动态电路的混合时序分析方法

 本文基于四事件周期波形模型,提出了一般动态门、LO-CMOS、NTP动态门和N-C²MOS锁存器正确工作的时序约束.将混合时序分析方法应用于动态电路的延时计算,提出了动态门延时测试波形的生成算法,能有效处理多个输入同时翻转对延时的影响.本文的研究成果已在SpiceTime中实现,并且应用于一个32位动态加法器的设计,取得了良好效果,如果不考虑伪路径的影响,求值延时和预充延时的最大误差分别为3.62%和8.26%.     

Analysis of Four-Frequency Nonlinear Reactance Circuits

Several advantages of multiple-frequency nonlinear reactance circuits are described in this paper. In particular, a circuit is considered in which a nonlinear reactance couples four basic frequencies: /spl omega//sub 0/, /spl omega//sub 1/,/spl omega//sub 2/, and /spl omega//sub 3/; these are so related that /spl omega//sub 2/ = /spl omega//sub 0/ + /spl omega//sub 1/ and /spl omega//sub 3/ = /spl omega//sub 0/ - /spl omega//sub 1/. Here, /spl omega//sub 0/ is taken to be the power source or pump. It is found to be desirable to allow for the possible presence of the pump harmonic, 2/spl omega//sub 0/, and individual cases are characterized by whether 2/spl omega//sub 0/, is present or not. The major results are as follows: 1) Unlimited amplification gain is theoretically possible at frequencies higher than the pump, by reflecting negative input resistance at /spl omega//sub 2/, but without relying on any effects due to pump harmonics. 2) Unlimited up- or down-conversion gains between /spl omega//sub 1/ and /spl omega//sub 2/ are theoretically possible in the additional presence of the first pump harmonic, but without reflecting negative input or output resistance. 3) Unlimited amplification gain is theoretically possible at frequencies both lower and higher than the pump fundamental, without reflecting negative input resistance.     

Synchronization and Small-Signal Analysis of Nonlinear Periodic Circuits

Common approaches to simulate the steady-state behavior of nonlinear periodic circuits forced by a periodic signal of small amplitude assume that the forcing signal effects are additive to the steady-state solution of the unperturbed circuit. This assumption leads to the adoption of the variational model of the nonlinear unperturbed circuit. The variational model does not pose any particular problem when dealing with nonautonomous circuits, but must be suitably formulated when autonomous circuits are considered and the frequency of the forcing signal is close to the working frequency of the unperturbed nonlinear circuit. We show that, in this case, synchronization effects must be accounted for, and, as synchronization phenomena are intrinsically nonlinear, it is impossible to take them into account using a variational model. In fact, conventional variational models are derived from the unperturbed nonlinear circuit working at steady state and with a fixed relative phase between perturbation and system, i.e., without any possibility of phase shifts (that is, of any dynamics leading to possible synchronization). In general, this yields inaccurate or even wrong results. In this paper, we investigate this limitation of the approaches based on the variational model. Some simulation results are reported that show the transition between the nonsynchronization region to the synchronization one of well-known simple oscillators, such as the Van der Pol one when the parameters of the small-signal perturbation are varied.     

非线性时变RLC电路的计算机辅助分析

本文导出非线性时变ＲＬＣ关于梯形算法和牛顿－拉夫逊算法的模型，提出一种便于用计算机对非线性时变ＲＬＣ电路进行瞬态分析的新方法，并介绍一个基于这种方法设计的计算机程序。     

SC电路混合分析的一种方法

本文提出了ＳＣ电路混合分析的一种方法，此法特别适合于计算机辅助电路分析，并且所推导的ＳＣ电路混合议程与状态议程有着紧密的联系，由此可方便地求得ＳＣ电路的频域传递函数。     

混合集成电路应用中的失效分析

通过对两种混合集成电路即温控电路及隔离放大器BB3656BG的失效分析,表明以下观点：（1）对混合集成电路的分析,应通过电路内部测试,测量电路工作状态下各个关键部位的参数乃至动态波形;（2）深入的分析过程有利于对电路透彻的了解及促进同类型电路分析的深度,有利于使分析结论更趋准确。     

Symbolic Steady-State Analysis for Strongly Nonlinear Circuits and Systems

A symbolic method for steady-state analysis of nonlinear circuits and systems is presented. This method is based on the principle of the Equivalent Small Parameter method (the ESP method), which is an improved perturbation technique combined with the harmonic balance method. Using this method, a set of high-order nonlinear differential equations can be solved and the symbolic expressions of the steady-state periodic solutions for the required variables can be obtained. Two examples are given and show that the method is general and can be used for both weakly and strongly nonlinear circuits, and time-variant nonlinear circuits such as switching mode circuits.     

