Reconfigurable High-Q Evanescent Mode Micromachined Filters for Wireless Communications Front-Ends

9979374Katehi提出了一种适合于开发电子可调谐微机械高Q逝去模式滤波器的新方法。通过使用适当地彼此耦合并耦合到输入/输出微带或共面波导传输线的微机械消逝模腔，可以实现小尺寸、高Q值的、相邻通道之间具有高隔离的滤光器或滤波器组。这些单片集成的滤波器能够通过使用适当的MEMS器件以电子方式重新调整其电性能。该方法基于硅(Si)微机械加工，通过将消逝模腔与MEMS器件集成在一个三维电路中，可以有效地提供非常高的Q值和可调性。为了实现电子频率调整或通带和带外性能的可重新配置，MEMS器件被放置在滤波器布局内的适当位置。这项工作将分两步进行：(A)利用S、L和X波段的微机械加工腔来开发逝去模式滤波器；(C)使用MEMS器件来重新配置滤波器特性；以及开发开关双工器。这种方法所需的制造技术与标准IC工艺兼容，因此提供了非常低的制造成本和非常高的精度。在所提出的滤光器配置中，通过垂直集成消逝微机械腔和结合有效的片上硅微机械封装来容纳MEMS器件并提供对滤光器谐振器之间的耦合的关键控制，将实现小尺寸和高密度。所开发的组件将尺寸非常小，但其性能可与最先进的波导滤波器相媲美，以展示除了单片特性、非常小的尺寸、低成本和高密度之外的良好的电响应。作为这项工作的一部分，将设计和实施电子调谐来控制适当的几何参数。此外，还将研究所设计的滤波器的调谐范围，并将研究具有开关进入和退出电路的能力的滤波器或双工器。将通过测量可能的调谐范围和调谐速度并评估滤波器的结果Q来评估MEMS器件在重新配置滤波器特性方面的有效性。拟议的研究的目标是论证单片高Q可重构滤波器的概念，并从性能、尺寸、制造成品率和成本方面研究设计中的权衡。拟议概念的开发和演示将通过使用全波分析工具和最先进的制造和测量技术来完成。这一努力的成功有可能使各种无线应用的通信前端发生革命性变化。*

9979374KatehiA novel approach is proposed appropriate for the development of electronically tunable micromachined high-Q evanescent-mode filters. Small size, high-Q filters or filter banks with high isolation between the adjacent channels can be achieved by use of micromachined evanescent-mode cavities that appropriately couple to each other and to the input/output micro-strip or coplanar waveguide transmission lines. These monolithically integrated filters have the ability to electronically reconfigure their electrical performance by use of appropriate MEMS devices. The proposed approach is based on silicon (Si) micromachining and can effectively provide very high-Q and tunability by integrating evanescent mode cavities with MEMS devices in a three dimensional circuit. To allow for electronically adjusted frequency or reconfigurability of pass-band and out-band performance, the MEMS devices are placed at appropriate locations within the filter layout. These MEMS switch-like, compliant or membrane structures will be optimized to achieve as low of an activation voltage as possible and will be used for electronic tuning and control of filter performance.The proposed work will be performed in two steps: (a) development of an evanescent mode filter using micromachined cavities in S, L and X Bands, Co) use of MEMS devices for reconfiguring filter characteristics and the development of a switched diplexer. The fabrication techniques required in this approach are compatible with standard IC processing and for this reason provide very low fabrication cost and very high precision. In the proposed filter configurations, small size and high density will be achieved by vertically integrating the evanescent micromachined cavities and by incorporating an effective on-wafer Si micromachined package to house the MEMS devices and provide critical control of the coupling between the filter resonators. The developed components will be very small in size but of performance comparable to the state of the art waveguide filters in order to demonstrate excellent electrical response in addition to monolithic character, very small size, low cost and high density. As part of this effort, electronic tuning will be designed and implemented to control appropriate geometrical parameters. In addition, the tuning range of the designed filters will be studied and a filter or diplexer with the capability to switch in and out of the circuit will be investigated. The effectiveness of the MEMS devices in reconfiguring the filter characteristics will be evaluated by measuring the possible tuning range and tuning speed and evaluating the resulting Q of the filter The proposed study has as a goal to demonstrate the concept of a monolithic high-Q reconfigurable filter and investigate trade-offs in design in terms of performance, size, fabrication yield and cost. The development and demonstration of the proposed concept will be accomplished via the use of full-wave analysis tools and state of the art fabrication and measurement techniques. Success in this effort has the potential to revolutionarize communications front ends for a variety of wireless applications.****