An array of antenna elements is a set of antennas used for transmitting or receiving electromagnetic waves. An array of antennas is a collection of N similar radiators with the same three-dimensional radiation pattern. All the radiating elements are fed with the same frequency and with a specified amplitude and phase relationship for the drive voltage of each element. The array functions as a single antenna, generally with higher antenna gain than would be obtained from the individual elements. In antenna arrays electromagnetic wave interference is used to enhance the electromagnetic signal in one desired direction at the expense of other directions. It may also be used to null the radiation pattern in ...