Graphical design of air-gap stacked Marchand balun

A new Marchand balun for MMIC is proposed which uses air-gap stacked structures and does not need any dielectric process. To design the newly proposed Marchand balun, simple graphical design method was used, which is based on Tsai and Gupta's generalized coupled lines model. The simple design results were compared with a general full-wave analysis. In this case, HP-Momentum simulator was used.