Loop filter design and optimization for quadrature delta-sigma converters

This work proposes an auxiliary tool for the well-known Schreier´s Delta-Sigma toolbox. The proposed tool is based on flow-graph analysis and offers means to generate a loop filter state-space model for the given topology. The state-space model can be used as the initial behavioral model for performance verification. The proposed approach also eases performing a loop filter coefficient mismatch sweep. The emphasis is here on complex Delta-Sigma converters. For the complex domain, novel optimization methods for quadrature-noise insensitive noise transfer function are also presented.