A volumetric electrically scanned two-dimensional microwave antenna array

By proper interelement phase control, the beam of a stationary two-dimensional antenna array can be scanned throughout a volume in space. This scanning is demonstrated with an array of radiating waveguides fed by a unique arrangement which permits both independent phase control of every element and frequency scanning along one dimension of the array. Volumetric scanning is achieved by various combinations of these phase-shifting schemes. The measured beam position corresponds very favorably with theory for any given phase distribution. The adverse sidelobes appearing in the measured radiation patterns correspond to systematic errors. Methods for suppressing these systematic errors are discussed in detail, and encouraging experimental results are reported.