The smallest transistor-based nonautonomous chaotic circuit

A nonautonomous chaotic circuit based on one transistor, two capacitors, and two resistors is described. The mechanism behind the chaotic performance is based on "disturbance of integration". The forward part and the reverse part of the bipolar transistor are "fighting" about the charging of a capacitor. Measurements and PSpice experiments are presented.     

A nonautonomous generator of chaotic radio pulses

Digital simulation methods (ADS package) and an experimental model are used to demonstrate that a train of chaotic radio pulses may be generated under the effect of a chaotic periodic signal on a nonlinear dynamic system generating chaotic oscillations in the range 300–600 MHz. The system’s modulation characteristics are studied.     

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     

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     

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     

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。     

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     

Simple 4D chaotic oscillator

An extremely simple 4D chaotic oscillator is presented. It contains a single op amp, two LC circuits and a diode used as a nonlinear device. The chaotic oscillations have been characterised using the correlation dimension of the strange attractor, the Lyapunov exponents and the Lyapunov dimension. The dimensions are found to be >3     

Electrical circuits with chaotic behavior

Several circuits that exhibit chaotic behavior are discussed. Evidence for such a behavior is given by laboratory experiments, by computer simulations, and, where available, by rigorous mathematical reasoning.     

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     

短波混沌跳频码的FPGA实现

基于离散混沌系统，为克服有限精度效应，采用了m序列对logistic映射进行异或扰动的方法来构造混沌跳频序列。并分别采用FPGA进行数字仿真。研究结果表明；其仿真得到的混沌跳频序列具有较长的周期，符合理论值的相关性和较小的平衡性。研究结果表明，该方法是可行的。适于用来构造短波跳频序列。     

Coherence resonance in chaotic electronic circuits

It is experimentally demonstrated that a chaotic electronic circuit exhibits the main features of coherence resonance. This phenomenon shows up as a quasi-periodic response when the circuit is subjected to an external white-noise source of the appropriate level     

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     

Sights and sounds of chaos [autonomous and nonautonomous circuits]

The concept of chaos is introduced using actual circuit experiments. Several well-known chaotic circuits are used as vehicles to demonstrate the many phenomena associated with chaos. They are divided into two classes, autonomous and nonautonomous. For the simplest autonomous circuits the authors examine strange attractors, the Lorenz circuit, Lyapunov exponents, and fractals. For the simplest nonautonomous circuits they consider period-doubling, the two-dimensional Poincare cross section, the Devil's staircase, and phase-locked loops     

High-performance crystal oscillator circuits: theory andapplication

A general theory that allows the accurate linear and nonlinear analysis of any crystal oscillator circuit is presented. It is based on the high Q of the resonator and on a very few nonlimiting assumptions. The special case of the three-point oscillator, that includes Peirce and one-pin circuits, is analyzed in more detail. A clear insight into the linear behavior, including the effect of losses, is obtained by means of the circular locus of the circuit impedance. A basic condition for oscillation and simple analytic expressions are derived in the lossless case for frequency pulling, critical transconductance, and start-up time constant. The effects of nonlinearities on amplitude and on frequency stability are analyzed. As an application, a 2-MHz CMOS oscillator which uses amplitude stabilization to minimize power consumption and to eliminate the effects of nonlinearities on frequency is described. The chip, implemented in a 3-μm p-well low-voltage process, includes a three-stage frequency divider and consumes 0.9 μA at 1.5 V. The measured frequency stability is 0.05 p.p.m./V in the range 1.1-5 V of supply voltage. Temperature effect on the circuit itself is less than 0.1 p.p.m. from -10 to +60°C     

Temperature-compensated CMOS ring oscillator for power-management circuits

The design of a temperature-compensated CMOS ring oscillator is introduced. The concept is to make use of a linear, positively or negatively temperature-sloped supply voltage to power-up the ring oscillator. Experimental results show that the oscillation frequency remains fairly constant using the proposed scheme.     

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、...     

一类非自治系统混沌细胞模型研究

该文研究非自治系统混沌吸引子,通过对Genesio系统深入的数学分析和数字仿真,得出一类非自治系统的混沌细胞模型。     

A one-pin crystal oscillator for VLSI circuits

The oscillator features the same stability, reliability, and ease of use as the common Pierce oscillator; however, only one package pin and no external components other than the crystal need be dedicated to the oscillator. The design is quite general, and may be implemented in either NMOS or CMOS technologies, using only a moderate amount of silicon area. Design examples are given, and the fabrication results are presented.