Fast optimization of 3D focusing system using genetic algorithm

Artificial constrained lenses have received much interest for potential use in millimeter ACC radar systems [1]. For next generation radar, it is considered to have high gain antennas with beam reconfiguration that allows both long and short-range operations (switching system). A general procedure to reduce aberrations produced by such high-gain antenna focusing elements is presented. The purpose is to design such element with minimum phase errors (aberrations) to reduce side lobe levels for relatively large beam tilt angles (±30°). The procedure involves a 3D fast optimization method based on genetic algorithm (GA) that reduces the geometrical aberrations. In a second step, the lens is treated by a full wave method to obtain the far field patterns. Finally, measurements made in a millimetre anechoic chamber are shown for a spherical lens implemented in foam technology.