Hetero acoustic impedance interface was engineered in the LNOI technology to form a low-loss waveguide using solidly mounted thin-films. This unique waveguide structure can not only confine the acoustic energy within the piezoelectric layer but also significantly suppress the unwanted substrate energy radiation loss. Therefore, a universal performance improvement on resonators, wide band filterslow loss acoustic delay lines can be achieved. The performance indexes of the novel surface acoustic device in LNOI technology is typically 5~10 times better than conventional SAW devices2~3 times better than commercial AlN bulk acoustic wave (BAW) devices, consolidating the huge potential for LNOI in next generation RF acoustic devices.

We have developed high performance surface acoustic wave resonators based on LNOI technology. The LNOI SAW resonator has a high electromechanical coupling coefficient of 39, a high quality factor of 1130, resulting in a high figure of merit (FOM) of over 440. Such a high FOM ranks #1 in the world for resonator operation in similar frequency bands. Additionally, we have successfully implemented a wideband filteran ultra-low loss wideband acoustic delay line on the same chip, outperforming most international competitors. The demonstrated device can be used in 5Gother emerging communication systems, such as in-band full-duplex radios.

The LNOI technology features great performance, frequency scalability, low cost,high yield,is expected to break the current situation in which wideband filters in 5G/B5G communication systems are dominated by integrated passive device (IPD) technology. By scaling up the operating frequency, wideband LNOI SAW filters are expected to meet the performance requirements of the most demanding frequency bands in 5G NR. The technology can also be used to develop chemicalenvironmental sensors, providing more opportunities for close cooperation with domestic semiconductor upstream, midstreamdownstream industries in various fields.