The word 'antenna' is from Guglielmo Marconi's test with wireless equipment in 1895. For the test, He used a 2.5 meter long pole antenna with a tent pole called ' "l'antenna centrale" ' in Italian. So his antenna was simply called ' "l'antenna" '. After that, the word 'antenna' became popular among people and had the meaning it has today. The plural of antenna is either "antennas" or "antennae" (U.S. and Canada tends to use "antennas" more than other places).