2 MODIFIED FOR CHAOS NEGATIVE IMPEDANCE CONVERTER OP AMP OSCILLATORS WITH SYMMETRICAL AND ANTISYMMETRICAL NONLINEARITIES

Two sinusoidal oscillator circuits, that employ an operational amplifi er (op amp) as a current negative impedance converter (CNIC), are modi fied for chaos using a nonlinear resistor of antisymmetrical current-v oltage characteristics formed by a junction field effect transistor (J FET) operating in the triode region. The internal op amp dominant pole is found to contribute significantly to the chaotic nature of one cir cuit while the other circuit develops different chaotic attractors whe n cubic and fifth power odd symmetrical nonlinearities are used. Mathe matical models of the two generators are presented. Experimental labor atory results, circuit simulations and numerical simulations of the ma thematical models well agree and are included.