Nikola Tesla worked on telecommunication technology in the US.
Electrical engineering . Electrical engineering has now subdivided into a wide range of subfields including electronics , digital computers , power engineering , telecommunications , control systems , radio-frequency engineering , signal processing , instrumentation , and microelectronics . Nikola Tesla ( Никола Тесла 10 July 1856 -- 7 January 1943 ) was a Serbian-American inventor , electrical engineer , mechanical engineer , physicist , and futurist who is best known for his contributions to the design of the modern alternating current ( AC ) electricity supply system . Tesla tried to put these ideas to practical use in his unfinished Wardenclyffe Tower project , an intercontinental wireless communication and power transmitter , but ran out of funding before he could complete it .