Early History of the Antennas and Propagation Field until the End of World War I, Part I - Antennas

The prediction by Maxwell in 1865 that electric oscillations in a circuit produce electric waves in the surrounding space stimulated scientists to devise experiments to detect the presence of these waves. Following the classical experiments of Hertz in 1888, many attempts were made to communicate at a distance by electric waves. Marconi was the first to demonstrate a complete workable system. His success was largely due to his clear understanding that high antennas with top loading were essential to transmitting signals over considerable distances. Since the early transmitters utilized spark gaps directly between the antenna and ground, the wavelength of the energy radiated increased as the dimensions of the antenna increased. This naturally led to the idea that long wavelengths were required for operation over long distances, particularly during day-light as indicated by Marconi. Thus, the usefulness of short waves for long-distance communication during daylight was destined to remain unknown until some 30 years later when Marconi himself pioneered the development of long-distance communication with short waves. The development of various types of long-wave antennas is described to the end of World War I.