Characterization of Hydrogen-Bonded Liquid Crystal Materials in the Millimeter-Wave Region
Characterization of Hydrogen-Bonded Liquid Crystal Materials in the Millimeter-Wave Region
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DOI：
10.1109/lmwc.2021.3062841
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发表时间：
2021-03
影响因子：
3
通讯作者：
T. Nose;R. Ito;M. Honma
中科院分区：
文献类型：
--
作者：
T. Nose;R. Ito;M. Honma
在毫米波电磁波谱范围内研究了一种新型氢键液晶材料。相对介电常数（或折射率）和损耗角正切（或吸收系数）使用矩形波导测试单元进行评估，并与传统的LC材料的值进行比较。最不寻常的结果是，折射率各向异性显着增加，在毫米波区域与可见光相比，这是在传统的LC材料中所观察到的相反。虽然决定LC器件可调谐性的各向异性在这一阶段不是很大，但损耗角正切与为微波应用而合成的优异的常规型LC材料一样小或更好。我们发现了一个潜在的氢键液晶作为一个最好的类液晶材料毫米波应用。
A novel liquid crystal (LC) materials consisting of hydrogen bonding are investigated in the millimeter-wave (MMW) frequency region of electromagnetic wave spectra. Relative permittivity (or refractive index) and loss tangent (or absorption coefficient) are evaluated using a rectangular waveguide test cell and are compared with those values of conventional LC materials. The most unusual result is that the refractive index anisotropy increases significantly in the MMW region comparing with that for visible light, which is contrary to what is observed in the conventional LC materials. Although the anisotropy, which determines the tunability of LC devices, is not so large in this stage, the loss tangent is as small as, or better than, those of the excellent conventional-type LC materials synthesized for the microwave applications. We find out a potential of the hydrogen-bonded LCs as one of the best classes of LC materials for MMW application.