节点文献
平板介质材料复介电常数单反射法变温测试
【作者】 唐晓明；
【导师】 李恩；
【作者基本信息】 电子科技大学 ， 电磁场与微波技术， 2011， 硕士
【摘要】 微波介质材料如今已被广泛应用于雷达、通信、微波遥感遥测、制导等各个领域。众所周知,飞行器和制导武器在高速飞行时,它们的介质天线罩等部位与空气摩擦,经气动加热,其表面温度波动剧烈,温度从负几百摄氏度到几千摄氏度不等。那么,天线罩表面温差,对电磁波传输性能有多大影响呢?国内外对此领域都做了大量的研究工作,并已广泛应用于实际当中,如高速飞行的航天飞机如何实现与地面控制中心通信、高速飞行的制导武器如何完成制导等问题已得到很好的解决。这些问题的解决离不开对微波材料电磁特性随温度变化规律的掌握和应用。复介电常数是描述微波材料电磁特性最重要的参数之一,对于非磁性介质,有μ≈μ0,故通常对材料的复介电常数进行变温测试。纵观国内外文献,就自由空间法测试材料复介电常数,传输/反射法用的居多,且测试系统和校准技术比较成熟,但对于使用单反射法对材料进行变温测试的文献资料相对较少。本文就是基于单反射法对材料的复介电常数实现变温测试。此方法的优点明显:测试系统对样品加热易于实现;标准件少且易制作,校准过程方便;待测网络为单端口,系统误差项少(只有3项,而二端口网络有12项系统误差),测试精度较高。本文主要工作一是建立单反射法的物理和数学模型,完成单反射法测试原理的理论分析;二是完成点聚焦透镜圆锥喇叭天线的研制;三是完成温度控制装置的研制;四是完成测试系统的搭建;五是分析误差来源、建立单端口网络误差模型,实现SOL校准。
【Abstract】 Microwave dielectric materials have now been widely used in radar, communications, microwave remote sensing, guidance and other fields. Is well known that when flying in high speed, the part of dielectric antenna radome of the aircraft and guided weapons will friction with the air and be Heated by the aerodynamic, the surface temperature of the dielectric antenna radome will volatility seriously, ranging from minus several hundred degree Celsius to several thousand degrees Celsius. So how much influence does the difference in the surface temperature of dielectric antenna radome have on the transmission performance of electromagnetic waves? A great of work have been done in this filed at home and abroad, and have been widely used on practice, the problems such as how the shuttle and flight communicated with the ground control centers, how the high-speed guide weapons finished the guidance and so on have been well handled. These problems can’t be handled without understanding and using the law between the microwave electromagnetic properties of materials and temperature.Complex permittivity is one of the most important parameters to describe the microwave electromagnetic properties of materials, as for nonmagnetic material, so it is usually test the complex permittivity of material change with temperature. According to the report at home and abroad, In terms of free-space method,the transform-reflection method has been used usually,the test system and calibration technology are mature as well, but relatively few documents using single-reflection method to test the temperature-dependence of complex permittivity of material. This paper is based on single-reflection method to test the temperature-dependence of complex permittivity of material. The advantages of this method are obvious: sample can be heated by the test system easily, only a few standard parts are needed and also made easily, the calibration process is simple, the network be tested is single port, with a little systematic error term and high test precision.The first work in this paper is to establish the physical and mathematical models of single-reflection method, to complete the Theoretical analysis of single-reflection method‘s test theory, the second is to build the spot focusing lens antenna; the third is to build the temperature control device; the fourth is to build the test system. And the fifth is to analyze the source of error, build the error model of single-port network to attain SOL calibration.