A Simple Method for Improving Accuracy in Determining the Beam Axis of an Antenna

The simplest method for determining the beam axis of an antenna, commonly used in measurement practice, is to search for the peak value within the three-dimensional (3-D) radiation pattern data. This letter shows that the accuracy in determining the beam axis can be improved statistically without repeated measurements. The proposed method is based on an analogy to the center of mass of a spherical region with given mass distribution. The method is straightforward and more accurate than the simple search for peak value and the competitive method of centroid, which uses level curves. The proposed method was verified numerically and experimentally, and its accuracy was confirmed.