Study on Phase Center of Large Phased Array Antenna

Here presents a technique to calculate the phase center(PC)—phase gradient method. After analyzing the characters of large phased array antenna（PAA）, authors give a result that the PC of PAA is on the surface of PAA, and moreover, authors bring out the equations to calculate the position of PC. At the last part of this paper, a typical PAA with unsymmetrical amplitude and phase is used to validate the method.