| 摘要 |
<p>A SAW filter having non-linear phase frequency characteristics (see figure 7) wherein the electrode fingers disposed between the central axes of the input and output transducers have a dimension in the direction of propagation that varies perpendicularly to the direction of propagation. Each of the transducers 54, 56 includes a pair of common electrodes 60, 62, 64, 66 extending towards the other common electrode in a diverging interdigitated comb-shaped arrangement An electric conductor (100 in figure 12) having a dimension in the direction of propagation that varies perpendicularly to the direction of propagation may be formed on the substrate between the transducers 54, 56. This conductor may be a metallized layer or a layer of silicon dioxide (SiO2) that varies the speed of propagation through the substrate. <IMAGE></p> |
