A robust broadband calibration method for wafer-level characterization of multiport devices

This paper describes the theory and practical results of the new multiport calibration procedure especially suited for wafer-level device characterization over a wide frequency range. An analysis of the currently available multiport calibration approaches was carried out. The advantages and drawbacks of each approach are demonstrated. It is shown that a robust wafer-level multiport calibration procedure should combine the strengths of both 7-term and 10-term based algorithms. It should also provide reference-match measurements on each VNA measurement port and be insensitive to the behavior of highly-reflective standards and the design of transmission standards. Corresponding to these requirements, the definition of the advanced multiport RRMT+ algorithm is given. The results of a practical experiment proved the theory and demonstrated the advantages of the new multiport RRMT+ calibration procedure.