Suspended lithium niobate acoustic resonators with buried electrodes for radiofrequency filtering

TL;DR

This paper introduces a novel suspended lithium niobate acoustic resonator architecture with buried electrodes, enabling multi-frequency, low-loss, wideband filtering suitable for 5G and 6G wireless communication systems.

Contribution

The work presents a new resonator design that achieves high performance and scalability for future high-frequency mobile communication filters.

Findings

Demonstrated filters for 5G n77 and n79 bands with 13% and 25% fractional bandwidths

Achieved low insertion loss of around 1 dB

Enabled multi-frequency and wideband filtering capabilities

Abstract

Data rates and volume for mobile communication are ever-increasing with the growing number of users and connected devices. With the deployment of 5G and 6G on the horizon, wireless communication is advancing to higher frequencies and larger bandwidths enabling higher speeds and throughput. Current micro-acoustic resonator technology, a key component in radiofrequency front end filters, is struggling to keep pace with these developments. This work presents a novel acoustic resonator architecture enabling multi-frequency, low-loss, and wideband filtering for the 5G and future 6G bands located above 3 GHz. Thanks to the exceptional performance of these resonators, filters for the 5G n77 and n79 bands are demonstrated, exhibiting fractional bandwidths of 13% and 25% respectively with low insertion loss of around 1 dB. With its unique frequency scalability and wideband capabilities, the reported architecture offers a promising option for filtering and multiplexing in future mobile devices.