Читать книгу Antennas - Yi Huang - Страница 27

(1.31)

This equation was modified by Maxwell by introducing the displacement current . It means that a magnetic field appears during the charge or discharge of a capacitor. With this concept, and the Faraday’s law, Maxwell was able to derive the wave equations, and by showing that the predicted wave velocity was the same as the measured velocity of light, Maxwell asserted that light waves are EM waves.

This equation shows that both the current (J) and time‐varying electric field can generate a magnetic field, i.e. H ≠ 0.