Abstract
This thesis explores the possibility of increasing the quality factor of a lamb wave resonator device with the use of a phononic crystal structure array on the surface of the bridge suspending the device.
In the growing industry of telecommunication, there is an increasing demand for high performance devices. As the amount of data transmission is rapidly increasing year on year, so is the need to implement higher frequency bands. Therefore, the demand for smaller devices which can operate in the GHz frequency range, has accelerated the research of lamb wave resonators.
This because they have the possibility of a highly adaptable frequency response based mainly on the geometrical structure of the device.
The Ain structure is a widely used material for both surface acoustic wave and lamb wave resonator devices. It offers a high phase velocity, mechanical strength, chemical inertness, and thermal stability making it very suitable for high frequency devices. However, in recent years there has been a push to explore the possibility of using lithium niobate and lithium tantalate for its higher mechanical coupling factors. Making the possible use of high-end devices quite attractive, regardless of the higher production cost.
Here we investigated the design prosses of a FEM simulation using COMSOL Multiphysics for the purpose of optimising and predicting the response rate of a lamb wave resonator using different materials. Both designing relevant boundary conditions as well as relevant simulations are investigated.