New differential phase shifters using novel right-handed metamaterial structures

The present paper proposes new schemes of the differential phase shifter, which employs novel metamaterial structures as the phase shifter arm to replace the conventional transmission line or the parallel-coupled transmission lines with one end connected together in the basic Schiffman phase shifter. The new circuits can obtain broadband phase shifts for 90 degrees and the phase deviations are quite small on the whole bands. The design procedure is entirely described to optimize the shifter´s performance and device prototypes of the novel phase shifters with the simulation results have been illustrated in this paper. The proposed novel metamaterial structures will exhibit good prospects for the microwave circuit applications.