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宽带混沌信号拥有良好的相关特性、低截获概率和高保密性等优点.本文介绍了一种基本的混沌信号产生电路-Colpitts振荡电路,在此基础上,对该电路作了相关改进,同时通过仿真对它们的性能进行了分析比较.结果显示:对三阶Colpitts振荡电路的改进方法是可行的;三阶Colpitts振荡电路频谱较为集中,且自相关性能差,应用... 相似文献
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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。 相似文献
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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。 相似文献
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基于经典蔡氏混沌振荡电路,引入一种双曲余弦函数的新型磁控忆阻器模型,设计含有两个双曲余弦忆阻器的混沌电路系统,讨论了系统平衡点集面的稳定区间.选择不同的忆阻初始值进行数值仿真,通过分岔图与Lyapunov指数谱研究双曲忆阻混沌系统的多稳态特性.结果表明,含双曲函数的双忆阻混沌电路具有复杂的动力学行为,运动轨迹不仅依赖于电路参数,还受电路的初始状态影响,由此产生了不同拓扑结构的混沌吸引子与不同周期运动的多稳态隐藏吸引子共存现象. 相似文献
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为了研究忆阻开关电路的动力学行为,该文提出一种具有多吸引子共存现象的忆阻开关混沌电路。在该电路中存在多吸引子分岔,当系统中发生边界碰撞之后,系统中将产生不同的吸引子共存现象。其中包括单周期极限环与混沌吸引子共存,不同的混沌吸引子共存,对称的2周期极限环共存现象,以及对称的2周期极限环与5周期极限环共存现象等。该文通过相图、分岔图等数值仿真,分析了该电路的动力学行为,并利用PSIM电路仿真验证了其电路的可行性,对开关电路中多吸引子共存现象和混沌应用的研究具有重要意义。 相似文献
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在经典的蔡氏混沌电路基础上,引入三次非线性磁控忆阻模型,利用一个磁控忆阻模型和一个荷控忆阻模型,外加一个负电导替换变形蔡氏电路中的蔡氏二极管,设计了一个五阶混沌电路,用常规的方法研究系统的基本动力学特性。通过数值仿真结果表明电路在参数变化情况下能产生Hopf分岔和反倍周期分岔两种分岔行为,并能产生双涡卷、单涡卷、极限环、同宿轨等不同轨道,出现了双单摆运动。观察混沌吸引子推广到功率与能量信号,观察到蝴蝶翅膀重叠的奇异吸引子。通过改变初始值,能产生共存吸引子和周期极限环共存现象。为了验证电路的混沌行为,将对设计的电路进行了PSpice仿真,电路仿真结果验证了理论分析的正确性。 相似文献
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采用非理想有源电压控制忆阻器和磁通控制型光滑3次非线性忆阻器,该文设计了一种不含电感的简单(只含5个电子元器件)双忆阻混沌电路。采用常规的非线性分析手段详细研究了电路参数变化时系统的基本动力学行为,例如平衡点稳定性分析,相轨图以及李雅普诺夫指数谱和分岔图等。通过调节系统控制参数,该系统可产生多涡卷、多翼以及暂态混沌等十分丰富的动力学现象。此外,还研究了系统依赖于忆阻器初始状态的多稳态,得到了一些有意义的结果。为验证电路的可行性及稳定性,通过对忆阻器的模拟等效电路的搭建,并将该等效电路应用于所提出的混沌电路中,硬件电路实验结果以及Multisim电路仿真结果与理论分析一致。 相似文献
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Synchronization and chaos in coupled memristor-based FitzHugh-Nagumo circuits with memristor synapse
The memristor has drawn a significant interest in the fields of neuromorphic circuits because the nanoscale memristor is a strong candidate to become the critical element of novel ultra-high density low-power non-volatile memories. In the present paper, we focus on networks of FitzHugh-Nagumo neuron circuits employing memristor. First, we build the memristor-based circuit of FitzHugh-Nagumo model. The details of the chaotic phenomena of the memristor-based FitzHugh-Nagumo circuit under external stimuli have been found with use of computer simulations, i.e., we have numerically calculated waveform diagrams, phase portraits, Lyapunov exponents and bifurcation diagram. And we also confirm these results of theoretical analyses and numerical calculations by circuit simulation experiments of the actual analog circuit realization using Multisim modeling. Then the synchronization of coupled memristor-based chaotic neurons with memristor synapse is discussed, and synchronization mechanism is also found. Finally, we have also derived the sufficient conditions of chaotic synchronization in unidirectional coupled neuron circuits and bidirectional coupled neuron circuits respectively, which are that the parameter of memristor synapse must meet certain conditions. These results of theoretical analyses have been confirmed by numerical simulation. 相似文献
