本論文提出適用於物聯網應用的新型微波濕度感測器及微波微流體感測器，其具有高靈敏度及輕巧化等優點，該特性將透過實作與量測進行驗證。本論文提出的兩種新型微波感測器在量測驗證上不需要使用笨重且昂貴之網路分析儀(vector network analyzer, VNA)，此部分將在論文中進行說明。

微波濕度感測器由基板合成波導(substrate integrated waveguide, SIW)振盪器及頻率解調器所組成，透過在基板合成波導共振腔嵌入穿透氣孔，使得電場可分佈於氣孔中及近場區域，以偵測感測器週邊的環境溼度。本論文所提出的濕度感測器操作頻率在7.67 GHz，量測結果顯示有效濕度感測範圍涵蓋50%到90%的環境相對濕度，其濕度檢測靈敏度高達165 kHz/RH。

微波微流體感測器由射頻信號源、功率分配器、增益/相位檢測器(gain/phase detector, GPD)及濾波器所組成，在濾波感測器結構上採用能集中感測電場指叉電極的耦合結構，以改善微波微流體感測器的靈敏度。此微流體感測器操作在1.53GHz，在進行量測驗證時，以8 µL水-乙醇混合物，注入毛細管中作為待測液體(liquids under test, LUT)進行驗證。量測結果顯示，在微量流體下仍具有高靈敏度。相較於商用介電係數探頭，且當LUT的ε_r^'範圍從26變化到72時，其ε_r^' 與 ε_r^''的最大量測誤差分別為-3.29%、14%。

In this dissertation, new microwave humidity and microfluidic sensors are proposed, fabricated, and measured with sensitivity improvement and compactness for IoT applications. Both of these two measurement systems eliminate the need for a bulky and costly vector network analyzer (VNA).
The humidity sensor is designed at 7.67 GHz and consists of a substrate integrated waveguide (SIW) oscillator and a frequency demodulator. The electric-field distribution at the embedded air holes of the SIW cavity is used to detect the humid air inside air holes and distributed in the surrounding area. The measurement results have demonstrated the efficient capability of humidity detection over a relative humidity (RH) range of 50% to 90%, while the sensitivity of this humidity sensor is 165 kHz/RH.
The microfluidic sensor consisted of the RF source, power divider, gain/phase detector (GPD), and filter-based sensor. In addition, the sensitivity of the microfluidic sensor is also improved by concentrating the sensing field of the interdigitated electrode (IDE) coupling structure of the filter-based sensor. The design frequency of the microfluidic sensor is 1.53 GHz. The measurement capabilities of the filter-based sensor are exemplified by testing 8 µL water-ethanol mixtures in the capillary tube as the liquids under test (LUT). This small volume of LUT has shown higher sensitivity compared with other works, with maximum errors of ε_r^' and ε_r^'' are -3.29% and 14%, respectively, with a range of ε_r^' of LUT from 26 to 72.

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