基于基片集成波导和消逝模谐振腔的压力传感器设计

Pressure Transducer Based on Substrate Integrated Waveguide and Evanescent Mode Resonator

提出一种新型的基于基片集成波导和消失模谐振腔的压力传感结构。设计了圆形空腔,当施加外界压力时,圆形空腔发生形变从而使谐振腔谐振频率变化。采用共面波导线对谐振腔进行耦合馈电并将频率信号传输出来。通过读取传感器的回波损耗参数(S11)来表征压力与频率的关系。利用高频仿真软件HFSS对谐振腔进行了仿真设计和优化,设计尺寸为30 mm×30 mm×1.93 mm,与传统谐振腔相比体积明显减小。传感器基底为Rogers 4003C板材,采用PCB技术进行加工。搭建压力测试平台对传感器进行测试,结果表明在0~3 N的压力范围内变化100 MHz,绝对灵敏度为25 MHz/N。仿真和实测结果比较吻合,验证了所设计压力结构的有效性。

The paper demonstrates a new pressure sensing structure based on substrate integrated waveguide（ SIW） and evanescent mode resonator is designed with cylindrical air cavity, which makes the frequency of evanescent mode resonator tunable. Coplanar waveguide（ CPW） is used as coupling unit to incent the resonator and transmit the output signal. By measuring the return loss （ S11 ） of the sensor, the frequency-pressure characteristic could be obtained. Ansoft High frequency structure simulator（ HFSS） is used to simulate and optimize the sensor structure. The dimension of pressure sensor is 30 mm×30 mm×1.93 mm,which reduced much volume compared to the tradi-tional resonator. The material used is Rogers 4003C and then the sensor is fabricated by using PCB technology. A pressure measurement platform is setup to test the sensor. The measured resonant frequency changes 100 MHz at the pressure range of 0-3 N with absolute sensitivity of 25 MHz/N. It appears that the simulated data fits well with the experimental data,which confirms the feasibility of this kind of pressure sensing structure.