Minimum Active Component Count Formant and Inverse Formant Filters Designs

Active-RC filter topologies capable of extracting the waveform of vowels from the associated glottal pulse trains as well as of performing the inverse procedure, are presented in this paper. Both are implemented using only few operational-amplifiers as active elements, offering minimization of the active component count and, also, of the dc power dissipation. The provided simulation results, obtained using the OrCAD PSpice suite, in both frequency and time-domain, confirm the operation of the presented structures.