الفهرس 
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Abstract
The aim of this thesis is to determine the parameters associated with the use of the quantum well for AIx GOI_xAs/GaAs quantum well infrared (IR) photodetectorS. Three types of photodetectors are considered with multi-quantum well structures. The insertion of quantum wells into the intrinsic region of a bulk PIN photodetector extends the absorption to longer wavelengths. The device is characterized and simulated to calculate the quantum efficiency of the device.
The results show that adding the group of quantum wells improves the spectral response of the device in the IR wavelength region started from 0.75 Ilm to 0.87 Ilm. The structure of these photodetectors are studied with different numbers of quantum wells at the infrared range. It is found that,the device efficiency increases with number of the quantum well number. The maximum achieved efficiency is 32 % at 0.85 Ilffi.
This thesis proposes a near range, low altitude, target detection and passive tracking system using Multi-Quantum Well Infrared Photodetector (MQWIP). The system used as a method for detecting and tracking objects which emitt infrared radiation such as jet aircraft and helicopters. Such systems are passive, meaning they do not give out any radiation of their own, unlike radar,and so, it can’t be detected by the enemy.
This system is used in addition to surveillance radars as a gap filler to detect low¬flying aircrafts penetrating gaps. Target tracking is often complicated by the measurement noise and IR sensors Field of View (FOY) uncertainty. The noise must be filtered out in order to predict the true path of a moving target. It analyzes the applicability of the Extended Kalman Filter (EKF) as a probabilistic prediction method to infrared visual tracking. Various situations were examined, including non¬maneuvering and maneuvering targets. Based on the results, the Kalman filter in conjunction with QWIP were successful in smoothing random deviations from the true path of the targets, improving its ability to predict the path of each target as more measurements from the tracker were processed.