Surface Acoustic Wave Structures and Devices Modeling Based on Coupled Waves Method

An important stage in the creation of SAW devices is the modeling of its design providing required electrical parameters. This task can be solved within the context of a device design synthesis problem. Here, requirements are set for the electrical parameters, on the basis of which the design of the device is simulated. The simulation allows for selecting other design parameters, among which are the materials of the piezoelectric and IDT, the number of electrodes and their thickness in the IDT, etc. Since a number of SAW filter designs with specific design parameters are currently used, the task seems to be over-complicated and is not considered here.

The presented method assumes device simulation based on its electrical characteristics for the given design parameters of the selected filter type. This approach offers an analysis of the selected type of device design (irrelevant to the reasons for its choice) to predict its design parameters based on simulation of its electrical characteristics for different values of its design parameters. Obviously, based on the described method, it is also possible to build algorithms for device synthesis, e.g. within the context of electrical parameters optimization problem of the device with selected design type.

The problem of filter topology synthesis is investigated for only one type of ladder SAW filter. The described method can be used to construct algorithms for the synthesis of various SAW filter types. 

Keywords: Bulk mode, Circuit theory, Green's function, Interdigital converter, Numerical methods, P-matrix, Reflection, SAW filter, Transmission and transformation, Transducer.