Thesis (M.S.) in Electrical Engineering--University of Maine, 2007. / Includes vita. Includes bibliographical references (leaves 92-96).

Thesis (Ph. D.)--Boise State University, 2009. / Includes abstract. Includes bibliographical references (leaves 104-112).

Thesis (Ph. D.)--Boise State University, 2009. / Title from t.p. of PDF file (viewed Apr. 26, 2010). Includes abstract. Includes bibliographical references (leaves 104-112).

No description available.

One class of Surface Acoustic Wave (SAW) devices employs reflecting arrays to determine device characteristics. Dots of metal film and grooves have been used as reflectors; reflection is caused by the mechanical discontinuity. This research project is a study of an alternative reflector, the thin metal dot, which reflects by interacting with the electric field that accompanies the SAW on a piezo-electric material. Experimental work is done on Y-cut LiNbO₃, a common SAW material, the aim being to characterise the reflection mechanism sufficiently to design devices, particularly on this material. Reflectivities of a large range of dot sizes is reported. Velocity change due to dots, another parameter required in device design, is also measured. In addition, holes in a metal film, physically the opposite of dots, are also studied. A theorectical model is developed to predict the behaviour of dots in devices. For a <strong>Z</strong>-propagating wave in LiNbO₃, the SAW velocity for completely free and completely metallised surfaces were used to specify the properties of the material. For propagation in other directions on the surface, particularly near the <strong>X</strong> direction, a different acoustic mode, the Leaky Surface Wave (LSW), has an influence on SAW reflections, and the model also requires the LSW velocities under the same two conditions. The model uses these parameters, together with dot geometry, to determine reflectivity in any direction and velocity change due to the dots. The results agree well with experiments. A device (a RAC) is designed using this model, to bring out any unforseen difficulties in the use of dot arrays. The device performed as expected except for some unanticipated attenuation in the arrays, which can almost certainly be predictably allowed for in future designs, being broadband and not very severe.

No description available.

A detailed theoretical study for the operation of the surface-acoustic-wave diode storage correlator is presented. A circuit model describing the device is developed which is used to analyze the signal storage characteristics and the different read-out modes of operation for both p-n and Schottky diode structures. The calculated predictions of the proposed theory are in excellent agreement with experimental data published by independent researchers. The theory presented is self consistent and takes into account, for the first time, the minority carrier lifetime in the dynamics of charging the p-n diode structures which was neglected in previous theories. A straightforward transmission line theory approach is developed for finding the surface-wave amplitude excited by the diode potential during the read-out process. The frequency response characteristics predicted for these structures is a fairly slowly varying function of frequency; hence such correlators are essentially bandlimited by the input and output surface-wave transducers.

No description available.

viii, 178 leaves : ill., graphs ; 31 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Thesis (Ph.D.)--University of Adelaide, Dept. of Electrical Engineering, 1976

viii, 178 leaves : ill., graphs ; 31 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Thesis (Ph.D.)--University of Adelaide, Dept. of Electrical Engineering, 1976