Extraction of Lumped Element Parameters of Bonding Pad and Internal Arrangement for Ladder-type SAW Filters Using Neural Network Techniques

Ladder-type surface acoustic wave (SAW) filter is commonly used RF filter in many communication systems. The circuit structure of a ladder-type filter consists of several one-port SAW resonators on a piezo-electric substrate arranged in series and parallel alternatively. The bonding pads of the one-port SAW resonators and the internal connections may present a significant influence on the performance of the filter Hence, how to incorporate the bonding pad and internal arrangement effects into early stage of the filter design is an important issue. In this paper, neural network was employed to extract the lumped element parameters of bonding pads and internal connections. As an example, an RF ladder-type SAW filter used in GPS system was examined. The result showed a good agreement with that obtained from full wave EM simulator.