Analysis of directivity as a function of scan angle for planar arrays of radiating slots

Computer-aided determination of phase scanned slot array directivity is obtained via the computation of individual array slot driving point admittances as a function of scan angle or both the E and H-planes of the array. Carter's equation s for mutual coupling and the duality principle are employed to compute mutual couplings among the half wave length radiating slots in the finite ground plane of a plate array. Using the previously computed mutual computing coupling expressions and the complex radiating slot excitations, which vary according to the main beam scan angle, driving point admittances are obtained for any desired array principal plane scan angle. Using the scan angle dependent point admittance values previously determined, the reflection coefficients for each radiating element and subsequently the entire array are computed and used in turn to evaluate numerically, changes in directivity of the array as the main beam is scanning in an E or H principal away from broadside.