Evaluation and modeling of measurement resolution of a vector network analyzer for extreme impedance measurements

Abstract

A broadband S-parameter measurement system for extreme impedance measurements is proposed and analyzed in terms of its accuracy. Measurement speed and system resolution at extreme impedance values is comparable to that of a conventional Vector Network Analyzer performance achieved for 50 Q device measurements. A dedicated one-port calibration method is modeled in a circuit simulator environment and implemented for the proposed system. Compared to the 0.05 % measurement resolution in extreme impedance measurements using a state-of-art 50 Q VNA, an almost fifty times lower 0.001 % resolution is achieved with the proposed VNA system utilizing an interferometric principle, with active compensation of reflected waves.