A technique to reduce the apparent noise floor of emissions measurements

The noise floor of emissions measurements is clearly important in defining the usefulness of test results as this defines the lowest possible value that can be measured. Even in a (semi) anechoic chamber with no ambient signals thermal noise provides a lower bound on signal measurements. This paper describes a new technique that can allow EMI measurements to be made below the apparent noise floor. It also allows accuracy limits to be placed on these measurements. This approach can allow a significant speedup in EMI testing