What is radio? Signal transmission principle

It’s impossible to convey how important radio is in the modern world. What is it? The definition says that it is one of the methods of transmitting information over distances through electromagnetic waves. Often, the word refers to 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 the story

The importance of radio in human life cannot be overestimated. It was a device created by a Russian scientist that saved a hundred lives from the sunken Titanic - they managed to send a signal of salvation.

A. S. Popov began to conduct his experiments in the distant 1889. He based his invention on the experiments of the German scientist Heinrich Rudolph Hertz with electric waves, during which it was possible to achieve the appearance of sparks of considerable strength. In 1894, Popov had already designed the first device.

radio is
A little later, the radio itself appeared. This happened in 1895. In an effort to amplify the signals of electromagnetic fields, the inventor uses the phenomenon of resonance. And to register the transmitted signals, it uses a coherer - a glass tube with metal filings, which was able to change its resistance. From this time 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 in order to understand what radio is, you need to understand the principles of the device.

radio what is it

A high-frequency carrier signal of a certain frequency is formed on the transmitting side, onto which an information stream is then superimposed. Modulation occurs. The streams of radio waves thus combined are emitted by a transmitting antenna into space.

Device Perception

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 processing the radio frequency signal, which happens in stages:

  1. Oscillations of electromagnetic fields generates electric currents in the receiver.
  2. A low-voltage electric current is filtered to eliminate interference and identify useful information.
  3. "Purified" signals are decrypted, detected, useful information is highlighted.
  4. The set of radio frequencies is converted into a form that is understandable for the device: sound, image, video.

In most cases, before decryption, the signal passes through a large number of devices - amplifiers, frequency converters - and also undergoes 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.

Radio in the modern world

In the modern world, radio has lost its popularity - it uses high-tech gadgets to listen to music, communicate with relatives from distant lands, and receive news. But 40 years ago this device was the main source of entertainment, information. Radio in the long evenings gathered around itself families, friends, groups.

The first radio station appeared back in 1907 in New York. Lee De Forest created a broadcast tower. However, the location of this radio was constantly changing. This slowed down the popularity of the new entertainment facility. Ten years later, radio stations began to appear in European countries - Czechoslovakia, Ireland, Holland. And after the 20s, they became widespread. And they are developing to this day.

radio what is the definition
Nowadays, Internet radio is very popular. What is it? In fact, the same broadcasting of music, news, but transmitted over distances through the protocols of the global network. But due to the constant development of data transmission tools, soon such a method of broadcasting will be squeezed out of our lives.

Source: https://habr.com/ru/post/A11246/

All Articles