Distributed ferroelectric phase shifter with slots periodically inserted into ground

A modified structure of a distributed ferroelectric phase shifter is presented, which is obtained by periodically inserting slots into the ground of a conventional distributed phase shifter. The principle is explained and electromagnetic simulation results are reported. It produces higher phase shift and, at the same time, matches port impedance better without reducing the width of the centre strip conductor of the coplanar waveguide, compared with the conventional structure.