Noise Analysis of Time Variant Shapers in Frequency Domain

In this paper we discuss the noise analysis of time variant shapers in the frequency domain, based on well established concepts of the theory of time varying circuits. A frequency domain extension of the techniques typically adopted for noise analysis in detector instrumentation is proposed and applied to a classic time variant shaper: the gated integrator. In some cases, this frequency domain method makes easier the study of systems in which one of the blocks or noise sources is better described in the frequency domain. In that sense, a practical case involving a gated integrator and a Correlated Double Sampler (CDS) time variant shaper is presented.