Development of low-loss quasi-slanted SPUDT filters

Abstract

The paper describes quasi-slanted SPUDTs with stepped electrodes. Using such transducers simplifies the fabrication of low-loss SAW filters for frequencies 400-600 MHz. To improve filter selectivity, two efficient simulation procedures have been developed, namely, the procedure of electrode withdrawal weighting of quasislanted SPUDTs and the procedure of simulating the effect of SAW diffraction on filter performance. The results of modeling and experiments for 385 MHz and 450 MHz WLAN filters are reported.