The microwave beam projected by this antenna is swept over the horizon ... Each element is wired in series with a phase shifter that can be adjusted arbitrarily by the radar’s control system.

This beam steering is achieved by the use of a phase shifter (or its equivalent) in series with each and every antenna element. To make the above explanation more interesting and understandable ...

The phase response of each radiator column in the team's antenna is tuned by a switchable delay line structure. This ...