高速CMOS电路的单元延时模型分析

由于互连线电阻引起的时序问题对IC设计带来了越来越大的影响，选取精确的模型来计算延时变得非常重要。本文结合传统延时模型的特点，对有效电流源模型(ECSM)作了改进，通过分段线性方法精确地匹配了负载激励点波形的非线性特性，有效地解决了原模型中存在的不足。经理论分析和实验验证，该模型能快速有效地求解延时，能很好地应用于超深亚微米工艺下的时序分析。     

Perturbation Analysis of Nonlinear Distortion in Analog Integrated Circuits

A method for predicting the distortion in weakly nonlinear analog circuits is presented, which relies on the classical theory of regular perturbation. Accordingly, a nonlinear circuit is described and analyzed as a perturbation of its linearized model, and the response to a periodic signal is analytically calculated through frequency-domain recurrent formulas. The method is simple and quite straightforward to apply, as it involves the calculation of frequency-domain transfer functions and of Fourier coefficients only, making it easily adaptable to any circuit topology. The method can be a valid alternative to the Volterra series method. A relationship between the proposed method and the Volterra series method is established, showing that they lead to very similar approximants to the solution. The method has been numerically tested in practical circuits wherein the devices are modeled by polynomial and exponential nonlinearities.     

Numerical Analysis of Nonlinear Solid-State Device Excitation in Microwave Circuits

This paper presents an efficient technique for the numerical determination of voltage and current waveforms when a microwave circuit containing one or more nonlinear elements is excited by a single frequency source. The approach described here is readily applied to microwave networks represented by a large number of equivalent circuit elements, either lumped or distributed. A significant feature of this paper is the detailed investigation of the problem of convergence, using this new technique. The generality of the techniqne is illustrated through its application to studies of the excitation of varactor, Schottky-barrier, and IMPATT diodes in waveguide circuits. In addition, the relationship of this method to the multiple reflection approach is discussed and the convergence mechanism of this reflection technique is studied.     

Nonlinear Kirchhoff Circuits and Relativity Theory

Kirchhoff circuits consist of interconnections of elements. They are of importance not only for studying electrical phenomena but are ideally suited to model a broad range of physical systems for purposes where conservation of power and energy and related concepts such as passivity and losslessness are of paramount importance. In order to properly characterize such properties in the nonlinear case, the defining relations for nonlinear inductances etc. must have a specific form, but the classical relation for a relativistic mass is not of this type. It is shown that, preserving the classical relativistic kinematics and imposing a very reasonable requirement concerning work done, thus energy rather than momentum, one is naturally led to an expression for force in terms of mass and velocity whose form is in full agreement with that referred to for a nonlinear inductance. This alternative way of modifying Newton's second law requires Newton's third law to be also modified. These two modifications combined produce the same conservation of momentum and the same dynamics of particles in fields as classical relativity. The expression for kinetic energy, however, is different. Logically consistent derivations are presented, and a theoretical and an experimental result are pointed out that tend to offer some support to the alternative theory, or at least do not outrightly contradict it, as implausible as that theory may a priori appear to be. The paper updates earlier results on the subject.     

非线性容差电路的故障诊断

文章着重讨论如何根据容差电路有限可及点上的电压测量，诊断其线性和（或）非线性元件故障，文章利用Ｇｒａｓｓｍａｎｎ流形中的子空间距离证明了ε－故障锥的存在，并由此导出容差干扰下的可诊性条件。为了区别非线性元件的自身故障与似故障。本文仔细分析了可及点电压变化阵的方向能量椭球，并提出了相对方向能量准则。仿真表明，该准则对容差影响是鲁棒的。     

混合集成电路DPA分析过程中的要点探讨

结合了混合集成电路（HIC）破坏性物理分析（DPA）的全过程,通过对DPA各项试验的特点进行分析,从而对DPA标准中规定的一些要求和难点问题进行了补充说明,尤其对一些试验如X射线检查、多余物检测、键合强度和扫描电子显微镜检查等的具体实施方法提出了独特的见解。     

基于小波平衡的非线性电路稳态模拟

本文提出一种基于小波理论的非线性电路稳态模拟算法――小波平衡法.该方法在时域中求解电路稳态响应,克服了频域模拟算法由于谐波次数较高导致计算量很大的缺点,具有复杂度低,精度高,存在一个自适应算法自动选择模拟阶数等优点.模拟结果证明,本文的小波平衡法是一种十分有效的方法.     

