摘要 |
An acoustic surface wave filter is described for receiving one of two electrical signals at either of a pair of input ports and for providing a filtered electrical signal at a common output port. The filter includes a pair of input electro-acoustic transducers on a substrate, each coupled to one of the input ports, for launching surface waves in response to an electrical input signal. Each of the input transducers is associated with a multistrip coupler and an output transducer for converting the surface waves to an electrical output signal. The layout and geometry of the filter components are such that all surface waves are launched in a direction which is oblique to the substrate boundaries to reduce interference due to reflected surface waves. The layout and geometry also result in a relatively small substrate and a simultaneous reduction of insertion loss.
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