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1.
Phase-locked loops (PLL) in radio-frequency (RF) and mixed analog-digital integrated circuits (ICs) experience substrate coupling due to the simultaneous circuit switching and power/ground (P/G) noise which translate to a timing jitter. In this paper. an analysis of the PLL timing jitter due to substrate noise resulting from P/G noise and large-signal switching is presented. A general comprehensive stochastic model of the substrate and P/G noise sources in very large-scale integration (VLSI) circuits is proposed. This is followed by calculation of the phase noise of the constituent voltage-controlled oscillator (VCO) in terms of the statistical properties of substrate and P/G noise. The PLL timing jitter is then predicted in response to the VCO phase noise. Our mathematical method is utilized to study the jitter-induced P/G noise in a CMOS PLL, which is designed and simulated in a 0.25-/spl mu/m standard CMOS process. A comparison between the results obtained by our mathematical model and those obtained by HSPICE simulation prove the accuracy of the predicted model. 相似文献
2.
Engineering with Computers - In this article, the 2D Chebyshev wavelets (CWs) are used for designing a proper procedure to solve the variable-order (VO) fractional version of the nonlinear... 相似文献
3.
Engineering with Computers - This paper introduces a new version for the nonlinear Ginzburg–Landau equation derived from fractal–fractional derivatives and proposes a computational... 相似文献
4.
Engineering with Computers - In this study, the Caputo-Fabrizio fractional derivative is applied to generate a new category of variable-order fractional 2D optimization problems in an unbounded... 相似文献
5.
Engineering with Computers - In this study, a new fractal-fractional (FF) derivative is defined by coupling the local conformable derivative and non-local Caputo fractional derivative. Using the... 相似文献
6.
Heydari Reza Farrokhi Mohammad 《International Journal of Control, Automation and Systems》2017,15(1):329-344
International Journal of Control, Automation and Systems - In this paper, an on-line gait control scheme is proposed for the biped robots for walking up and down the stairs. In the proposed... 相似文献
7.
Heydari P. Mohanavelu R. 《Circuits and Systems II: Express Briefs, IEEE Transactions on》2006,53(12):1358-1362
This brief presents the design and implementation of a 40-GHz flip-flop-based frequency divider which incorporates a novel latch topology with two distinct tail current sources and an enabled cross-coupled pair during the tracking mode. The proposed topology will speed up the latch operation and increase the driving capability. It is capable of performing frequency division at 40 GHz without shunt or series peaking inductors. The circuit was fabricated in a 0.18-mum SiGe BiCMOS process, where only CMOS transistors were used. It draws an average current of 5 mA from a 1.8-V supply voltage 相似文献
8.
Vahid Heydari Fami Tafreshi Ebrahim Ghazisaeedi Haitham Cruickshank Zhili Sun 《中兴通讯技术(英文版)》2014,(2):41-49
Network securityprotocolssuch as IPsechave been used for many years to ensure robust end-to-end communication and are impor-tant in the context of SDN.Despite the widespread installation of IPsec to date,per-packet protection offered by the protocol isnot very compatible with OpenFlow and flow-like behavior.OpenFlow architecture cannot aggregate IPsec-ESP flows in transportmode or tunnel mode because layer-3 information is encrypted and therefore unreadable.In this paper,we propose using the Secu-rity Parameter Index(SPI)of IPsec within the OpenFlow architecture to identify and direct IPsec flows.Thisenables IPsec to con-form to the packet-based behavior of OpenFlow architecture.In addition,by distinguishing between IPsec flows,the architectureis particularly suited to secure group communication. 相似文献
9.
The selective separation of carbon dioxide (CO2) from a wet gaseous mixture of CO2/H2 through facilitated transport membranes containing immobilized aqueous solutions of monoethanolamine (MEA), diethanolamine (DEA), ethylenediamine (EDA) and monoprotonated ethylenediamine (EDAH+) and their blends was experimentally investigated. The effect of CO2 partial pressure, amine concentration, feed side pressure and amine species on the CO2 and H2 permeances were studied. The CO2 permeability through amine solution membranes decreased with increasing CO2 feed partial pressure but the H2 permeance was almost independent of the H2 partial pressure. A comparison of experimental results showed that single or blended amines with low viscosity and a moderate equilibrium constant, i.e., large forward and reverse reaction rate of CO2‐amine, are suitable for effective separation of CO2. The permeability of CO2 generally increased with an increase in amine concentration, although this increase may be compromised by the salting out effect and decrease in diffusivities of species. The results obtained indicated that CO2 permeance across a variety of amines are in the order of DEA (2 M) > MD (2 M) > MD (1 M) > MEA (2 M) > MEA (4 M) > MD (4 M) > DEA (1 M) > DEA (4 M) > MEA (1 M) for various concentrations of MEA + DEA blend and are in the order of EDAH+ (2 M) > DEA (2 M) > MH (2 M) > DH (2 M) > ED (2 M) > EDA (2 M) > MEA (2 M) for various blends of amine. 相似文献
10.
Majid Ghashang Hadi Taghrir Mohammad Najafi Biregan Negar Heydari Fateme Azimi 《Journal of Sulfur Chemistry》2016,37(1):61-69
An eco-friendly procedure for synthesis of 2-(2-oxo-2H-chromen-4-yl)-3-arylthiazolidin-4-one derivatives by three-component reaction of 2-oxo-2H-chromene-4-carbaldehydes, aromatic amines and thioglycolic acid, with tetramethylbutane-1,4-diammonium acetate as a low-cost ionic liquid catalyst under reflux condition is described. The use of an ionic liquid as a catalyst has the advantages of high yields, short reaction time and environmentally friendly reaction media. 相似文献