6 GHz lamb wave acoustic filters based on A1-mode lithium niobate thin film resonators with checker-shaped electrodes

Autor: Xin Tong, Yang Zou, Zhiwei Wen, Zesheng Liu, Tiancheng Luo, Jie Zhou, Huajun Liu, Yuqi Ren, Qinwen Xu, Wenjuan Liu, Yan Liu, Yao Cai, Chengliang Sun
Jazyk: angličtina
Rok vydání: 2024
Předmět:
Zdroj: Microsystems & Nanoengineering, Vol 10, Iss 1, Pp 1-10 (2024)
Druh dokumentu: article
ISSN: 2055-7434
DOI: 10.1038/s41378-024-00776-4
Popis: Abstract The first-order antisymmetric (A1) mode lamb wave resonator (LWR) based on Z-cut LiNbO3 thin films has attracted significant attention and is widely believed to be a candidate for next-generation reconfigurable filters with high frequency and large bandwidth (BW). However, it is challenging for traditional interdigitated electrodes (IDTs) based LWR filters to meet the requirement of a clean frequency spectrum response and enough out-of-band (OoB) rejection. To solve the problem, we propose LWRs with checker-shaped IDTs for the design of filters that meet the Wi-Fi 6E standard. By taking advantage of checker-shaped IDTs with unparalleled boundaries, the fabricated 6-GHz resonators successfully suppress higher-order A1 spurious modes, demonstrating a spurious-free impedance response and a high figure-of-merit (FOM) up to 104. Based on the demonstrated checker-shaped electrode design, the filter features a center frequency (f 0 ) of more than 6 GHz, a 3 dB BW exceeding 620 MHz, and an excellent OoB rejection >25 dB, consistent with the acoustic-electric-electromagnetic (EM) multi-physics simulations. Furthermore, through the capacitance-inductance matching network technology, the filter’s voltage standing wave ratio (VSWR) is successfully reduced below 2, showing an excellent 50 Ω impedance matching. This study lays a foundation for ultra-high-frequency and ultra-wideband filters for the Wi-Fi 6/6E application.
Databáze: Directory of Open Access Journals