A noise model for the analog correlator

A noise model for the analog correlator used in the ultra wideband (UWB) receivers is described in this paper due to the lack of simulation capability of current EDA tools on noise performance of the correlator. The circuit is divided into several parts to calculate the equivalent noise sources. The ideal impulse generators are then applied instead of the noise sources to obtain the time varying transfer functions. Fourier transforms are applied to explore the relationship between the noise input and output in frequency domain for each part. Then the symmetrical noise sources are grouped together and the periodicity of the circuit is utilized lo further simplify the model. This model can fairly be used to evaluate the noise performance of the correlator and other linear time-varying (LTV) circuits for impulse radio systems.