Chaos generator with high energy potential

An original scheme is proposed for generator of chaos oscillations of the microwave wavelength range. Generator contains nonlinear positive feedback amplifieran and inertial converter of the output signal of a nonlinear amplifier, the signal of which modulates the supply voltage of the active element (transistor). In the case when the value of the inertia parameter of the inertial converter becomes less than 0,06, the generator demonstrated chaotic behavior. An experimental model of a chaotic signal generator based on a powerful transistor 2T982A-2 was created. The generator was created using hybrid microstrip technology on the material FLAN-10 with a thickness of 1 mm. The inertial converter circuit contained a diode performing half-wave conversion of a part of the generator output signal and an RC circuit with a time constant equal to 0,05 of the time one oscillation at the central frequency of the generator. The signal from the output of the inertial converter was applied to the emitter power supply circuit of the transistor. Modulation of the supply voltage led to the fact that the output signal of the generator was a sequence of non-repeating oscillation trains with a random duration and a random initial phase. The frequency band of the generated chaos with an uneven power spectrum of 4 dB occupied a frequency range from 3,1 to 3,3 GHz with an integrated power of 1,2 W. The averaged spectral density of noise oscillations was 6 10-3 W/MHz. Generator efficiency 15%.

Hidden Coexisting Attractors in a Chaotic System Without Equilibrium Point

This paper proposes a new three-dimensional chaotic system with no equilibrium point but can generate hidden chaotic attractors. Dynamic characteristics of the system are analyzed in detail by theoretical analysis and simulating experiments, including hidden attractors, transient period and coexisting attractors. Different hidden coexisting attractors exist in this system, which shows abundant and complex dynamic characteristics and can be used to generate pseudorandom sequences for encryption fields. Besides, the presented system is realized by the digital signal processing (DSP) technology to construct a chaotic signal generator, whose statistical properties are tested by National Institute of Standards and Technology (NIST) software. The obtained results are better than that of the Lorenz system and imply the presented system can be used in the encrypted fields.

Design and FPGA Implementation of a Universal Chaotic Signal Generator Based on the Verilog HDL Fixed-Point Algorithm and State Machine Control

In this paper, a novel design methodology and its FPGA hardware implementation for a universal chaotic signal generator is proposed via the Verilog HDL fixed-point algorithm and state machine control. According to continuous-time or discrete-time chaotic equations, a Verilog HDL fixed-point algorithm and its corresponding digital system are first designed. In the FPGA hardware platform, each operation step of Verilog HDL fixed-point algorithm is then controlled by a state machine. The generality of this method is that, for any given chaotic equation, it can be decomposed into four basic operation procedures, i.e. nonlinear function calculation, iterative sequence operation, iterative values right shifting and ceiling, and chaotic iterative sequences output, each of which corresponds to only a state via state machine control. Compared with the Verilog HDL floating-point algorithm, the Verilog HDL fixed-point algorithm can save the FPGA hardware resources and improve the operation efficiency. FPGA-based hardware experimental results validate the feasibility and reliability of the proposed approach.

A Switchable Chaotic Oscillator with Two Amplitude–Frequency Controllers

A simple chaotic system with a single nonquadratic term is developed to be a switchable chaotic signal generator in this paper. Additional nonlinearity of the absolute value function is introduced for reforming the structure without damaging the basic dynamics but yielding a new independent amplitude–frequency controller. A switchable chaotic experimental oscillator is designed afterwards, where two coefficients corresponding to two independent rheostats rescale the amplitude and frequency of the chaotic signals smoothly. To our knowledge, this has never been found in other chaotic oscillators.