A novel 0.2–7 GHz microwave hyperchaotic generator based on Hartley oscillator

Abstract

In this paper, a miniaturized microwave-band hyperchaotic generator prototype has been designed and realized. By improving the topology of Hartley oscillator, the proposed single-stage common-collector structure oscillator enables us to generate a microwave 0.2 − 7 GHz smooth spectrum signal with a power around −30 dBm. Using BFP650 SiGe transistor as a non-linear component, the proposed circuit has been implemented and simulated then experimentally approved. Introducing the parasitic capacitors CBC and CBE and using the exponential model to describe the active component non-linearity, a simplified electrical model for the developed circuit has been proposed. To exhibit the deterministic chaotic character of the mentioned circuit, mathematical and schematic implementation results using Matlab and Advanced Design System (ADS) simulations have been presented. The concordance between the two simulation results permits us to adopt the simplified state equation model to describe the circuit behavior. The Lyapunov spectrum exponents representation allowed us to verify the hyperchaotic behavior in the presented generator. Finally, an autonomous simple prototype architecture of the generator using the PTFE (Polytetrafluoroethylene) substrate with εr = 2.2 has been realized and experimentally validated. The achieved performances made the proposed circuit suitable for various fields of telecommunications.

Experimental validation of new non-coherent chaotic modulation via SDR implementation

“…It is known that chaotic signals are non-periodic, difficult to predict and random-like signals which are derived from non-linear dynamical systems. In addition, chaotic signals in nature have a large bandwidth, they can be generated at any frequency band with small size electronic circuits, low power consumption and especially with low cost [8]. This is a good motivation to use chaotic signals in communication systems [9][10][11][12].…”