Nikola Tesla’s Contributions to Radio Developments

Abstract

Following research and inventions into the field of polyphase low frequency alternating current system of generation, transmission and utilization, Nikola Tesla, around 1890, entered into a new and unknown field of high frequency currents. After developing new generators capable of producing higher frequency alternating currents, he turned his attention to generating alternating currents by discharging condenser through a coil coupled to another coil – secondary of “Tesla transformer”. In the three famous lectures between 1891 and 1893 he presented many new characteristics and possible uses of high frequency currents: for illumination, in medicine, industry and for wireless energy transmission. For wireless energy transmission, in 1891-1892 he developed connection of generator to antenna-ground through tuned Tesla transformer. In 1893 he disclosed the principle of wireless energy transmission system with already explained radio transmitter and receiver tuned to operating frequency of the transmitter. In 1897 Tesla submitted two patents on apparatus and system of electrical energy transmission, issued in 1900. These patents were used in the Supreme Court case brought by the Marconi Wireless Telegraph Company of America against the United States of America, alleging that they have used wireless devices that infringed on Marconi patent of June 28, 1904. After 25 years, the United States Supreme Court on June 21, 1943 invalidated the fundamental American radio patent of Marconi, as containing nothing which was not already contained in patents granted to Lodge, Tesla and Stone. However, in spite of this and many others who are recognizing Tesla as one of the radio pioneers, inventing basic radio principle of four tuned circuits, Tesla’s name is still waiting the fool recognition of his role in the development of radio.