الفهرس | Only 14 pages are availabe for public view |
Abstract The most important characteristic of the surface acoustic wave (SAW) device is its insertion loss (IL). So, this characteristic was discussed from point of view of different parameters that can be used to minimize it. The equivalent circuit of the SAW delay line (SAWD), was studies and that corresponding to matching and tuning circuit for the IL minimization. The application for most of the SAW devices for communications. A simple model for calculating the input impedance of SAW transducers is explained. The calculation of SAWD insertion loss, based on this model, is presented. It has been introduced a detailed part of the main design aspects of the SAWD. Themain parameters values, dependences, and plots are presented. Similar design considerations are derived for SAW filter, where the effect of the interdigital transducer (IDT) aperture width ”a” was the dominant factor that improves the SAW filter performance. Three configurations of SAW filter were suggested and studied so as to attain minimum triple transit echo distorrtion and noise level. The aperture (width) of the SAW device is found to the only parameter that is not determind by thy frequency dependence of the transfer and therefor it can be used to optimize the SAW device. Noise and dynamic rang on an amplifier-filter-amplifier configuration are performed, and the maximum dynamic range, is introduced, The SAW oscillator (SAWD) was given as a last example, showing its main characteristic dependnce corresponding to the phase noise characteristic as function of its frequency offset. A comparative study of noise characteristics for bulk acoustic wave oscillator (BAWO) and surface acoustic wave oscillator (ASWO) is introduced. In SAWO and BAWO devices. Based on the analysis of crystal oscillator noise, an expression for the oscillators noise is obtained. With this expression the BAWO AND sawo noise are characterized. The comparative study indicates the superiority of SAWO specially at high frequencies. Thus SAWO device can elliminate the need for a multipliers (which are necessary for the BAW devices) and this generally leads to more compact devices consuming less power. The computer simulation reslts are verified by comarison with published experimental results and good agreement is obtained. The practical part in the work, is the fabrication of a locally SAWD. For this objective, we explained the different stages through which the SAWD specimen fabrication process pass. The IL (f) of the SAWD is measured for three serial IL minimization configurations. The experimental results and plots are presented. |