Tong Xin, Zou Yang, Wen Zhiwei, Liu Zesheng, Luo Tiancheng, Zhou Jie, Liu Huajun, Ren Yuqi, Xu Qinwen, Liu Wenjuan, Liu Yan, Cai Yao, Sun Chengliang
The Institute of Technological Sciences, Hubei Key Laboratory of Electronic Manufacturing and Packaging Integration, Wuhan University, Wuhan, China.
Institute of Materials Research and Engineering (IMRE), Agency for Science, Technology and Research (A*STAR), Singapore, Singapore.
Microsyst Nanoeng. 2024 Sep 19;10(1):130. doi: 10.1038/s41378-024-00776-4.
The first-order antisymmetric (A1) mode lamb wave resonator (LWR) based on Z-cut LiNbO 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) 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.
基于Z切铌酸锂薄膜的一阶反对称（A1）模式兰姆波谐振器（LWR）引起了广泛关注，并且被广泛认为是下一代具有高频和大带宽（BW）的可重构滤波器的候选者。然而，传统的基于叉指电极（IDT）的LWR滤波器难以满足纯净频谱响应和足够的带外（OoB）抑制要求。为了解决这个问题，我们提出了具有棋盘形IDT的LWR，用于设计符合Wi-Fi 6E标准的滤波器。通过利用具有无与伦比边界的棋盘形IDT，制造的6GHz谐振器成功抑制了高阶A1杂散模式，展示了无杂散的阻抗响应和高达104的高品质因数（FOM）。基于所展示的棋盘形电极设计，该滤波器的中心频率（f）超过6GHz，3dB带宽超过620MHz，并且具有超过25dB的出色带外抑制，这与声电电磁（EM）多物理场模拟结果一致。此外，通过电容电感匹配网络技术，滤波器的电压驻波比（VSWR）成功降低到2以下，显示出出色的50Ω阻抗匹配。这项研究为Wi-Fi 6/6E应用的超高频和超宽带滤波器奠定了基础。
