In this paper, we have presented a simple, miniaturized, and highly sensitive liquid sensor, which determines the dielectric properties of liquids at microwave frequency. In the proposed design, the concept of interdigital capacitor (IDC) is employed to construct the sensor. The proposed IDC based sensor responds differently depending on the liquids' dielectric property. The proposed structure utilizes the shift in resonance frequency and peak attenuation as the sensing parameter to determine the complex dielectric permittivity of the unknown liquids. The advantage of the proposed sensor structure lies in its compactness (0.08λ₀ × 0.08λ₀ × 0.003λ₀) and high sensitivity, 0.42%. The designed sensor can also be used in the biomedical field for noninvasive bio‐liquid characterization.

中文翻译：

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微波频率小型化高灵敏度液体传感器的设计

在本文中，我们提出了一种简单，小型化且高度灵敏的液体传感器，该传感器可确定液体在微波频率下的介电特性。在提出的设计中，采用叉指电容器（IDC）的概念来构造传感器。所提出的基于IDC的传感器的响应取决于液体的介电特性。所提出的结构利用共振频率的变化和峰值衰减作为感测参数来确定未知液体的复介电常数。所提出的传感器结构在于其紧凑的优点（0.08λ ₀  ×0.08λ ₀  ×0.003λ ₀）和0.42％的高灵敏度。设计的传感器还可用于生物医学领域的非侵入性生物液体表征。