High-Q, spurious free Lamb wave resonator with Acoustic Speeder structure

In this work, a high-quality factor (Q), spurious-free Lamb wave resonator (LWR) with Acoustic Speeder structure was designed and fabricated. By implementing the Acoustic Speeder structure above the surface of the bus and support tethers, the mass loading effect in the covered region was altered, reducing the acoustic wave velocity and thereby suppressing lateral parasitic modes and anchor loss. Measured results show that at a frequency of 412.8 MHz, the LWR with the Acoustic Speeder structure achieved a Q value of 1649 and an effective electromechanical coupling coefficient ($k_t^2$) of 2.80%, with no spurious signals in band.