Directly coupled lumped element isolator with three windings

Abstract

A new directly coupled lumped element isolator with three windings is proposed. A dummy load and a capacitor are connected to the additional third winding in parallel. As a result of circuit analysis, the configuration of the third winding must be parallel or anti parallel to the first winding, which has a role of direct coupling between the input and the output. When the cross angle between the first and the second windings is nearly 115 degrees, the band width of insertion loss becomes widest. Using HFSS, we confirmed the fundamental behavior of the new isolator.