A Steerable Series-fed Phased Array Architecture Using Tunable PRI/NRI Phase Shifters

This paper presented a steerable series-fed phased array architecture using zero-degree tunable positive/negative-refractive-index (PRI/NRI) phase shifters. Using PRI/NRI phase shifters centered around the 0deg mark makes the array capable of steering its beam off broadside. The patch antennas of the array are moved off the centerline of the main feed line allowing for the inclusion of impedance transformers, which in turn, allows using identical inter-stage phase shifters, and allows using the same bias/control voltages to tune all stages.