Error analysis in a practical digital beamformer

The authors discuss a novel approach used to identify, isolate, and correct some of the receiver errors that exist in the digital beamforming (DBF) testbed at Rome Laboratory. Their effects on the antenna´s receive radiation pattern are illustrated. In particular, the effects are demonstrated via the ability to obtain a low sidelobe antenna pattern. The fast Fourier transform (FFT), applied to the output response of the array, is used as a diagnostic tool, first to identify the errors and later to isolate the errors, making it possible to filter them out. Because of the nature of DBF systems, the FFT can be applied at the element level to assist in pinpointing the source of the described errors.<>