Abstract

This paper provides knowledge about how to decrease the overall physical size and insertion loss of the filter. Metamaterial is taken as a reference to achieve this goal. Physical size and light weight is a major concern in today's integrated circuit. The application of low pass filter is very wide in the field of communication engineering and the complex receiver in which frequency selection is a primary factor and much more. The rate of change of magnitude with respect to frequency (roll off) and the magnitude in pass band are two most important features of any filters. The particular shape of metamaterial having various unit cell has ability to improve the overall performance of filter. This improves selectivity to great extent. Metamaterial in shape of hexagonal-omega structure provides the negative permittivity.

Abstract

This monograph provides an epistemological rational for the novel “Tri–Factor Analysis” statistical model and metric. This new statistic is an innovative and in–depth way of investigating the overall effectiveness of teaching and learning in digital learning environments and Ecosystems. Tri–Factor Analysis is grounded in the Eduscience (Osler, 2013a) Tri–Factors of: Performance, Efficacy, and Content. Along with the Tri–Squared Test (first introduced in the Journal on Mathematics) it is a mathematically–grounded analytical methodology designed to provide educators with quantitative tools, metrics, and analytics that aid in pedagogical (and andragogical) investigation. The use of the Tri–Factor Analysis methodology also adds value to educational inquiry that has been formatted as an eduscientifically–engineered research design that involves the critical analysis of overall classroom and individual learning in digital learning Ecosystems.

Abstract

This paper presents a light DC thermal model of recessed gate P-HEMT devices, based on the Chaibi model, where the authors have identified the transistor parameters having greater influence on the device behaviour for temperature variations. The main aims are to improve the accuracy of modelled I-V curves, in particular in the knee and saturation regions and above all to give the device source-drain current as a function of external voltages, as seen at the device gates, by-passing the very difficult measurement of parasitic resistances for the I-V characterisation. To verify the accuracy of the proposed model, the results are compared with those of Chaibi model, obtaining a negligible relative error, with however a compilation time and a run time much more low.

Abstract

Mixed mode circuit design is the current trend in VLSI industry, where both analog and digital circuitry can be fabricated using standard digital CMOS technologies. However, these technologies do not lend themselves to analog design, requirting novel circuit design techniques that are compatible with standard CMOS processes. Consequently, over the last few decades Current-Mode (CM) processing has evolved as a novel design technique which has resulted in emergence of numerous analog building blocks. The operational transresistance amplifier (OTRA) is one among those. It is a high gain current input voltage output device which provides the advantages of current mode design techniques and can readily be used for voltage-mode applications.

This paper presents a new voltage mode Multi-Input Single Output (MISO) first order universal filter using single OTRA. The presented topology can be used to realize low-pass, high-pass and all-pass filter functions through appropriate input selections. The configuration is made fully integrated by implementing the resistors using matched transistors thereby reducing chip area. The proposed circuit is insensitive to parasitic capacitances and resistances due to internally grounded input terminals of OTRA. The effect of non-ideality of OTRA on the proposed circuit is also analysed. Functionality of the proposed configuration is verified through PSPICE simulations using 0.5 μm CMOS process parameters. The simulation results are in tune with the theoretical propositions.

Abstract

The manufacturing and utilization of photovoltaic arrays have advanced dramatically in the recent years. The use of new, efficient Photovoltaic Solar Cells (PVSCs) has emerged as an alternative measure of renewable green power, energy conservation and demand side management. Maximum Power Point Tracking (MPPT) techniques are employed in photovoltaic (PV) systems to make full utilization of PV array output which depends on solar irradiation and temperature. These techniques vary in many aspects as range of effectiveness, hardware, sensor required and cost. This paper presents an optimized controller design which increases the conversion efficiency of a photovoltaic system under variable temperature and irradiance conditions. It also includes the comparison of the efficiency of the PV system by incorporating the controller circuit on the existing MPPT algorithms in real time and in simulation. Different development stages are presented and then the optimized controller is simulated and evaluated which has shown better performances. Matlab Simulink tools have been used for performance evaluation on energy point. Simulation will consider different solar irradiance and temperature variations. The real time model produced includes rotating the panel under uniform and non uniform shaded conditions which is driven by a brush motor.