多层非线性介质板的电磁反射和传输

本文根据由Ｖｏｌｔｅｒｒａ泛函级数理论所得到的非线性介质中的色散关系，讨论了单色平面波斜入射多层平板非线性介质的传输问题；导出了反射率和透射率的一级近似公式；对非线性单层和具有周期性的双层介质板进行了数值计算；最后讨论了非线性介质对电波传播特性的影响。     

多层非线性介质板的电磁反射和传输

本文根据由Volterra泛函级数理论所得到的非线性介质中的色散关系,讨论了单色平面波斜入射多层平板非线性介质的传输问题;导出了反射率和透射率的一级近似公式;对非线性单层和具有周期性的双层介质板进行了数值计算;最后讨论了非线性介质对电波传播特性的影响。     

板状非线性介质表面耦合波的反射和透射

本文详细分析了平面波激励非线性介质后介质的非线性极化、麦克斯专方程及其解、广义的反射和透射定律；导出了板状非线性介质表面任意阶耦合波的反射场和透射场；对介质满足相位匹配和泵浦波正入射下的场进行了深入的讨论；给了非线性介质表面的布儒斯特角。     

非线性反铁磁介质中双稳和多稳态研究

本文分析了远红外光（或亚毫米波）在线性介质－－非线性反铁磁介质－－线性介质系统中的透射特性，数值分析表明该系统具有双稳和多稳特性。分析了非线笥反铁磁介质厚度ｄ、介电常数ε２以及线性介质的介电常数ε２以及线性介质的介电常数ε１，ε２对系统输出功率与输入功率关系的影响，结果表明：非线性反铁磁介质层越厚，实现双稳工作所要求的门限功率越小，输出效率越低；ε２越大，门限功率越小，输出效率越高，双稳动态范围越     

有限光束穿过薄介质板的类Goos—Haenchen位移

研究了有限光束穿过薄介质板时透射光束存在类Coos-Hitnchen位移、角偏转、束腰宽度的修正以及焦点的纵向移动4种非几何光学效应；给出了位移反向时入射角及介质板的厚度所需满足的必要条件；报道了利用微波技术首次在实验上观测到穿过薄介质板时波束的反向GHL位移，这些奇异的光学现象将在光学器件和集成光学中具有潜在的应用。     

非线性平板介质波导传输特性的网络分析

本文提出了分析包含非线性介质的层状介质波导特性的等效传输线方法。通过把线性和非线性介质分别用等效传输线表示,从而把非线性介质这一复杂的电磁场问题等价成一个电路问题求解。其本征方程可以利用横向谐振原理得到。本文最后分析了层状介质波导包含饱和和非饱和非线性介质时TE模的传播功率与归一化传播常数之间的关系。所获得的结果与有关文献符合得相当好。     

非线性平板介质波导传输特性的网络分析

本文提出了分析包含非线性介质的层状介质波导特性的等效传输线方法，通过把线性和非线性介质分别用等效传输线表示，从而把非线性介质这一复杂的电磁场问题等价成一个电路问题求解，其本征方程可以利用横向谐振原理得到，本文最后分析了层状介质波导包含饱和非饱和非线性介质时ＴＥ模的传播功率与归一化传播常数之间的关系。所获得的结果与有关文献符合得相当好。     

光等效时间采样技术研究

光等效时间采样技术是利用非线性介质形成采样窗口,并根据等效时间采样原理对高速光信号进行测量的一种手段.重点讨论了光等效时间采样介质,研究了利用高非线性光纤、非线性晶体与半导体光放大器等非线性介质进行光等效时间采样的实现方法,对其各自优势及存在的主要问题进行了分析；对光等效时间采样光源、采样结果光电展宽转换及采样数据后处...     

非线性外自聚焦透镜的几何光学特征

利用高斯光束在非线性介质中传布的稳态自聚焦理论以及高斯光束在线性介质中传布的ABCD 定律,计算了非线性外自聚焦透镜的焦距和束腰宽度。给出了焦距与束腰宽度同入射激光功率的依赖关系。对于研究非线性外自聚焦透镜的几何光学特征以及非线性光学器件的设计提供了更为普适的理论依据。     

异向介质板应用于吸波隐身的FDTD方法分析

由异向介质的本构关系出发,给出了描述异向介质场与流的微分方程组,将其离散得到用于FDTD计算的一维递推表达式。最后,计算了异向介质板的反射系数。计算表明:由于模拟的异向介质是匹配介质,其吸波性能要明显的优于等离子体的,适当选取异向介质参数,可以使异向介质板有效地减小目标的雷达回波。     

Study of Nonlinear Oscillation Behavior of a Gyrotron Traveling-Wave Tube

The gyrotron traveling wave tube (gyro-TWT) is a high-power, broadband, millimeter-wave amplifier. This study employed a nonlinear self-consistent code to analyze nonlinear oscillation behavior of a gyro-TWT. There are three operating regimes in the gyro-TWT, including amplification, nonlinear oscillation and mode competition regimes. Based on theory of nonlinear oscillation, the amplification and nonlinear oscillation modes are the stable modes and compete with each other in the mode competition regime. An oscillator plane of the gyro-TWT is elucidated in the paper. This work shows that the amplification mode transits to the nonlinear oscillation mode where the input power exceeds the critical power and the beam current is above the start-oscillation current on the free-running operation. Moreover, the peak gain for the nonlinear oscillation mode is enhanced as the frequency of the input sign approaches the oscillation frequency on free-running operation.     

