非平面微波生物感測器應用於葡萄糖溶液即時監測

Abstract

本文提出一種由互補式開口共振環所組成的非平面式互補式開口共振環(Non-planar Complementary Split Ring Resonator, NPCSRR)進行感測，由於材料的介電常數會影響電磁場分佈，因此藉由將待測物放置在感測區，以此觀測共振環的散射參數。在本文中先以等效電路模擬以及三維電磁模擬，了解所設計共振環的特性例如散射參數、品質因子、電磁場分佈等。在設計上藉由CSRR結構對於介電常數變化較為敏感，以及增加與待測物感測面積等方法達到較高的靈敏度。所提出裝置共振頻率為4.41GHz、電場強度為307.48 kV/m，對於介電常數變化的靈敏度可到達51.89 MHz/Δε。

確認所設計裝置符合預期後便以FR-4基板製作出來，並藉由網路分析儀量測確認與模擬是否相符，以確認製作出來之成品是否符合設計要求，接著進行了不同濃度的葡萄糖溶液量測，濃度範圍從100 mg/dL到600 mg/dL，並觀測此時裝置的共振頻率，由於葡萄糖濃度與介電常數有所關聯，因此為更好的分析其關聯性便以德拜模型(Debye model)與等效電路進行分析，了解葡萄糖濃度、介電常數、共振頻率三者的關係，為了確認本研究裝置的性能，所以與其他文獻中的裝置進行比較，確立了本研究裝置具有良好的靈敏度可以達到非接觸式感測。

This thesis proposes a non-planar Complementary Split Ring Resonator (NPCSRR) composed of complementary split ring resonators for sensing. The electromagnetic field distribution is influenced by the dielectric constant of the material, so the scattering parameters of the resonator are observed by placing the target substance in the sensing area. In this paper, equivalent circuit simulations and 3D electromagnetic simulations are conducted to understand the characteristics of the designed resonator, such as scattering parameters, quality factor, and electromagnetic field distribution. The design aims to achieve higher sensitivity by using the CSRR structure, which is more sensitive to changes in the dielectric constant, and increasing the sensing area with the target substance. The proposed device has a resonance frequency of and an electric field intensity of , with a sensitivity of to changes in the dielectric constant.

After confirming that the designed device meets the expectations, it is fabricated on an FR-4 substrate. Measurements with a network analyzer are conducted to verify if the fabricated device matches the simulation. Subsequently, glucose solutions of different concentrations ranging from 100 mg/dL to 600 mg/dL are measured, and the resonance frequency of the device is observed. As glucose concentration is related to the dielectric constant, the Debye model and equivalent circuit analysis are employed to analyze the relationship between glucose concentration, dielectric constant, and resonance frequency. To confirm the performance of the proposed device, a comparison is made with other devices in the literature, establishing that the research device exhibits good sensitivity for non-contact sensing.