一种硅基MEMS微波SIR交指带通滤波器

A Microwave SIR Interdigital Band-Pass Filter in Silicon-Based MEMS Technology

基于7阶SIR交指结构滤波器,提出了一种基于硅MEMS技术的微波S波段交指带通滤波器。不仅保留了交指结构的高通带选择性,而且可以通过调整SIR的阻抗比和电长度比来实现宽阻带。采用MEMS工艺,在双层高电阻率的硅片上完成了滤波器的制作和自封装,它具有体积小、损耗低的优点。仿真结果表明,该滤波器在中心频率2.35GHz处的相对带宽为30%,带内插损小于1.5dB,回波损耗大于15dB,在频率f_0±0.8GHz处的阻带抑制比大于50dB。该交指带通滤波器的体积仅为(11×7×0.8)mm^3。

Based on seventh-order step-impedance resonator（SIR）, a microwave S band SIR interdigital band-pass filter in silicon-based MEMS technology was presented. Not only the high band-pass selectivity of the interdigital topology was preserved, but also the wide stopband range could be achieved by regulating the impedance ratio and electrical length ratio of the SIR. Based on MEMS technology, the filter was fabricated and self-packaged on double high-resistivity silicon wafers. It had advantages of small size and low dissipation. The simulation results showed that the filter had a relative bandwidth of 30% at the center frequency of 2.35 GHz. The in-band insertion loss was less than 1.5 dB, and the return loss was more than 15 dB. The rejection ratio was more than 50 dB at the frequency of f0±0.8GHz. The size of the interdigital filter was（11 ×7 × 0.8） mm3.