Editing Reflective array antenna (section)

== Radiation pattern and beam steering ==
When driven in phase, the [[radiation pattern]] of the reflective array is a single [[main lobe]] perpendicular to the plane of the antenna, plus several [[sidelobe]]s at equal angles to either side. The more elements used, the narrower the main lobe and the less power is radiated in the sidelobes.

The main lobe of the antenna can be steered electronically within a limited angle by [[phase shift]]ing the drive signals applied to the individual elements. Each antenna element is fed through a [[phase shifter]] which can be controlled digitally, delaying each signal by a successive amount. This causes the wavefronts created by the superposition of the individual elements to be at an angle to the plane of the antenna. Antennas that use this technique are called [[phased array]]s and often used in modern radar systems. 

Another option for steering the beam is mounting the entire antenna structure on a pivoting platform and rotating it mechanically.