| 摘要 |
A differential SAW filter having a cascaded structure includes including an input SAW stage and an output SAW stage. The two SAW stages are configured so that the distance of travel of the surface acoustic waves from a single unbalanced input of the input stage to the dual balanced outputs of the output stage is electrically equidistant, thus resulting in a balanced differential output. The input stage includes a single unbalanced input coupled to a pair of outer IDTs, which both launch a surface acoustic wave to a single input stage inner IDT. The input stage inner IDT connects to the input IDT of the output SAW stage, which launches a surface acoustic wave to a pair of identical, but inverted output IDTs that form the differential, balanced output signals. |
