Simple log-domain chaotic oscillator

A log-domain chaotic oscillator generated from a simple model with double-scroll-like dynamics is presented. The circuit operates in current-mode and is well suited to integrated circuit implementation. Experimental verification of the proposed circuit is provided     

Simple RC chaotic oscillator

An RC oscillator exhibiting chaotic behaviour is described. It contains two opamps, a Wien bridge and a diode used as a nonlinear device. The typical waveforms, the phase portraits, the power spectra and the correlation dimension of the attractor are presented to illustrate the chaotic oscillations     

Implementation of a memristor-based 4D chaotic oscillator and its nonlinear control

Analog Integrated Circuits and Signal Processing - In this study, an electronic model of a memristive-based 4D autonomous chaotic system with a line equilibrium is proposed. A memristor offers many...     

Two-stage chaotic Colpitts oscillator

A novel version of the chaotic Colpitts oscillator is proposed. It contains two bipolar junction transistors coupled in series. The resonance loop consists of an inductor and three capacitors. The two-stage oscillator, compared with the classical circuit, enables the fundamental frequency of chaotic oscillations to be increased by a factor of three. The PSpice simulations performed with 9 GHz threshold frequency transistors demonstrate that the highest fundamental frequencies of chaotic behaviour are 1 and 3 GHz for the classical and the two-stage Colpitts oscillator, respectively     

混沌振荡器的计算机仿真

提出了用频变负电阻(FDNR)实现混沌振荡器的新电路,该电路结构简单,易于集成,仅用一个接地的频变负电阻作为有源器件,用二极管提供必要的非线性。并给出了电路的数学模拟和PSpice仿真。模拟和仿真结果表明,二者取得了很好的一致。     

微波混沌信号发生器技术研究进展

混沌(Chaos)是非线性动力学系统特有的一种运动形式,是确定性系统中出现的极其复杂的、类似随机的现象.合理利用混沌的多种特性可以有效地改善通信系统性能.基于其原理的混沌载波扩频通信是一种鲁棒性强、保密性好、实现简单的潜在应用价值的方案,可对当前的CDMA扩频体制做出重要的性能改善.     

High frequency Wien-type chaotic oscillator

A Wien-type oscillator based on a current feedback opamp (CFOA) employed as a non-inverting voltage-controlled voltage source is modified for chaos by adding an inductor and a general purpose signal diode. By using a CFOA as the active element, high operating frequencies are possible. The chaotic oscillator is described by a fourth order system of differential equations. Experimental results, PSpice simulations and numerical simulation of the proposed model are included     

Generation of multi-scroll delayed chaotic oscillator

A novel delayed chaotic oscillator capable of generating multi-scroll chaos is investigated. The nonlinear activation function can be represented as a piecewise linear function, and its circuitry implementation requires only a few operational amplifiers. The typical waveforms and phase portraits of the attractor are presented to illustrate mono-, two- or four-scroll chaotic oscillations     

RC op-amp implementation of hysteresis chaotic oscillator

An RC op-amp implementation of an oscillator based on hysteretic nonlinearity is proposed. Experimental results are reported, showing its main dynamic behaviours     

Improved chaotic Colpitts oscillator for ultrahigh frequencies

A novel version of the Colpitts oscillator is presented generating chaotic oscillations at gigahertz frequencies. In contrast to the standard oscillator the inductor is moved from the collector circuit of the transistor to the base circuit. PSpice simulations demonstrate chaos at the fundamental frequencies of 0.5, 1 and 2 GHz employing transistors with a threshold frequency of 9 GHz.     

一种新的混沌振荡器设计方法

介绍了一种具有普适性的混沌振荡器设计方法,该方法完全基于无量纲状态方程设计,整个电路由反相加法模块、积分模块和反相器模块三大模块组成.各状态变量以原变量和反变量的形式出现,设计者只需根据系统状态方程,将各模块连接起来就可实现,大大简化了混沌电路的设计,实现了混沌电路的模块化设计.根据该方法,文中分别设计了Lorenz、...     

Delayed feedback chaotic oscillator with improved spectral characteristics

A chaotic oscillator, including a nonlinear unit, an amplifier, an RC filter and a delay line, is described. Depending on the gain the circuit exhibits mono- or two-scroll chaotic oscillations. The two-scroll oscillations, in comparison with the mono-scroll oscillations, are characterised by three times higher fundamental frequency.     

Novel chaotic oscillator configuration using a diode-inductor composite

A general sinusoidal oscillator configuration is designed and then modified for chaos using a second-order nonlinear grounded diode-inductor composite. The configuration has an operating frequency that can be electronically tuned by varying the gain of an inverting amplifier stage. In addition to this amplifier, a single positive-type second generation current conveyor (CCII+), two noninverting integrators and two grounded resistors are required. The case where one of the integrators is replaced with an all-pass filter is investigated. Since the configuration is designed at a functional level, different circuit realizations are possible. Experimental results and PSpice simulations of a constructed implementation based on current feedback op amps are included. Numerical simulations of the derived chaotic mathematical models using a piecewise linear approximation of the diode current-voltage characteristics are also shown.     

