一种X波段RF MEMS开关的设计与制作研究

设计并制作了一种X波段的电容式RF MEMS开关。该开关在共面波导上的悬空金属膜桥的支撑梁呈螺旋结构，其等效电感值高达134pH．有效降低了“关”态的谐振频率。结合开关的等效电路模型．使用Agilent ADS软件以及理论公式计算对该开关进行了设计和优化。与传统桥膜电容式开关相比，所介绍的开关”关”态隔离性能得到了很大提高。利用表面微机械工艺，在高阻硅衬底上制备了开关样品。X波段MEMS开关的在片测试结果表明：驱动电压为9V，“开”态的插入损耗约0．69dB@11．6GHz；“关”态的隔离度约27．7dB@11．6GHz。

Design and Fabrication of X-Band Capacitive MEMS Switches

Design and fabrication of a novel X-band capacitve RF MEMS switch is reported. The switch consists of a suspended metallic membrane supported by a like-coil structure over the coplanar waveguide. The equivalent inductance of the like-coil structure is 134 pH, which greatly decrease the off-state resonance frequency of the switch. The design is optimized based on a series of simulations, which is realized with commercial EDA tools. The simulations show that the proposed switch structure present better isolation than traditional switch in relative low RF frequency(X band). This switch is made using silicon surface micromachining process. On wafer measurement results have been carried out. The threshold voltage is less than 9 V, the insertion loss is 0.69 dB at 11.6 GHz, and the isolation is 27.7 dB at 11.6 GHz.