Improvement on frequency characteristics of integrator-based filters by reducing spread of unity-gain frequencies

摘要

In the design of integrator-based filters, there are degrees of freedom in selection of the signal flow graph representing the connection state of the integrator. In this paper, a procedure is proposed for selecting the signal flow graph for a filter with a small deviation from the ideal frequency characteristics. In general, the integrator works ideally near the unit-gain frequency. Hence, in order to realize a filter with excellent characteristics, a guideline is described for selecting the signal flow graph such that the unit-gain frequencies of all integrators used in the filter are close to each other.