Highly sensitive open-ended coaxial cable-based microwave resonator for humidity sensing
Highly sensitive open-ended coaxial cable-based microwave resonator for humidity sensing
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DOI：
10.1016/j.sna.2020.112244
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发表时间：
2020-10
影响因子：
4.6
通讯作者：
Chen Zhu;R. Gerald;Jie Huang
中科院分区：
文献类型：
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作者：
Chen Zhu;R. Gerald;Jie Huang
提出了一种新型的便携式开放式中空同轴电缆谐振器(OE-HCCR)，无需任何湿敏材料即可直接测量相对湿度(RH)。该传感器由自制的中空同轴电缆平台制成，易于修改，并提高了健壮性。微波腔谐振器是一种金属柱耦合的开放式同轴谐振器，它包括两个高反射反射器，即金属柱和金属板背衬的同轴线开口端。金属板和开口端之间的间隙距离由圆形间隔物限定。通过简单的一步调整垫片厚度，可以大大提高OE-HCCR的相对湿度测量灵敏度。对器件物理进行了讨论，并通过数值计算和实验研究验证了OE-HCCR对RH传感的灵敏度提高。由于灵敏度的提高，据我们所知，这是第一个能够直接检测气体分析物的开放式同轴传输线。所提出的具有灵敏度增强的OE-HCCR具有将高灵敏度的化学传感与功能材料相结合的潜力。
A novel portable open-ended hollow coaxial cable resonator (OE-HCCR) is proposed and demonstrated for direct relative humidity (RH) measurements without the assistance of any humidity-sensitive material. The sensor is fabricated from a homemade hollow coaxial cable platform that provides ease of modification and improved robustness. The microwave cavity resonator is a metal post-coupled open-ended coaxial resonator, which includes two highly-reflective reflectors, i.e., the metal post and the metal plate-backed open end of the coaxial line. The gap distance between the metal plate and the open end is defined by a circular spacer. By simple one-step adjustments of the thickness of the spacer, the RH measurement sensitivity of the OE-HCCR can be greatly enhanced. The device physics is discussed; numerical calculations and experimental investigations are conducted to verify the sensitivity enhancement of the OE-HCCR for RH sensing. Due to the increased sensitivity, this is the first report of an open-ended coaxial line that is able to directly sense gaseous analyte, to the best of our knowledge. The proposed OE-HCCR with the sensitivity enhancement has the potential for highly sensitive chemical sensing combined with functional materials.