Digital Bandpass IIR Filers with High Selectivity
Peter Apostolov
Electronic Devices, Vol. 12, No. 2, 2023.
DOI: https://doi.org/10.6025/ed/2023/12/2/45-53
Link: https://www.dline.info/ed/fulltext/v12n2/edv12n2_3.pdf
Abstract:
This paper proposes an optimal third-degree polynomial, which approximates Kroneckerâ€™s delta function with high precision. The polynomial is obtained by a new approximation method, called â€œmethod with compressed cosinesâ€. The method is based on Chebyshevâ€™s optimality norm. The polynomial is used for narrow bandpass IIR filter design. The filterâ€™s selectivity depends on the parameter Q without increasing the polynomialâ€™s order. With the proposed method an IIR filter with 5(6) multipliers, a very narrow passband and a high stopband attenuation can be designed.