R. Rohith Krishnan ¹, S. Krishnakumar ¹

Affiliations
1 Department of Electronics, School of Technology and Applied Sciences, M. G. University Regional Centre, Edappally, Ernakulam - 682024, Kerala, IN

Abstract

Network theorems or circuit theorems are special aids, which can reduce the amount of effort involved in circuit analysis to a considerable degree. For linear networks, there exists interdependence between various network theorems. Thus, by careful analysis, one theorem can verify in terms of another theorem and it is advantageous for pedagogical reasons. A scheme for analogue circuit analysis is presented in this paper. Here piece-by-piece or part-by-part analyzing strategy is employed which can reduce the complexity associated with analyzing or biasing design of large analogue circuits. Fixatornorator pair plays the key role in this methodology. Hybrid equivalent circuit, an alternative for Thevenin’s or Norton’s equivalent model is realized with fixator-norator pair, and is seen to be more dynamic and flexible since it contains both voltage source and current source. Thevenin’s theorem, compensation theorem and maximum power transfer theorem are analyzed in terms of fixator norator pairs, and the study indicates the importance and capabilities of fixator-norator pair and hence hybrid equivalent circuit in analogue circuit design and analysis.

Keywords

Compensation Theorem, Fixator-norator Pair, Hybrid Equivalent Circuit, Maximum Power Transfer Theorem, Thevenin’s Theorem.

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T. N. Tilak ¹, S. Krishnakumar ¹

Affiliations
1 School of Technology and Applied Sciences, Mahatma Gandhi University Regional Center,Changampuzha Samadhi Road, Devankulangara, Palarivattom, Ernakulam, Kochi – 682024, Kerala, IN

Abstract

Objectives: This is to investigate the performance of two orthogonal, compactly supported, near symmetric wavelet families’ viz., coiflets and symlets in denoising satellite images. Methods/Statistical Analysis: We use the Stationary Wavelet Transform (SWT) which is a shift-invariant transform and three levels of image decomposition. Additive White Gaussian Noise (AWGN) is used to produce the corrupted images used for the study. Findings: The study identified the most suitable wavelet in each of the above two wavelet families, for denoising satellite images. A comparison between the denoising performances of these wavelet families has also been made. It has been found that the denoising performance of wavelets belonging to both the families decrease as the wavelet order increases. Applications/Improvements: The study finds application in the denoising of satellite images and images obtained by space exploration and such images corrupted by a combination of several types of noise distributions.

Keywords

Compact Support, Denoising, Gaussian, Near-Symmetry, Orthogonal

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K. S. Sreekala ¹, S. Krishnakumar ¹

Affiliations
1 Department of Electronics, School of Technology and Applied Sciences, Mahatma Gandhi University, Edappally, Kochi – 682024, Kerala, IN

Abstract

Objectives: This work aims to analyze the the dependency of VDD, T and CR (Cell Ratio) on cell stability in terms of Read Noise Margin (RNM) in 32nm technology by the N- curve and butterfly graphical methods. The advantages of considering both voltage and current information for SRAM cell stability measurement have been reported. Methods/Statistical Analysis: The cell stability calculation of SRAM is a central concern in submicron CMOS process nodes, as they reason for increase in dies variability and voltage scaling. The cell Stability of the SRAM is typically calculated by Static Noise Margin (SNM). As it varies with different operating modes of a cell, a detailed analysis is required. In this article, the RNM of SRAM cell is computed by N curve, which compares with the SNM by bufferfly method. SRAM with PMOS access transistor for improved read stability and low voltage application is also presented. Findings: Results show that proposed SRAM gives 50% cell stability in read mode of operation over conventional SRAM cell for CR=3. Application/Improvements: The typical SRAM bit cell with PMOS access transistor shows improved read stability at low voltage application than standard SRAM cell.

Keywords

Butterfly Curve, Cell Ratio, N-Curve, Pull-Up Ratio, Read stability, RNM, SNM, SRAM, Write Stability

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