Assessing the performance of uncertainty calculations by simulation

Some RF and microwave measurements pose difficulties for uncertainty calculations. A case in point is when the magnitude of the complex reflection coefficient of a weakly reflecting device is measured, such as a load or power sensor. To investigate this, simulations are used to generate a large number of independent sets of data for testing different calculation methods. We find that, while several standard methods of calculating uncertainty perform badly, a simple ad hoc modification can overcome these problems. The study shows that the simulation approach is a pragmatic way of assessing uncertainty calculation performance.