On-wafer multi-port circuits characterization technique with a two-port VNA

This paper describes a simple technique for on wafer passive multi-port circuits characterization. This method gives an efficient measurement of the scattering S-parameters of these devices at their ports reference planes. Furthermore, it provides cost saving in terms of used wafer surface and equipments by using an universal two-port Vector Network Analyzer (VNA). This method is applied to the characterization of a branch-line coupler designed on a lossy silicon substrate at millimeter waves (30 GHz). The de-embedding and the experimental procedures are presented in this paper. The experimental measurements extracted from our method show a good agreement with those made with a four-port VNA.