Broadband parallel stubs phase shifter using defected ground structure

In this paper, a broadband phase shifter is presented and employs a defected ground structure (DGS) under parallel stubs. Compared with the one without DGS, the proposed design has a wider bandwidth, smaller size and with the very high impedance microstrip lines eliminated. For demonstration purposes, a novel broadband phase shifter using H shaped DGS was designed to operate over a frequency range from 2.2 GHz to 6.1 GHz. It was measured to have insertion loss and phase variation within 2.2 dB and 3.3deg over the desired frequency band.