High-Accuracy Planar Near-field to Far Field Transform for Low Side-Lobe Antennas

Planar near-field to far-field transform (NF-FF) by the Fast Fourier Transform (FFT) in antenna measurement is often insufficiently accurate, especially for low side-lobe antennas. This paper presents a new highly accurate FFT based on Gaussian Quadrature, and applies it to discretize the double integrals in NF-FF. An example of the low side-lobe antennas show that although the proposed method is slightly slower than the conventional method, it obtains a much more accurate pattern than the latter does.