Perturbation-Based Stochastic Modeling of Nonlinear Circuits

This paper presents a general model for a nonlinear circuit, in which, the circuit parameters (e.g. resistance and capacitance) are subject to random fluctuations due to noise, which vary with time. The fluctuating amplitudes of these parameters are assumed to be Ornstein–Uhlenbeck (O.U.) processes and not the white noise owing to temporal correlations. The nonlinear circuit is represented by a system of nonlinear differential equations depending upon a set of parameters that fluctuate slowly with time. To model these fluctuations, we use the theory of Ito’s stochastic differential equations (SDEs). Then the driving force of the circuit dynamics is in accordance with the general perturbation theory decomposed into the sum of a strong linear component and a weak nonlinear component by the introduction of a small perturbation parameter. The circuit states are expanded in the powers of this small perturbation parameter and recursive solutions to the various approximates obtained. Finally, the approximate expressions for the output states are obtained as stochastic integrals with respect to Brownian motion processes. The proposed method is applied to a half-wave rectifier circuit which is built out of a diode, a resistor and a capacitor. The diode is represented by nonlinear voltage–current equation, and resistance and capacitance are subject to random fluctuations due to noise, which vary slowly with time. The results, obtained using the proposed method, are compared with those obtained via the conventional perturbation-based deterministic differential equations model for a nonlinear circuit. Hence, the noise process component, present at the output, is obtained.     

Planar Models of Reconfigurable MEMS Circuits

This paper presents a general procedure for the electromagnetic modeling of arbitrarily shaped reconfigurable planar circuits using RF microelectromechanical systems switches. In this model, the reconfigurable structure is represented by a linear time-invariant planar multiport, which is connected through internal ports to as many variable lumped-element circuits as the switches. Unlike conventional equivalent circuits, in this technique, the lumped elements represent only a small portion of the switch, and their values are not affected by the proximity of the switch to line discontinuities or to other switches. For this reason, the same values can be reused, with no substantial constraint, in the modeling of very different reconfigurable structures. For any type of switch, the lumped elements are deduced from the experimental or simulated frequency response of a simple prototype. The (arbitrarily shaped) environment of the switches is taken into account in the planar multiport, which is modeled by using very efficient 2-D electromagnetic simulators. Therefore, a lot of different geometries can be easily experimented and the corresponding frequency responses can be readily calculated for any set of the switch states     

微波非线性电路稳态响应分析的理论与算法

本文建立了适于非线性微波电路ＣＡＡ与ＣＡＤ的谐波平衡算法，通过增广谐波平衡方程，微分线性化网络，非线性伴随网络等概念的引入，使得谐波平衡方程的求解和电路灵敏度的计算简捷，高效，概念清晰，且易于和已有的线性微波电路频域分析软件结合。提出了多级网络分析的松驰谐波平衡法，使得在一般的微机上可进行中等以下规模非线性微波电路的分析与设计。     

General Stability Analysis of Periodic Steady-State Regimes in Nonlinear Microwave Circuits

The problem of analyzing the stability of periodic equilibrium regimes in nonlinear microwave circuits is tackled by a general-purpose computer-aided approach. By means of a perturbation technique, the search for instabilities is reduced to a generalized eigenvalue equation expressed in matrix form, and is then carried out by Nyquist's analysis. The use of a vector processor allows the computer time requirements to be kept well within reasonable limits, even in the case of large-size problems. In perspective, this could open the way to the complementation of existing nonlinear CAD packages by an on-line facility for automatic stability analysis.     

供混合微波集成电路用的直流偏压电路的研究

使用现有的微波电路CAD软件,对几种微带直流偏压电路进行了优化设计,并用HP8510网络分析仪测试了所设计的这几种偏压电路的性能.结果表明,经过优化设计,这几种偏压电路的工作带宽均可达到倍频程以上.