Examination of the SVSWR methods using the Monte Carlo Method

Site Voltage Standing Wave Ratio (SVSWR) based EMC test site validation methods for the frequency range 1 to 18 GHz are analyzed with the Monte Carlo method. Simulations with a simple ray tracing simulation model are performed with certain assumptions for chamber size and absorber return loss. Since none of the methods define a measurand a proposal is given which can be applied to several measurement methods. This creates a possibility to compare the different methods but leads to negative systematic errors. The magnitude of the systematic error depends on the site validation method itself. The higher the number of measurement points of a method the lower is the systematic error. Another outcome of the Monte Carlo simulation is the repeatability for each method. It can be shown that the repeatability is improved by the application of a post processing filter as proposed by the Time Domain SVSWR method. A second approach to improve the repeatability is a large number of measurement points.