Parabolic antenna be exploited. Italian radio pioneer Guglielmo Marconi used a parabolic reflector during the 1930s in investigations of UHF transmission from his boat in the Mediterranean. In 1931 a 1.7 GHz microwave relay telephone link across the English Channel using 10 ft. (3 meter) diameter dishes was demonstrated. The first large parabolic antenna, a 9 m dish, was built in 1937 by pioneering radio astronomer Grote Reber in his backyard, and the sky survey he did with it was one of the events that founded the field of radio astronomy. The development of radar during World War II provided a great
Guglielmo Marconi maximum transmission distance for radio waves. A breakthrough came in the summer of 1895, when Marconi found that much greater range could be achieved after he raised the height of his antenna and, borrowing from a technique used in wired telegraphy, grounding his transmitter and receiver. With these improvements, the system was capable of transmitting signals up to and over hills. The monopole antenna reduced the frequency of the waves compared to the dipole antennas used by Hertz, and radiated vertically polarized radio waves which could travel longer distances. By this point, he concluded that a device could become capable