Full 2-Port Vector Network Analyzer using Nonlinear Calibration of Six-Port Reflectometer

This paper represents implementation of a low cost full 2-port vector network analyzer based on six port reflectometer (SPR). It consists two SPRs of different topologies designed at 2 GHz and a power splitter. A full two-port nonlinear calibration method has been followed to determine all the calibration coefficients. After determining the calibration coefficients, the nonlinear equations are solved using Levenberg-Marquardt algorithm to obtain magnitude and phase of S₁₁, S₂₁, S₁₂ & S₂₂ for various arbitrary loads. The results obtained through this system are comparable with that of a commercial VNA.