Compact Tunable Phase Shifters on Screen-Printed BST for Balanced Phased Arrays

Two designs for compact continuously tunable phase shifters are presented employing integrated ferroelectric varactors based on screen-printed barium-strontium-titanate thick film. The circuits are based on left-handed transmission-line topologies that allow to realize very compact modules. The proposed designs have total lengths of 2.1 and 3.8 mm and provide a differential phase shift of more than 360° and a figure of merit of 51°/dB at 10 GHz. Furthermore, the phase shifters are in coplanar strip configuration, making them attractive for systems composed of balanced components.