基于CCII的集成混沌振荡器设计

集成化混沌振荡器是混沌在实际应用中的一种重要趋势,特别是在大规模的混沌系统的电子实现方面。为了使混沌振荡器的集成度更高,并且具有较宽的频带,本文提出了一种新型的电流模式混沌振荡器。通过对自治混沌振荡器的电路模型分析,在文氏混沌电路基础上,采用CCII电路代替电压运算放大器、跨导运算放大器等传统运算放大器,实现了正弦波振荡电路,通过采用NMOS管将两个正弦振荡电路耦合最终实现电流模式混沌振荡器,通过对该电流模式混沌振荡器建模并进行仿真分析,描述了该振荡器的混沌行为,验证了该混沌电路的有效性和可行性。再通过仿真结果对比表明该混沌振荡器相比于传统的文氏混沌振荡器功耗更小、噪声抑制能力更强,由其产生的混沌信号在频带宽度、随机程度方面都有明显提高,更适合芯片集成。     

Nonautonomous pulse-driven chaotic oscillator based on Chua's circuit

A novel nonautonomous chaotic oscillator based on the passive structure of Chua's circuit is proposed. Unlike most of the available members of this class of chaotic oscillators, the proposed circuit is driven by a periodic bipolar pulse-train rather than by sinusoidal excitation. This results in equilibrium points which have fixed positions in space. The circuit employs self feedback via a single comparator, which is the only nonlinear device involved. The output of this comparator is a chaotic bipolar pulse-train. A mathematical model which captures the behavior of the circuit is derived and experimental results are presented. Also, a version of the circuit with a practical realization of the driving pulse generator is considered and a variant structure with an alternatively excited node is discussed.     

Modeling and simulation of a chaotic oscillator by MATLAB

A MATLAB-based system is presented to model and simulate a chaotic oscillator. Chua’s circuit is selected to describe the chaos phenomenon. Furthermore, the nonlinear resistor (Chua’s diode) is modeled by an I-V piecewise-linear characteristic whose current and voltage ranges can be varied by the user. It is shown how to generate a sequence of chaotic behaviors by varying the value of a linear resistor. The simulation results can be plotted in a 2D and 3D graphs. Finally, it is described the synthesis of the chaotic oscillator by using standard CMOS integrated-circuit technology.     

Simple sinusoidal oscillator using opamp compensation poles

The Letter introduces a new, extremely simple, sinusoidal oscillator based on opamp compensation poles. The circuit employs only four components, two internally compensated opamps, one resistor and a grounded capacitor, and can generate sinusoidal oscillations of frequencies up to the gain bandwidth product of the opamps. with modification(s), using an additional opamp or two analogue multipliers, the circuit can be readily converted into a VCO. Experimental results and SPICE simulations have confirmed the workability of the various modes of operation of the proposed configuration.<>     

Cascode混沌电路负阻模型与电路设计

针对Cascode结构振荡器进行研究,通过理论推导和分析,给出两级负阻提升的通用模型,该模型可以被广泛应用于混沌电路设计中,实际电路设计时可以用合适的负阻电路单元替代两级结构中的下级部分,实现电路负阻的提升。仿真设计结果表明,基于该模型设计的混沌电路的混沌振荡基频f0为4.2 GHz,f0/fT值达到0.46,较经典单级电路有较大提升。     

On the realization of circuit-independent nonautonomous pulse-excited chaotic oscillator circuits

The aim of this paper is to present a simple circuit design method for realizing a nonautonomous chaotic oscillator given a second-order sinusoidal oscillator with two capacitors. The proposed method relies on applying a periodic pulse train, as an exciting source, and the addition of a signum-type nonlinear transconductor to the given sinusoidal oscillator. Experimental results of designed circuits are shown.     

Truly random number generators based on a non-autonomous chaotic oscillator

A non-autonomous chaotic circuit which is suitable for high-frequency integrated circuit (IC) realization is presented. Simulation and experimental results verifying the feasibility of the circuit are given. We have numerically verified that the bit streams obtained from the stroboscopic Poincaré map of the system passed the four basic tests of FIPS-140-2 test suite. We also have verified that the binary data obtained from the hardware realization of this continuous-time chaotic oscillator in the same way pass the full NIST random number test suite. Then, in order to increase the output throughput and the statistical quality of the generated bit sequences, we propose a TRNG design which uses a dual oscillator architecture with the proposed continuous-time chaotic oscillator. Finally, we have experimentally verified that the binary data obtained by this oscillator sampling technique pass the tests of full NIST random number test suite without Von Neumann processing for a higher throughput speed while compared with the previous one where the proposed continuous-time chaotic oscillator is used alone.