Equipment for measurement of complex permittivity

复介电常数的推导在许多电学和生物医学工程应用中具有重要意义。在电子工程中，新的制造工艺和系统集成技术被引入，这些制造工艺和系统集成技术通常使用薄衬底或半导体载体。为了表征在这些新兴紧凑系统中使用的互连和衬底，应该提取传播常数和有效复介电常数。为此目的采用的实验方法必须提供在使用矢量网络分析仪的宽带测量中经常遗漏的低频区域的准确表征。因此，需要专门的阻抗测量仪器来覆盖低频区域。本应用中要求的射频阻抗和材料分析仪具有这样的能力，并产生复杂的介电常数和磁导率分布。事实上，复介电常数的推导已经在生物医学工程中得到了应用，并成为一种非侵入性细胞生长监测的创新方法。再生医学最具挑战性的领域之一是胰岛素依赖型糖尿病的治疗。组织工程学原理的实施允许胰岛的原位再生和体外新生。基于复介电常数测量的方法可以用于现场监测细胞行为，这对于实现岛的体外培养至关重要。此外，关于复杂衬底特性的信息对于预测和评估微波电路的性能至关重要，特别是那些基于慢波传播、电磁带隙和超材料概念设计的微波电路。短脉冲传输测量提供了这些电路的宽带特性。利用低频复介电常数对由短脉冲技术获得的数据进行内插，以提取从DC到几十GHz的宽频率范围内的损耗正切。本赠款申请中要求的一套设备将用于检查跨学科的材料表征问题。

Derivation of complex permittivity is important to many electrical and biomedical engineering applications. In electronic engineering, new fabrication processes and system integration techniques are introduced that often utilize thin substrates or semiconductor carriers. To characterize the interconnects and substrates used in these emerging compact systems, propagation constant and effective complex permittivity should be extracted. The experimental methods that are employed for this purpose must provide accurate characterization of the low frequency region that is often missed in wide band measurements using vector network analyzers. Therefore, especial impedance measurement instruments are needed to cover the low frequency region. The RF impedance and material analyzer requested in this application has such capability and yields the complex permittivity and permeability profiles. In fact, derivation of complex permittivity has found application in biomedical engineering and emerges as the innovative method of non-invasive cell growth monitoring. One of the most challenging fields of regenerative medicine is the treatment of insulin-dependent diabetes mellitus. Implementation of tissue engineering principles allows for islet regeneration in situ and islet neogenesis in vitro. A method based on complex permittivity measurement can be employed for monitoring cell behavior in situ which is of critical importance in implementing in vitro culturing of the islets.Additionally, the information about complex substrate characteristics is crucial in predicting and evaluating the performance of microwave circuits, and in particular, those that are designed based on slow-wave propagation, electromagnetic bandgap and metamaterial concepts. Short pulse transmission measurements provide wideband characterization of these circuits. The low frequency complex permittivity is used in interpolation of the data obtained from short pulse technique to extract loss tangent in a wide frequency range starting from DC to tens of GHz. The set of equipment requested in this grant application will be used for inspection of cross-disciplinary material characterization problems.