The importance of radio in today's world is indescribable. What's this? The definition says that it is one of the methods of transmitting information over distances by means of electromagnetic waves. Often, the word means the device itself, which was invented by the domestic scientist Popov Alexander Stepanovich in 1895. And since then it has not lost its relevance.
Step into history
The importance of radio in a person's life cannot be overestimated. It was the device created by the Russian scientist that saved a hundred lives from the sunken Titanic - they managed to send a rescue signal.
A. S. Popov began to conduct his experiments back in 1889. He based his invention on the experiments of the German scientist Heinrich Rudolf Hertz with electric waves, during which he managed to achieve the appearance of significant sparks. In 1894, Popov had already designed the first device.
A little later, the radio itself appeared. This happened in 1895. In an effort to amplify the signalselectromagnetic fields, the inventor uses the phenomenon of resonance. And to register the transmitted signals, he uses a coherer - a glass tube with metal filings, which was able to change its resistance. Since then, the era of radio technology begins.
Signal transmission principle
The whole modern world is based on electronic equipment, which is controlled by the forces of radio signals. And to understand what a radio is, you need to understand the principles of the device.
A high-frequency carrier signal of a certain frequency is formed on the transmitting side, on which the information flow is then superimposed. Modulation takes place. The streams of radio waves combined in this way are radiated by the transmitting antenna into space.
Device picks up signal
In a place far from the source, the sent signal is picked up by the receiving antenna of the radio. This marks the stage of RF signal processing, which occurs in stages:
- Electromagnetic field fluctuations generate electric currents in the receiver.
- Low-power electric current is filtered to eliminate interference and reveal useful information.
- "Purified" signals are decoded, detected, useful information is highlighted.
- The set of radio frequencies is converted into a form understandable for the device: sound, image, video.
In most cases, before decoding, the signal passes through a large number of devices - amplifiers, frequency converters - as well assubjected to digitization and software processing. And only then can we understand the information received by the radio. It also improves the quality and perception of information at the same time.
Radio in the modern world
In the modern world, radio has lost its popularity - technological gadgets are used to listen to music, communicate with relatives from distant lands, and receive news. But even 40 years ago this device was the main source of entertainment and information. Radio spent long evenings gathering families, friends, and groups around it.
The first radio station appeared back in 1907 in New York. Lee De Forest built the broadcast tower. However, the location of this radio was constantly changing. This slowed down the popularity of the new entertainment medium. Ten years later, radio stations began to appear in European countries - Czechoslovakia, Ireland, Holland. After the 1920s, they became widespread. And they are developing to this day.
Now Internet radio is very popular. What's this? In fact, the same broadcasting of music, news, but transmitted over distances via global network protocols. But due to the constant development of data transmission, soon this method of broadcasting will be forced out of our lives.
