An Improved Method for the Evaluation of Uncertainty of Channel Power Measurement with a Spectrum Analyzer

The paper deals with the uncertainty of channel power measurements when performed with a superheterodyne spectrum analyzer. In particular, a simple yet effective method for the evaluation of uncertainty is proposed. The method is based on the measurement of some suitable parameters associated to the input signal\´s spectrum and on the use of a suitable post-processing formula. This formula is deduced by applying the "Law of propagation of uncertainty in measurement" and by considering a suitable idealized spectral trace instead of the one displayed by the analyzer for the signal under test. The method allows a user to greatly simplify the computation of the measurement uncertainty without loss of accuracy. The effectiveness of the method is verified both theoretically and practically. Practical guidelines for the optimization of the spectrum analyzer setup and the reduction of uncertainty are also provided