Karabi Biswas

Realization of a Constant Phase Element and Its Performance Study in a Differentiator Circuit

A simple method for fabricating a constant phase element (CPE) has been discussed. Dependence of the phase angle on several physical parameters have also been elaborated. Finally, a fractional-order differentiator circuit has been constructed using the CPE, and its performance has been compared with the simulated results

Fabrication of a Fractional Order Capacitor With Desired Specifications: A Study on Process Identification and Characterization

This paper reports the fabrication of a fractional order element (FOE) with predefined specifications. The FOE is a circuit element similar to resistance, capacitance, and inductance generally used in electrical network. The specifications of integer order elements, i.e., inductance, resistance, and capacitance, are defined by the magnitude only as their exponents are of fixed value, namely, - 1, 0, and +1, respectively. The specialty of FOE is that both its magnitude and exponent value have to be defined, where the value of the exponent dictates the behavior. This paper elaborately discusses the methodology of realizing a fractional order capacitor named here as FOE (or, in general, FOE). It has been found that a FOE can be realized by dipping a capacitive-type probe, coated with a porous film of polymer of particular thickness, into a polarizable medium. The thickness, uniformity, and stability of the porous film, on the electrode, are responsible for different exponent values.

Experimental studies on realization of fractional inductors and fractional-order bandpass filters

This paper presents the hardware realization and performance study of fractional inductors of order 0<α<2. The fractional inductors used in this work have been realized with the help of general impedance converter circuit and fractional capacitors. Impedance characterization of fractional inductors with different exponents has been carried out experimentally. Also a generalized approach to design a fractional-order bandpass filter is discussed in this work. The fractional-order bandpass filter consists of a series combination of a resistor, a fractional inductor of order 1<α<2, and a fractional capacitor of order 0<β<1. The performance of fractional-order bandpass filters has been studied and compared with corresponding integer-order filters through both experimentation and simulation. Copyright

Performance study of fractional order integrator using single-component fractional order element

A single-component fractional order element (FOE) is realised and its performance is compared with the conventional FOEs such as cross resistance-capacitance (RC) ladder network and domino ladder network in the analogue domain. The single-component FOE is a capacitive-type probe coated with a porous film of poly-methyl-methacrylate (PMMA) and is dipped in polarisable medium. The fractional exponent of the fabricated single-component FOE and domino ladder can be varied between 0 and 1 whereas that of cross RC ladder realised in this work is 1/2. The performance of fractional order integrator (FOI) using these FOEs is studied in both frequency and time domain by simulation and experimentation. A comparative analysis of the performance of FOI is carried out.

A Design Example of a Fractional-Order Kerwin–Huelsman–Newcomb Biquad Filter with Two Fractional Capacitors of Different Order

Design, realization and performance studies of continuous-time fractional order Kerwin–Huelsman–Newcomb (KHN) biquad filters have been presented. The filters are constructed using two fractional order capacitors (FC) of orders α and β (0<α, β≤1). The frequency responses of the filters, obtained experimentally have been compared with simulated results using MATLAB/SIMULINK and also with PSpice (Cadence PSD 14.2), where the fractional order capacitor is approximated by a domino ladder circuit. It has been observed that fractional order filters can give better performance in certain aspects compared to integer order filters. The effects of the exponents (α and β) on bandwidth and stability of the realized filter have been examined. Sensitivity analysis of the realized fractional order filter has also been carried out to investigate the deviation of the performance due to the parameter variation.

Practical Realization of Tunable Fractional Order Parallel Resonator and Fractional Order Filters

This paper introduces a tunable fractional order parallel resonator (FOPR) whose resonating frequency can be tuned by the coefficient of a fractional order (FO) element (fractor). At the same time, its Q-factor can be set very high (theoretically infinite) by varying its resistor. Using this FOPR circuit, two simple FO filters (FO bandpass and FO notch) are also developed. The paper includes detail sensitivity analyses of these circuits for various circuit parameters and describes how different design parameters of proposed FOPR and FO filters are chosen accordingly. Proposed FOPR and FO filters are simulated in MATLAB and realized in hardware. The hardware circuits are tested practically, and detail experimental results are provided. It is found that the experimental data are in good agreement with the simulation data. In hardware, the realized FOPR has achieved a Q-factor up to 360, and the realized FO notch filter has Q > 10 when its attenuation is more than 30 dB. Different practical aspects of filter tuning are also described in detail.

Packaging of Single-Component Fractional Order Element

In this paper, packaging issue of a single-component fractional order element (FOE) is presented. Packaging is required for better longevity and miniaturization of dimensions. In addition, it helps in fabrication of a single-component FOE as a discrete element similar to the existing passive circuit elements. An alternate electrode (platinized silicon) for fabricating single-component FOE other than the existing copper electrode has been proposed for the first time in this paper. A comparative analysis has been carried out between the performances of packaged FOEs using copper and platinized silicon electrodes.

Design and performance study of phase-locked loop using fractional-order loop filter

The present work reports the realization of an analog fractional-order phase-locked loop FPLL using a fractional capacitor. The expressions for bandwidth, capture range, and lock range of the FPLL have been derived analytically and then compared with the experimental observations using LM565 IC. It has been observed that bandwidth and capture range can be extended by using FPLL. It has also been found that FPLL can provide faster response and lower phase error at the time of switching compared to its integer-order counterpart. Copyright

Guest Editorial: Fractional-Order Circuits and Systems: Theory, Design, and Applications

Nowadays, there is a significant research interest in the area of fractional-order circuits. This originates from the fact that they find applications in biochemistry,medicine, electrical engineering, and many other fields. For example, the modeling of viscoelasticity as well as of biological cells and tissues has been performed through the utilization of fractional-order calculus. This special issue is focused on the theory, design, and applications of fractional-order circuits and systems, with the purpose of offering to the circuits and systems community the opportunity to explore recent advances in fractional-order circuits and systems theory and design as well as of their applications. A total of 20 papers have been accepted in this special issue and are arranged to cover the following subjects: circuit theory of fractional-order circuits, fractional-order filter and oscillator design and applications, digital circuits and systems approximating

A microfluidic device for continuous manipulation of biological cells using dielectrophoresis.

The present study demonstrates the design, simulation, fabrication and testing of a label-free continuous manipulation and separation micro-device of particles/biological cells suspended on medium based on conventional dielectrophoresis. The current dielectrophoretic device uses three planner electrodes to generate non-uniform electric field and induces both p-DEP and n-DEP force simultaneously depending on the dielectric properties of the particles and thus influencing at least two types of particles at a time. Numerical simulations were performed to predict the distribution of non-uniform electric field, DEP force and particle trajectories. The device is fabricated utilizing the advantage of bonding between PDMS and SU8 polymer. The p-DEP particles move away from the center of the streamline, while the n-DEP particles will follow the central streamline along the channel length. Dielectrophoretic effects were initially tested using polystyrene beads followed by manipulation of HeLa cells. In the experiment, it was observed that polystyrene beads in DI water always response as n-DEP up to 1MHz frequency, whereas HeLa cells in PBS medium response as n-DEP up to 400kHz frequency and then it experiences p-DEP up to 1MHz. Further, the microscopic observations of DEP responses of HeLa cells were verified by performing trapping experiment at static condition.