Calculating the Phase Center of an Antenna: A Simple Experimental Method Based on Linear Near-Field Measurements

Abstract

In this paper, a simple experimental method based on linear Near-Field measurements for finding the real position of the phase center of an antenna is presented. In order to do that, measurements along both principal axes of the antenna are carried out. Then, each set of data is treated individually to determine the phase center for each principal plane. In this method, the measured phase is expressed in terms of the relative position to the axis as a quadratic expression, in which the independent term gives the perpendicular distance from the points of the measurement to the estimated phase center. Thus,this value is obtained by adjusting a second-order polynomial expression to the curve of the measured phased. The operational limits of the method are generally determined by the amplitude variation of the measured field. In order to establish these limits and verify its functionality, a series of simulations have been carried out. Finally, the method has been used to characterize some real antennas