ABSTRACT
Vector network analyzers (VNA) find very wide application as a primary tool in measuring and characterizing circuits, devices, and components. Sources of uncertainty or error in VNA measurements are primarily the result of systematic, random, and drift errors. Systematic errors, however, arise from imperfections within the VNA, are repeatable, and can be largely removed through a process of calibration. In addition, practical limitations of the VNA in the form of limited dynamic range, isolation, imperfect source/load match, and other imperfections contribute systematic error to the measurement. A mathematical description of systematic errors is accomplished using the concept of error models. The error models are intended to represent the most significant systematic errors of the VNA system up to the reference plane — the electrical plane where standards are connected. Basic measurements consist of applying a stimulus and then determining incident, reflected, and transmitted waves.
