Design and analysis of VDIBA-based chaotic oscillators and their applications in communication system

Abstract

This paper presents three new implementations of Chua's chaotic oscillator using the voltage differencing inverting buffered amplifier (VDIBA). The first implementation replaces the active nonlinear resistor in the classical third-order Chua's circuit with a single VDIBA and two resistors. The second implementation substitutes the bulky passive inductor with a compact VDIBA-based active inductor realized using two VDIBAs and a capacitor. Finally, a sinusoidal oscillator based chaotic oscillator implementation using VDIBAs is explored. A non-ideal analysis is conducted to assess the practical feasibility of the proposed chaotic system. A comprehensive analysis is presented, including bifurcation diagrams, Lyapunov exponents, Routh stability criteria, and basins of attraction determining stability of the proposed circuits. Numerical simulations in MATLAB and circuit simulations in LTspice, using 0.18 μm CMOS TSMC technology parameters, validate the proposed designs. A comparative analysis with existing literature highlights the advantages of the proposed implementations. The experimental results of the proposed chaotic oscillators are presented to validate the theoretical analysis. Furthermore, the potential application of the proposed design in secure chaotic transmission and reception for both analog and digital signals is demonstrated, showcasing the system's high reliability and security through the non-recoverability of the message signal under small parameter variations. Additionally, bit error rate (BER) versus signal to noise ratio (SNR) performance is evaluated under both AWGN and Rayleigh fading conditions to validate the robustness of the communication system.