First experimental <a href="https://en.wikipedia.org/wiki/phased_array" class="extiw" title="w:phased array">phased array</a> antenna, invented by <a href="https://en.wikipedia.org/wiki/Karl_Ferdinand_Braun" class="extiw" title="w:Karl Ferdinand Braun">Karl Ferdinand Braun</a> in 1905 in Strasbourg, Germany. This was a 3 element <a href="https://en.wikipedia.org/wiki/array_antenna" class="extiw" title="w:array antenna">array antenna</a> which transmitted a beam of radio waves whose direction could be rotated electronically to 3 directions 120° apart.   It consists of 3 monopole antennas at the corners of an equilateral triangle whose bisector is a quarter <a href="https://en.wikipedia.org/wiki/wavelength" class="extiw" title="w:wavelength">wavelength</a> long.  Two of the antennas are fed in phase but a quarter wave phase delay can be switched into the feed line of one.  Braun won the Nobel Prize in Physics in 1909 for his radio work.  Phased arrays are now widely used in radar and many other applications.
Karl Ferdinand Braun
Retrieved January 14, 2017 from <a rel="nofollow" class="external text" href="https://www.nobelprize.org/nobel_prizes/physics/laureates/1909/braun-lecture.pdf">Karl Ferdinand Braun (December 11, 1909) Nobel Lecture: <i>Electrical oscillations and wireless telegraphy</i>, nobelprize.org Nobel Media AB, p. 230, fig. 14</a>.  Credited on site to <i>Nobel Lectures: Physics 1901 to 1921</i>, Elsevier Publishing Co., Amsterdam, 1967