A New CCII-Based Universal Biquad

This paper proposes a CCII-based structure from which one can derive, with minimum of adjustments, a series of biquads, able to realize not only the most usual second-order transfer functions – low-pass, band-pass, all-pass – but also transfer functions with imaginary and complex zeroes. Other interesting features of this universal biquad are its cascadability and the fact that it provides the orthogonal tuning of its transfer function coefficients. A design example illustrates the wide range of sizing and tuning options available.