In this study, a critical evaluation of analyte dielectric properties in a microvolume was undertaken, using a microwave biochemical sensor based on a circular substrate integrated waveguide (CSIW) topology. These dielectric properties were numerically investigated based on the resonant perturbation method, as this method provides the best sensing performance as a real-time biochemical detector. To validate these findings, shifts of the resonant frequency in the presence of aqueous solvents were compared with an ideal permittivity. The sensor prototype required a 2.5 µL volume of the liquid sample each time, which still offered an overall accuracy of better than 99.06%, with an average error measurement of ±0.44%, compared with the commercial and ideal permittivity values. The unloaded Q_u factor of the circular substrate-integrated waveguide (CSIW) sensor achieved more than 400 to ensure a precise measurement. At 4.4 GHz, a good agreement was observed between simulated and measured results within a broad frequency range, from 1 to 6 GHz. The proposed sensor, therefore, offers high sensitivity detection, a simple structural design, a fast-sensing response, and cost-effectiveness. The proposed sensor in this study will facilitate real improvements in any material characterization applications such as pharmaceutical, bio-sensing, and food processing applications.

在这项研究中，使用了基于圆形衬底集成波导（CSIW）拓扑结构的微波生化传感器，对微量样品中的分析物介电性能进行了严格的评估。这些介电特性是基于共振扰动方法进行数值研究的，因为这种方法作为实时生化检测器提供了最佳的感测性能。为了验证这些发现，将水性溶剂存在下的共振频率变化与理想的介电常数进行了比较。传感器原型每次需要2.5 µL的液体样品，与商业和理想的介电常数值相比，其总精度仍高于99.06％，平均误差测量值为±0.44％。已卸载的Q _u圆形基片集成波导（CSIW）传感器的倍数系数达到400以上，以确保精确测量。在4.4 GHz时，在1至6 GHz的宽频率范围内，仿真结果和测量结果之间观察到很好的一致性。因此，提出的传感器提供了高灵敏度检测，简单的结构设计，快速的响应和成本效益。这项研究中提出的传感器将有助于在任何材料表征应用（例如制药，生物传感和食品加工应用）中进行真正的改进。