1) Microwave technology 2) Radio astronomy aid 3) Radio frequency antenna type 
[electromagnetic] An antenna array is a set of individual antennas used for transmitting and/or receiving radio waves, connected together in such a way that their individual currents are in a specified amplitude and phase relationship. This allows the array to act as a single antenna, generally with improved directional characteristics (thu...
(from the article `antenna`) More powerful antennas were constructed during the 1920s by combining a number of elements in a systematic array. Metal horn antennas were devised ...
A system of antennas coupled together to obtain directional effects, or to increase sensitivity.
a directional antenna or system of antennas for radio transmission or reception. Also called