Memcapacitor response under step and sinusoidal voltage excitations

Recently, mem-elements have become fundamental in the circuit theory through promising potential applications based on the built-in memory-properties of these elements. In this paper, the mathematical analysis of the memcapacitor model is derived and the effect of different voltage excitation signals is studied for the linear dopant model. General closed form expressions and analyses are presented to describe the memcapacitor behavior under DC step and sinusoidal voltage excitations. Furthermore, the step and sinusoidal responses are used to analyze the memcapacitor response under any periodic signal using Fourier series expansion where the effect of the DC component on the output response is investigated. In addition, the stored energy in the memcapacitor under step, sinusoidal and square wave excitations is discussed. Moreover, the analysis of series and parallel connection of N non-matched memcapacitors in general is introduced and special cases of matched memcapacitors are discussed. The derived equations are verified using SPICE simulations showing great matching.     

Frequency-domain steady-state analysis of circuits with mem-elements

The paper deals with frequency-domain models of memristor, memcapacitor, and meminductor, and their use in the steady-state analysis by means of the harmonic-balance method. The models are based on a polynomial approximation of constitutive relations, allowing analytical formulation of relations between the spectral components of stimulus and response, for both periodic and quasi-periodic steady-state conditions. The method does not require transforming signals between the time and the frequency domains to obtain the mem-element response. Examples of the analysis of a mem-resonance circuit with long settling time and the HP memristor with nonlinear dopant drift are presented.     

Mutator-Based Meminductor Emulator for Circuit Applications

A mutator-based meminductor emulator whose inductance can be varied by an external current source is proposed. The implementation of a meminductor emulator is very important, since real meminductors are not physically realizable with current technology. Though there is active research on memristor or memcapacitor emulators, no significant contribution for the meminductor emulator has been presented yet. In this paper, a meminductor emulator has been built using the principle of a mutator, in that a memristor with \(v-i\) at one port functions as a meminductor in the other port, whose input is characterized by \(\varphi - i\) curve. It is shown that multiple meminductor circuits can be built in various configurations with memristors combined with a single mutator. The feasibility of our meminductor emulator and its expandable configurations are verified experimentally and SPICE simulation.     

基于Matlab的忆感器建模仿真及应用

忆感器是一种有记忆能力的非线性电感器,其电感值的变化依赖于流过它的电荷数或磁通量。对于这种新的纳米级的电子元件,从电路学的基本原理出发,推导了它的基本公式,从数值分析的角度提出了一种新的基于Matlab的忆感器的建模及仿真方法,验证了忆感器的典型的磁滞回环现象,并利用这种方法重点分析了忆感器在非易失性存储和人工神经网络中的应用。实验表明,该建模方法准确地反映了忆感器的特性,同时也说明了忆感器在众多的领域里具有很高的潜在的应用价值。     

Steady-state analysis of piecewise-linear systems with periodic inputs

A specific form of a recently proposed algorithm is derived for the rapid determination of the steady-state response of large classes of piecewise-linear systems subjected to periodic inputs. It can be directly incorporated at marginal cost into a computer-oriented state space approach for generating the time domain response of such systems. The algorithm has been successfully applied to several circuits.     

Transient response of a dissipative earth by use of image theory

Simple, closed form formulas are derived for the transient response between dipoles at arbitrary locations above a dissipative earth. Both early time and late time responses are displayed. The case of an homogeneous earth is treated, using a single image for early times and an additional set of continuous images for late times. The results are checked favorably against published work. Multiple images are used for the case of a two-layered earth.     

Critical conditions of saddle-node bifurcations in switching DC–DC converters

Although existence of multiple periodic orbits in some DC–DC converters have been known for decades, linking the multiple periodic orbits with the saddle-node bifurcation (SNB) is rarely reported. The SNB occurs in popular DC–DC converters, but it is generally reported as a strange instability. Recently, design-oriented instability critical conditions are of great interest. In this article, average, sampled-data and harmonic balance analyses are applied and they lead to equivalent results. Many new critical conditions are derived. They facilitate future research on the instability associated with multiple periodic orbits, sudden voltage jumps or disappearances of periodic orbits observed in DC–DC converters. The effects of various converter parameters on the instability can be readily seen from the derived critical conditions. New Nyquist-like plots are also proposed to predict or prevent the occurrence of the instability.     

