Parabolic Reflector Near-field to Far-field Transformation Using FDTDM and Pocklington Equation

We present a technique to define far field radiation pattern of an antenna. Methodology applies the discrete Pocklington equation to transform the surface field data into a current distribution along the antenna, defining virtual currents over its surface and then through array theory obtain far field patterns. We apply the method over a 1.5m diameter parabolic reflector, using Finite Difference Time Domain Method (FDTD), to geometricaly acquire magnitude and phase of field over the surface, where the electric field must be known; the acquired electric field is transformed into a current vector using the discrete Pocklington equation, and then we apply array theory, defining an array factor to obtain the field pattern in the Fraunhofer region. To validate our results, we compare them measuring an actual reflector at 2.45 GHz.