Measurement of Complex Permittivity Under Atmosphere and High-Temperature Environment by Using a Thermal Separation Resonator

In this article, a complex permittivity test system for wave-transparent materials under a complex atmosphere and high-temperature environment is proposed. Compared with the traditional high- {Q} resonator that needs to be heated as a whole at high temperatures, an improved thermal separation high- {Q} resonator is designed in which only the sample is heated and the main chamber is water-cooled. The high-temperature (1600 °C) complex permittivity test of the nitride composite material under the mixture of nitrogen, oxygen environment is realized at 8-18 GHz. Furthermore, this article analyzes the influence of sample volatiles on the complex permittivity inversion for TE _{\text {01{p}}} mode. An error analysis is proposed to estimate the errors due to the uncertainty of different error sources. This system can provide a variable temperature and controllable atmosphere environment, which provides a support for the test of the complex permittivity of wave-transparent materials in a simulated working environment.