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忆阻器是一种拥有记忆功能的电阻,目前忆阻器的研究热点及难点在于新模型的建立以及相关方面的应用。该文提出一种基于双曲正弦函数的新型磁控忆阻器模型,通过分析电压和电流的相轨迹关系,发现其具有典型的忆阻器电压-电流特性曲线。利用新建的忆阻器模型构造新型忆阻混沌系统,通过数值仿真绘出新系统的相轨迹图、分岔图、Lyapunov 指数谱等,分析了不同参数时系统的混沌演化过程。另外,基于电路仿真软件Multisim研制了实验仿真电路, 该电路结构简单、易于实际制作,且仿真实验与理论分析结论十分吻合,证实了提出的忆阻混沌系统电路在物理上是可以实现的。最后,利用新系统混沌序列对图像进行加密,重点分析了加密直方图、相邻像素相关性以及抗攻击能力与密钥敏感性,结果表明新系统对图像密钥及明文都非常敏感,密钥空间较大,新提出的忆阻混沌系统应用于图像加密具有较高的安全性能。 相似文献
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In this paper, a novel third-order autonomous memristor-based chaotic circuit is proposed. The circuit has simple topology and contains only four elements including one linear negative impedance converter-based resistor, one linear capacitor, one linear inductor, and one nonlinear current-controlled memristor. Firstly, the voltage-current characteristic analysis of the memristor emulator for different driving amplitudes and frequencies are presented. With dimensionless system, the symmetry, equilibrium point and its stability are analysed. It is shown that the system has two unstable saddle-foci and one unstable saddle. A set of typical parameters are chosen for the generation of chaotic attractor. Differing from the common period-doubling bifurcation route in smooth dynamical systems, this memristive system shows abrupt transition from the coexisting period-1 limit cycles to robust chaos when varying system parameters. Various dynamical behaviors are analysed using the numerical simulations and circuit verifications. 相似文献
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Design and implementation of n-scroll chaotic attractors from a general jerk circuit 总被引:2,自引:0,他引:2
Simin Yu Jinhu Lu Leung H. Guanrong Chen 《IEEE transactions on circuits and systems. I, Regular papers》2005,52(7):1459-1476
This paper proposes a novel nonlinear modulating function approach for generating n-scroll chaotic attractors based on a general jerk circuit. The systematic nonlinear modulating function methodology developed here can arbitrarily design the swings, widths, slopes, breakpoints, equilibrium points, shapes, and even the general phase portraits of the n-scroll chaotic attractors by using the adjustable sawtooth wave, triangular wave, and transconductor wave functions. The dynamic mechanism and chaos generation condition of the general jerk circuit are further investigated by analyzing the system stability. A simple block circuit diagram, including integrator, sawtooth wave and triangular wave generators, buffer, switch linkages, and voltage-current conversion resistors, is designed for the hardware implementations of various 3-12-scroll chaotic attractors via switchings of the switch linkages. This is the first time to experimentally verify a 12-scroll chaotic attractor generated by an analog circuit. In particular, the recursive formulas of system parameters and real physical circuit parameters are rigorously derived for the hardware implementations of the n-scroll chaotic attractors. Moreover, the adjustability of the nonlinear modulating function and the rigorous recursive formulas together provide a theoretical principle for the hardware implementations of various chaotic attractors with a large number of scrolls. 相似文献