基于MEMS可重构超材料的动态可调太赫兹滤波器理论与关键技术

The terahertz (THz) filters with dynamically tunable central frequency and bandwidth are important for THz communication, spectroscopy detection and spectroscopy imaging. However, the central frequency and the bandwidth of the existing THz filters can not be dynamically tuned..First of all, the project constructs the model of dynamically tunable THz filters which based on microelectromechanical systems (MEMS) reconfigurable metamaterials, and studies the electromagnetic response performance, transmission spectroscopy and reflection spectroscopy of the tunable THz filters by using finite integral method. At the same time, by using equivalent circuit theory, the project sets up an equivalent circuit model of the tuning structures of the MEMS reconfigurable metamaterials and establishes an analysis formula of the resonant frequency. And these are very useful to reveal the mechanism of the tuning of central frequency and bandwidth. Then, the project sets up the MEMS model of the tunable filter and use finite element analysis (FEA) method to study the law of central frequency and bandwidth changing with the applied voltages. Finally, based on the MEMS bulk silicon micromachining process, the project studies the method to fabricate the filter and decrease the insertion losses. Moreover, the method to test the performance of the types is also implemented. The key technologies of the study contain how to effectively tune the bandwidth, decrease the insertion losses and increase the tuning range of frequency. .This study will reveal the mechanism of tuning central frequency and bandwidth of the THz filters which based on the MEMS reconfigurable metamaterials. And it can also provide the theory and technological references for the development of new THz filters and other relational THz devices.

中心频率和带宽动态可调的太赫兹(THz)滤波器在THz通信、光谱探测和光谱成像等领域有十分重要的应用价值，而现有THz滤波器都不能动态调节中心频率和带宽。本项目首先引入微机电系统（MEMS）可重构超材料来构建动态可调THz滤波器，用有限积分方法研究滤波器的透射、反射光谱特性和电磁响应特性，并用等效电路理论建立可重构超材料调谐结构的等效电路模型和谐振频率表达式，以揭示中心频率和带宽调节机理。然后，建立可调THz滤波器的MEMS模型，用有限元分析方法研究中心频率和带宽变化量随驱动电压的变化规律。最后，基于MEMS体硅工艺研究器件加工和减小插损的方法，同时研究用THz时域光谱系统进行样片性能表征和测试的方法。其关键技术是如何有效调节带宽、减小插损和增加频率调节范围。本项目将揭示MEMS可重构超材料对THz滤波器中心频率和带宽调控的物理机理，为新型THz滤波器及相关器件研发提供理论依据和技术参考。

中心频率和带宽动态可调的太赫兹(THz)滤波器在THz通信、光谱探测和光谱成像等领域有十分重要的应用价值，而现有THz滤波器都不能动态调节中心频率和带宽。.本项目首先引入微机电系统（MEMS）可重构超材料来构建动态可调THz滤波器，用有限积分方法研究了滤波器的透射、反射光谱特性和电磁响应特性，并用等效电路理论建立了可重构超材料调谐结构的等效电路模型和谐振频率表达式，揭示出中心频率和带宽调节机理。然后，建立了可调THz滤波器的MEMS模型，用有限元分析方法研究了中心频率和带宽变化量随驱动电压的变化规律。最后，基于MEMS体硅工艺研究了器件加工和减小插损的方法，同时研究了用THz时域光谱系统进行样片性能表征和测试的方法。其关键技术是如何有效调节带宽、减小插损和增加频率调节范围。.本项目重要结果是：1）在理论上，引入镜像电流理论来解释可调滤波器的幅值可调机理；2）引入相变材料氧化钒来构建幅值可调的太赫兹带通滤波器，研究了幅值可调控的机理。3）在实验上，MEMS工艺用于制作可调太赫兹滤波器样片。.本项目研究成果，揭示了MEMS可重构超材料对THz滤波器中心频率和带宽调控的物理机理，对新型THz滤波器及相关器件研发提供了理论依据和技术参考。