关于前馈网络分类器隐层单元变换特性的研究

本文研究了线性与非线性前馈网络隐层单元的变换特性,深刻揭示了线性怀非线性网络用于信息表示的机理,证明线性网络的隐输出模式是相关的,而非线性网络的隐输出模式是不相关的,并就非线性网络突破性网络的“瓶颈”行为,给出一个定理,最后,以三元奇偶问题为偶,给出有关实验结果。     

Stability of black, gray, and bright nonlinear guided waves in athin film bounded by a self-defocusing medium

Stability of nonlinear guided waves trapped in a thin linear film bounded by an infinite self-defocusing nonlinear medium is investigated. In addition to the trapped black and gray nonlinear guided waves, the existence of a novel class of bright nonlinear guided waves (with nonzero intensity background) is demonstrated. The gray and fundamental bright nonlinear guided waves are found stable whereas the black nonlinear guided waves are unstable to an asymmetric perturbation (but stable to a symmetric perturbation). The instability of the black nonlinear guided waves is shown to develop into various states, including stable gray and bright nonlinear guided waves, depending on initial excitations     

关于完全非线性函数的非线性度的界

非线性函数在编码和密码领域中扮演着非常重要的角色,衡量函数的非线性性质很重要。非线性度和差分概率是衡量函数非线性性质的重要指标,差分概率均匀的函数称为具有完全非线性的函数。文中改进了Carlet和Ding所给出的完全非线性函数的非线性度的上界和下界,提出了更好的界的优化问题模型。     

Model of a nonlinear electromagnetic crystal

2D electromagnetic crystal with lumped nonlinear elements is considered. An electrodynamic model with a rectangular grid is developed for a crystal that is infinite in one coordinate and finite in the other. In the case when the structure is excited by a plane wave, linear boundary value problems are formulated for electromagnetic fields at multiples of the fundamental frequency. The nonlinear problem is solved by means of the harmonic balance method. A system of nonlinear equations for the amplitudes of voltage harmonics at nonlinear elements is derived. Results of numerical solution of the system are presented for resistive and capacitive nonlinear elements.     

非线性回波抑制综述

针对实际通信中存在的非线性回波问题,介绍了现有的非线性回波抑制解决方案,将各种纷杂的方案按照不同的模型分为三类,分析对比了不同类别解决方案的优劣,同时对不同解决方案之间进行了比较;最后指出现有解决方案的不足,展望了未来的非线性回波研究方向。     

Measured and modeled conducted susceptibility characteristics of alithium niobate electrooptic modulator

The electromagnetic (EM) susceptibility of an electrooptic (E-O) modulator is characterized. A nonlinear susceptibility model and measured results are presented for a Crystal Technology MZ385P optical guided-wave intensity modulator. The transfer function for the E-O modulator is expressed in closed form and a Bessel function expansion of this transfer function is used to predict nonlinear effects. The nonlinear effects which are modeled include gain compression, radiant power offset, harmonic generation, and intermodulation generation. The model predictions are compared to measured data at in-band and out-of-band frequencies. At in-band frequencies, excellent agreement is obtained between measured and modeled nonlinear product levels. At out-of-band frequencies, variations in the nonlinear output product levels are explained by the frequency-dependent gain characteristics of the modulator     

铂电阻测温非线性补偿的研究

针对铂电阻在测量温度中存在的非线性,分析了产生非线性误差的主要原因,讨论了改善铂电阻线性度以及消除测量电路非线性误差的方法,为铂电阻的非线性补偿方法提供了理论依据.最后给出误差分析和实验结论.     

A Scattering Variable Approach to the Volterra Analysis of Nonlinear Systems

A new mathematical model is developed which extends Volterra series analysis of nonlinear systems with memory to high-frequency systems, including those containing linear distributed component devices. A generalized set of nonlinear scattering parameters is defined which can be used to describe power transfer and distortion in nonlinear multiports, and which reduce to the classical scattering parameters for linear networks. The methodology is based on Volterra functional series, and is most useful for the small-signal case where the response can be approximated by a finite number of terms of the series. Nonlinear scattering kernels, derived by extending the Volterra analysis, are simply related to previously developed nonlinear voltage and current Volterra kernels. For sinusoidal inputs nonlinear scattering parameters are defined which are shown to be particularly helpful when power relationships are studied. The principal applications are for microwave networks terminated in real-valued site reference impedances. To evaluate the average power dissipated in a load at some intermodulation frequency, the concept of nonlinear transducer gain is defined and shown to be proportional to the squared magnitude of a nonlinear scattering parameter. Examples are presented illustrating the analysis procedure for a tunnel diode reflection amplifier and for a linear lossless transmission line terminated by a non-linear network.     

Design and performance of adaptive systems based on structured stochastic optimization strategies

The theory and design of linear adaptive filters based on FIR filter structures is well developed and widely applied in practice. However, the same is not true for more general classes of adaptive systems such as linear infinite impulse response adaptive filters (MR) and nonlinear adaptive systems. This situation results because both linear IIR structures and nonlinear structures tend to produce multi-modal error surfaces for which stochastic gradient optimization strategies may fail to reach the global minimum. After briefly discussing the state of the art in linear adaptive filtering, the attention of this paper is turned to MR and nonlinear adaptive systems for potential use in echo cancellation, channel equalization, acoustic channel modeling, nonlinear prediction, and nonlinear system identification. Structured stochastic optimization algorithms that are effective on multimodal error surfaces are then introduced, with particular attention to the particle swarm optimization (PSO) technique. The PSO algorithm is demonstrated on some representative IIR and nonlinear filter structures, and both performance and computational complexity are analyzed for these types of nonlinear systems.