An Error Analysis for the RF-Attenuation Measuring Equipment of the PTB Applying the Power Method

Abstract

After a short review on the different attenuation measuring techniques, some special points of view in the application of the power method are described. By employing exactly measured standard attenuators in cascade, the modified measuring equipment can be used over a range of more than 100 dB. An error analysis is given considering all essential sources of systematical errors the limits of which are calculated. It is shown that the systematical error of the system described is less than 1 · 10-4 dB for very small attenuation values. It is in the order of |δA| ≈ 1 · 10-4 (1 + A) dB over the whole range, when A is the numerical value of the attenuation (in dB) being measured.