Focused near-field adaptive nulling: experimental investigation

Focused near-field adaptive nulling has been demonstrated using an experimental linear phased array and a four-channel receiver. The measured adaptive cancellation of one near field interference source was in good agreement with theoretical predictions. The theory assumes that a dipole array without ground plane is the approximate dual of a rectangular waveguide array with ground plane. The results indicate that adaptive antenna performance testing using focused near-field adaptive nulling at approximately one aperture diameter range distance is a viable alternative to conventional far-field testing.<>