Design and Simulation of a SAW Filter and a new approach for bandwidth´s tuning

In this paper the analysis and structure of the SAW devices including SAW filters are examined and improved. The SAW devices have good stability and reliability and they are widely used in high-frequency communication systems such as mobile and TV sets. The design procedure of band-pass SAW filter is explained and accordingly a band-pass SAW filter with center frequency of 100 MHz is designed and simulated by COMSOL MULTIPHYSISC and MATLAB soft ware. The idea of adding a sensitive layer between the input and out inter digital transducers (IDT) is also examined. It is shown that by changing the dimension of this layer, the specification of the filter is changed. Hence, it can be used as an effective tool for adjusting the desired specification of the filter such as the bandwidth and insertion loss.