Do bench-tests keep up with current technology in EMI receivers?

Today, instruments can exploit Fast Fourier Transform (FFT) processing to measure electromagnetic interferences (EMIs). The advantages of such an approach are undisputed. EMI receivers benefit from the extremely short measurement time, compared to that obtained with traditional (super-) heterodyne technology, and of the complete digitalisation of the signal processing. However, not all processing techniques that work correctly in other application fields suit well the demanding measurements of EMIs. Unfortunately, current standards do not prescribe specific tests to check the validity of newly introduced techniques. In this paper, we show that techniques, such as multi-resolution analog-to-digital conversion and measurement repetition, do not always bring advantages in the EMI context and cannot be used to compensate deficiencies in the hardware. We validate our argumentations with lab experiments, where we prove our claims with one of the most well-performing FFT-based EMI receivers that is available today on the market.