Study on absolute calibration methods for mixer-based NVNA

This paper studies on the calibration of a 0.1-20 GHz mixer-based two-port coaxial Nonlinear Vector Network Analyzer (NVNA), especially the absolute calibration techniques. And from the 8-term error model, we present two alternative two-port calibrating procedures, whose outcomes are revealed equivalent to those of the traditional "unknown thru" method by experiments. The new methods not only relax the requirements of "thru" line, provide more choices and more convenience for calibration, but also offer a way to examine the rationality and validity of the 8-term error model for NVNA.