This proposal is addressed to the technical problem of determining the far-field performance of adaptive array antennas using near-field measurements. The innovative concept proposed is to focus the array in the near field by the Fresnel transform approximation to, in effect, make planar the spherical wavefronts from near-field jammers, so that they appear to be located in the far-field when the array is focused at the near-field range of the jammers. The concept has the potential of providing a highly accurate and efficient near-field measurement technique for adaptive arrays at very low cost. In addition, the concept eliminates the transformations generally necessary to obtain the far-field pattern from near-field measurements. The requirements for probe pattern compensation and high probe position accuracy are obviated since the far-field pattern is measured directly in the near field.
