Wireless communication begins with the experiment of Heinrich Hertz (1857-1894) in 1886. In his experiment, Hertz set up two circuits. The first of the two circuits had a small gap. He connected this circuit to a high voltage source. As long as the high voltage had built up in the ends of the gap, a spark is observed, jumping back and forth across the gap.

The second circuit whom Hertz experimented was a simple conductor. This was bent into a circle and like the first circuit, it also has a small gap between its ends. In the experiment, Hertz observed that whenever a spark were produced at the first circuit connected to a high voltage, another spark were also observed in the second circuit. This was became possible even though the two circuits were 2 meters away from each other and there were no connections between them. The event is that, the spark from the first circuit was carried and being propagated in the air and was received by the second circuit. The energy from the first circuit was carried to the second circuit by the electromagnetic waves.

In 1896, Guglielmo Marconi (1874-1937) sent messages over a distance of few kilometers. He used a spark gap transmitter and a simple receiver which indicated the presence of a signal in a telephone by clicks. He used similar system in 1901 to recieve Morse signals across the Atlantic. He was able to developed the first “wireless telegraphed”.

Today telephone, radio and satellites are also wireless, making communication through the use of electromagnetic waves.

 


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