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Transmitting Radio Signals over EM Waves
Dec 10,2006 00:00
by
admin
The German scientist Heinrich Hertz demonstrated in 1887 that electrical energy could be transmitted through space by way of EM waves. Even though Professor Hertz was the first to demonstrate this phenomenon, he did not grasp the impact of his discovery. It took the work of Nikola Tesla and Guglielmo Marconi, who were inspired to use Hertz’s discovery to transmit signals—thus, the first radio was born. Electric fields are induced by the separation of positive and negative charges. Moving charges (electric current flow) induce electric fields. Changing electric fields induces magnetic fields.Therefore, alternating current flow—such as current flow into and out of an antenna—induces an oscillating electric field, which then induces an oscillating magnetic field.An EM wave is the propagation of electrical energy caused by oscillating electric fields inducing oscillating magnetic fields, which then induce further oscillating electric fields, which then induce further oscillating magnetic fields, and so on |