5.9 GHz Longitudinal Leaky SAW Filter With FBW of 9.2% and IL of 1.8 dB Using LN/Quartz Structure

Improving frequency and bandwidth is the essential path for the surface acoustic wave (SAW) filter to keep its leadership in the 5G or sub-6G system. In this work, we present high frequency longitudinal leaky SAW (LLSAW) devices based on 128° ${Y}$ -90° ${X}$ LiNbO3/160° ${Y}$ -90° ${X}$ Quartz structure, whose parameters were optimized through simulation. Moreover, unlike other substrates suffering from obvious ripples, device using Quartz substrate exhibits near spurious free response in a wide frequency range. The fabricated resonator features phase velocity of 6194 m/s, effective electromechanical coupling factor of 12.0%. Subsequently, 5.924 GHz LLSAW filter with fractional bandwidth (FBW) of 9.2% and insertion loss (IL) of 1.82 dB was realized.