Structure generation and design of multiple loop feedback OTA-grounded capacitor filters

Abstract

This paper addresses the structure generation, analysis and synthesis of multiple loop feedback OTA-C filters. A systematic approach is proposed for all-pole filters, and the generation and design of minimum component structures are extensively exemplified. Two general methods for transmission zero realization are also suggested and two architectures with simple design formulas are illustrated. Using the theory many new interesting configurations can be produced alongside some known structures. All the filter architectures contain only grounded capacitors and all internal nodes in canonical realizations have a grounded capacitor. A general method for sensitivity analysis of the structures is formulated. Numerical design examples and simulation results are also presented. The essence of the theory is the establishment of the relationship between the filter structure and the feedback matrix, which makes systematic structure generation and general design equation formulation possible.