| We have extended the K-Model, a Green’s function model previously developed for the precise simulation of surface acoustic wave (SAW) device at radio frequencies (RF), to the computation of Lamb wave resonators (LWR). The effective permittivity for Lamb wave excitation on thin aluminum nitride plates with different electrode configurations is compared. The results of the electromechanical coupling coefficient k2 computed from the effective permittivity agree closely with the classical approximation based on the open and shorted velocities v0 and vm. Although a backside metallization increases the value of k2 the frequency spacing of resonance and anti-resonance is reduced due to capacitive feedthrough through the bottom electrode. Finally, we demonstrate the ability of the model to predict the numerous spurious modes that are excited with low-electrode-count interdigital transducers (IDT). |