Next Article in Journal
Analysis of SNR for High-Orbit Target Detected by Ground-Based Photoelectric System
Next Article in Special Issue
Calibration for Sample-And-Hold Mismatches in M-Channel TIADCs Based on Statistics
Previous Article in Journal
Prediction of Douglas-Fir Lumber Properties: Comparison between a Benchtop Near-Infrared Spectrometer and Hyperspectral Imaging System
Previous Article in Special Issue
An Efficient Method to Learn Overcomplete Multi-Scale Dictionaries of ECG Signals
Open AccessArticle

Validation of Fractional-Order Lowpass Elliptic Responses of (1 + α)-Order Analog Filters

1
Department of Telecommunications, Brno University of Technology, Technicka 12, 616 00 Brno, Czech Republic
2
Department of Electrical and Computer Engineering, The University of Alabama, Tuscaloosa, AL 35487, USA
*
Author to whom correspondence should be addressed.
This paper is an extended version of paper published in 2018 41st International Conference on Telecommunications and Signal Processing (TSP), Athens, Greece, 4–6 July, 2018.
Appl. Sci. 2018, 8(12), 2603; https://doi.org/10.3390/app8122603
Received: 15 November 2018 / Revised: 4 December 2018 / Accepted: 10 December 2018 / Published: 13 December 2018
In this paper, fractional-order transfer functions to approximate the passband and stopband ripple characteristics of a second-order elliptic lowpass filter are designed and validated. The necessary coefficients for these transfer functions are determined through the application of a least squares fitting process. These fittings are applied to symmetrical and asymmetrical frequency ranges to evaluate how the selected approximated frequency band impacts the determined coefficients using this process and the transfer function magnitude characteristics. MATLAB simulations of ( 1 + α ) order lowpass magnitude responses are given as examples with fractional steps from α = 0.1 to α = 0.9 and compared to the second-order elliptic response. Further, MATLAB simulations of the ( 1 + α ) = 1.25 and 1.75 using all sets of coefficients are given as examples to highlight their differences. Finally, the fractional-order filter responses were validated using both SPICE simulations and experimental results using two operational amplifier topologies realized with approximated fractional-order capacitors for ( 1 + α ) = 1.2 and 1.8 order filters. View Full-Text
Keywords: fractional-order filters; fractional calculus; Chebyshev filters; low-pass filters; magnitude responses fractional-order filters; fractional calculus; Chebyshev filters; low-pass filters; magnitude responses
Show Figures

Figure 1

MDPI and ACS Style

Kubanek, D.; Freeborn, T.J.; Koton, J.; Dvorak, J. Validation of Fractional-Order Lowpass Elliptic Responses of (1 + α)-Order Analog Filters. Appl. Sci. 2018, 8, 2603.

Show more citation formats Show less citations formats
Note that from the first issue of 2016, MDPI journals use article numbers instead of page numbers. See further details here.

Article Access Map by Country/Region

1
Back to TopTop