In this chapter we describe a design cycle for autonomous chaotic oscillators. From a circuit-design perspective and since the linear circuit theory of design still dominates, we find it more appropriate to use the design techniques that have been developed using this theory to establish this design cycle, particularly for the following reasons:

1. The theory of nonlinear dynamics does not yet provide a set of necessary and sufficient conditions for chaos generation.

2. Geometrical interpretation techniques of nonlinear dynamics (Poincar sections, one dimensional return maps, recurrence plots, etc.) are analysis-biased tools that cannot be related to the design phase of a chaotic oscillator circuit. As for statistical measures, it is not clear whether the available measures are sufficient to identify different types of chaos or to provide comparison guidelines. It is not even known how to produce a system with a predefined dimension, set of eigen-values, Lyapunov exponents and power spectral density distribution. Mapping transformations from nonlinear dynamic concepts to circuit-design concepts are also lacking.

3. On the application front, and to the best of our knowledge, none of the reported applications for chaotic signals strictly refers to a specific type of chaos associated with certain statistical measures or qualitative dynamics. For a circuit designer, it seems that all types of chaos are equally useful. There is no evidence that...