The influence of source impedance on charge amplifier

Abstract

This contribution discusses the influence of the source impedance on the complex sensitivity of a charge amplifier (CA). During calibration of a CA with varying source impedances deviations at higher frequencies were observed, which if not properly taken into account may generate systematic errors beyond the limits of the measurement uncertainty budget. The contribution discusses a model to describe the effect as well as an extension to established CA calibration procedures which allow to quantify and correct the effect.