Karl Ferdinand Braun

Karl Ferdinand Braun was born on 6 June 1850 in Germany and worked as an applied physicist at a time when wireless communication was still theoretical. In 1874 he constructed the first semiconductor diode, a quiet landmark that would eventually open the door to all of electronics. Twenty-three years later, in 1897, he built the first cathode-ray tube — the ancestor of every television screen for the next century. His two-circuit system made long-range radio transmission practical, and in 1905 he invented the phased array antenna, the architecture underlying radar and modern smart antennas. He…