Chen Zeji, Kan Xiao, Yuan Quan, Wang Tianyun, Yang Jinling, Yang Fuhua
Institute of Semiconductors, Chinese Academy of Sciences, Beijing, 100083, P. R. China.
Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing, 100049, P. R. China.
Sci Rep. 2020 Mar 16;10(1):4795. doi: 10.1038/s41598-020-61744-2.
Resonators with multi-frequency generations at the device-level are highly desired in the future multi-band, reconfigurable, and compact wireless communications. In this work, a switchable radio frequency micro-electro-mechanical system (RF-MEMS) resonator with multiple electrodes is presented. The resonator is designed to operate at the whispering gallery modes (WGMs). Simultaneous excitations of the second to seventh modes with high Q values are implemented within a single device using a pair of electrodes for driving and sensing. For effective multi-frequency excitations, the electrode span angle is optimized. The frequencies of the 37 μm and 18 μm-radius resonators range from 53 MHz to 176 MHz and 112 MHz to 366 MHz, respectively. The Q values in each mode are over 10. Moreover, with the multi-electrode configurations, the specific mode can be enhanced with other modes suppressed. A more than 6 dB improvement of the spectrum peak is realized and the high Q values are maintained. A comprehensive theory is built up to clarify the driving/sensing principles under different electrode configurations. Furthermore, the air damping is found to have a significant effect on Q values for resonator with high stiffness vibrating in all the WGMs. The Q values in vacuum have at least two times improvement. The high-performance switchable resonator could dramatically reduce the power consumption, simplify the processing circuits, and occupy less footprint, which has great potential applications in future advanced RF front end systems.
在未来的多频段、可重构和紧凑型无线通信中，非常需要在器件层面实现多频率产生的谐振器。在这项工作中，提出了一种具有多个电极的可切换射频微机电系统（RF-MEMS）谐振器。该谐振器设计为在回音壁模式（WGMs）下工作。使用一对用于驱动和传感的电极，在单个器件内实现了第二至第七模式的高Q值同时激发。为了实现有效的多频率激发，对电极跨度角进行了优化。半径为37μm和18μm的谐振器频率分别在53 MHz至176 MHz和112 MHz至366 MHz范围内。每个模式下的Q值超过10。此外，通过多电极配置，可以增强特定模式并抑制其他模式。实现了频谱峰值超过6 dB的改善，并保持了高Q值。建立了一个综合理论来阐明不同电极配置下的驱动/传感原理。此外，发现空气阻尼对在所有WGMs中高刚度振动的谐振器的Q值有显著影响。在真空中Q值至少提高了两倍。这种高性能的可切换谐振器可以显著降低功耗、简化处理电路并占用更少的空间，在未来先进的射频前端系统中具有巨大的潜在应用。
