超高温条件下介质材料复介电常数测量理论与技术研究

A novel quasi optical measurement method, which has simultaneously the merit of free space method and open cavity method, is proposed to measure the complex permittivity of dielectric material at super high temperature situation. In the method only the materials to be measured need to be heated to high temperature over 1500ºC, the oxidation of metal components at high temperature, the vacuum box that close the measurement system components and cooling water system can be eliminated. The measurement system is convenient for using, simple for maintenance, and has high measurement precision. The mathematical function relation between the complex permittivity of the material and the parameters of measurement system will be studied, and the transcendental equation from that the permittivity of the material can be educed will be deduced. The practical measurement system, which contains mechanical, electrical and calorific components, will be built to validate the measurement theory, and realize the precise measurement of the complex permittivity of material at super high temperature over 1500ºC. It will provide a technology support for the development of radomes of radar and communication system in the high ultrasonic aerocrafts.

提出了一种兼具自由空间法和开放腔法优点的新的准光测量方法，测量超高温条件下的介质材料复介电常数。该方法只需对被测材料升温，可消除测量系统中金属材料高温氧化问题以及把测量系统构件封闭起来的真空箱与冷却水系统，被测材料温度可达1500ºC以上，具有使用方便、维护简单、测量精度高的优点。将研究测量系统参数与材料复介电常数之间的数学函数关系，推导反演介电常数的超越方程；构建包括有机、电、热组件的实际测量系统，验证测量理论，实现1500ºC以上介质材料复介电常数的精准测量。为超高音速飞行器上雷达、通信系统屏蔽罩的研制提供技术支撑。

根据项目提出的新的准光测量方法，基于准光高斯束理论，推导出测量系统参数与材料复介电常数之间的数学函数关系，获得反演介电常数的超越方程；设计构建成功包括有机、电、热组件、能在超高温条件下测量介质材料复介电常数的测量系统。.该测量系统只需对被测材料升温，从而消除测量系统中金属材料的高温氧化问题，冷却水系统以及把测量系统构件封闭起来的真空箱。.在从室温到高温的测量实验中被测材料温度已超过1500ºC，具有使用方便、维护简单、测量精度高的优点。该项目已达到预定目标，圆满完成任务。该项技术将为工业部门研发超高音速飞行器上雷达、通信系统屏蔽罩提供技术支撑。