Advancing acoustic devices towards mmwave

As the sub-6G spectrum becomes overcrowded with applications, the research community has begun to explore beyond 6 GHz for new spectral venues to advance wireless capabilities. Acoustic filters are indispensable front-end components in telecommunication, and it is challenging to scale acoustic filters to higher frequencies. Frequency scaling without compromising performance remains challenging due to various technical bottlenecks in material integration, device fabrication, and filter design for acoustic filters. This dissertation presents the design approach as well as the first demonstration of a wideband hybrid monolithic acoustic filter in the K-band, which exceeds the limitation of electromechanical coupling on the fractional bandwidth (FBW) of acoustic filters. The hybrid filter utilizes the co-design of electromagnetic (EM) and acoustic to attain wide bandwidth while keeping the advantages of small size and high Q in the acoustic domain. The performance trade space and design flow of the hybrid filter, which allow this technology to be applied to filters with different center frequencies and FBWs, are also presented in this dissertation. The hybrid filter is simulated by hybridizing the EM and acoustic finite element analysis, which are carried out separately and combined at a system level. At high frequencies beyond 10 GHz, the influence of substrate loss on device performance becomes increasingly significant. By characterizing the loss in several commonly used dielectric-on-Si substrates, a hybrid filter with improved performance due to reduced substrate loss is demonstrated.

Name thesis:degree_name

Ph.D.

Level thesis:degree_level

Dissertation

Discipline thesis:degree_discipline

Electrical & Computer Engr

Grantor

University of Illinois at Urbana-Champaign

Year dc:date

2022

Author dc:creator

• Gao, Liuqing

Contributors dc:contributor

• Gong, Songbin
• Jin, Jianming
• Goddard, Lynford L.
• Zhou, Jin

• Microelectromechanical Systems
• Millimeterwave Devices
• Piezoelectric Devices

Statement dc:rights

• Copyright 2022 Liuqing Gao

Language dc:language

en, eng

Handle dc:identifier

https://hdl.handle.net/2142/117543

OAI record oai:identifier

https://www.ideals.illinois.edu/oai-pmh?verb=GetRecord&metadataPrefix=etdms&identifier=oai%3Awww.ideals.illinois.edu%3A2142%2F117543