Concave Spherical Feed Array for Luneberg Lens

This paper presents a design of concave spherical base Vivaldi feed array for beam steering without the use of any phase shifters. The research goal is reached through the use of Luneberg lens aperture and switching of active feed array element. Vivaldi array element has solid metal sheet design with stripline feeding for linear polarization. Special elements are used for mutual coupling effects weakening and directional pattern back lobe suppression at low frequencies. The design has such advantages, like broad bandwidth, wide scan angle in azimuth and elevation, low loss level, and machining simplicity of feed array.