Gregorio Sciuto

Design of Time-Delay Chaotic Electronic Circuits

This paper investigates the problem of the design and the implementation of time-delay chaotic circuits. A simple feedback scheme consisting of a nonlinearity, a first-order RC circuit and a delay block has been fixed and a procedure to design the characteristics of these blocks in order to obtain chaotic dynamics has been introduced. A series of n Bessel filters in cascade is used to implement the time-delay. The suitability of the approach is demonstrated with an example: a new chaotic circuit has been first designed and, then, implemented with off-the-shelf discrete components. The approach allows us to design and implement a new class of time-delay chaotic circuits with simple components, like resistors, capacitors, and operational amplifiers.

MEMRISTIVE CHAOTIC CIRCUITS BASED ON CELLULAR NONLINEAR NETWORKS

Memristors are gaining increasing interest in the scientific community for their possible applications, e.g. high-speed low-power processors or new biological models for associative memories. Due t...

CHUA'S CIRCUITS SYNCHRONIZATION WITH DIFFUSIVE COUPLING: NEW RESULTS

In this communication, synchronization of two diffusively coupled Chuas circuit is studied from the analytical and experimental points of view. The conditions under which complete synchronization is ensured are derived by applying a strategy based on the Master Stability Function. The experimental realization, that makes use of the State-Controlled Cellular Nonlinear Network based implementation of Chuas circuit, shows the synchronized behavior of two circuits coupled with a passive resistor as diffusion coefficient. The results obtained indicates diffusive coupling as a mutually reduced order state observer, in the sense that one circuit observes the other and vice versa. Moreover, the concept of synchronization by using passive elements can be extended to spatially extended reaction–diffusion systems.

COUPLED INDUCTORS-BASED CHAOTIC COLPITTS OSCILLATOR

In this paper, a new chaotic circuit is introduced, conceived by considering a Colpitts oscillator with the inclusion of two further elements: a coupled inductor and a variable resistor. The propos...

FPAA-Based Implementation of Chaotic Circuits

In this chapter, three examples of the use of FPAA for the implementation of chaotic circuits are given. In the three examples, the design is based on the procedure of Chap. 2, by taking now into account the bounds of the internal voltage signals of the FPAA board. The implementation is based on a FPAA device produced by ANADIGM: the AN221E04 FPAA [1].

Synchronization of Chaotic Circuits

Aim of this chapter is to show techniques and examples of synchronization of chaotic circuits. Two cases are dealt with: synchronization of nominally identical chaotic circuits and synchronization of circuits with parametric or structural differences. In the first case, the circuits are assumed to be regulated by the same dynamics but having slightly different parameters (in the limit of component tolerances), while in the second case circuits with different dynamical behaviors either due to a different parameter or to different dynamical equations are considered.

From the Mathematical Model to the Circuit

Starting from the mathematical model of a nonlinear system, it is always possible to realize an electronic circuit, which is equivalent to the mathematical model, in the sense that it obeys to the same set of equations. In this chapter, the approach for designing the electronic circuit, equivalent to a given mathematical model, is illustrated.

Four Examples of Chaotic Circuits

In this chapter, four examples of chaotic circuits are given to show the variety of principles underlying chaos generation in electronic circuits. This chapter presents just a sample of the possibilities arising. The analysis of the circuits presented leads to the conclusion that many different mechanisms, not straightforwardly generalizable, can be used for the design of chaotic circuits. The next chapter introduces a procedure, which instead starts from a mathematical model showing chaos and then transfers the mathematical rules of the model into circuit laws of a physical device.

A Gallery of Chaotic Circuits

In this chapter, a gallery of nonlinear chaotic circuits is presented. Each section deals with a specific circuit derived from the mathematical model of a nonlinear system. The electrical scheme and a sample of the behavior that the circuit can generate are reported, so that the reader can find a reference for his/her own experiments. Examples of both autonomous and nonautonomous circuits are presented.

A new Cellular Nonlinear Network-based memristive chaotic circuit

Memristors are nonlinear memory devices which are gaining increasing interest in several scientific fields. Due to their characteristics they can be used in the design of new dynamical circuits able to show complex behavior, like chaos. In this paper, a new chaotic circuit with a memristive element, whose implementation is based on Cellular Nonlinear Networks, is introduced. This approach allows to obtain memristors with common off-the-shelf components and to observe the onset of new chaotic attractors.