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Home 공유 자료실 Basic EM Wave Study
       
history of antenna 조회수 : 506
history of antenna.pdf
IT is not surprising thawt ire antennas were inaugurated
in 1842 by the inventor of wire telegraphy, Joseph
Henry, Professor of Natural Philosophy at Princeton,
NJ. By “throwing a spark” to a circuit of wire in an
upper room, Henry found that the current received in a
parallel circuit in a cellar 30 ft below could magnetize needles.
With a vertical wire fromh is study to the roof of his house, he
detected lightning flashes 7-8 mi distant. Henrya lso sparked
to a telegraph wire running from his laboratory to his house,
and magnetized needles in a coil attached to a parallel wire
220 ft away. Later experiments may have extended the range
to half a mile.