radio signals are broadcast at different frequencies, and AM signals are broadcast at lower frequencies than FM. The frequency of a signal determines how far the signal can travel, and AM signals can travel farther than FM signals.

Comparison Between AM and FM

Parameter of ComparisonAMFM  
Radio wavesCarrier wave, frequency and phase do not change.Carrier wave, the amplitude and phase are constant.  
TransmissionIt can send signals farther.Less farther than AM  
Sound QualityPoor Audio quality than FMSuperior Audio quality  
FrequenciesRanging from 535 to 1705 kHz.Ranging from 88 to 108 MHz.  
NoiseMore sensitive to sound    Less sensitive to sound


  1. https://ieeexplore.ieee.org/abstract/document/9069423
  2. https://opg.optica.org/ol/abstract.cfm?uri=ol-31-15-2254