Orcad Tutorial

L'objectif de ce TP est de vous familiariser avec l’outil de simulation ORCAD/PSPICE sous  Windows.  La  simulation  de circuit  électronique  permet  de  prédire  les  caractéristiques d’un circuit  électronique  et  son  comportement  à  des  stimuli donnés, et donc  de  le  dimensionner  avant fabrication. 
La première partie de ce document détaille les différentes étapes à suivre pour saisir un schéma électrique, le simuler avec PSPICE et visualiser les résultats.

Nesta atividade em laboratório, com o auxílio do software OrCAD Capture
SIS, foram realizadas simulações referentes a transistores de efeito de campo JFET e MOSFET. Deste modo, foram gerados gráficos de sua curva característica, curva de transferência e também de sua sensibilidade à variações de temperatura como abordado teoricamente em sala de aula.

In minimally invasive diagnostic imaging systems, especially on nuclear magnetic resonance machines, the detection of the formed signal presents a high sensitivity, being passive from interference, noise, and instabilities. In order for the final image quality to be obtained, the detection signal needs to be received, filtered, and amplified, with that the remaining process-ing can be carried out. The low noise amplifier is responsible for amplifying the detected signal, whose peak voltage is in the range of millivolts. This amplifier must be a stable and suitable system for signal transmission (impedance matching definition), with the application of sufficiently large gain, through the FET (Field Effect Transistor) amplifier for its processing and that it has the lowest noise injection index (noise figure definition). The present work presents a grounded study and the improvement of a circuit, with adaptations, using the FETHEMT (High Electron Mobility Transistor - ATF-34143) and inductor modeling, as well as the complete project of an LNA (Low Noise Amplifier), using software capable of obtaining feasible results. This work identifies that the influence of the amplifier device model and the real high-frequency inductor modeling must be taken into account for the design of an LNA. The resulting design features polarization configuration, stability, and impedance matching circuits with 20.25 dB gain and 0.58 dB noise figure.

This paper involves the design and development of an embedded camera with built in image processing. For this, initially the components have been chosen based on low cost without compromising on fit, form and function. The design (schematics and layout) was implemented using Or CAD tool. This paper also shows some image processing algorithm which can be used for number plate reading simulated using MATLAB. The required code for this algorithm has been developed.

Este relatório contém a realização prática de um dos roteiros do laboratório. Inicialmente foi projetado os circuitos proposto pelo roteiro, e simulado, utilizado como ferramenta gráfica, ORCAD. Primeiro foi projetado um filtro Chebyshev para baixas frequencias e no segundo um filtro ressonante LC para sintonizar uma faixa de frequência.