The radiation pattern of an antenna from near-field correlation measurements

A new method is proposed for evaluating the radiation characteristics of a test planar-aperture antenna from its near-field behavior. The technique is based on calculating the Fourier transform of the autocorrelation function describing the measured output of a probe located in the near field of the test antenna. The method is established in practice with the aid of experimental results using horn, horn-reflector, and paraboloidal antennas. It is shown that the method is relatively simple and leads to a significant improvement in the accuracy of the gain and radiation pattern of antennas when compared with present methods.