Measurement Uncertainty Research On Vector Network Analyzer

The vector network analyzer(VNA)is the most common and complex instrument for microwave component measurement.The calibration and measurement uncertainty analysis of VNA are of great theoretical and practical significance for measurement.This paper researches the measurement uncertainty and calibration method of two-port and multi-port vectors,accordingly the research works and innovation are as follows:1.The measurement uncertainty of two-port vector network analyzer with random error in measurement is introduced.In the process of the formula derivation for the uncertainty,not only systematic errors but also new errors(random errors)which are generated during the actual test are introduced.By considering random errors,a complete two-port VNA error model is obtained based on the general 12 error models of classical vector network analyzer.Through the stream graph simplification and derivation,the evaluation formula of measurement uncertainty is obtained,and the accuracy of the formula is verified by multiple tests.2.According to the above complete two-port error model,the measurement uncertainty of multi-port analyzer is researched.Taking the four-port vector as an example,with the help of the generalized node equation and the stream graph simplification,the calculation formula for evaluating the measurement uncertainty of the scattering parameters is derived.3.A LZZ(line-offset offset-open offset-short)calibration method based on ABCD matrix is studied and the uncertainty of the two-port vector network analyzer due to non-ideal calibration standards is discussed.