Rapid estimation of true Direction Of Arrival for dielectric lens based adaptive array antennas

Smart antenna involves array processing to manipulate the signals induced on various antenna elements to accomplish beam steering and improve interference rejection. To improve directivity a shaped dielectric lens is used to further collimate the rays in a specified direction and help reduce interference. Direction Of Arrival (DOA) estimation algorithms specifically Multiple SIgnal Classification (MUSIC) and Minimum Variance Distortionless Response (MVDR) are employed for a planar array - shaped dielectric lens combination to locate a desired user. Refractive effect of the lens has to be compensated for in these algorithms rapidly in real time to extract the true arrival angles. Geometrical optics is employed to trace the rays from an aperture in front of the lens through the shaped lens boundaries to the individual antenna elements to determine the DOA of the user signal. Angle dependent modifications for the DOA of the signal in both elevation and azimuth planes have been introduced to correct for the refractive effects of the lens and extract the correct angle of arrival using a new mapped column peak search technique.