What is FM ?

The word ‘broadcasting’, referring to radio transmissions, was originally an agricultural term for the wide scattering of seeds.

Easy to apply modulation at a low power stage of the transmitter: Another advantage of frequency modulation is associated with the transmitters.

It is possible to apply the modulation to a low power stage of the transmitter, and it is not necessary to use a linear form of amplification to increase the power level of the signal to its final value.

The existence of radio waves and the feasibility of radio transmission was predicted by James Clark Maxwell in the 1860s.

In 1903, Marconi enabled US President Roosevelt to send a radio message to Edward VII.

In 1903, Marconi enabled US President Roosevelt to send a radio message to Edward VII.

It is possible to use efficient RF amplifiers with frequency modulated signals: It is possible to use non-linear RF amplifiers to amplify FM signals in a transmitter and these are more efficient than the linear ones required for signals with any amplitude variations (e.g. AM and SSB).

In 1903, Marconi enabled US President Roosevelt to send a radio message to Edward VII.

It is possible to use efficient RF amplifiers with frequency modulated signals:   It is possible to use non-linear RF amplifiers to amplify FM signals in a transmitter and these are more efficient than the linear ones required for signals with any amplitude variations (e.g. AM and SSB).

FM has poorer spectral efficiency than some other modulation formats: Some phase modulation and quadrature amplitude modulation formats have a higher spectral efficiency for data transmission than frequency shift keying, a form of frequency modulation. As a result, most data transmission system use PSK and QAM.

In 1903, Marconi enabled US President Roosevelt to send a radio message to Edward VII.

Requires more complicated demodulator: One of the minor disadvantages of frequency modulation is that the demodulator is a little more complicated, and hence slightly more expensive than the very simple diode detectors used for AM.

However this is much less of an issue these days because many radio integrated circuits incorporate a built in frequency demodulator .

Radio waves are electromagnetic waves, not sound waves as many people believe. Radio waves are considered to be one of human's most important discoveries as it made communication much more efficient. A radio wave is created when an electric field and magnetic field join. Radio waves travel very fast - at the speed of light

Some other modes have higher data spectral efficiency: Some phase modulation and quadrature amplitude modulation formats have a higher spectral efficiency for data transmission that frequency shift keying, a form of frequency modulation. As a result, most data transmission system use PSK and QAM.

If you turn on a radio, the radio receives the radio waves in the air and converts them into an electrical signal, which is converted to sound waves, and the radio amplifier then boosts the sound waves so that you can hear the music.
Interesting Radio Waves Facts:

Sidebands extend to infinity either side:   The sidebands for an FM transmission theoretically extend out to infinity. They are normally significant for wideband frequency modulation transmissions, although small for narrow band FM.

It was Clerk Maxwell in the 1860s that first predicted that radio waves existed. His theory is called Maxwell's equations and described radio and light waves to be electromagnetism waves that were traveling through space.

To limit the bandwidth of the transmission, filters are often used, and these introduce some distortion of the signal.

Heinrich Hertz demonstrated radio waves in his lab in 1887. A Hertz is a radio wave unit of measurement as is named after Heinrich Hertz.

Normally this is not too much of an issue although care has to be taken to include these filters for wideband FM and to ensure they are properly designed.

In the 1890s Guglielmo Marconi created the first practical and usable radio transmitter and receiver.

Frequency modulation is widely used in many areas of radio technology including broadcasting and areas of two way radio communication.

Radio waves are not the only type of electromagnetic wave. Other types include radar, bluetooth, ultraviolet light waves, microwaves, x-rays, and infrared.

A radio wave is broadcast in different frequencies which can include FM radio waves that broadcast between 88 MHz and 108 MHz, and AM radio waves that broadcast between 550 kHz and 1600 kHz