Design and performance of bilateral interdigital coplanar waveguide phase shifter for rf communication applications

摘要

A new design of a bilateral interdigital coplanar waveguide (BI-CPW) phase shifter using tunable barium strontium titanate thin film is presented and analyzed. This new design has shown a phase shift of 203°/cm at 25 GHz. Compared to a normal coplanar waveguide (CPW) type, a two-thirds size BI-CPW phase shifter is realized by interdigital capacitive loading., The phase shifter is fabricated with processes fully compatible with current SiGe technology. In addition, it is shown that operating voltages can be reduced significantly within a practical range by the inclusion of a polysilicon layer as a control electrode.