Study Of Test System For Dielectric Properties Of High Temperature Dielectric Materials Using Short-circuited Line Method

Microwave radome dielectric materials are widely applied in radome, antenna window, etc. The fabrication technology of radome materials is one of the key technologies of strategic and tactical missile nose. The electrical performance of remote sensing antenna, guidance homing missile nose, and real time igniter antanna should not influenced by the high temperature and high speed air flow so as to guarantee the communication system and guidance system working properly. As to radome materials, their dielectric properties have direct relations with the wave-transmitting ratio, image uniformity, and other electrical performances of missile nose antenna system. Dielectric property means dielectric constant and loss tangent which are two important parameters to value the performance of radome materials. Therefore, the two parameters are the key parameters used to check and test the performance of radome materials during the development, fabrication, and application process.The paper brings forward the test method and test system for the dielectric properties of radome materials under the special working environment of high temperature in order to offer technological support and storage for the development of high temperature radome materials.The paper studied the test physical model and calibration model for short-circuited line method through room temperature test system, and obtained the initial value for dielectric constant by using time domain method. Responsive resonant cavity was built to calibrate the size and microwave surface resistor of the waveguide during high temperatures, and contrast method was used at the same time to complete the study of test physical model and calibration model at high temperatures. Materials and fabrication techniques are selected for high temperature test sensor. Key components and sub-systems are developed for the test system, and automatic test software was compiled. Finally, the test system was built and debugged. Quartz and sapphire sample were fabricated and measured near 10GHz. The test errors were analyzed and calculated by using Matlab software. The technical specifications of the test system were as follows: ABSTRACTTest temperatures:room temperature～2200℃Test frequency:near 10GHzTest range: Room temperature:ε'r=2.0～15 tanδε=0.001～0.05 2200℃:ε'r=2.0～15 tanδε=0.01～0.05Test errors: Room temperature:|Δε'r/ε'r|≤4% |Δtanδε|≤13%tanδε+0.001 2200℃:|Δε'r/ε'r|≤10% |Δtanδε|≤30%tanδε+0.02...