Braun, Carl Ferdinand

Born June 6, 1850, in Fulda; died Apr. 20, 1918, in New York. German physicist.

Braun graduated from the University of Berlin in 1872. He was a professor at the polytechnic school in Karlsruhe from 1883 and at Tübingen from 1883 to 1895 and became a professor at the University of Strasbourg in 1895. Braun’s basic works are in the field of radio engineering. In 1898 he combined A. S. Popov’s open oscillator with a closed condenser circuit, which significantly raised the quality of transmission. In 1897, Braun proposed the application of a cathode-ray tube (the so-called Braun tube) to electric oscillations research. In 1906 he discovered unipolar conductivity in crystals, which led him to devise crystal detectors. Braun also proposed several types of antennae, among them the loop antenna (1913). He was awarded a Nobel Prize in 1909 for his work in radio engineering.