Karl Ferdinand Braun

Karl Ferdinand Braun was born on June 6, 1850, in Fulda as a son of a court official. After attending high school, he studied mathematics in Fulda and physics in Marburg. From 1869 he was in Berlin with Gustav Magnus, and in 1872 he earned a doctorate with H. Helmholtz. He went to Würzburg, then to Leipzig, and again back to Würzburg. From 1880 he worked in Strasbourg, in 1883 in Karlsruhe and starting from 1885 for 10 years in Tübingen. Finally, he returned to Strasbourg in 1895.

In 1909, he received the Nobel Prize for physics for his fundamental work in the area of wireless telegraphy together with G. Marconi. In 1914, he was called to be a witness before a court in New York in a patent case. He was caught there by the First World War and remained in the USA, whereupon he died in 1918, bitter, far from his homeland. He had two sons and two daughters.

In 1874, he discovered the electric rectifier effect with sulfur metals. Along with his scientific work, he also knew how to express his interest and understanding of the natural sciences in popular-scientific lectures and essays to broad audiences.

In 1897, he created the Braun tube (CRT - cathode ray tube), a predecessor of the modern TV picture tube. In 1898, he developed the Braun transmitter, which became overwhelmingly significant for wireless telegraphy. The principle of his transmitter, on which the modern communications technology, including radio and television, drew, was based on the separation into a non-radiating primary system (consisting of resonant circuit and spark gap) and a secondary system for radiation over an antenna.

As early as 1898, he recommended his crystal electric rectifier as a detector for fast electrical waves. For this reason, this component represents the start of the enormous prominence of semiconductor electronics today. In 1903, he described for the first time coils with a powder core made out of iron powder, the predecessors to our current ferrite cores. In 1913, Braun conducted the first absolute field strength measurement with a coil aerial of the transmitter on Paris Eiffel Tower.