A C-band digital beamforming array

A 32-element C-band digital beamforming (DBF) array which serves as a testbed for algorithm development and demonstration of digital beamforming technology is presented. Cost reduction, primarily in the areas of receiver modules, I/Q generation, and array alignment/calibration, was an overall consideration. Individual components of the beamforming system are discussed. Topics covered include receiver modules, I/Q generation, calibration/array alignment, and the technique used for monitoring quality and integrity of digitized array data. The subject of system drift is addressed by comparing single-source receive patterns taken at various times. RF isolation is demonstrated using IF spectral plots computed from digitized receiver module data. In addition, single-source receive patterns for various arrival angles are presented. The experimental data is used to illustrate the performance of a DBF array in two rather important application areas, namely, spatial analysis for source detection and localization and adaptive nulling.<>