HIGHLY SELECTIVE RC-ACTIVE FILTERS USING MUCROER POLYNOMIALS.

The aim of this paper is to show the complete approximation, design, and realization procedure of a narrow bandpass filter. The filter to be designed is centered at 120 Hz, with a 2% passband, a maximum reflection coefficient in the passband of 25%, and a monotonic attenuation alpha in the stopbands, such that alpha greater than equivalent to 55 dB for f less than equivalent to 1160 Hz and f greater than equivalent to 1240 Hz. The use of the classical Chebyshev polynomials yields very high Q-factors for the critical sections, whereas a suitable mucroer polynomial substantially lowers the critical Q-factors and allows the use of low-cost sections with only one o. a.