Equi-Spaced-Points-Method (ESPM) for Antenna Radiation Pattern (ARP) Measurements with 3D- Rotation

The antenna radiation pattern (ARP) is a mathematical function or graphical representation of the radiation properties of the antenna as a function of the spherical coordinates. In the equi-spaced point method (ESPM), the antenna radiated power and maximum directivity are calculated without any complex integration, i.e. the fundamental concept in this paper is that rather than selecting points and then weighting their contributions to the power integral, the measurement points themselves all carry the same weight. The individual points are placed on the sphere in the center of their own equal area segment. This equi space sampling of the antenna radiation pattern results in the equi-spaced antenna radiation pattern (ES-ARP). The ARP analysis is carried out in MATLAB reg V7.3 and Mathematica reg V5.2 for a generalized antenna pattern. The analytical and numerical values of the radiation power and directivity are computed for this pattern both, without rotation and with rotation. After 5pi/16(radians) rotation in 3D, the deviation between the equal angle based numerical value and analytical value of the radiation power and directivity is maximum, i.e. 23.5% for 324 Equi angle samples. Finally by using the ESPM method it was found that the deviation is reduced to 0.004% for 100 Equi spaced samples, independent of rotational position. The ESPM gives more accurate results than the Equi angle based numerical method for reduced number of sampling points, irrespective of 3D rotation.