A new high frequency balun with simplified impedance matching technique

In this paper, a high frequency balun with a very simple and intuitive impedance matching procedure is presented. Owing to the presence of symmetry in the proposed structure, the even-odd mode analysis is applied which results into closed-form design equations. Since, the proposed design has many variables that can be chosen independently, the design equations are investigated to assess the limitation of the choice of different variables. Based on the proposed theory, a balun has been designed for operation at 2GHz and implemented on RO4350B substrate. The EM simulation and the measured results match well and thus validate the design.