Chua's Fourth Fundamental Element for Chaotic Applications in Secure Communication

Chaos is an unpredictable phenomenon that arises in a nonlinear dynamic system when the paths of the state variables become repetitive and extremely sensitive to the starting conditions. The study of chaos is frequently observed from Chua's fourth element and obtained by combining one inductor (L) and two capacitors (C_1 andC_2) as an energy-storing element. It consists of two types of resistors: linear and nonlinear. The nonlinear resistor is known as Chua's diode. The circuit is the most vital and novel electronic component that displays various attractors and bifurcation phenomena. The research works represent the design methodology and the op-amp-based with or without inductor less Chua circuit realization with chaotic behavior. The proposed Chua circuit configuration is simulated in the LTspice environment, and it shows a small variation in resistance and large variations in the output dynamic patterns. The memristor is a two-terminal bipolar device that exhibits a pinched hysteresis curve and its inconstant resistance value. This paper also shows the implementation of the memristor based chaotic circuit. These nonlinearities of the memristor based chaotic circuit are designed for secure communication. The chaotic signal is mixed with the modulated signal as a carrier signal and then transmitted through a channel. All essential characteristics of the chaotic system are getting in the spice simulator.