Inorganic, dielectric composite materials as sensitive elements for chipless wireless high temperature microwave RFID sensors

温度测量是工业过程自动控制的重要组成部分。尤其是对于高温过程的控制和优化(例如燃烧)，需要高达1000°C或更高的测量设置，因此，远程或无线测量通常是有益的或强制的。存在几种无线测量极高温度的可能性，例如红外温度计或声表面波温度传感器。然而，大多数方法不使用驻留在炎热环境中的专用传感器元件，这将允许更高的精度和非视线操作，并且使用专用传感器元件的方法在操作持续时间或低最高操作温度方面受到限制。无芯片无线传感器技术是解决这些问题的一种很有前途的方法，它提供的传感器甚至可以通过炉子的厚电介质温度屏蔽层进行无线读数。尤其是介质谐振器(DR)的使用已被证明是极其可靠和通用的。然而，到目前为止，合适的系统布局参数之间的关系是相当未知的，因为提出该项目的研究团队内外对此主题的研究受到可用材料的限制，并且几乎没有对电磁和材料科学部分进行传感器和系统优化。因此，该项目的任务是研究无机复合材料和新型电磁谐振器结构，以实现高自由度的传感器系统设计，该项目的核心思想是基于层状介质的DRS设计。高Q(低损耗)、低介电常数材料不具有明显的温度依赖性，以及低Q、高介电常数高度依赖于温度的材料的组合将导致广泛的不同的优化方向，例如，对于具有中等分辨率的宽温度范围传感器或对于在窄温度窗口中的高精度传感器。首先，将利用已知的材料在低温下研究新的层状DR概念。在第二步，这一概念将通过利用新调查的材料转移到更高的温度。最终，要实现RFID和完全集成的RFID传感器标签的传感器部分，需要与温度无关的和可工程的温度相关材料。虽然这种传感器的主要应用是一般动机，但分层DR方法可以用于在极高温度下表征低Q材料，从而为传感器研究的材料提供新的表征概念和第一个表征数据。因此，研究一种新颖的、基于模型的、基于分层DRS的介电参数表征方法是该项目的另一项任务。

Temperature measurements are an essential part of the automatic control of industrial processes. Especially for the control and optimization of high temperature processes (e.g. combustion), measurement setups up to 1000 °C and beyond are required, and, therefore, a remote or wireless measurement is often beneficial or mandatory. Several possibilities exist to measure extremely high temperatures wirelessly, e.g. infrared thermometers or SAW temperature sensors. However, most of the approaches don't use a dedicated sensor element that resides in the hot environment, which would allow for more accuracy and non-line of sight operation, and approaches that do use a dedicated sensor element are limited either in operation duration or by a low maximum operation temperature. Chipless wireless sensor technology is a promising approach to solve these issues and provide sensors that even allow wireless readout through thick dielectric temperature shielding of furnaces. Especially the use of dielectric resonators (DR) has proven extremely reliable and versatile. However, the relationship of parameters for appropriate system layout are rather unknown to date, since research on this topic, inside and outside of the research team that proposes this project, is limited by available materials, and sensor and system optimization was hardly performed for the electromagnetic as well as for the material science part. Therefore, the task of the proposed project is the research on inorganic composites and new electromagnetic resonator structures to enable a high number of degrees of freedom for sensor system design.The central idea of the project is the design of DRs from layered dielectrics. A composition of high-Q (low loss), low permittivity materials without noticeable temperature dependence, and low-Q, high permittivity materials that are highly temperature dependent will lead to a broad range of different optimization directions, e.g. for broad temperature range sensors with moderate resolution or for highly accurate sensors in a narrow temperature window. First, the novel layered DR concept will be investigated at low temperatures with known materials. In a second step, the concept will be transferred to higher temperatures by the utilization of newly investigated materials. Eventually, both, temperature-independent and engineerable temperature-dependent materials are required to realize the RFID and the sensor part of a fully integrated RFID sensor tag.While the main application of such sensors serves as the general motivation, the layered DR approach can be utilized for the characterization of low-Q materials at extremely high temperatures, thus delivering a new characterization concept as well as first characterization data for the materials that are investigated for the sensor. Therefore, the investigation of a novel, model-based characterization method for dielectric parameters based on layered DRs is the another task of the project.