几乎周期MA信号参数的闭式递推估计

本文利用高阶循环统计量讨论几乎周期滑动平均(APMA)信号参数的闭式递推估计.建立了两组关于APMA信号系数和奇数阶时变累量的关系式,并据此提出了两种直接估计信号参数的方法.在此基础之上,导出了信号参数的闭式递推估计.最后,给出了所提方法的模拟结果.     

An interpretation of tunneling time

The time required for tunneling through a wide potential barrier has been obtained, in general, using a closed form method. We show that a knowledge of the phase delays at the boundary surfaces yields the tunneling time and as a consequence the tunneling time is independent of the barrier thickness. For the particular case of a rectangular barrier the tunneling time is identical with that derived by Hartman [1] and by Franz [2].     

适用于任意阵列的多径信道二维方向角与相对时延的联合估计方法

在多径传输的情况下,经常需要估计各路径的二维波达方向角度及相对时延.本文给出了在信道冲激响应可以估计的前提下,一种基于波达方向矩阵法的二维方向角与相对时延的联合估计方法,该方法充分利用了已知的信号码形信息,给出了一种无需进行搜索的闭式解,与基于多维MUSIC或多维ESPRIT的方法相比,具有运算量小的优势.     

A Petri Net Method for Schedulability and Scheduling Problems in Single-Arm Cluster Tools With Wafer Residency Time Constraints

With wafer residency time constraints for some wafer fabrication processes, such as low pressure chemical–vapor deposition, the schedulability and scheduling problems are still open. This paper aims to solve both problems. A Petri net (PN) model is developed for the system. This model describes when the robot should wait and a robot wait is modeled as an event in an explicit way. Thus, to schedule a single-arm cluster tool with wafer residency time constraint is to decide how long a robot wait should be. Based on this model, for the first time, we present the necessary and sufficient conditions under which a single-arm cluster tool with residency time constraints is schedulable, which can be checked analytically. Meanwhile, a closed form scheduling algorithm is developed to find an optimal periodic schedule if it is schedulable. Also, a simple method is presented for the implementation of the periodic schedule for steady state, which is not seen in any previous work.      

Quadratic phase error loss in circular apertures

A very simple expression in closed form has been derived for the loss in gain of a circular aperture suffering quadratic phase error. It is applicable to amplitude distributions that can be approximated by a truncated Gaussian form that tapers to any arbitrary edge value.     

Some new results on a class of periodically varying systems

The analysis and stability properties of a special class of R-L-C network, where the energy storage elements vary periodically with time and the dissipative elements are held constant, is discussed. In the analysis, fast Fourier transform technique has been utilized to obtain rapidly an accurate response of the network when excited by any arbitrary periodic signal. In the stability results, it has been shown that the network's stability can be ensured in a very simple manner if the connection matrix of the network is in Jordan normal form.     

A Low-Pass Prototype Network for Microwave Linear Phase Filters

A new approximation theory is presented for a low-pass prototype filter which simultaneously optimizes both the passband amplitude and phase response of the scattering transfer coefficient over the same finite band. This closed form solution is expressed in terms of single polynomial, which is readily generated through a simple recurrence formula, and has been termed the equidistant linear phase polynomial since its phase deviation from linearity vanishes at equidistant points along the real frequency axis. A synthesis procedure is presented for the realization of this transfer function using a resistively terminated, symmetrical, lossless, two-port network where extensive use is made of the immittance inverter concept. The even-mode admittance, which defines the network, possesses a simple closed form representation in terms of the equidistant linear phase polynomial and its derivative, and consequently, the entire theory is derived in an analytic form. Typical performance characteristics are graphically presented for networks of up to 14th degree, illustrating the superiority of this new approach over any other known form of approximation theory for selective linear phase filters.     

