Radiation distortions in fast frequency-scanned antenna arrays

The pattern deterioration that occurs at high scanning speeds in frequency-scanned arrays is studied. Four major effects are observed; these are 1) fall in main beam amplitude, 2) rise in sidelobe level, 3) angular shift in the location of the main beam, and 4) widening of the main beam. A theoretical limit on scanning rates is established beyond which pattern distortion becomes excessive. The results are illustrated by a numerical example.