The parasitic components of MOS switches at high speeds affect the linearity and resolution of CMOS sample and hold circuits. CCD-based circuit design can offer good performance at high speeds. This thesis presents the design of sample and hold circuits using charge-coupled device structures in a standard CMOS process. Three sample and hold circuits have been built and tested for linearity and speed performance. The CCD S/Hs have been characterized using a continuous-time integrator and a Δ∑ ADC. The CCDs, with a switched capacitor amplifier at the output, achieve an SFDR of 54dB for an input signal V[subscript in]=2.6V+0.4Vpp at f[subscript in]=10.1KHz. / Graduation date: 2003

Thesis (M.S.)--Rochester Institute of Technology, 1992. / Typescript. Includes bibliographical references.

Thesis (M.S.)--Rochester Institute of Technology, 1992. / Typescript. Includes bibliographical references.

Thesis (M.S.)--Rochester Institute of Technology, 1987. / Typescript. Includes bibliographical references (leaves 96-98).

Los dispositivos CCDs (por las siglas en inglés de Charge Coupled Devices) son aún hoy en día la tecnología líder para la toma de imágenes de baja distorsión y son ampliamente utilizados en aplicaciones de astronomía en el rango de la luz visible y en el infrarrojo cercano. En esta tesis se estudia y desarrolla su utilización para la detección de otras partículas diferentes a los fotones de luz, en particular para partículas con muy poca probabilidad de detección y muy poca deposición de energía logrando que esta nueva tecnología presente una ventaja respecto a detectores disponibles hoy en día. Los resultados de esta tesis son la base del desarrollo de una aplicación de un sistema de CCDs para la detección de neutrinos provenientes de un reactor nuclear. Se estudian las características principales de los CCDs que los hacen aptos para esta novedosa aplicación, y se encuentra que la mayor limitante de su rendimiento es el ruido de lectura agregado por su etapa de salida. Se desarrolla una técnica para reducir su incidencia, y mejorar así la capacidad de detección. A partir de estas características se analiza la capacidad de los CCD para detectar neutrinos provenientes de un reactor nuclear por medio de la interacción coherente entre el neutrino y los núcleos de los átomos de silicio. Para optimizar la detección de eventos de este tipo en las imágenes de salida, se deriva un modelo matemático que estudia el mecanismo de generación de carga en el CCD y se desarrolla una técnica de calibración que permite obtener información de la profundidad a la que se produce la ionización Estos resultados se plasmaron en el desarrollo de un prototipo instalado en la Central Nuclear Almirante Álvaro Alberto, en Angra dos Reis, Brasil. Se muestran algunos resultados preliminares obtenidos con este prototipo, y se comentan las mejoras que se realizarán próximamente en este sistema. / Charge Coupled Devices are still nowadays the best available technology for low distortion digital imaging applications and are extensively used for ground and spacebased astronomy for visible light and near infrared. In this thesis, studies to extent its use to applications for the detection of particles different to light photons are presented, in particular for those particles having low probability of interaction and small deposition of energy for which this technology presents advantages over available detectors. These studies are the base for the development of a CCD system aiming the detection of low energy neutrinos coming out from a nuclear reactor. The most important aspects of scientific CCDs for particle detection are revisited, and its main detection limitation produced by the readout noise added by the output amplifier of the device is explained. A technique to reduce the effect of this noise and to improve the detection performance is developed. The main features of CCDs are then used to analyze the feasibility of detecting low energy neutrinos through their coherent scattering with nuclei. A mathematical model of the expected signal in the output images is obtained and a new technique for the calibration of the CCDs to obtained the depth of the interaction in the silicon is developed. This result is used to improve the detection performance of the system The first CCD system prototype for this application is presented together with some details of its installation at Central Nuclear Almirante Alvaro Alberto in Angra dos Reis, Brazil, and some preliminary results are discuSSED.

No description available.

Thesis (M.S.)--Worcester Polytechnic Institute. / Keywords: digital x-ray imaging; pixel size; scintillator. Includes bibliographical references (p. 57-59).

There is a need for monolithic devices capable of spatial resolution in imaging and ionizing radiation detection. In this thesis, a GaAs acoustic charge transport device (ACT) was studied for this purpose. A new method of charge injection has been demonstrated for the ACT. Using near-infrared optical pulses incident through thin semi-transparent chromium windows, electron-hole-pairs were separated by the electric field in a depleted n-type channel region of the device. For light penetration less than the depth of the electron potential minimum, and for small injection levels, calculations indicated that electrons and holes were separated at their saturation velocities. Holes moving toward the surface of the substrate could recombine with electrons at an evaporated Schottky metal plate. Electrons moving toward the channel centre were bunched and transported by the electric field coupled to a <110> propagating surface acoustic wave (SAW) on (100) cut GaAs. Quantum efficiency, defined as the number of electrons collected at the output per incident photon on the GaAs surface, was greater than 9% at an optical wavelength of 730 nm. When compensation was made for the loss and reflection due to the chromium windows, the quantum efficiency was in excess of 24%. Charge transfer efficiency was greater than 0.992 with the ACT clocked at 360 MHz. The demonstrated optical injection technique may be of use in future ACT imaging devices. / Applied Science, Faculty of / Electrical and Computer Engineering, Department of / Graduate

Digital imagers including Charge-Coupled Devices (CCD) are essential to most forms of modern photographic technologies. The quality of the data produced by digital imagers have made them an invaluable scientific measurement tool. Despite the numerous advantages of digital imagers, there are still factors that limit their performance. One such factor is the stability of the camera's gain, the ratio that dictates the imager's ability to convert incident photons to a measurable output voltage. Variations in gain can affect the linearity of the device and produce inaccurate measurements. One of the factors that determines the gain of the camera is the sensitivity of the output amplifier. The purpose of this study is to compare the performance of two different output amplifier structures: the traditional source follower (SF) and the charge feedback amplifier (CFA). In studies of other solid state detectors, the CFA has shown a greater stability against variations in certain system parameters and environmental conditions such as operating temperature. It is thought that the CFA shows a superior stability over the SF, because the gain of the SF is dependent on multiple capacitances associated with the reset and output transistors, whereas the CFA gain is only dependent on its feedback capacitance. Furthermore, the CFA is able to handle a larger amount of charge than the SF, which increases the dynamic range of the output amplifier. In this research, output amplifier stability is measured using gain and linearity data collected from a CCD manufactured with both types of amplifiers. Preliminary data is presented that indicates the CFA exhibits a greater linearity, larger dynamic range, and a more stable gain than the SF. Despite this the CFA suffers from a significantly larger level of noise. Suggestions for future research are also given as to how to verify and expand upon the results presented here.

Following the development of detector technology, remote sensing image detection is being implemented with charge-coupled devices (CCD), which have promising features. The French SPOT system is the first civilian satellite sensor employing a CCD in its detection unit. In order to obtain the system transfer function (TF), a linear system model is developed in the across- and along-track directions. The overall system TF, including pixel sampling effects, is then used in the Wiener filter function to derive an optimal restoration function. A restoration line spread function (RLSF) is obtained by the inverse Fourier transform of the Wiener filter and multiplied with a window function. Simulation and empirical tests are described comparing the RLSF to standard kernels used for image resampling for geometric correction. The RLSF results in superior edge enhancement as expected.