A planar microwave phase shifter using microstrip–CPW–microstrip transition with defected ground structures

Abstract

A novel planar printed phase shifter design is proposed in this paper. The design is developed with microstrip–conductor-backed coplanar waveguide– microstrip (MP–CBCPW–MP) transition line with different defected ground structures (DGS). The differential phase shift can be controlled by altering the DGS dimensions. Three prototypes with DGS dimensions 5 × 10, 10 × 20, and 10 × 30 mm2, are employed at the finite ground plane to achieve 5°, 20°, and 30° shift in phase respectively and are validated with the phase delay relation. The prominent effect of the transition region is to confine the field area. The resonance is at 700 MHz with a bandwidth of 400 MHz (0.4–0.8 GHz). The proposed phase shifter can be used for broadcasting applications. The proposed MP–CBCPW–MP transition phase shifter design with DGS is simulated, fabricated, and measured to analyze its performance.