DGS based microstrip phase shifters

Phase shifter design for system application requires consideration of many factors such as bandwidth, phase shift, insertion loss, gain variation etc. This paper focuses on the development of microstrip phase shifters using defected ground structure (DGS). DGS has the characteristics of slow wave, wide stop band and compact size. The basic concept of DGS is introduced and the parametric characterization for variety of shapes of DGS is considered. The paper also focuses on alphanumeric shapes of DGS and compares the performance of phase shifter for all possible DGS shapes. The shapes of DGS in microstroip phase shifters are investigated for optimizing their phase variation, phase shift bandwidth, insertion loss, and return loss. The objective is to reduce the size of the phase shifter.