悬臂梁式扫描微波探针设计

Design of cantilever beam scanning microwave probe

微波芯片的高度集成化对扫描微波成像技术提出了新的挑战,设计了一种结构简单、辐射效率高和耦合低特性的悬臂梁式扫描微波探针。通过建立探针三维有限元数值模型,在不同微波频率和不同探针结构下分别研究了探针针尖倏逝电场分布。有无屏蔽结构的探针针尖与样品间的电场分布表明,屏蔽层有效降低了悬臂梁下方非针尖部分微波信号的辐射,悬臂梁—样品的寄生电容显著减小,且在多个工作频率段具有高空间分辨与高辐射效率的特性。设计的探针满足微波芯片对高频、高空间分辨扫描微波成像的需求。

The high integration of microwave chips proposes a new challenge to technology of scanning microwave imaging.A cantilever beam scanning microwave probe with simple structure,high radiation efficiency and low coupling characteristics is designed.By establishing three-dimensional finite element numerical model of probe,the electric field distribution of tip of probe is studied under different microwave frequencies and different probe structures.The electric field distribution between the probe tip and the sample with or without shielding structure shows that the shielding layer effectively reduces the radiation of the microwave signal in the nonprobe tip part below the cantilever beam,and the parasitic capacitance of the cantilever beam-sample is significantly reduced.Moreover,it has the characteristics of high spatial resolution and high radiation efficiency in multiple working frequency segments.The designed probe meets the requirement of microwave chip for high frequency and high spatial resolution scanning microwave imaging.