基于不确定集的稳健MIMO雷达波形设计算法

针对雷达目标回波信号存在不确定性导致MIMO雷达波形优化设计性能下降问题,该文提出一种扁平椭球不确定集约束下的稳健自适应发射-接收波形联合优化设计方法。首先将目标脉冲响应的误差推广到更为一般的扁平椭球不确定集约束条件,并利用Lagrange乘子法对优化过程进行推导,得出扁平椭球不确定集约束下的闭式表达式。其次为了提高目标脉冲响应不确定集范围较大时的优化性能,采用了迭代鲁棒最小方差法进行求解(IRMVB),求得更为精确的目标脉冲响应,提高了SINR改善性能。然后进一步分析了基于扁平椭球不确定集约束条件与球体约束条件优化问题的内在联系,推导得出该文求解过程为广义对角加载方法。最后通过仿真实验表明所提算法对于目标回波信号不确定性具有更高的稳健性。     

Model for the decrease in HBT collector current under DC stress based on recombination enhanced defect reactions

Based on simplifying assumptions a model is developed to describe decreasing HBT collector current under DC bias stress. The underlying processes are recombination enhanced defect reactions (REDR), namely defect generation and defect annealing. The simplification of the derived equation under particular boundary conditions leads to a form of the Eyring relationship generally employed to describe the decrease in collector current under DC bias stress. Additionally, pulsed tests with an emitter current density of J_E=200 kA/cm² have been performed. The comparison between measured data from these tests and their fit proofs the applicability of the derived equation. Of course this can not be an evidence for the real running physical processes.     

Sampled-data modeling and digital control of resonant converters

A sampled-data model to describe the dynamics of large signals and of small perturbations away from a cyclic steady state is developed. Associated transfer functions are obtained. The application of the model is illustrated by correlating the analysis with simulation results obtained for a series resonant DC/DC power converter. A discrete-time microprocessor-based controller, designed using the aforementioned dynamic model, has been built and tested using a simulation for a series-resonant DC/DC converter set up on the Massachusetts Institute of Technology Parity Simulator. The control methods implemented are state feedback and periodic output feedback, each designed to achieve a specified set of closed-loop poles. The controller has been implemented using the Parity Simulator generalized controller. Results of the closed-loop response showed an improvement over the open-loop response. In addition, the effect of the microprocessor computation delay on the closed-loop dynamics of the converter is investigated     

Formulas useful for the synthesis and optimization of general,uniform contradirectional couplers

Explicit formulas allowing the synthesis and optimization of general, uniform, contradirectional couplers are derived. The well-known method of compensating for different phase velocities of the coupler modes with shunting capacitors is also mathematically formulated in a stringent form so that a lossless coupler of the general class mentioned above can be made ideal at any chosen frequency. Previously, only specialized cases have been treated in closed mathematical form. Compensated and uncompensated microstrip coupler designs are compared under the influence of realistic losses. It is shown that a considerably better directivity is attainable with capacitive compensation, even over a frequency range as large as one octave. The value of the formulas is confirmed by application to previously published experimental results     

New grounded passive elements-based external multiplier-less memelement emulator to realize the floating meminductor and memristor

A novel memelement emulator configuration has been reported in the presented work. This proposed configuration can be used to realize the function of a floating meminductor as well as the memristor element through proper selection of employed passive elements. The presented emulator circuit is based on MVDCC (modified VDCC) and OTA, which are CMOS implemented electronically tunable ABBs (Active Building Blocks). The designed circuit employs only two ABBs and three grounded passive elements. As per the knowledge of the authors, no such emulation configuration with a floating architecture has been reported so far, which can realize the behaviour of two mem-elements without the use of any external multiplier IC/circuitry, passive inductor or mutation through any externally employed memelement. It can be considered as a notable design feature along with its other advantages like electronically/resistively tunable emulated response and use of only grounded passive elements. Moreover, proposed circuit has been investigated for the consideration of non-idealities and different port parasitics of employed blocks. For the verification purpose, PSPICE simulation environment with CMOS 0.18 µm TSMC technology parameters, has been selected. The functioning of the realized meminductive and memristive behaviour has also been verified through the application example circuits designed using developed emulator circuit. Afterwards, the commercial IC based realization of the proposed emulator circuit has been shown and experimental results are discussed.