What is FM ?

In these applications its particular advantages can be used to good effect. For the future, other forms of digital modulation are becoming more widely used - DAB for radio broadcasting and a number of other formats such as TETRA for two-way radio communication systems.

Despite these changes, FM will remain in use for many years to come as there are many advantages of frequency modulation for the areas in which it has gained a significant foothold in recent years.

Wi-fi uses radio waves that are routed through a wireless internet router using radio waves in frequencies between 2.4 and 5.8 GHz.

Radio waves will bounce off items if not absorbed. This means radio waves can bounce off the ground or a cloud or any electric conductor object.

A text message being sent from a cell phone to another cell phone is a radio wave

The radio wave leaves the sender's cell phone and is sent to a tower that sends the wave to the recipient of the text. These are all unique radio waves being sent which makes it possible to reach the right person.

A radio wave can be very short or very long. Wavelengths can reach 62 miles.

In 1932 it was discovered that astronomical objects emit radio waves, and a system has been developed that makes it possible to create pictures from the radio waves.

Astronomers use radio telescopes to study the radio waves being emitted from planets, dust, stars, gas clouds, comets, and other galaxies.

At astronomy observatories they use diesel cars instead of gas powered cars. Gas powered cars create sparks that interfere with the observations.

When a radio wave is received in a radio the tuner is what makes it possible to pick up a specific radio station because it makes it possible to listen to particular radio waves and tune out others.

Radio waves are a type of electromagnetic radiation, as are microwaves, infrared radiation, X-rays and gamma-rays. The best-known use of radio waves is for communication; television, cellphones and radios all receive radio waves and convert them to mechanical vibrations in the speaker to create sound waves that can be heard.

Electromagnetic radiation is transmitted in waves or particles at different wavelengths and frequencies. This broad range of wavelengths is known as the electromagnetic (EM) spectrum.

The spectrum is generally divided into seven regions in order of decreasing wavelength and increasing energy and frequency. The common designations are radio waves, microwaves, infrared (IR), visible light, ultraviolet (UV),\.

According to the Stanford VLF Group, the most powerful natural source of ELF/VLF waves on Earth is lightning. Waves produced by lightning strikes can bounce back and forth between the Earth and the ionosphere, so they can travel around the world.

Radio waves are also produced by artificial sources, including electrical generators, power lines, appliances and radio transmitters. ELF radio is useful because of its long range, and its ability to penetrate water and rock for communication with submarines and inside mines and caves. However, the carrier frequency is often lower than the frequency range of audible sound, which is considered to be 20 to 20,000 Hz.

For this reason ELF radio cannot be modulated fast enough to reproduce sound, which is why it is only used for digital data at a very slow rate.

LF and MF radio bands include marine and aviation radio, as well as commercial AM radio. Most radio in these bands uses amplitude modulation (AM) to impress an audible signal onto the radio carrier wave.

The power, or amplitude, of the signal is varied, or modulated, at a rate corresponding to the frequencies of an audible signal such as voice or music. AM radio has a long range, particularly at night, but it is subject to interference that affects the sound quality. When a signal is partially blocked, the volume of the sound is reduced accordingly.

The power, or amplitude, of the signal is varied, or modulated, at a rate corresponding to the frequencies of an audible signal such as voice or music. AM radio has a long range, particularly at night, but it is subject to interference that affects the sound quality. When a signal is partially blocked, the volume of the sound is reduced accordingly.

The power, or amplitude, of the signal is varied, or modulated, at a rate corresponding to the frequencies of an audible signal such as voice or music. AM radio has a long range, particularly at night, but it is subject to interference that affects the sound quality. When a signal is partially blocked, the volume of the sound is reduced accordingly.

HF, VHF and UHF bands include FM radio, broadcast television sound, public service radio, cellphones and GPS. These bands typically use frequency modulation to impress an audio or data signal onto the carrier wave.

In this scheme, the amplitude of the signal remains constant while the frequency is varied slightly higher or lower at a rate and magnitude corresponding to the audio or data signal.

In this scheme, the amplitude of the signal remains constant while the frequency is varied slightly higher or lower at a rate and magnitude corresponding to the audio or data signal.

This results in better signal quality than AM because environmental factors do not affect the frequency the way they affect amplitude, and the receiver ignores variations in amplitude as long as the signal remains above a minimum threshold.