A Study of Monolithic Integrated Multiband Filters Based on Y124° Lithiun Niobate on Insulator (LNOI) Platform

In this work, we introduce a novel architecture for monolithic integrated multiband filters based on lithium niobate on insulator (LNOI) platform. The advantages of the crystal cut of Y124° are introduced compared to Z-cut. Three typical acoustic modes are excited simultaneously in different in-plane directions of a 400 nm Y124°-cut LiNbO
3
thin film. Combining with the buried electrode structure, the multiband filters with a wide operating frequency range from L band to C band, and a wide fractional bandwidth (FBW) range from 3.5% to 26% are achieved. The proposed structure provides an attractive solution for monolithic integration of filters.