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Radio Waves: Definition, Types, How it Works, Emitting, Advantages and Disadvantages

For this discussion we will review Radio Waves which in this case include the meaning, benefits, types and ways of working, so that you can understand and be understood more, see the full review below.

Definition Radio Waves: Radio waves are part of the electromagnetic waves that have the lowest frequency. Frequency is the number of wave vibrations every second. Radio signal frequencies range from 1 hertz (vibrations/second) to 100 billion hertz (100 giga hertz).

The band for radio broadcasts varies from 100,000 hertz (100 kilohertz) to a little over 100 million hertz (100 mega hertz). The radio signal frequencies used for TV range between 54 and 890 megahertz.

Not all radio signals are reflected back by the ionosphere from the Earth's atmosphere. Only short waves (Short Wave/SW) i.e. signals with a frequency between 2 and 30 megahertz are reflected. SW broadcasts are divided into SW1, SW2, SW3, SW4 used for remote broadcasts.

There are 2 kinds of sending radio program signals to listeners, namely Amplitude Modulation (AM) and Frequency Modulation (FM). In AM, the number of vibrations is fixed, but the amplitude of the waves changes with the source sound.

In FM broadcasts that change is the vibration, the amplitude is fixed. FM produces better sound quality and suffers almost none of the buildup that AM broadcasts often suffer from.

FM waves have a frequency between 80 and 108 megahertz, while Medium Wave (MW) for local has a frequency between 500 and 1,600 kilohertz, there are Low Wave (LW) broadcasts with low frequency, 150 – 280 kilohertz.

How Radio Waves Work

Radio waves propagate in free air with a speed of 300,000 km/sec. Sound vibrations in telephone conversations, or vibrations generated by the sender of telegraph or facsimile signals are converted into electrical pulses during transmission.

Arriving at the destination, the electrical pulses are converted back into vibrational information that can be heard and understood by the recipient of the news, via telephone, telex, facsimile or the monitor of a television receiver.

Types of Radio Waves

Here are several types of radio waves, consisting of:

1. Long waves

This type of wave has a long signal so it can reach a very wide range of areas. The disadvantage of this wave is that it requires a very large amount of electric power so it is expensive to operate, because the long and wide wave types make it susceptible to interference (noise).

2. Short waves

Waves that use air as a mediator. This type of wave is SW (short wave). The advantage of this wave is that it can reach a wide area (coverage area). Widely used by international or intercontinental transmitters. 

The disadvantage of this wave is a lot of noise, especially from the sun, weather, air, lightning and so on. The human voice can be heard well, but the use of sound effects loses its quality (blurred).

3. Medium waves

Waves that use the earth's surface as a mediator. In general, most of the waves used by radio stations. The types used by these waves are AM (amplitude modulation) and FM (frequency modulation).

The advantage of these waves is that the earth's surface is less affected by the weather so there is no noise. Broadcast quality is better in sound quality and sound effects. The disadvantage of this wave is that the ground absorbs the wave faster than the air, which causes the broadcast range to be narrower, requiring a booster.

Radio Wave Emitting

Here are some radio wave broadcasts, consisting of:
  1. Radio waves over wires. This is an easy way of transmitting sound over a radio, but it is also the most expensive. The principle of transmitting waves like this is generally used inside buildings or better known as in-house radio (for example on campuses in America or in-house radio at Matahari department store). The advantage of this wave is that the sound is very good, there is no interference. The disadvantage of this wave is requires a lot of money because it takes thousands of cables.
  2. Radio waves through the air Broadcasting in this way usually uses short waves. The mechanism of action is to throw sound waves at a certain angle into the sky. Sound in the form of waves is then reflected at the same angle to the earth's surface.
  3. Streaming Radio / Online Radio, online radio is that which is broadcast using digital-based technology, which is sent via data sending media such as satellites and cable networks. Sound and music from radio stations will be converted into binary numbers, which form codes that are later the code can be converted back into the form of sound that we can hear.

Advantages and Disadvantages of Radio Wave Transmission

Following are some of the advantages and disadvantages of radio wave transmission, consisting of:

1. Advantages of Radio Wave Transmission:
  • Can send signals in any position (does not have to be straight) and is possible in a state of motion.
  • Has a fairly large work area.
  • Installation costs are generally quite cheap.

2. Disadvantages of Radio Wave Transmission:
  • Quality and performance is less than the maximum.
  • Frequent signal interruption