This work is a first step in the development of a radar simulation model. The aim of the model is to study the influence of various sub-components on the performance of radar systems. The subcomponents concerned are primarily those in the receiver chain, occurring before the digital signal processing. The first step includes the modeling of receiver filters and the A/D converter. In order to calculate the performance of a radar system, besides the components the modeling includes an idealised simulation of the transmitted waveform, wave propagation, target reflection, antenna, and signal processing. Such an idealised simulation has been implemented in a first version.