High tuning accuracy design of variable IIR digital filters

Our recent results in the design of high tuning accuracy variable IIR filters are given in this work. The accuracy and the range of tuning are increased by minimization of the sensitivity of the structures (real and complex) used and by developing of new method of design based on cascaded identical sub-filters. Several new variable multioutput second-order IIR digital filter sections also are proposed. All theoretical results derived are verified experimentally.