Microwave Power Absorption in Low-Reflectance, Complex, Lossy Transmission Lines.
Microwave Power Absorption in Low-Reflectance, Complex, Lossy Transmission Lines.
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DOI：
10.6028/jres.112.015
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发表时间：
2007-07
影响因子：
1.5
通讯作者：
Gaitan M
中科院分区：
文献类型：
--
作者：
Geist J;Shah JJ;Rao MV;Gaitan M
推导了一组简单的方程，用S参数反射和传输幅度描述了三区有耗传输线对微波功率的吸收。假设每个区域都是均匀的，在区域边界处具有不连续性。推导出不同的方程组来描述关于不同边界处的反射系数的幅值的不同假设。这些方程，这是有用的，当由于多次反射的干扰效应是小的，被用来分析的传输线上的S-参数测量，在其中间区域有一个微流体通道。对于一组测量，通道是空的，对于第二组测量，通道充满水。这里考虑的反射假设产生了类似的结果，所施加的微波功率的一部分被吸收的水填充的微通道。这表明，只要能量在分析中守恒，吸收功率对反射细节相对不敏感。这项工作的另一个重要结果是，在充满水的通道中吸收的功率与在相同的空通道中吸收的功率之间的差异可能是在存在竞争吸收过程（例如传输线金属的吸收）的情况下在水中吸收的功率的不良预测。
Simple sets of equations have been derived to describe the absorption of microwave power in three-region, lossy transmission lines in terms of S-parameter reflection and transmission amplitudes. Each region was assumed to be homogeneous with discontinuities at the region boundaries. Different sets of equations were derived to describe different assumptions about the amplitudes of the reflection coefficients at the different boundaries. These equations, which are useful when interference effects due to multiple reflections are small, were used to analyze S-parameter measurements on a transmission line that had a microfluidic channel in its middle region. The channel was empty for one set of measurements and filled with water for a second set of measurements. Most of the reflection assumptions considered here produced similar results for the fraction of the applied microwave power that was absorbed by a water-filled microchannel. This shows that the absorbed power is relatively insensitive to the reflection details as long as energy is conserved in the analysis. Another important result of this work is that the difference between the power absorbed in a water-filled channel and the power absorbed in the same empty channel can be a poor predictor of the power absorbed in the water in the presence of competing absorption processes such as absorption by the transmission-line metal.