小型高选择性MEMS射频滤波器的设计

Design of Compact MEMS RF Filters with High-Selectivity

该文设计了一款基于微机电系统(MEMS)工艺的小型高选择性的射频滤波器,与传统MEMS滤波器相比,该滤波器采用阶跃阻抗谐振器(SIR)降低器件尺寸,利用谐振器的场分布形成结构紧凑的交叉耦合,免去了传统的飞杆电耦合结构,在提高滤波器选择性的同时实现器件的紧凑布局。滤波器表面金属谐振腔通过金属化的硅通孔实现谐振器的接地,形成四分之一波长谐振结构。对性能和结构参数各异的滤波器进行设计和分析,并采用三维电磁仿真软件对滤波器进行模拟仿真。结果表明,滤波器尺寸为10 mm×10 mm×0.4 mm,驻波比<1.3 dB,插入损耗<3.5 dB。在2.5~2.7 GHz和3.4~3.5 GHz时,带外抑制>30 dB。

In this paper,a compact and high-selectivity RF filter based on MEMS technique is designed.Compared with the traditional micro-electro-mechanical system(MEMS)filter,the proposed filter adopts a stepped impedance resonator(SIR)to reduce the size of device,and uses field distribution of the resonator to form a compact cross-coupling which eliminates the traditional flying rod and structure,and the compact layout of the device is achieved while improving the selectivity of the filter.The surface metal resonator cavity of the filter is grounded by the metalized through silicon via,forming a quarter-wavelength resonant structure.The filter with different performance and structural parameters are designed and analyzed,and simulated by the three-dimensional electromagnetic simulation software.The results show that the filter size is 10 mm×10 mm×0.4 mm,the stationary wave is less than 1.3 dB,the insertion loss is less than 3.5 dB,and the out-of-band rejection is larger than 30 dB at 2.5-2.7 GHz and 3.4-3.5 GHz.