Surface acoustic wave generator - has propagation velocity reducing electrodes and minimises Rayleigh wave coupling

摘要

The configuration of electrodes for the generation of surface waves and for their reception in substrates is intended for general coupling applications and filters. The electrode layout is in the form of a cavity resonater maintaining a close to surface standing wave in the substrate of the unit and providing minimum coupling due to Rayleigh waves at the transducer frequency. The electrodes of the transmitting and receiving transducers are interdigitalised at opposite ends of the substrate, the space between them being almost entirely occupied by a further set of electrodes which act to reduce the propagation speed of the transmitted waves.