A novel compact planar magic-T using CPS and microstrip-to-CPS transition

Abstract

This letter proposes a novel planar magic-T employing microstrip lines and a coplanar stripline (CPS) integrating a microstrip-to-CPS transition. The proposed magic-T uses a CPS instead of the slot line used in conventional planar magic-Ts to reduce the radiation loss. Defected ground structures (DGSs) are also used to suppress undesired common modes. This circuit has several attractive advantages in comparison with the conventional similar designs such as excellent amplitude and phase performance, compactness, and widely useable structure using a microstrip-to-CPS transition. The design, analysis and prototype parameters are discussed, followed by the measured and simulated results of the proposed magic-T.