Facts about Radio Waves

A significant discovery in the field of communication transmission, radio waves were discovered in the year 1867 by a Scottish physicist, James Clerk Maxwell.

Have you ever noticed that most of the devices we use in our day-to-day lives work based on the concept of data transmission through radio waves.

The television antenna receives electromagnetic waves from the television station and in turn broadcasts various channels. Right from a microwave oven to a phone, almost all our devices require radio waves to operate or transfer data.

Radio waves are used mainly for transferring information through space. Its main function is transmission of data via modulation. They have an edge over many other types of signals because of the fact that their speed is equal to the speed of light when traveling in a vacuum.

High transmission speeds make the process of transmission very effective. However, while passing through vacuum, their speed gets affected by factors such as permeableness and permittivity of the object.

Carrier signal is one such electromagnetic waveform used to transmit information through space. The carrier signal is modulated to carry different types of data. AM and FM are examples of these modulations used for broadcasting radio waves.

Let's consider an example to understand this concept better. A radio antenna is a must to receive signals from AM and FM stations. It makes the radio capable of catching a number of signals at the same time. Radio tuner is then used to tune-in to the required frequency. The radio converts the received signals into sound for the listener.

◾ Wavelength of radio waves refers to the distance from one peak to the next in the electric field of the wave. It ranges from as low as 1 millimeter to 100 kilometers.

◾ Frequency of radio waves is the degree of closeness of these waves. The frequency of these type of waves ranges from 3 kHz to 300 GHz. Amplitude defines the height of the radio waves.
◾ Wavelength and frequency of radio waves are inversely proportional.

◾ Usually mistaken as sound waves, radio waves are electromagnetic waves.
◾ Radio waves can travel long distances using very little power.
◾ Radio waves take about 8 minutes of time to move from Earth to Sun.

◾ FM has better sound quality as compared to AM.
◾ AM is cheaper than FM and can be transmitted over longer distances without being altered.
◾ Radio wave is almost 100,000 times as long as a visible light wave.

◾ They have the ability to bounce around the planet earth, clouds, and layers of ionosphere.
◾ Radio waves can be propagated in different frequencies.
◾ Radio waves can be generated naturally by making use of astronomical bodies or lightning.

◾ The use of radio waves is governed by various laws. This is implemented in order to avoid interference between different frequencies.
◾ Radio waves are used in telescopes, radio, x-ray machine, radiation therapy machine, cellular phones, and remote toys to list a few.
◾ Astronauts from moon, use radio waves to communicate with the earth.

◾ Aircraft and large ships use radio compass, or radio range for ease in the process of navigation.
◾ Antennas and telescopes also make use of radio waves for data transmission and receiving respectively.

Human body absorbs a certain amount of these frequencies which are determined by the SAR (Specific absorption ratio). Large amount of radio waves are harmful to human body and can cause health hazards like sleeping disorders, headache, tumors, leukemia, and cancer, to list a few.

Besides some widely-used devices such as radio and television, GPS receivers and cell phones also make use of radio waves for their operation. Such devices need data transmission to happen in real-time.

Since radio waves travel at the same speed as that of light, they are the fastest means to transfer information from one point to the other over a wireless medium. No wonder, these waves find their applications in the field of astronomy as well.